Showing papers in "Acta Anaesthesiologica Scandinavica in 1983"
TL;DR: The practice of recording exhaled carbon dioxide during the intubation procedure as an additional measure for detection of accidental oesophageal intubated CO2 concentrations was tested.
Abstract: The clinical diagnostic signs for detecting inadvertent oesophageal intubation may all be misleading. We therefore tested the practice of recording exhaled carbon dioxide during the intubation procedure as an additional measure for detection of accidental oesophageal intubation. Twenty patients were intubated simultaneously into the trachea and oesophagus and the carbon dioxide concentration was continuously recorded from both sources. Manual ventilation of the lungs always resulted in a typical CO2 curve pattern. Ventilation by mask prior to the intubation obviously resulted in some filling the stomach by exhaled gas in 9 of the 20 patients. In these cases some CO2 could be detected during oesophageal ventilation. As the oesophageal CO2 concentrations were very low initially, compared to the tracheal recordings, and carbon dioxide completely disappeared after a few ventilations into the oesophagus, distinguishing between the tracheal and oesophageal capnography tracings was easy.
146 citations
TL;DR: It is concluded that the transient mental impairment occurring within the first postoperative week is caused by factors other than general anesthetic agents and the endocrine‐metabolic response to surgery.
Abstract: The postoperative course of mental performance during the first week and at 3 months after operation was studied in 30 patients above the age of 60, undergoing total hip replacement arthroplasty. The patients were randomly allocated to receive either general anesthesia, epidural analgesia, or general anesthesia plus epidural analgesia. The surgically induced increase in plasma cortisol and glucose was inhibited in the two groups receiving epidural analgesia. Mental performance was studied with psychological methods. An equal degree of postoperative impairment of mental performance of 3-4 days' duration was found in all groups. Three months after surgery, mental function had improved slightly and to the same extent in all groups. We conclude that the after surgery, mental function had improved slightly and to the same extent in all groups. We conclude that the transient mental impairment occurring within the first postoperative week is caused by factors other than general anesthetic agents and the endocrine-metabolic response to surgery.
129 citations
TL;DR: Perivascular axillary blockade was performed on 150 patients with the aid of a catheter technique and a high frequency of analgesia was found in all cutaneous areas, apart from the axillary, musculocutaneous and radial nerves.
Abstract: Perivascular axillary blockade was performed on 150 patients with the aid of a catheter technique. Blockade failure due to injection outside the neurovascular sheath was found in 5.7% of the subject material. The patients were randomly allocated to three groups. The amount of local anaesthetic was constant in each group: 400 mg mepivacaine with adrenaline. However, the injected volume was a variable factor, namely 20, 40 or 80 ml. Sensory and motor blockade was tested 30 min after each injection. The following results were obtained: 1) Apart from the axillary, musculocutaneous and radial nerves, a high frequency of analgesia was found in all cutaneous areas (over 85%). 2) In the axillary area, improvements were found with increasing volume. 3) Analgesia in the musculocutaneous area occurred in 52% of the patients in group 1 (20 ml) and improved to 75% in group 2 (40 ml). However, no difference was found between group 2 and group 3 (80 ml). 4) Volume had no influence on analgesia in the radial area. 5) Motor blockade was intensified with decreasing volume, i.e. with an increase of concentration of local anaesthetic solution.
111 citations
TL;DR: In a concomitant study the results indicate that there is a significantly lower incidence of thrombus formation in catheters with a bending stiffness below 16×10‐6 Nm2.
Abstract: Catheter stiffness has been suggested to be a principal factor in the thrombogenesis encountered after central venous cannulation. However, no data have been published to date about the stiffness of central venous catheters. A method for measuring catheter stiffness has been developed. The force needed to deflect a catheter tip 1.2 mm from a fastening point was measured with the help of a cantilever beam (Grass Model DA-7). Six different sections of each catheter were measured, and the final results expressed as an average of these. Twenty-seven central venous catheters made of silicone elastomer, polyurethane, polyvinylchloride, polyethylene and teflon were tested. The bending stiffness, EI (E = elastic modulus of the material, I = moment of inertia of catheter (a geometrical property)) was below 16 X 10(-6) Nm2 for all catheters made of silicone elastomer, polyvinylchloride and polyurethane. Polyethylene catheters were stiffer, but could be made softer by reduction of their diameters. Teflon catheters were up to 10 times stiffer than the catheters in the soft group. Heparinization and radioopacity of catheters do not significantly alter their bending stiffness. In a concomitant study the results indicate that there is a significantly lower incidence of thrombus formation in catheters with a bending stiffness below 16 X 10(-6) Nm2.
97 citations
TL;DR: D‐tubocurarine is the relaxant of choice for the prevention of the prolongation of QT interval as well as ECG changes during the induction of anaesthesia.
Abstract: QT interval was studied in 156 adults and in 127 children during the induction of anaesthesia. Both in adults and in children, QT interval was prolonged statistically significantly after thiopentone 5 mg/kg and the most marked prolongation occurred after suxamethonium 1 to 1.5 mg/kg. In adults, d-tubocurarine 0.06 mg/kg, but not alcuronium 0.03 mg/kg or pancuronium 0.01 mg/kg, prevented statistically significantly the prolongation of the QT interval after suxamethonium 1.5 mg/kg. In children, all three muscle relaxants prevented statistically significantly the effect of suxamethonium 2 mg/kg and pancuronium also prevented the effect of thiopentone. The most common ECG changes were ventricular ectopic beats (VEB) which occurred in 26% of the adults and in 22% of the children who were not pretreated with the muscle relaxants. After pretreatment with d-tubocurarine, the incidence of VEB was 3% in both groups. In adults, alcuronium was as effective as d-tubocurarine in the prevention of VEB but in the alcuronium group supraventricular ectopic beats and junctional rhythm occurred in 6% and 9% of the patients, respectively. Pancuronium did not significantly prevent the incidence of VEB. On the basis of the present results, d-tubocurarine is the relaxant of choice for the prevention of the prolongation of QT interval as well as ECG changes during the induction of anaesthesia.
90 citations
TL;DR: The Cusum technique, originally designed for industrial production control, could successfully be applied to solve the problem of minimal effective onset time of the new topical anaesthetic EMLA and demonstrated a minimal effective application time of 45 min in adults.
Abstract: The minimal effective onset time of the new topical anaesthetic formulation EMLA (a eutectic mixture of lidocaine and prilocaine), was evaluated by the double-blind technique in 53 female and 66 male patients (median age 40 and 36 years, respectively) subjected to intravenous cannulation. Conventional plotting and regression analysis failed to answer the question. The Cusum technique, originally designed for industrial production control, could successfully be applied to solve the problem. It demonstrated a minimal effective EMLA application time of 45 min in adults.
86 citations
TL;DR: Clinical experience as well as the extensive body of literature on humidification requirements support the conclusion that in most cases the new generation of heat and moisture exchangers, which have hygroscopic properties, are superior to conventional HME units.
Abstract: The performance of four hygroscopic condenser humidifiers (HCH) and two conventional heat and moisture exchangers (HME), all commercially available, have been evaluated in laboratory tests. A clinical study was also made in order to confirm the test results. It was found that the new generation of heat and moisture exchangers, which have hygroscopic properties, are superior to conventional HME units. When dry inspired gases are used, the HCH units, but not the HME units, deliver a moisture level that is comparable to what is produced in the upper trachea during normal breathing through the nose. Our clinical experience as well as the extensive body of literature on humidification requirements support the conclusion that in most cases they can be recommended to be used for extended time periods even with dry gases. The humidification efficiency decreases with increasing tidal volume for all units. However, the best units can be used up to tidal volumes of 1000–1500 ml. The dead space of these units varies from 90 ml to 100 ml and the resistances are only about 50 Pa at 0.5 1/s. The weight is in the range 18–40 g. One of the best HCH devices also has distinct antimicrobial properties. The others are found at least not to promote organism growth. This feature added to others such as safety and simplicity in use make an HCH device an attractive alternative to conventional humidification techniques.
69 citations
TL;DR: Laser Doppler flowmetry seems to be a useful tool in the further evaluation of the influence of spinal analgesia on the extent of tile associated sympathetic blockade.
Abstract: Changes in skin blood flow provoked by spinal analgesia were evaluated by laser Doppler flowmetry. This method permits a continuous and noninvasive measurement of the microvascular flow in the superficial skin layer. All recordings were made under control environmental conditions on 40 patients submitted to transurethral resection. During spinal analgesia a significant (P less than 0.001) reduction in skin blood flow was obtained in the shoulder and chest, while an increase (P less than 0.001) in skin blood flow was seen in the lower part of the body. In the postoperative period these changes still persisted, although they were less significant, indicating the individual duration of analgesia. The relations between intra-individual relative changes in skin blood flow and skin temperature during spinal analgesia were found to be virtually uncorrelated. Laser Doppler flowmetry seems to be a useful tool in the further evaluation of the influence of spinal analgesia on the extent of the associated sympathetic blockade.
68 citations
TL;DR: It is found that lidocaine in this dose given prophylactically just before extubation was able to inhibit and prevent coughing in the recovery period after general anaesthesia.
Abstract: The preventive effect of lidocaine against coughing in the recovery period after general anaesthesia was observed. The study was carried out as a double-blind sequential trial. At the same time the incidence of laryngospasm was registered. Lidocaine or placebo was given intravenously just before extubation. Nineteen patients for tonsillectomy, all of them over the age of 15, randomly received a 2% solution of lidocaine 2 mg/kg body weight or placebo (saline) 2 min prior to expected extubation. We found that lidocaine in this dose given prophylactically just before extubation was able to inhibit and prevent coughing in the recovery period after general anaesthesia. None of the patients included in this study got laryngospasm, and none of the patients developed serious side-effects.
60 citations
TL;DR: The circulatory intubation response was studied in 75 normotensive, otolaryngological patients and the combination of halothane 2% with N2O is recommended, considering the total effect on arterial pressure, heart rate and rate‐pressure product.
Abstract: The circulatory intubation response was studied in 75 normotensive, otolaryngological patients after a thiopentone-suxamethonium induction followed by 2 min artificial ventilation with 100% oxygen (control), 70% nitrous oxide in oxygen (N2O), halothane 2% with N2O, enflurane 3% with N2O or enflurane 5% in oxygen. The above study groups (n = 15) were chosen after preliminary experiments performed in 25 different patients with halothane 2% (n = 8) or enflurane 3% (n = 6) in oxygen, which did not prevent the increase of arterial pressure after intubation, or with halothane 3% (n = 11) which attenuated the pressor response but caused cardiac arrhythmias in 55% of patients. Enflurane 5% in oxygen attenuated the increase of systolic arterial pressure by 53%, enflurane 3% with N2O by 34% and halothane 2% with N2O by 31%. The increase in heart rate after intubation was lowest in the halothane 2% with N2O group, but there were no statistically significant differences between the groups. Cardiac arrhythmias were commonest in the enflurane 3% with N2O group (20%) and they did not occur in the halothane 2% with N2O group. Considering the total effect on arterial pressure, heart rate and rate-pressure product, we recommend the combination of halothane 2% with N2O.
59 citations
TL;DR: Findings indicate a lymphocyte depressing factor in serum from patients operated under general anaesthesia, which is absent during operations in epidural anaesthesia.
Abstract: The blastogenic responses of lymphocytes to PHA-stimulation and lymphocyte lymphokine production have been studied in 27 patients undergoing total hip replacement, operated under either general anaesthesia or epidural anaesthesia. The lymphocytes were isolated from the patients the day before operation, during the operation and on the first postoperative day. The assays were carried out with lymphocytes cultured in medium containing 25% of the patient's serum (Au-medium) and in medium containing 25% of pooled AB+ serum (AB-medium). In the epidural anaesthesia group, the blastogenic response to PHA of lymphocytes incubated in Au-medium increased per- and postoperatively to 132% (n.s.) and 155% (P less than 0.05) compared to preoperative values. In the general anaesthesia group, the PHA-response decreased to 63.7% peroperatively (P less than 0.05) and 88.7% postoperatively (n.s.). When the lymphocytes were incubated in AB-medium, the PHA-response increased in both groups. Lymphocyte lymphokine production in the epidural group was unchanged both per- and postoperatively in both media. However, in the general anaesthesia group there was a reduction in lymphokine activity both per- and postoperatively. This reduction was most pronounced peroperatively when the lymphocytes were incubated in Au-medium (64.2%, P less than 0.05). Control lymphocytes incubated in sera from general anaesthetized patients resulted in significantly lower lymphokine activity (P less than 0.05) in comparison with cultures with sera from patients in the epidural group. These findings indicate a lymphocyte depressing factor in serum from patients operated under general anaesthesia, which is absent during operations in epidural anaesthesia.
TL;DR: Catheter stiffness seems to play an important role in inducing mural thrombus formation in central venous cannulation in man, and neither the surface topography of the catheter materials, nor the platelet adhesion on their surfaces in contact with human blood in vitro offered conclusive arguments for interpretation of their thrombogenicity in vivo.
Abstract: Central venous catheters of two types were inserted through basilic or cephalic veins punctured at the fossa cubiti in 61 patients: 39 soft silicone elastomer (S.E.) and 22 stiffer polyethylene (P. E.) catheters were compared regarding their thrombogenicity. Mean duration of catheterization was 6.5 days. Radiological thrombi in the peripheral and central veins visualized by phlebography were significantly smaller, and the incidence of the mural thrombi in the central veins significantly lower with the S.E. than with the P.E.-catheters, but the use of S.E.-catheters did not reduce the incidence of clinical thrombophlebitis in arm veins: 14 cases in the group with S.E. and four in that with P.E.-catheters. In both groups, the maximum incidence of clinical thrombophlebitis occurred 4–8 days after catheterization. Later, there seems to be a low risk for the appearance of clinical thrombophlebitis with both catheters. Neither the surface topography of the catheter materials, nor the platelet adhesion on their surfaces in contact with human blood in vitro offered conclusive arguments for interpretation of their thrombogenicity in vivo. Catheter stiffness seems to play an important role in inducing mural thrombus formation in central venous cannulation in man.
TL;DR: It is concluded that abdominal surgery interferes with gas exchange, presumably because of a cranial shift of the diaphragm which lowers FRC and thereby promotes airway closure.
Abstract: Nine patients, 61-72 years old, were studied awake and during halothane anaesthesia before and during upper abdominal surgery. Central circulation was evaluated by means of pulmonary artery catheterization and gas exchange by multiple inert gas elimination technique. Awake and supine, a rather wide distribution of VA/Q was observed, with regions of low VA/Q in five patients and a small shunt (1-3%) in three patients. The overall dispersion of blood flow was log s.d. 0.93. With anaesthesia and mechanical ventilation, cardiac output fell by 30%, whereas pulmonary vascular pressures remained unaltered. The dispersion of pulmonary blood flow against VA/Q ratios was further increased with a log s.d. of 1.67. Perfusion of regions with a low VA/Q was significantly increased. With surgery, no significant changes were seen in cardiac output or vascular pressures. True shunt appeared or increased in seven patients, ranging from 1.3 to 17%. Perfusion to regions with low VA/Q did not change. It is concluded that abdominal surgery interferes with gas exchange, presumably because of a cranial shift of the diaphragm which lowers FRG and thereby promotes airway closure.
TL;DR: Impedance cardiography was found to be a safe, reliable, non‐invasive technique for the measurement of changes in stroke volume during cesarean section and was unaffected by the anesthetic procedures employed or by delivery of the child.
Abstract: Simultaneous determination of cardiac stroke volume by impedance cardiography and the dye dilution technique was compared in ten women undergoing elective cesarean section performed under general or epidural anesthesia. The influence of delivery and the anesthetic procedures used on stroke volume determination by the two methods was evaluated and compared. The correlation coefficients for measurements performed before and during anesthesia showed little variation and were largely unchanged after delivery of the child (r = 0.90-0.97). Mean stroke volume determined by impedance cardiography was significantly (P less than 0.001) lower than mean stroke volume calculated from the dye dilution technique. However, there was no significant difference between the mean change in stroke volume determined by the two techniques during serial measurements. Impedance cardiography was found to be a safe, reliable, non-invasive technique for the measurement of changes in stroke volume during cesarean section. The ability of the impedance method to determine changes in stroke volume was unaffected by the anesthetic procedures employed or by delivery of the child.
TL;DR: The findings of this study indicate that premedication, anaesthesia and surgery cause a rapid and transient increase in NK cell activity, followed by a decline in activity postoperatively.
Abstract: Natural killer (NK) cell activity of peripheral blood mononuclear cells was measured against K-562 target cells in a 51Cr release assay in eight patients undergoing total hip replacement surgery. Eight consecutive blood samples were taken from each patient. A significant increase of NK cell activity was observed after premedication with diazepam per os. The activity increased further during a combined anaesthesia (thiopentone + N2O + O2 + buprenorphene + pancuronium) and remained increased during surgery. Postoperatively, NK cell activity fell and remained depressed for a period of at least 5 days. The findings of this study indicate that premedication, anaesthesia and surgery cause a rapid and transient increase in NK cell activity, followed by a decline in activity postoperatively. The transient increase in activity may be explained by mobilization of natural killer cells from extravasal space, spleen or lymph nodes into the circulation. The clinical significance of the alterations in NK cell activity is unknown and needs further investigation.
TL;DR: Local scavenging is an excellent complement to the scavenging of excess gases at the expiratory valve, and it may be considered an alternative to expensive, high‐capacity ventilation systems.
Abstract: Despite evacuation of excess anaesthetic gases at the expiratory valve of the anaesthetic circuit and a general ventilation system producing 17-20 air changes per hour, mask anaesthesia often causes occupational exposure to anaesthetic gases exceeding the threshold limit values. The effect of a local air exhaust system, a local scavenger, on occupational exposure to nitrous oxide during paediatric mask anaesthesia was studied. The scavenger evacuated 140 m3 of air per hour and was placed at a distance of 20 cm from the face mask. In a very poorly ventilated operating theatre the exposure to nitrous oxide was reduced by 75% during the anaesthetic sessions and exposure to concentrations above 500 ppm was almost eliminated. The experiences from the installation and clinical use are discussed. Local scavenging is an excellent complement to the scavenging of excess gases at the expiratory valve, and it may be considered an alternative to expensive, high-capacity ventilation systems.
TL;DR: Bupivacaine 0.75% (3 ml, 22.5 mg) in solution with glucose produced a more marked effect on the blood pressure than the other solutions tested, particularly suitable for hip surgery of long duration.
Abstract: Spinal analgesia with bupivacaine, tetracaine and mepivacaine was studied in 103 patients in two studies, one open and one double-blind. Injections were given with the patients sitting and they remained seated for 2 min after the injection. Regardless of the agent used, the mean cephalad spread of analgesia was T6-8 15 min after injection. Mepivacaine 4% (60 mg) in glucose produced analgesia and motor blockade of good quality but of short duration. Bupivacaine 0.5% and 0.75% and tetracaine 1%, all solutions with glucose, produced long-lasting blockades, tetracaine 14 mg having a longer duration of action than 15 mg bupivacaine. When 15 mg of bupivacaine was administered in solutions containing glucose, no difference in sensory blockade was seen, regardless of volume (2 or 3 ml, 0.75% and 0.5%, respectively) injected. 3 ml of bupivacaine 0.75% (22.5 mg) in glucose-free solution produced a very long-lasting blockade with deep motor engagement, particularly suitable for hip surgery of long duration. Bupivacaine 0.75% (3 ml, 22.5 mg) in solution with glucose produced a more marked effect on the blood pressure than the other solutions tested.
TL;DR: It is concluded that enflurane blocks the sympatho‐adrenal response to surgical stress more effectively than conventional neurolept anaesthesia.
Abstract: To evaluate the influence of enflurane and neurolept anaesthesia on the sympatho-adrenal response to surgery, arterial plasma concentrations of adrenaline and noradrenaline were measured at 11 carefully defined events before, during and after cholecystectomy in two groups of five patients. During steady-state anaesthesia prior to operation and after cholangiography, when the operative procedure had been interrupted for 10 min, adrenaline concentrations were similar in the two groups. During periods of stress such as intubation, skin incision and abdominal exploration, adrenaline levels were 4-6 times higher in the neurolept patients compared to the enflurane patients (P less than 0.01), in whom adrenaline levels were very stable. Noradrenaline levels also varied with stress but without difference between the two groups. Systolic blood pressure was approximately 20 mmHg higher during operation in the neurolept group than in the enflurane group (P less than 0.05). It is concluded that enflurane blocks the sympatho-adrenal response to surgical stress more effectively than conventional neurolept anaesthesia.
TL;DR: With correct diagnosis and indication, guanethidine injections may play an important part in the treatment of reflex sympathetic dystrophy and may replace sympathetic blocks with local anaesthetics because of the longer duration of action and lower incidence of serious side‐effects.
Abstract: Twenty patients with documented reflex sympathetic dystrophy were treated with a series of regional intravenous guanethidine blocks. The mean delay between the first clinical symptoms and the start of guanethidine blocks was 3.6 months. The overall result was good in 11 patients, moderate in two patients and poor in seven patients. Poor results are due mainly to incorrect diagnosis and to application either too late in the third phase or too early in the first phase when only signs of increased blood flow are part of the symptomatology. Side effects, except pain after the injection, were few and of minor importance. The tolerance of the procedure may be improved by preceding the injection of guanethidine by an injection of a local anaesthetic agent. It may be concluded that with correct diagnosis and indication, guanethidine injections may play an important part in the treatment of reflex sympathetic dystrophy and may replace sympathetic blocks with local anaesthetics because of the longer duration of action and lower incidence of serious side-effects.
TL;DR: Acidosis and/or hyperkalemia in man appears to increase the myocardial susceptibility to bupivacaine toxicity into the range of arterial concentrations of the drug normally produced by plexus blocks, even in the absence of drug‐induced cerebral toxicity, seizures and hypoxia.
Abstract: Bradycardia and hypotension were the first major signs of toxicity from a 250 mg bupivacaine axillary brachial plexus block experienced by a patient with chronic renal failure, who had an anion gap acidosis and hyperkalaemia. Without these metabolic abnormalities, this patient received four similar blocks: three were without incident and one was complicated by seizure. Acidosis and/or hyperkalaemia in man appears to increase the myocardial susceptibility to bupivacaine toxicity into the range of arterial concentrations of the drug normally produced by plexus blocks, even in the absence of drug-induced cerebral toxicity, seizures and hypoxia.
TL;DR: The material consisted of 25 patients undergoing orthopaedic or plastic surgery of the upper extremity, including seven cases of replantation surgery, and the high doses and the rather high venous peak concentration of bupivacaine in some of the patients, no toxic side‐effects were observed during the block or during the recovery period.
Abstract: The material consisted of 25 patients undergoing orthopaedic or plastic surgery of the upper extremity, including seven cases of replantation surgery. The total doses of bupivacaine, 150-267 mg as a single dose, 280-440 mg as a supplementary dose and 247-629 mg as a continuous infusion, resulted in maximum venous concentrations of 0.68-3.33 micrograms/ml, 1.21-2.44 micrograms/ml and 0.51-1.89 micrograms/ml, respectively. These usually occurred 30-60 min after the injection of bupivacaine and always following the second injection when a supplementary dose was needed. The highest individual value noted occurred 15 min after single injection, possibly as a result of an exceptionally rapid absorption. Despite the high doses and the rather high venous peak concentration of bupivacaine in some of the patients, no toxic side-effects were observed during the block or during the recovery period.
TL;DR: High epidural block (Th I‐IV) with bupivacaine was carried out in 16 dogs, and mean arterial blood pressure decreased to 52% of control value owing to nearly equal decreases in systemic vascular resistance and cardiac output.
Abstract: High epidural block (Th I-IV) with bupivacaine was carried out in 16 dogs. Mean arterial blood pressure decreased to 52% of control value owing to nearly equal decreases in systemic vascular resistance and cardiac output. Portal venous blood flow decreased from 25.8 +/- 8.6 to 16.7 +/- 7.2 ml/kg b.w. X min-1 following epidural block, while hepatic arterial blood flow remained unchanged at 9.1 +/- 3.1 ml/kg b.w. X min-1 owing to a reduction in hepatic arterial resistance of 51%. Hepatic oxygen uptake was maintained during the epidural block through increased oxygen extraction. However, total oxygen uptake decreased by 18% and, in spite of this, arteriovenous oxygen content difference increased by 25%, indicating circulatory depression.
TL;DR: D‐tubocurarine and alcuronium seem to have advantages over pancuronium, ORG NC‐45 and gallamine for precurarization.
Abstract: Five different non-depolarizing muscle relaxants and a control solution of saline were studied as precurarization agents. Two hundred and twenty-two surgical patients (ASA I-II) were allocated in a double-blind fashion to one of the following groups: d-tubocurarine 0.05 mg/kg, alcuronium 0.03 mg/kg, pancuronium 0.01 mg/kg, gallamine 0.25 mg/kg, ORG NC-45 (vecuronium) 0.01 mg/kg and saline solution 0.005 ml/kg. Pretreatment was performed 4 min before administering a 1.5 mg/kg bolus of succinylcholine (SCh). Fasciculations, intubation conditions, duration of neuromuscular blockade after SCh, serum potassium changes and postoperative myalgias (in 60 patients) were recorded. All the drugs studied prevented fasciculations significantly (P less than 0.05) more than in the control group. d-Tubocurarine and alcuronium were superior to the others in this respect. Intubation conditions were best in the control and pancuronium groups, but there was no significant difference between the pancuronium and d-tubocurarine or between the d-tubocurarine and alcuronium groups. Pancuronium pretreatment prolonged the SCh block significantly, whereas other agents shortened the duration of the SCh block. The antagonism of the SCh block apparently also affected intubation conditions, although intubation remained satisfactory. A statistically significant rise in serum potassium level was measured only in the control and pancuronium groups. In the control and pancuronium groups, four patients out of 10 had postoperative myalgias, whereas in the other groups only one or none out of 10 had them (0/10 vs. 4/10; 0.10 greater than P greater than 0.05). In conclusion, d-tubocurarine and alcuronium seem to have advantages over pancuronium, ORG NC-45 and gallamine for precurarization.
TL;DR: It was concluded that the pattern of temperature change was evidence of an abnormality of the heat dissipation mechanisms in the MHS subjects, which could indicate an abnormally of sympathetic activity in individuals susceptible to malignant hyperpyrexia.
Abstract: Body temperature at a variety of sites (external auditory meatus, rectum, thigh, chest wall, pad of thumb), blood cortisol, lactate and free fatty acid levels and urinary adrenaline, noradrenaline and dopamine excretion were measured in five human subjects susceptible to malignant hyperpyrexia (MHS) and five normal subjects during a period of progressively severe exercise, starting at rest and going up to an exercise intensity producing heart rates in excess of 180 beats/min. In addition, results are reported of a further study of rectal temperature measurements made during a period of mild exercise in a different group of nine MH susceptible and nine non-susceptible subjects. The results of the progressive exercise study indicated that as the exercise increased in severity, central (external auditory meatal) temperature rose more in the MHS subjects than it did in the controls. Thumb temperature in both groups rose with exercise but in the MHS subjects this rise was significantly delayed compared with the control subjects. It was thought that this was due to a delay in the onset of vasodilatation which usually accompanies high intensities of exercise. Serum free fatty acids and cortisol levels rose more in the MHS subjects than the controls and during the early stages of exercise blood lactate concentrations in the MHS subjects were higher than in the controls group. During mild exercise, rectal temperature in the MHS subjects was lower than in the controls. It was concluded that the pattern of temperature change was evidence of an abnormality of the heat dissipation mechanisms in the MHS subjects. This, together with the rise in the free fatty acids, could indicate an abnormality of sympathetic activity in individuals susceptible to malignant hyperpyrexia.
TL;DR: The results indicate that as long as any baro‐reflex activation of the sympathetic nervous system and acceleration of the nonshivering thermogenesis is avoided, the recommended treatment with alpha adrenergic receptor blocking agents can be performed without any increase in plasma concentration of catecholamines.
Abstract: Treatment with alpha adrenergic receptor blocking agents has been used clinically for many years to obviate peripheral vasoconstriction in patients suffering from circulatory or thermoregulatory distress. Various reports indicating that administration of these agents may be followed by an increased plasma concentration of catecholamines, and subsequently an increased oxygen demand, led to 29 investigations on humans who were placed in a horizontal position in a thermoneutral environment and given 25 mg chlorpromazine intravenously, dissolved in 500 cc low molecular weight dextran. Blood pressure and heart rate remained unchanged during the infusions and significant changes in plasma noradrenaline (average fall: 4.42 nmol X 1(-1), range: -31.9- + 5.1) and in plasma adrenaline (average fall: 1.06 nmol X 1(-1), range: -16.3- + 5.11) were observed (P less than 0.01). The results indicate that as long as any baro-reflex activation of the sympathetic nervous system and acceleration of the nonshivering thermogenesis is avoided, the recommended treatment with alpha adrenergic receptor blocking agents can be performed without any increase in plasma concentration of catecholamines.
TL;DR: It is concluded that differential ventilation with equal tidal volumes in the lateral position can substantially improve gas exchange and central haemodynamics in patients with ARF due to diffuse lung disease.
Abstract: Eight patients with acute respiratory failure (ARF) due to diffuse and rather uniform lung disease were intubated with a double-lumen bronchial tube and ventilated in the lateral decubital position by two synchronized ventilators. Ventilation of each lung was individually adjusted to match the expected regional blood flow (differential ventilation). When ventilation with equal volumes (i.e. 50% of tidal volume to each lung) was performed, a 19% reduction of venous admixture (P less than 0.001) and a 22% increment in arterial oxygen tension (P less than 0.001) were seen. Comcomitantly, the cardiac output increased by 17% (P less than 0.001), to which a reduced pulmonary vascular resistance may have contributed. The net result was a 14% increment of the oxygen availability (P less than 0.001). An attempt to go further, giving 2/3 of the tidal ventilation to the dependent lung, was made on six of the patients. However, this ventilatory pattern did not further improve the gas exchange and also had detrimental effects on the haemodynamics. It is concluded that differential ventilation with equal tidal volumes in the lateral position can substantially improve gas exchange and central haemodynamics in patients with ARF due to diffuse lung disease.
TL;DR: The ability of the pulmonary circulation to clear the blood of lidocaine is high, and that it is not affected markedly by those situations studied in the present investigation.
Abstract: Pulmonary uptake of lidocaine was investigated in patients before surgery, and aimed at elucidating the influence of general anaesthesia, the presence of another local anaesthetic agent in the blood, or the possible impact of lung insufficiency. When the lung uptake of lidocaine, injected as a bolus together with indocyanine green dye, was calculated as uptake at 95% pass of the dye, there were no statistically significant differences between the four groups. When the extraction in each of the arterial blood samples was calculated on the basis of the relation between relative concentrations, there were statistically significant differences, with a general tendency towards higher extraction of lidocaine in the awake, healthy volunteers, not given mepivacaine, compared to the other groups. In the group in whom mepivacaine was infused, the arterial concentration of mepivacaine increased transiently after the injection of lidocaine. This probably reflects a displacement of mepivacaine from binding sites for both agents. From this study, it is postulated that the ability of the pulmonary circulation to clear the blood of lidocaine is high, and that it is not affected markedly by those situations studied in the present investigation.
TL;DR: The results suggest that the endocrine‐metabolic response to major upper abdominal surgery can be inhibited by epidural analgesia.
Abstract: Blood concentrations of glucose, lactate, non-esterified fatty acids (NEFA) and insulin (IRI) were measured in two groups of ten patients undergoing elective gastrectomy under general anesthesia with halothane (Group G) or epidural analgesia extending from Th3–4 to L1–2 without halothane (Group E) The rise in blood glucose and the rise in NEFA in group E during operation were significantly less than in Group G Blood lactate levels during operation were lower in group E than in group G although the difference was not statistically significant The increase in IRI/glucose ratio on postoperative day 1 was significantly less in Group E than in Group G, suggesting that insulin sensitivity after surgery was higher in Group E The postoperative course was uneventful in all subjects These results suggest that the endocrine-metabolic response to major upper abdominal surgery can be inhibited by epidural analgesia
TL;DR: The effects and pharmacokinetics of thiopental were studied in eight patients undergoing renal transplantation and the results were compared with findings in a group of patients with normal renal function.
Abstract: The effects and pharmacokinetics of thiopental were studied in eight patients undergoing renal transplantation. The results were compared with findings in a group of patients with normal renal function. No differences were observed in induction doses or between arterial or venous sleep concentrations. The average V3 in the renal failure group was 1441 or 2.5 times the value of the control group (P less than 0.01). The apparent differences indicating longer elimination half-lives and higher serum clearances in the renal patients were not significant. The average binding of thiopental to serum protein shortly after the induction was 83.9% (78.2-88.1) in the renal patients and 89.0% (85.2-91.6) in the control patients (P less than 0.05). The difference in V3 could be explained by the differences in protein binding and when the serum clearance was calculated by using the unbound fraction, this "intrinsic clearance" was significantly lower in the renal failure group (P less than 0.05). Haemodynamic parameters were determined during the initial 5 min. No significant difference was observed between the thiopental-induced changes in stroke volume. Cardiac output was unchanged in both patient groups.
TL;DR: Only two patients displayed increasing shunting suggestive of alveolar collapse during the 3.5 h observation period, lower than expected incidence may indicate protective mechanisms against atelectasis, such as mechanical interdependence between lung units, or collateral ventilation.
Abstract: Alveolar stability was studied during prolonged enflurane anaesthesia by using a multiple inert-gas elimination technique for the assessment of the "continuous" distribution of ventilation-perfusion ratios (VA/Q). All 10 patients (mean age: 61 years, six smokers) presented with increased VA/Q mismatching during anaesthesia, with a redistribution of lung blood flow to regions with low or high VA/Q. Five patients had perfusion of units with VA/Q less than or equal to 0.07 which may cause unstable alveoli with the presently used inspiratory gas mixture. However, only two patients displayed increasing shunting suggestive of alveolar collapse during the 3.5 h observation period. This lower than expected incidence may indicate protective mechanisms against atelectasis, such as mechanical interdependence between lung units, or collateral ventilation.