Showing papers in "Acta Anaesthesiologica Scandinavica in 1969"

The Effect of Regional Sympathetic Blocks in the Treatment of Herpes Zoster: A Survey of 300 Cases

Abstract: SUMMARY In our experience, regional sympathetic blocks is a therapy that ought to be resumed as it seems to be very efficient in the treatment of pain due to acute, idiopathic zoster. In addition, this therapy apparently prevents the lesion from progressing into the postherpetic syndrome. However, if favourable results are to be obtained, it is absolutely necessary that the patients are treated in a very early stage of the disease. In the treatment of the postherpetic syndrome, sympathetic blocks seem to be without any effect. ZUSAMMENFASSUNG Unserer Erfahrung nach sollten regionale Sympathikusblockaden wegen ihrer guten Wirksamkeit in der Schmerzbehandlung beim akuten ideopathischen Zoster wieder eingefuhrt werden. Uberdies verhindert diese Behandlungsmethode anscheinend auch das Fortschreiten der Laesion in ein postherpetisches Syndrom. Allerdings ist es absolut notwendig, daβ die Patienten in einem sehr fruhen Stadium der Erkrankung zu behandeln begonnen werden, wenn man gunstige Resultate erzielen will. Zur Behandlung des postherpetischen Syndroms sind Sympathikusblockaden anscheinend wirkungslos.

Clinical evaluation of the new analgesic piritramide

Abstract: SUMMARY The clinical analgesic efficacy of piritramide was studied in 9756 patients receiving a total of 25,206 intramuscular injections, usually of 15 mg. Piritramide provided good or excellent relief of pain in most cases and had a long duration of effective action (379±9.1 minutes) in postoperative treatment of patients who had undergone gall-bladder operations. Side effects induced by piritramide compared very favourably with those induced by morphine at equianalgesic therapeutic dosages: respiratory depression was slightly less marked with piritramide; vomiting occurred in only 1.0% of the patients, and addiction, physical dependence and tolerance were never observed. Piritramide is recommended for clinical relief of pain, particularly for postoperative analgesia. ZUSAMMENFASSUNG Die klinisch-analgetische Wirksamkeit von Piritramid wurde bei 9756 Patienten untersucht, die insgesamt 25.206 intramuskulare Injektionen von durschnittlich 15 mg erhalten hatten. Piritramid fuhrte in den meisten Fallen zu guter oder ausgezeichneter Schmerzerleichterung und zeigte eine lange Wirkungsdauer (379±9,1 Minuten) bei der postoperativen Behandlung von Patienten nach Gallenblaseoperationen. Bezuglich der Nebenwirkungen schnitt Piritramid im Vergleich zu gleichwirksamen therapeutischen Dosen von Morphin gunstig ab: die Atemdepression war etwas weniger ausgepragt mit Piritramid; nur etwa 1% der Patienten erbrachen, und Sucht, korperliche Abhangigkeit oder Gewohnung wurden niemals beobachtet. Piritramid kann zur klinischen Schmerzbekampfung, insbesondere zur Erzielung einer postoperativen Analgesie, empfohlen werden.

Effects of intravenous and intra-arterial procaine and lidocaine on neuromuscular transmission in man.

Abstract: SUMMARY 1 The effects of procaine and lidocaine on neuromuscular transmission were determined in man. 2 These agents when injected intravenously did not decrease the twitch response. However, if a partial neuromuscular block was produced by succinyl-choline or d-tubocurarine, the block was increased by procaine or lidocaine. 3 A neuromuscular blocking action of procaine and lidocaine could be demonstrated following intra-arterial injection. 4 A decrease in respiration or apnea could be produced by doses of procaine and lidocaine which did not depress neuromuscular transmission. 5 It was suggested that although local anesthetic agents may affect the motor nerve terminal, the release of ACh, and skeletal muscle directly, at present the neuromuscular blocking activity of local anesthetics appears to be attributable mainly to their acetylcholine inhibiting action at the motor end plate.

Blood Circulation in the Kidney of the Cat Under Halothane Anaesthesia

Abstract: SUMMARY In order to establish whether the response in the renal vascular bed contributes to the arterial hypotension associated with halothane anaesthesia, the renal venous flow was measured by means of a drop-recording technique in 10 cats under halothane anaesthesia (23 exposures). For purposes of comparison, similar measurements were made when the animals were exposed to ether (10 exposures). Arterial pressure was recorded simultaneously, and the renal vascular resistance was calculated. With a few exceptions, both halothane and ether caused a reduction of the renal vascular resistance during increasing anaesthetic depth. An increase in the anaesthetic depth beyond the stage corresponding to loss of the corneal reflex usually did not cause any noteworthy further decrease in vascular resistance. At that stage of anaesthesia the resistance was about 72 per cent (halothane) or 83 per cent (ether) of control level. The reduction in vascular resistance may contribute to the blood-pressure fall, but since the blood-pressure fall was proportionately more pronounced than the reduction in resistance, and since the pressure continued to fall without any further reduction in resistance during increasing anaesthetic depth, other hypotensive causes must be assumed. Other investigations showed that the vascular resistance was not uniformly influenced in different tissues, and thus a reduction in cardiac output in agreement with an observed heart-rate decrease may be of more importance for the hypotension than would be the observed reduction of peripheral resistance. Reduction in circulating blood volume or venous return seems to be less likely hypotensive causes, since central venous pressure was virtually unaffected or was slightly increased. Autoregulation and depression of sympathetic activity are assumed to explain the reduction in the renal vascular resistance. A differentiation of the vascular response in the kidney from that in other tissue regions may be due partly to a differentiation in the bulbar vasomotor centre when released from baroreceptor inhibition owing to the blood-pressure fall, and partly to a differentiation at the ganglionic level of the sympathetic pathway. A certain increase in vascular resistance was observed during the phase of deep anaesthesia, when autoregulation and reduction of sympathetic activity may be expected to have more or less eliminated vascular tone. This phenomenon is here tentatively explained by an elastic recoil of the vessel walls, or even by closure of part of the vascular bed owing to a reduction in transmural pressure, and by rheological factors such as increased viscosity and blood-cell “sludging” owing to a greatly reduced flow rate in the vascular bed. ZUSAMMENFASSUNG Um festzustellen, ob die Reaktion im Nierengefassbett zur arteriellen Hypotension beitragt, die mit der Halothan-Narkose einhergeht, wurde der venose Blutstrom der Niere mit Hilfe einer Tropfenregistriermethode bei 10 Katzen unter Halothan-Narkose (23 Einzelversuche) gemessen. Zum Vergleich wurden ahnliche Messungen unter Ather-Narkose vorgenommen (10 Einzelversuche). Der arterielle Druck wurde gleichzeitig registriert und der renale Gefasswiderstand berechnet. Mit wenigen Ausnahmen fuhrten sowohl Halothan als auch Adier zu einer Verminderung des renalen Gefasswiderstandes mit zunehmender Narkosetiefe. Eine weitere Vertiefung der Narkose uber das Stadium des Cornealreflexverlustes hinaus bewirkte keinen nennenswerten Abfall des Gefasswiderstandes. In diesem Narkosestadium betrug der Widerstand etwa 72 Prozent (bei Halothan), bzw. 83 Prozent (bei Ather) des Ausgangswertes. Die Verminderung des Gefasswiderstandes konnte zum Blutdruckabfall beitragen, da aber der Blutdruckabfall im Verhaltnis starker ausgepragt war als die Widerstandsverminderung und da der Druck auch ohne zusatzliche Widerstandsabnahme bei Vertiefung der Narkose weiter fiel, mussen andere Grunde fur die Hypotension angenommen werden. Andere Untersuchungen zeigten, dass der Gefasswiderstand in verschiedenen Geweben nicht einheidich beeinflusst wurde und dass daher die Verminderung des Herzminutenvolumens in Ubereinstimmung mit der beobachteten Abnahme der Schlagfrequenz fur den Blutdruckabfall von grosserer Bedeutung zu sein scheint als die beobachtete Verminderung des peripheren Gefasswiderstandes. Eine Verminderung des kreisenden Blutvolumens bzw. des venosen Ruckflusses erscheint als Grund fur den Blutdruckabfall unwahrscheinlicher, da der zentrale Venendruck praktisch unverandert blieb oder leicht erhoht war. Autoregulation und Dampfung der Sympathikusaktivitat werden zur Erklarung des verminderten renalen Gefasswiderstandes herangezogen. Eine Unterschiedlichkeit in der Gefassreaktion der Niere gegenuber anderen Geweben konnte zum Teil durch die unterschiedliche Reaktion des bulbSaren Vasomotorenzentrums, wenn dieses infolge des Blutdruckabfalls von der Barorezeptorenhemmung abgeschaltet ist, zum Teil durch eine Unterschiedlichkeit der Schaltganglien des Sympathikusleitsystems bedingt sein. Eine gewisse Zunahme des Gefasswiderstandes wurde in der Phase der tiefen Narkose beobachtet, wenn man annehmen musste, dass durch die Autoregulation und die verminderte Sympadiikusaktivitat der Gefasstonus mehr oder weninger geschwunden sein sollte. Dieses Phanomen lasst sich mit einigen Vorbehalten vielleicht durch elastische Verengung der Gefasswande erklaren oder sogar durch Verschluss eines Teiles des Gefassbettes infolge Abnahme des transmuralen Druckes und durch Stromungsfaktoren, wie erhohte Viskositat und Blutkorperchen-Aggregationen infolge der stark verminderten Stromungsgeschwindigkeit im Gefasssystem.

Choice of anesthetic agents for intravenous regional anesthesia.

Abstract: The choice of any anesthetic agent must be made on the basis of two factors, effectiveness and safety. The safety factor must always be paramount, and this is especially true in dealing with the intravenous administration of an anesthetic agent, since removal of the agent once administered is not practical. The importance of effectiveness is obvious. In addition to considering the use of different drugs for the production of intravenous regional anesthesia, one also has the variables of the total dose given, the concentration used, and any other factors which might influence the effectiveness, toxicity, or both, such as pre-injection ischemia of the limb. I will have more to say about pre-injection ischemia later in the paper, but a word of introduction here is in order. We have studied extensivelylsg the influence on the effectiveness of a period of total ischemia of the l i b prior to injection of the local anesthetic agent of a given dose. It is clear from all of our studies that some factor associated with the metabolic changes secondary to the ischemia enchances the effectiveness of the drug in producing anesthesia or, stated conversely, the effective dose level can be reduced by using a period of prior isolation of the limb from the systemic circulation. In a series of 312 subjects, both patients and volunteers, we have studied these variables in connection with three agents; namely chlorprocaine, lidocaine, and prilocaine. The onset and effectiveness of anesthesia, the central nervous system signs and symptoms of toxicity, the response of the cardiovascular system, and, in the case of prilocaine, the appearance of methemoglobinemia, were all studied. Serial blood level determinations of each of the three agents were carried out. The effectiveness of the anesthesia was graded as follows: The loss of all sensory modalities, including touch, pin prick, deep pressure and pain sensation, accompanied by a marked or total paralysis and associated with the absence of pain or discomfort during the operative procedure, constituted

Post mortem studies of damage following prolonged endotracheal intubation and i n a number of cases secondary tracheostomy

Abstract: Macroscopic and microscopic examinations were performed on 78 specimens, and on 1 further specimen microscopic examination alone. In preparation of the laryngeal specimens for post mortem examination, some of them were damaged, but none of them had to be excluded for this reason. In 16 specimens less than y3 of the length of the trachea was available for examination. At the histological examination a few sections in some specimens could not be evaluated with certainty and were excluded.

The history and development of intravenous regional anaesthesia.

Abstract: In 1908 AUGUST BIER, Professor of Surgery at Berlin, described an unusual method of producing analgesia of a limb. He exsanguinated the arm or leg by means of a tourniquet, and injected a local anaesthetic solution into a vein. The recent resurgence of interest in this technique, culminating in this Symposium, is evidence of its usefihess even today, but also reflects the paucity of our knowledge of the exact mechanism of the production of anaesthesia in this method. However, in 1908 the principle was truly revolutionary, and we have good reason to be thankfid that “Bier was always an innovator”’. August Karl Gustav Bier was born at Helsen, Germany in 1861. He graduated M.D. from the University of Kiel in 1888, was initially assistant to von Esmarch and later Professor of Surgery successively at Kiel, Greifswald, Bonn and Berlin. He died at Sauen, in the Russian sector in 1949 at the age of 87. Bier was elected an Honorary Fellow of the Royal College of Surgeons of England in 1913, but in the biographical notes which appear in “Lives of the Fellows” there is no mention of intravenous regional anaesthesia. In fact, there appears the sentence : “The three new methods which he most prided himself on having introduced to surgery were spinal anaesthesia, artificial hyperaemia, and the treatment of amputation stumps”. I t would almost seem as if Bier himself, though obviously initially enthusiastic about the technique, later forgot about it as did so many others. To understand the circumstances that may have played a part in the development of this technique, it is necessary briefly to examine the early history of local anaesthesia. Cocaine was isolated by Gaedicke in 1855 and purified and named by Niemann in 1860, but it was not until 1884 that Koller, a pupil of Sigmund Freud, put its local anaesthetic property to practical use. However, thereafter the use of cocaine spread like wildfire, so that by the time Bier qualified as a surgeon (1888), certain techniques of local anaesthesia were fairly well advanced. Halsted was the acknowledged expert in nerve

Dead space, compliance and venous admixture during heart surgery.

Abstract: SUMMARY Twenty-eight patients scheduled for open-heart or major vascular surgery were investigated during anaesthesia and controlled ventilation with measurements of oxygen uptake, physiological dead space, blood-gas tensions and acid base balance and, in some cases, cardiac output. Oxygen uptake was generally slightly decreased during anaesthesia with oxygen, muscle relaxation and small amounts of halothane and controlled ventilation as compared with predicted values. An increase occurred at the end of the procedures. The dead space to tidal volume ratio was 0.51-0.56 with no significant changes during the operation and extracorporeal bypass. Compliance increased slightly when the chest was opened, but was uninfluenced by the bypass procedure. Venous admixture amounted to about 20% of systemic flow and was associated with high arterio-venous oxygen differences. This in combination with an increased oxygen uptake explains the alveolar-arterial oxygen tension differences in the patients. Patients with mitral disease exhibited very high VD/VT ratios around 0.6-0.8. During rewarming after hypothermia for closure of atrial septal defects, a decrease in VD/VT ratio was observed in three patients. It is evident from our results that the heart patient presents a complicated pathophysiological picture to the anaesthesiologist. The combination of increased VD/VT ratio, low cardiac output and a substantial amount of venous admixture combined with a tendency to increased oxygen uptake at the end of the surgical procedure makes it necessary to carry out anaesthesia and ventilation with special precaution. High oxygen concentration of the inspired gas mixture is necessary in order to compensate for changes in ventilation/perfusion ratios and to minimize the effects of pulmonary shunts. A respirator which permits optimal distribution of ventilation in combination with the slightest possible side effects on circulation should be used. The observed physiological state of the patients at the end of the anaesthesia and cardio-vascular surgery further suggests that many should be maintained on controlled ventilation postoperatively until all compensatory mechanisms have returned. The measurements of the VD/VT ratios in combination with the calculation of the amount of venous admixture according to the methods outlined in this investigation will serve as useful guides in the postoperative course of the patients and their treatment. ZUSAMMENFASSUNG Bei 28 Patienten, die fur offene Herz- oder grose Gefasoperationen vorgesehen waren, wurden wahrend der Narkose und kontrollierten Beatmung folgende Parameter gemessen: Sauerstoffaufnahme, physiologischer Totraum, Blutgasdrucke und Saure-Basen-Verhaltnisse, sowie in einigen Fallen das Herzzeitvolumen. Im Vergleich zu den vorausgeschatzten Werten war die Sauerstoffaufnahme wahrend der Narkose mit Sauerstoff, Muskelrelaxantien und kleinen Mengen von Halothan bei kontrollierter Beatmung im allgemeinen leicht reduziert. Lediglich am Ende der Operationen kam es zu einem Anstieg. Die Relation zwischen Totraum und Atemvolumen war 0,51-0,56, und anderte sich nicht signifikant wahrend der Operation und der extrakorporalen Perfusion. Die Compliance stieg beim offenen Thorax geringgradig an, blieb aber wahrend der Perfusion unbeeinflust. Die venose Zumischung betrug etwa 20% des systemischen Blutstroms und war mit hohen arteriovenosen Sauerstoffdifferenzen vergesellschaftet. In Verbindung mit der erhohten Sauerstoffaufnahme erklart dies die alveolo-arteriellen Sauerstoffdifferenzen bei diesen Patienten. Bei Patienten mit Mitralfehlern war das Verhaltnis von Totraum zu Atemvolumen mit 0,6-0,8 sehr hoch. Wahrend Wiederaufwarmen nach Hypothermie fur den Verschlus von Vorhofseptumdefekten wurde bei drei Patienten ein Absinken dieses Quotienten beobachtet. Nach unseren Ergebnissen ist es evident, das der Herzpatient fur den Anaesthesiologen ein kompliziertes pathophysiologisches Bild bietet. Die Kombination eines erhohten Totraum-Atemvolumen-Quotienten, niedrigem Herzzeitvolumen und einer betrachdichen Menge venoser Beimischung, verbunden mit einer Tendenz zu erhohter Sauerstoffaufnahme am Ende des chirurgischen Eingriffes, macht es notwendig, Anaestesie und Beatmung mit besonderer Vorsicht auszufuhren. Hohe Sauerstoff-konzentrationen in der eingeatmeten Gasmischung sind erforderlich, um Veranderungen des Ventilations-Perfusions-Quotienten zu kompensieren und den Effekt intrapulmonarer Shunts zu vermindern. Dabei sollte ein Respirator verwendet werden, der eine optimale Verteilung der Ventilationsluft in Verbindung mit moglichst geringen Nebenwirkungen auf den Kreislauf ermoglicht. Aus dem beobachteten physiologischen Zustand der Patienten am Ende der Narkose und des kardiovaskularen Eingriffes kann ferner der Schlus gezogen werden, das vielleicht auch postoperativ so lange kontrolliert beatmet werden sollte, bis alle Kompensationsmechanismen zuruckgekehrt sind. Die Messung des Totraum-Atemvolumen-Quotienten in Verbindung mit einer Berechnung der venosen Beimischungsmenge, entsprechend der in dieser Untersuchung dargestellten Methode, kann als brauchbare Richtschnur fur den postoperativen Verlauf und die Behandlung dieser Patienten dienen.

Peroperative hydration with lactated ringer's solution versus a saltfree restrictive fluid regimen

Abstract: SUMMARY Two groups of patients undergoing partial gastrectomy in light halothanenitrous oxide anaesthesia with muscle relaxant and controlled ventilation were studied. One group (R group, 14 patients) received an average of 1700 ml of lactated Ringer's solution during surgery plus 1500 ml glucose/water on the day of operation. The other group (Gl group, 13 patients) received only 2000 ml glucose in water on the day of operation. The R group had a larger urinary output on the day of operation and on the first and second postoperative days. Endogenous creatinine clearance was within the normal range on the day of operation. Haematocrit decreased as expected from the operative blood loss, and there was not more retention of salt and water than expected to replace blood loss. The urinary K/NA ratio increased only slightly, indicating a small increase in aldosterone activity. Serum sodium and potassium decreased less in this group than in the Gl group. The Gl group suffered a fluid deficit on the day of operation as shown by haemoconcentration, negative fluid balance and a small urinary output. The low endogenous creatinine clearance indicates that the output on the day of operation was not large enough for normal renal clearance of metabolic waste products. This group excreted minimal amounts of NaCl in the urine postoperatively and showed “intolerance” to salt when this was given on the second postoperative day. The urinary K/Na ratio increased markedly, indicating an activation of the renin-angiotension-aldosterone system by uncorrected losses of blood and extracellular fluid during surgery. These findings are discussed in relation to recent reports on acute changes of functional extracellular fluid volume during surgery, the feasibility of replacing moderate blood losses with a balanced salt solution alone, and the pathogenesis and prophylaxis of postoperative renal failure. It is concluded that the administration of approximately 500 ml of lactated Ringer's solution per hour of operating time is a definite advantage. ZUSAMMENFASSUNG UND SCHLUSSFOLGERUNGEN Es wurde eine Vergleichsuntersuchung an zwei Gruppen von Patienten mit Magen-Teilresektionen in oberflachlicher Halothan-N20-Narkose mit Muskelrelaxans und kontrollierter Beatmung angestellt. Die eine Gruppe (Gruppe R, 14 Patienten) erhielt durchschnittlich 1700 ml Ringer-Laktat-Losung wahrend der Operation und 1500 ml Glukose in Wasser am Operationstag. Die andere Gruppe (Gruppe Gl, 13 Patienten) erhielt nur 2000 ml Glukose in Wasser am Operationstag. Die Gruppe R hatte sowohl am Operationstag als auch an den ersten beiden postoperativen Tagen eine grossere Harnausscheidung. Die endogene Kreatinin-Clearance blieb am Operationstag im normalen Bereich. Der Haematokrit fiel erwartungsgemass entsprechend dem operativen Blutverlust und die Salz- und Wasserretention war nicht starker als sie zum Ausgleich des Blutverlustes zu erwarten war. Der nur schwach erhohte K-Na-Quotient im Harn deutete auf einen geringen Anstieg der Aldosteronaktivitat hin. Serum -Na und -K waren in dieser Gruppe weniger vermindert als in der Gl-Gruppe. Die Gl-Gruppe litt am Operationstag an einem Flussigkeitsdefizit, wie sich in der Haemokonzentration, der negativen Flussigkeitsbilanz und der geringen Harnausscheidung zeigte. Die niedrige endogene Kreatinin-Clearance deutete darauf hin, dass die Ausscheidung am Operationstag nicht ausgiebig genug war, urn eine normale Nieren-Clearance der metabolischen Abfallstoffe zu gewahrleisten. Diese Gruppe schied postoperativ nur geringe Kochsalzmengen im Harn aus und zeigte eine «Salz-Intoleranz», wenn dieses am zweiten postoperativen Tag verabreicht wurde. Der K-Na-Quotient im Harn war deutlich erhoht, was auf eine Aktivierung des Renin-Angiotensin-Aldosteron-Systems durch die unkorrigierten Blut- und Extrazellularflussigkeitsverluste wahrend der Operation hinwies. Diese Befunde werden unter Hinweis auf neuere Literaturberichte uber akute Veranderungen des funktionellen EZF-Volumens wahrend Operationen, der Zulassigkeit des Ersatzes massiger Blutverluste durch ausgewogene Salzlosungen allein, sowie der Pathogenese und Prophylaxe des postoperativen Nierenversagens diskutiert. Dabei kommt der Autor zu dem Schluss, dass die Verabreichung von etwa 500 ml Ringer-Laktat-Losung pro Operationssrunde ein ausgesprochener Vorteil ist.

Rise in intragastric pressure caused by suxamethonium fasciculations.

Abstract: SUMMARY Some controversy exists as to the frequency of a marked rise in intragastric pressure caused by suxamethonium fasciculations. In order to study this problem, the intragastric pressure was recorded in 69 adult patients subjected to elective surgery in whom the pre-oxygenation-barbiturate-suxamethonium-intubation sequence was used for induction of anaesthesia. It is shown that suxamethonium causes an appreciable rise in intragastric pressure in about 7% of the cases. The study did not provide any evidence suggesting that a change in the suxamethonium dose from 40 to 60 mg/m2 body surface would change the risk of a considerable rise in intragastric pressure; nor was any difference in the reactions of women and men observed. ZUSAMMENFASSUNG Es bestehen gegensatzliche Auffassungen uber die Haufigkeit von starken intragastralen Druckanstiegen, verursacht durch die Muskelfaszikulationen nach Suxamethonium. Um dieses Problem zu studieren wurde der Mageninnendruck bei 69 Patienten registriert, die chirurgischen Routineeingriffen mit Sauerstoff-anreicherung, Barbiturat-Succinylcholin-Intubations-Narkoseeinleitung unterzogen wurden. Dabei konnte gezeigt werden, daβ Suxamedionium in 7% der Falle eine merkliche Erhohung des Mageninnendruckes verursacht. Die Untersuchungen ergaben keinen Hinweis zur Annahme, daβ eine Erhohung der Suxamethoniumdosis von 40 auf 60 mg/m2 Korperoberflache das Risiko eines betrachtlichen Anstieges des intragastralen Druckes verandert; des weiteren wurden auch keinerlei Unterschiede zwischen mannlichen und weiblichen Patienten beobachtet.

PARACERVICAL BLOCKADE WITH MARCAINE/ADRENALINE: Plasma Concentration of Marcaine and Foetal Acid‐Base Balance

Abstract: SUMMARY Paracervical blockade (PCB) was performed for alleviation of labour pains in 10 normal patients who had no signs of foetal asphyxia. The anaesthetic agent used was 20 ml of 0.5% Marcaine (bupivacaine) with adrenaline (1:200,000). The maternal plasma concentration of Marcaine was determined by gas chromatography from venous blood drawn 5, 10, 15, 20, 30, 45 and 60 minutes after PCB. The Marcaine concentration was also determined at the time of delivery from samples taken simultaneously from the mother and the umbilical vein of the infant. The acid-base balance of the infant was observed before and after PCB from capillary blood samples taken by Saling's technique. The median values of the maternal plasma concentrations of Marcaine remained below 0.25 μ/ml. At the time of delivery, the Marcaine concentration in the maternal plasma was definitely higher than that in umbilical vein blood, which was very low. As labour progressed there was, as in normal deliveries, a steady fall in the foetal pH and an increase in metabolic acidosis. The slowly increasing foctal metabolic acidosis showed no obvious correlation to simultaneous changes in maternal plasma concentrations of Marcaine (cf. fig. 3). ZUSAMMENFASSUNG Paracervikalblockade (PCB) wurde zur Erleichterung des Wehenschmerzes bei 10 gesunden Patientinnen ausgefuhrt, bei denen keine Zeichen von foetaler Asphyxie vorlagen. Als Lokalanaesthetikum wurde 20 ml halbprozentiges Marcain (Bupivakain) mit Adrenalin (1:200,000) verwendet. Die mutterliche Plasmakonzentration von Marcain wurde mittels Gaschromatographie aus dem venosen Blut bestimmt, das 5, 10, 15, 20, 30, 45 und 60 Minuten nach Anlegen der Blockade abgenommen worden war. Die Konzentrationen von Marcain wurden auch zum Zeitpunkt der Geburt bestimmt, und zwar aus Blutproben, die gleichzeitig von der Mutter und aus der Nabelvene des Kindes abgenommen wurden. Der Saure-Basen-Status des Kindes wurde vor und nach der PCB aus kapillaren Blutproben bestimmt, die nach der Saling'schen Tech-nik entnommen worden waren. Die mitderen Werte der mutterlichen Plasmakonzentration von Marcain blieben unter 0,25 μ/ml. Zum Zeitpunkt der Geburt war die Marcain-Konzentration im mutterlichen Plasma eindeutig hoher als im Nabelvenenblut, wo sie sehr gering war. Mit fortschreitender Wehentatigkeit zeigte sich, wie bei normalen Entbindungen, ein stetiger Abfall des foetalen pH und ein Ansteigen der metabolischen Azidose. Die langsam ansteigende foetale metabolische Azidose stand in keiner eindeutigen Relation zu gleichzeitigen Veranderungen in der m|uUtterlichen Plasmakonzentration von Marcain (siehe Abbildung 3).

Intravenous regional anesthesia — report of 497 gases with a toxicity study

Abstract: I would like to add our experiencewith intravenousregional anesthesia at the at the US. Army General Hospital, Landstuhl, Germany and the Valley Forge General Hospital, Phoenixville, Pa., to that of Dr. FLEMING’S. During the period of September 1964 to August 1966, 497 intravenous regional anesthetics were administered. The distribution of cases is shown in Table 1. All adult inpatients received pentobarbital and meperidine as premedication. A technique similar to that described by Bier was used to produce anesthesia.l-a A pneumatic tourniquet was placed high on the arm. When surgery was on the foot or ankle the tourniquet was placed on the mid-calf at least three inches below the head of the fibula. This was done to avoid compression of the peroneal nerve as it crosses the fibula. A 21 gauge scalp vein needle was inserted in a superficial vein as close as possible to the operative site. The extremity was elevated and then exsanguinated by tightly wrapping it in a rubber (Esmarch) bandage. If the needle was in the hand or foot, application of the rubber bandage was started at the wrist or ankle to avoid dislodging the needle. The tourniquet was then inflated to 250-30

Continuous intravenous regional anesthesia

Abstract: Intravenous regional anesthesia has been established as a satisfactory technique in several series of patients and v~lunteersl-~. One of the limitations of the technique, however, has been the apparent necessity of constant inflation of the tourniquets*@. Because a tourniquet can remain inflated on an extremity for only a limited period of time (1 to ly2 hours) the technique, as described, was applicable only to surgical procedures which could be completed within thii time. In prolonged surgery on the extremity, performed under tourniquet, it may be necessary to deflate and re-inflate the tourniquet several times during the course of the operation. It occurred to us that if we could leave an indwelling catheter in place, we ought to be able to re-establish anesthesia by the simple expedient of injecting an additional quantity of anesthetic agent after reinflation of the tourniquet. We first attempted this technique in two relatively short surgical procedures in which the surgeon requested that we release the tourniquet prior to completion of the procedure so that he could control the bleeding with ligatures. When the anesthesia began to wane, the tourniquet was reinflated, half the original dose of lidocaine was injected and intense anesthesia was re-established. These experience encouraged us to attempt this continuous technique in a number of extensive and prolonged operations on the upper extremity. The technique of continuous intravenous regional anesthesia is quite uncomplicated. After raising a skin wheal, an indwelling polyethelene catheter is placed in a suitable vein sufficiently far removed from the operative site so that it will not interfere with the sterile surgical field. The catheter is attached to an intravenous solution containing 500 cc of 5% dextrose in water. The tubing should be of sufficient length to make it convenient for the anesthesiologists to inject the local anesthetic agent whenever necessary during the procedure without encroaching upon the sterile field. The intravenous catheter and tubing is securely fastened so that it will not become dislodged during the surgical procedure.

Blood circulation in the skeletal muscles and the skin of the cat under halothane anaesthesia.

Abstract: SUMMARY In five cats the blood flows in the skeletal muscles and the skin were simultaneously recorded with a drop-counting technique during exposures to halothane or ether. During both halothane and ether exposures, very similar qualitative response patterns were found, viz. arterial hypotension, increased or moderately decreased muscle vascular resistance, markedly decreased skin vascular resistance, decrease in heart rate and a more or less unchanged or slightly increased central venous pressure. The combination of the changes in peripheral resistances in the two tissue regions investigated is not considered to contribute greatly to the rather pronounced arterial hypotension, for which other causative factors are suggested, e.g. a reduction in cardiac output. Even though depression anywhere in the sympathetic pathway may explain a skin vasodilatation, it is suggested that the divergence of the vascular responses in the two investigated tissue regions is caused mainly by a differentiation within the bulbar vasomotor centre when released from baroreceptor inhibition owing to the blood-pressure fall leading to a reflexly induced increase in vasoconstrictive discharge to the skeletal muscles but not to the dilated cutaneous vascular bed. The quantitative differences between the responses to halothane and to ether, i.e. a less pronounced hypotension and a smaller decrease in skin vascular resistance and heart rate, as well as a seemingly more pronounced increase in muscle vascular resistance during the influence of ether, are, it is suggested, caused by the sympathicomimetic properties of this anaesthetic. ZUSAMMENFASSUNG Bei 5 Katzen wurde wahrend Halothan- oder Athernarkose die Blutdurchstromung im Skelettmuskel und in der Haut mit einer Tropfenzahlmethode simultan registriert. Die qualitativen Reaktionsmuster waren bei beiden Narkoseagentien sehr ahnlich, das heisst arterielle Hypotension, erhohter oder schwach verminderter Gefasswiderstand im Muskel, deutlich verminderter Gefasswiderstand in der Haut, Abfall der Herzfrequenz und ein mehr oder weniger unveranderter oder schwach erhohter zentraler Venendruck. Die Kombination der Veranderungen im peripheren Widerstand dieser zwei untersuchten Gewebsregionen kann wohl kaum besonders zu dem ziemlich ausgepragten arteriellen Blutdruckabfall beitragen, fur den andere ursachliche Faktoren herangezogen werden mussen, z. B. eine Verminderung des Herzminutenvolumens. Obwohl eine Depression an irgendeiner Stelle der sympathischen Leitungsbahnen die Gefasserweiterung in der Haut erklaren konnte, wird doch angenommen, dass die Divergenz der vaskularen Reaktionen in den beiden untersuchten Gewebsregionen hauptsachlich durch eine Unterschiedlichkeit im Bereich des bulbaren Vasomotorenzentrums bedingt ist, wenn dieses von der Barorezeptorenhemmung infolge des Blutdruckabfalls abgeschaltet ist, was zu einer reflexbedingten Erhohung der vasokonstriktiven Reize zur Skelettmusku-latur, aber nicht zu dem erweiterten Gefassbett der Haut fuhrt. Was die quantitativen Unterschiede zwischen der Reaktion auf Halothan und auf Ather betrifft, das heisst die schwacher ausgepragte Hypotension und der geringere Abfall des Gefasswiderstandes in der Haut, sowie der Herzfrequenz, als auch die anscheinend ausgepragtere Erhohung des Gefasswiderstandes im Muskel unter dem Einfluss von Ather, wird angenommen, dass diese durch die sympathiko-mimetischen Eigenschaften dieses Narkotikums bedingt sind.

The effects of intravenous local anesthetic agents on the central nervous system.

Abstract: Although the topic of my presentation is the effect of local anesthetics on the central nervous system, I will start by reviewing of our experiments on the renal excretion of local anesthetics, because the kidney happens to be a very good place to study the manner in which local anesthetics diffuse through cell membranes. GRANBERG, ORTENGREN and this author1 investigated the renal excretion of lidocaine and prilocaine in renal clearance studies on human volunteers. The subjects were given ammonium chloride orally on the day before the experiment in order to render the urine acid. We found high clearance values with both agents in the acid urine (Figures 1 and 2). When the urine was made alkaline with sodium bicarbonate (Figure 1) or Diamoxa (Figure 2) the clearance values dropped dramatically in spite of increased urinary output. When we acidified the urine with Edecrina (etacrynic acid) in a volunteer with slightly alkaline urine (Figure 3), the clearance of both agents immediately increased. This phenomenon is due to so called “non-ionic diffusion” or “passive tubular secretion”. This type of excretion has been well explained by MILNE, SCRIBNER and CRAWORD~ in their classical paper. Local anesthetics are weak bases and in the blood at normal pH they are present as both charged cations and uncharged free base in an equilibrium mixture. The free base has a high fat solubility and therefore can pass through renal tubular cells. The charged cation has a low fat solubility and cannot pass through these cells so easily. When the free base reaches the acid urine it is converted to the non-penetrating cation, thereby giving rise to a chemical gradient. When the urine is made more alkaline than the blood, however, the chemical gradient will be reversed and the local anesthetic will diffuse back from the urine into the blood. Thus, changes in urinary pH greatly affect the output of local anesthetics in renal

Blood levels of local anesthetics following intravenous regional anesthesia

Abstract: In 1963 HOLMES~ introduced a technique of local anesthesia for limb surgery by means of an intravenous injection of lidocaine. This method was a modification of a technique originally described by BIER^ in 1908. By virtue of its simplicity this method of anesthesia rapidly achieved popularity. However, it was not long before there were reports of toxic effects which occurred when the tourniquet was released. Since then numerous articles have appeared, some questioning the safety of the technique and others reporting large series of cases without major complications. At the present time it would appear that intravenous regional block wi$ lidocaine is accepted by most investigators as having an acceptable margin of safety. Prilocaine (Citanest@) has been reported by many authors as being significantly less toxic than lidocaine in equipotent doses. I t thus seemed that this drug might offer real advantages in intravenous regional block. The present paper contains the results of our studies on prilocaine blood levels following intravenous regional anesthesia and direct intravenous injection. In addition, these levels are compared with those obtained earlier in a similar trial with lidocaine.

The mode of action of intravenous regional anesthetics

Abstract: Intravenous regional anesthesia has gained increased popularity and considerable discussion has been provoked by differing methods of administration and various explanations of action. This is probably why a purely descriptive term like “intravenous regional”, has found popular acceptance. Attempts to classify in the spaces provided on the usual anesthesia record are unrewarding since it may be considered a local, intravenous, or regional block technique. Discussion of the site of action is rendered more difficult because, in addition to multiple techniques in use, their exact method of employment and emphasis varies from author to author. Exsanguination, ischemia and venous perfusion with a local anaesthetic agent are invariably recommended to some extent. Lidocaine without epinephrine, the most widely used agent, is a local anesthetic of rapid onset. To a certain extent one may separate the effects of various factors on a temporal basis. Events observed early in the block will be mainly due to the local anesthetic agent, while as time passes effects of ischemia and acidosis will be superimposed. The phenomenon of intravenous regional anesthesia is immediate and, therefore, observations made early after exsanguination and the prompt administration of the local agent are apt to be more significant of the mode of action. The clinical technique we have most frequently used, however, is is that previously reported‘ and does not differ significantly from the modification of BIER^ described by HOLMES~. It would seem appropriate to discuss the distribution of drugs achieved by this route of adminiitration because this is intimately connected with any theory concerning the site of action. Curare is a suitable drug with which to examine distribution, since its action is localized to one site and its effects are easy to demonstrate. Accordingly, Dr. Jerome Modell, of the University of Miami, and I undertook experiments injecting dilute d-tuboctmarine into the isolated limb. The dosage was of the order of 3 mgm in 4Occ of saline. Profound neuromuscular block developed rapidly and lasted until the tourniquet was released. With the injection of a sufficient volume, therefore, a small dose

Blood concentrations of local anaestetics after intravenous regional anaesthesia.

Abstract: SUMMARY The concentrations of local anaesthetics in the blood after intravenous regional anaesthesia were studied. Samples were taken from (1) the venous outflow from the anaesthetised limb after releasing the tourniquet, (2) the arterial circulation and (3) the contralateral venous circulation. In the venous outflow from the anaesthetised extremity the concentration was initially high, its maximum level followed very quickly by a second peak. On the whole, the pattern was the same in the arterial circulation, although the first peak was noted somewhat later and the second one was lower. In the contralateral venous circulation a fairly flat peak occurred relatively late. The rapid rise in the concentration in the venous outflow from the blocked arm after the release of the occlusion suggests that if intermittent occlusion is aimed at in order to reduce the danger of toxic reactions, re-occlusion must be achieved within a very short time (less than 30 seconds). Comparative studies were also carried out on differences in these respects between prilocaine and lidocaine. These showed that there is no difference in the postanesthetic concentration of these agents in a draining vein, while the arterial blood has a higher content of lidocaine than of prilocaine, and the concentration of prilocaine is even lower in the contralateral venous circulation. Dilatation of the blood vessels due to the local anaesthetic agent administered may also be of importance. Prilocaine 2 per cent was found to have no dilatatory effect, while lidocaine produced significant vasodilatation. However, this latter effect is eliminated if the two local anaesthetics are mixed, as has been demonstrated by Astrom et al. (1966)14. ZUSAMMENFASSUNG Es wurden die L-A-Konzentrationen im Blut nach intravenosen Regional-anaesthesie untersucht. Die Blutproben wurden entnommen: 1) aus der abfuhrenden Vene der anaesthesierten Extremitat nach Offnen der Abschnurung, 2) aus dem arteriellen System und 3) aus dem venosen Blut der gegengleichen Extremitat. Im venosen Ruckstrom aus der anaesthesierten Extremitat war die Konzentration anfanglich hoch; der hochste Spiegel wurde schnell von einer zweiten Konzentrationsspitze gefolgt. Prinzipiell war der Verlauf auch im arteriellen Blut der gleiche, nur trat die erste Spitze etwas spater auf, und die zweite war niedriger. In der contralateralen venosen Zirkulation kam es relativ spat zu einem flachen Konzentrationsgipfel. Der rasche Konzentrationsanstieg im venosen Ruckflut aus dem blockiert gewesenen Arm deutet darauf hin, dass Re-okklusion innerhalb kurzester Zeit (weniger als 30 Sekunden) wiederher-gestellt werden muss, falls man zur Vermeidung toxischer Reaktionen einen intermittierenden Verschluss plant. In der gleichen Hinsicht wurden auch Vergleichsuntersuchungen zwischen Prilocain und Lidocain durchgefuhrt. Dabei konnten im abfuhrenden Venenblut keine Unterschiede der postoperativen Konzentration beider Agentien aufgedeckt werden, wahrend im arteriellen Blut ein hoherer Spiegel von Lidocain gegenuber Prilocain festgestellt wurde und die Prilocainkonzentration im contralateralen Venenblut sogar noch niedriger war. Gefasserweiterung durch die Lokalanaesthetika kann auch gewisse Bedeutung haben. Prilocain in 2%-iger Losung zeigte keinen dilatatorischen Effekt, wahrend die Gefasserweiterung nach Lidocain signifikant war. Allerdings kann diese letztere Wirkung verhindert werden, wenn man die beiden Lokalanaesthetika mischt, was schon Astrom und Mitarbeiter (1966) gezeigt haben.

Experimental studies on intravenous regional analgesia using radioactive lidocaine.

Abstract: Since the reintroduction of intravenous regional analgesia to clinical practice by HOLM&, there has been a growing enthusiasm for this analgesic technique. Most of the clinical reports point to its usefulness and safety. Our experience with t h i s method, at the Hadassah University Hospital in Jerusalem, has certainly been favorable. While its clinical value is fairly well established, information on the mode and site of action of the local anesthetic agent administered in this manner is still lacking. Site of action at the nerve trunk level is claimed by some, while others consider the site of action to be at the nerve endings. It was therefore decided to investigate the distribution of radioactive labelled lidocaine administered by the intravenous regional technique in experimental animals. The experiments were performed on the forelimbs of 16 large, pentobarbitalanesthetized, mongrel dogs. The intravenous analgesic technique was carried out so as to resemble as closely as possible the method described by Holmes and used in man. The solution used was 0.5% lidocaine in which the carbon atom of the carbonyl group in the side chain was labelled. Radioactive lidocaine was supplied by AB Astra of Sweden, and was diluted so that its specific activity was 0.04 microcuries/ml. A volume of 6.5 ml of this solution was injected for each 100 ml of limb volume. Surgical biopsies of skin, nerve and muscle were taken 10 to 20 minutes after injection, and repeated 15 to 30 minutes after restoration of circulation in the limb. Arterial tourniquet was held in place for 30 to 60 minutes. The axillary vein, draining the limb was cannulated proximal to the tourniquet, and axillary venous blood samples obtained immediately before, immediately after, and 10, 20, 30 and 60 minutes after tourniquet release. All tissue and blood samples were counted in Butler’s solution using the Tri-carb liquid scintillation counter. Results were recorded as counts/minute/gm tissue or ml blood.

VASOCONSTRICTORS AND GENERAL ANAESTHESIA: Ornithine‐8‐Vasopressin and Noradrenaline during Halothane Anaesthesia in a Double‐Blind Study

Abstract: SUMMARY In a double-blind study, the synthetic vasopressin derivative ornithine-8-vasopressin (POR-8) was compared with noradrenaline and a placebo as a haemostatic to be used locally during halothane anaesthesia. In the concentrations selected, POR-8 was found to be far more effective than noradrenaline. Both compounds caused a moderate rise in blood pressure. Extrasystoles occurred after injection of POR-8 in one patient. It is concluded that there is no reason to advise against the use of POR-8 during halothane anaesthesia although the experience in this field is at present too limited to exclude completely the possibility of cardiac complications. Caution is recommended when patients suffer from marked coronary insufficiency. ZUSAMMENFASSUNG Im Doppelblindversuch wurde der synthetische Vasopressinabkommling Ornithin-8-Vasopressin (POR-8) mit Noradrenalin und einem Plazebo als wahrend der Halothannarkose lokal anwendbares Haemostyptikum verglichen. In den gewahlten Konzentrationen erwies sich POR-8 gegenuber Noradrenalin als wesentlich wirksamer. Beide Mittel verursachten einen geringen Blutdruck-anstieg. Extrasystolen kamen nach Injektion von POR-8 bei einem Patienten zur Beobachtung. Es kann die Schlussfolgerung gezogen werden, dass gegen die Anwendung von POR-8 wahrend einer Halothannarkose kein Grund zur Ablehnung vorliegt, obwohl die Erfahrung auf diesem Gebiet augenblicklich noch zu beschrankt ist, urn die Moglichkeit von kardialen Komplikationen vollig auszuschliessen. Vorsicht ist geraten bei Patienten mit ausgepragter Koronarinsuffizienz.

BLOOD-VOLUME MEASUREMENTS BEFORE AND AFTER OPERATION AND DETERMINATION OF OPERATIVE BLOOD LOSS: A Comparative Study

Abstract: SUMMARY The purpose of this study comprising 54 surgical operation was to compare the value of measurement of external blood loss and of pre- and postoperative blood-volume determination, respectively, in guiding blood-volume replacement during major surgery. The external blood loss was measured partly by weighing the sponges, partly by washing all linen in a Haemoporrhometer®. The pre- and postoperative blood volumes were determined by a semi-automatic apparatus (Volemetron®). From the blood-volume measurements it was calculated how the peroperative loss is distributed between plasma volume and red-cell volume. The external blood loss measured averaged 1500 ml. The blood-volume determinations revealed a further average loss of 200 ml with a scatter of ±500 ml (2 xSD). In 28 cases of laparotomy an excess plasma loss averaging 25 % of the total volume loss was revealed. In thoracic and vascular operations the excess plasma loss was 6-8%. In six out of 54 cases the changes found in blood volume could not be accounted for. It is recommended to make duplicate determination of the blood volume pre-operatively. When postoperative serial determinations of blood volume are deemed to be necessary, a catheter placed in a central vein should be used for blood sampling and injection of tracer substance. ZUSAMMENFASSUNG Zweck dieser Untersuchung bei insgesamt 54 chirurgischen Operationen war es, den Wert der Messung des ausseren Blutverlustes mit der prae- und postoperativen Blutvolumsbestimmung zu vergleichen, um eine Richtschnur fur den Blutvolumsersatz bei grosseren chirurgischen EingrifFen zu gewinnen. Der aussere Blutverlust wurde zum Teil durch Abwiegen der Operationstucher, zum Teil durch Auswaschen der gesamten Operationswasche in einem Hae-moporrhometer bestimmt. Die Bestimmung des prae- und postoperativen Blutvolumens wurde mit Hilfe eines halbautomatischen Gerates (Volemetron) durchgefuhrt. Dabei wurde gleichzeitig errechnet, wie sich der intraoperative Blutverlust zwischen Plasmavolumen und Erythrozytenvolumen verteilt. Der gemessene aussere Blutverlust betrug im Mittel 1500 ml. Die Blutvolumsbestimmungen deckten einen weiteren durchschnitdichen Blutverlust von 200 ml auf, mit einer Streuung von ±500 ml (2 mal SD). Bei 28 Laparotomien ergab sich ein zusatzlicher Plasmaverlust von durchschnittlich 25% des gesamten Volumenverlustes. Bei Thorax- und Gefassoperationen war der zusatzliceh Plasmaverlust nur 6-8%. Bei 6 von 54 Fallen konnten die aufgefundenen Veranderungen des Blutvolumens nicht ausreichend erklart werden. Es wird empfohlen, Doppelbestim-mungen des praeoperativen Blutvolumens durchzufuhren. Wenn Serienbe-stimmung des Blutvolumens in der postoperativen Phase notwendig erscheinen, sollte durch Blutabnahme und Injektion der markierten Substanzen ein zentraler Venenkadieter eingelegt werden.

Clinical experience of disinfection of the engström respirator by ultrasonic nebulized ethyl alcohol.

Abstract: UMMARY A method of disinfecting the Engstrom respirator by means of ultrasonic nebulized ethyl alcohol, by the method of Peterson and Rosdahl, was tested in clinical practice. HNE nebulizers with oscillating frequencies were used. The disinfection procedure was carried out by regular members of the ward staff. The results were controlled bacteriologically. Satisfactory disinfection was obtained with two nebulizers in the system and a disinfection time of two hours. The standard humidifying unit of the Engstrom respirator was filled with a sterile solution of chlorhexidine 0.1% in water. No growth of vegetative micro-organisms occurred in the standard humidifying unit with this method, and no toxic reactions were observed in the patients. ZUSAMMENFASSUNG Eine von Peterson und Rosdahl beschriebene Desinfektionsmethode fur den Engstrom-Respirator mittels, durch Ultraschall vernebelten, Athylalkohol wurde in der klinischen Praxis erprobt. HNE-Vernebler mit oszillierenden Frequenzen wurden dabei verwendet. Die Desinfektionsprozeduren wurden vom standigen Stationspersonal durchgefuhrt. Die Ergebnisse wurden bakterio-logisch kontrolliert. Zufriedenstellende Desinfektion wurde erzielt, wenn zwei Vernebler im System eingeschaltet waren und wenn die Desinfektionszeit zwei Stunden betrug. Die Standard-Befeuchter-Einheit des Engstrom-Respirators wurde mit einer sterilen Losung von 0,1% Chlorhexidin in Wasser gefullt. Bei dieser Methode kam kein vegetativer Mikroorganismen zustande, und bei den Patienten wurde keine toxischen Reaktionen beobachtet.

Effect of H56-28 (Aptine) on catecholamine-induced arrhythmias and neuromuscular transmission in man.

Abstract: SUMMARY The beta adrenergic blocking agent H56/28 was found to be effective in the prevention of catecholamine-anesthetic cardiac arrhythmias in man. It was suggested that this antiarrhythmic action was due to beta adrenergic blockade rather than the local anesthetic activity which H56/28 is known to possess. Although some beta blockers are capable of producing a neuromuscular block in animals, in the present study in man H56/28 did not depress twitch height from control levels, nor increase the neuromuscular blocking action of succinylcholine or d-tubocurarine. ZUSAMMENFASSUNG Der Betablocker H 56/28 erwies sich beim Menschen als wirksam zur Verhutung von katecholamin- und narkosebedingten kardialen Arrhythmien. Es wird angenommen, dass diese antiarrhythmische Wirkung eher durch die beta-adrenergische Blockade bedingt ist, als die lokalanaesthetische Wirkung, die H 56/28 bekanntermassen besitzt. Obwohl einige Betablocker imstande sind, am Tier eine neuromuskulare Blockade hervorzurufen, konnte bei dieser Untersuchung am Menschen keine durch H 56/28 bedingte Abnahme der Zuckungshohe vom Ausgangswert oder eine Verstarkung der neuromuskularen Blockadewirkung von Succinylcholin bzw. d-Tubocurarin aufgedeckt werden.

Distribution of radioactive local anesthetics following intravenous regional anesthesia

Abstract: SUMMARY A technique of intravenous regional anesthesia utilizing lidocaine tagged with radioactive C14 was performed on adult monkeys. Levels of radioactivity after determined time intervals were obtained from extremity muscle biopsies, blood levels, and organ biopsies at autopsy. The labeled material rapidly perfuses throughout the tissue distal to the site of injection and is held within the area bounded by the tourniquet until release. Within 30 minutes after release it was found in approximately equal amounts throughout the body tissues. The concentration of radioactive drug present intravascularly within the anesthetized forelimb did not diminish significantly over a 90 minute period and, therefore, release of the tourniquet may allow a significant concentration of lidocaine to suddently enter the systemic circulation. Symptoms of systemic toxicity upon tourniquet release are possible 90 minutes following injection of the local anesthetic.

Subjective estimation and electronic determination of operative blood loss.

Abstract: SUMMARY The operative blood loss in 248 operations was estimated clinically and determined electronically by the washing method. It is concluded that visual evaluation gives too low values for the blood loss in many cases. The reasons for this are discussed. In estimating the operative blood loss, the importance of the blood contained in the drapes and swabs is emphasised. ZUSAMMENFASSUNG Bei 248 Operationen wurde der Blutverlust klinisch geschatzt und elektro-nisch mit Hilfe der Auswaschmethode bestimmt. Dabei kam man zu dem Schluss, dass die visuelle Schatzung zu niedrige Werte fur den Blutverlust in vielen Fallen ergibt. Die Grunde dafur werden diskutiert. Insbesondere wird bei der Schatzung des operativen Blutverlustes auf die Bedeutung der Blutmenge hingewiesen, die in den Abdecktuchern und in den Tupfern verbleibt.

Change in PaO2 During Artificial Ventilation With Added Dead Space

Abstract: SUMMARY When patients during anaesthesia were ventilated with large tidal volumes which produced a mean PaCO2 of 26 mm Hg, insertion of a 500 ml dead space increased PaCO2 to 48 mm Hg, and was accompanied by a rise in PaO2 from 172 mm Hg to 212 mm Hg, probably caused by an increase in cardiac output. It is suggested that a state of normocapnia should be attempted when respiration and circulation are interfered with, as under anaesthesia. ZUSAMMENFASSUNG Wenn Patienten in Narkose mit so grossen Atemvolumina beatmet werden, dass ein durchschnittliches PaCO2 von 26 mm Hg resultiert, kann man durch Zwischenschalten eines Totraumes von 500 ml das PaCO2 wieder auf 48 mm Hg erhohen. Dies ist von einem PaO2-Anstieg von 172 mm Hg auf 212 mm Hg begleitet, der wahrscheinlich die Folge eines erhohten Herzminutenvolumens ist. Es wird vorgeschlagen, einen Zustand der Normokapnie anzustreben, wenn, wie unter der Narkose, die Atem- und Kreislaufverhaltnisse gestort sind.

Effect of Altered Arterial Carbon Dioxide Tensions on the Electroencephalogram During Hypothermia

Abstract: SUMMARY The effect of strictly controlled changes in PaC02 on the electro-encephalogram was observed in dogs under stable anaesthesia and moderate systemic hypothermia. Pulmonary ventilation and amounts of carbon dioxide given were regulated to produce: (1) relative hypocapnia, (2) a constant PaCO2, and (3) relative hypercapnia. Changes in PaCO2 did not significantly affect coldinduced depression of the electro-encephalogram, thereby negating the prospect that the administration of carbon dioxide may prevent the depression of the electrical activity of the brain which accompanies hypothermia. Inertness of raised PaC02 on the electro-encephalogram was demonstrated also in hypothermic patients. ZUSAMMENFASSUNG Bei Hunden wurde unter gleichbleibenden Narkosebedingungen und masiger allgemeiner Hypothermic die Wirkung genau kontrollierter Veranderungen des arteriellen Kohlensauredrucks auf das EEG untersucht. Die Lungenventilation und Zugabe von Kohlensaure wurden so reguliert, das sie 1) eine relative Hypokapnie, 2) ein konstantes PaC02 und 3) relative Hyperkapnie erzeugten. Veranderungen des PaC02 beeinflusten die k#aUlteinduzierte Dampfung des Elektroenzephalogramms nicht signifikant. Womit die Vorstellung zu negieren ist, das die Gabe von Kohlensaure imstande ist, die mit der Hypothermic einhergehende Dampfung der elektrischen Aktivitat des Gehirns zu verhindern. Die Wirkungslosigkeit erhohter arterieller Kohlensauredrucke auf das EEG wurde auch bei hypothermen Patienten demonstriert.

The use intravenous regional anaesthesia in orthopedic surgery

Abstract: Because the tourniquet is an essential part of intravenous regional anaesthesia, of necessity, this technique is utilized only in procedures carried out in the extremities and, with some exceptions, for conditions occurring below the knee and elbow. Of course, in these circumstances it is not surprising that most patients are treated for orthopedic conditions. Ideally, the patient is scheduled for an operation requiring an estimated time of less than one half hour. Although longer procedures can be performed by the application of a double tourniquet, in our experience and in most of the cases reported, most surgical procedures carried out under intravenous regional anaesthesia have been minor. A few of the conditions which have been surgically treated under the anaesthetic procedure are: ingrown toenail, bunions, hallux valgus, ganglions in several locations, stenosing tenosynovitis of the wrist or De Quervain’s disease, scar tissue, foreign bodies, hammer toes, abscesses and reduction of fractures. The operating time is therefore an important factor when considering this type of anaesthesia although it is mentioned that in particular incidences it can be lengthened to over 100 minutes. Intravenous regional anaesthesia has been mainly used in adults because children are often apprehensive and do not tolerate well the discomfort of the tourniquet. In our practice, the majority of patients anaesthetized with intravenous regional Xylocaine@ are adults with closed fractures of the upper extremity, mainly the very common Colles’ fracture. This anaesthesia is particularly suitable for this kind of fracture for a number of reasons. First of all, these patients are often treated as outpatients. They frequently come in from the street after eating a sizable meal which precludes the immediate use of general anaesthesia. In addition, the syndrome of dizziness, nausea and drowsiness,