Showing papers in "Acta Anaesthesiologica Scandinavica in 1994"
TL;DR: It is concluded that PP causes signs of elevated preload and afterload, and it is suggested that the haemodynamic response to PP, especially in combination with a head–down tilt, may be hazardous to patients with compromised heart function.
Abstract: The laparoscopic operating technique is being applied increasingly to a variety of intra-abdominal operations. Intra-abdominal gas insufflation, i.e. pneumoperitoneum (PP), is then used to allow surgical access. The haemodynamic effects of PP in combination with different body positions have not been fully examined. Eleven patients without signs of cardiopulmonary disease were studied before and during laparoscopic cholecystectomy under propofol-fentanyl anaesthesia with controlled ventilation. Swan-Ganz and radial arterial catheterization were used to determine haemodynamic data in the horizontal position, with a 15-20 degree head-down tilt and a 15-20 degree head-up tilt. The measurements were repeated after insufflation of carbon dioxide to an intraabdominal pressure of 11-13 mmHg, as well as during surgery. The ventricular filling pressures of the heart were strictly dependent on body position. PP in the horizontal position increased pulmonary capillary wedge pressure by 32% (P < 0.01), central venous pressure by 58% (P < 0.01), and mean arterial pressure by 39% (P < 0.01). When PP was combined with a head-down tilt, there was a further increase in filling pressures by approximately 40% (P < 0.01), while the reduction in filling pressures during the head-up tilt was counteracted by PP. During PP with a head-up tilt, the filling pressures did not differ from those in the horizontal position without PP. CI showed a certain dependency on filling pressures. It is concluded that PP causes signs of elevated preload and afterload. The combination of PP and a head-up tilt is associated only with signs of an elevated afterload.(ABSTRACT TRUNCATED AT 250 WORDS)
215 citations
TL;DR: The data indicate that inadequate gut perfusion leads to a measurable imbalance between oxygen delivery and the needs of the tissues, i.e., ischaemia, which leads to multiple organ failure.
Abstract: Multiple organ failure remains the leading cause of death in the intensive care unit. Increasing numbers of investigators have focused their attention on the role of gastrointestinal tract in the pathogenesis of this syndrome. Their data indicate that inadequate gut perfusion leads to a measurable imbalance between oxygen delivery and the needs of the tissues, i.e., ischaemia. Gut ischaemia of sufficient duration impairs gastrointestinal tract barrier function, facilitating the passage of enteric bacterial endotoxin into the circulation. It has been hypothesized that production of tumor necrosis factor α, and other biologic mediators by endotoxin–stimulated macrophages, triggers a generalized and uncontrolled inflammatory response that ultimately leads to multiple organ failure.
Preliminary evidence suggests that survival can be improved significantly if gut ischaemia is promptly identifed and aggressively treated by administration of fluids and inotropic drugs, using gastric intramucosal pH as the therapeutic endpoint. Future studies are needed to determine whether additional treatment modalities can improve outcome once the inflammatory response has fully developed.
164 citations
TL;DR: The results suggest that 2 Hz electrical stimulation is the mode of choice when using acupuncture in the treatment of chronic nociceptive low back pain.
Abstract: A controlled study of different modes of acupuncture stimulation was conducted on patients fulfilling clinical criteria for chronic low back pain of nociceptive origin. Forty patients were randomly entered into the study. Thirty had three trial treatments with manual stimulation of needles (MS), electrical low frequency stimulation at 2 Hz (LF), and high-frequency stimulation at 80 Hz (HF), and then continued treatment with the mode they felt most benefitted them. Ten patients were put on the waiting list for treatment but served as the untreated control group. The results were evaluated after 6 weeks and at 6 months for: activity related to pain; mobility; verbal descriptors of pain and the patient's subjective assessment of his condition. After 6 weeks, patients receiving treatment showed significant improvement (P < 0.05 to P < 0.001) on three of the four measures compared to the untreated controls. After 6 months a similar measure of significant improvement was seen in patients continuing with low-frequency (LF) acupuncture, but not in those groups continuing with manual stimulation (MS) or high-frequency (HF) acupuncture. The results suggest that 2 Hz electrical stimulation is the mode of choice when using acupuncture in the treatment of chronic nociceptive low back pain.
138 citations
TL;DR: The data suggest that mild hypothermia during anesthesia significantly impairs resistance to dermal infection and mild hyperthermia does not appear to be protective, which is a major factor influencing resistance to wound infection.
Abstract: Small changes in core temperature profoundly alter cutaneous blood flow, a major factor influencing resistance to wound infection Furthermore, when measured in vitro, various immune functions are temperature dependent in the physiological range Accordingly, we tested the hypothesis that mild hypothermia impairs and mild hyperthermia improves resistance to dermal infections Thirty-two guinea pigs were anesthetized for 6 h using 15% (125 MAC) inspired isoflurane Their core temperatures were maintained at either 39 degrees C (normal for guinea pigs, n = 11), 36 degrees C (n = 12), or 41 degrees C (n = 9) One h after induction of anesthesia, 2 x 10(8) E coli were injected intradermally with a 26-g needle at eight sites on each animal's back Core temperatures were not controlled after recovery from anesthesia, and animals in each group were maintained in the same environment Twenty-four h after injection, the area of induration surrounding each injection site was measured This is a standard test of resistance to wound infection Values were compared using one-way ANOVA and Scheffe's S tests Results are presented as means +/- standard deviations; differences were considered significant when P < 005 Areas of inflammation on the hypothermic animals were significantly larger (48 +/- 10 mm2) than those on normothermic (36 +/- 10 mm2) or hyperthermic (37 +/- 6 mm2) animals These data suggest that mild hypothermia during anesthesia significantly impairs resistance to dermal infection In contrast, mild hyperthermia does not appear to be protective
131 citations
TL;DR: The effects of LA administered at the wound site on nociception and the inflammatory response are described and the effects ofLA on pain and morbidity after abdominal and gynaecological surgery in adult patients are reviewed.
Abstract: In recent years there has been increasing interest in peripheral mechanisms of nociception and the afferent nerve terminal and its surroundings as a possible target for analgesics and modification of the response to surgical injury (1-3). Systemic administration of non-steroidal antiinflammatory drugs (NSAID), due to modulation of the arachidonic acid cascade, have been demonstrated to be of value as adjuncts to other analgesics after surgery (1) . Administration of local anaesthetics (LA) into the surgical wound may modulate pain at the peripheral level and has been widely used in minor surgical procedures (4-10) as well as attracting renewed interest in major surgery. However, despite the widespread use, its scientific documentation from controlled studies has been relatively sparse and not hitherto reviewed. This review describes the effects of LA administered at the wound site on nociception and the inflammatory response. Furthermore, the effects of LA on pain and morbidity after abdominal and gynaecological surgery in adult patients are reviewed, based upon controlled clinical studies. It was not intended to include paediatric procedures, since postoperative paediatric pain represents separate problems of acute pain management.
128 citations
TL;DR: Internal jugular vein cannulation is a popular approach for central venous access as it has few complications, of which failure to locate the vein and carotid artery puncture are the most common.
Abstract: Internal jugular vein (IJV) cannulation is a popular approach for central venous access as it has few complications, of which failure to locate the vein and carotid artery puncture are the most common. A variety of manoeuvres and body positioning has been used to maximise IJV size and thereby increase cannulation success rate and decrease complications. Realtime 2D ultrasound can be used to view neck vascular anatomy in vivo and allow IJV size to be measured. Thirty-five volunteers had the lateral diameter of their IJV measured using the SiteRite ultrasound machine to discover the most effective methods of increasing its diameter. No correlation was found between the IJV lateral diameter and subject height, weight, age or neck circumference. Carotid artery palpation and full neck extension reduced its diameter considerably. Increasing Trendelenberg increased diameter. Abdominal binder and the Valsalva manoeuvre were the most efficient methods of increasing its size.
124 citations
114 citations
TL;DR: The effect of TEA on the endocrine metabolic response to aortocoronary bypass surgery (ACBS) is investigated.
Abstract: Thoracic epidural analgesia (TEA) may offer haemodynamic benefits for patients with coronary heart disease going through major surgery. This may-in part-be secondary to an effect on the endocrine and metabolic response to surgery. We therefore investigated the effect of TEA on the endocrine metabolic response to aortocoronary bypass surgery (ACBS). Thirty male patients (age 0.5) were randomized into 3 groups; the HF group receiving a high dose fentanyl (55 micrograms.kg-1) anaesthesia, the HF+TEA group with the same fentanyl dose+TEA with 10 ml bupivacain 5 mg.ml-1, followed by 4 ml every hour, and the LF+TEA group receiving fentanyl 15 micrograms.kg-1 + TEA. Adrenalin, noradrenalin, systemic vascular resistance (SVR), glucose, cortisol, lactate and free fatty acids were followed during the operation and for 20 h postoperatively. A significant increase in adrenalin, noradrenalin and SVR was found in the HF group whereas this increase was blocked in both epidural groups. An increase in glucose and cortisol was noticed in all groups, but the increase was delayed in the epidural groups. Our results suggest that a more effective blockade of the stress response during ACBS is obtained when TEA is added to general anaesthesia than with high dose fentanyl anaesthesia alone.
108 citations
TL;DR: It is concluded that effective early (48 h) postoperative pain relief with balanced analgesia does not per se lead to important improvements in convalescence and hospital stay.
Abstract: Forty-two patients scheduled for total knee arthroplasty (n = 20) or hip arthroplasty (n = 22) were randomly allocated to receive either continuous epidural bupivacaine/morphine for 48 h postoperatively plus oral piroxicam, or general anaesthesia followed by a conventional intramuscular opioid and acetaminophen regimen. Patients undergoing knee- or hip arthroplasty treated with epidural analgesia had significantly lower pain scores during mobilization under the 48 h epidural infusion compared with patients receiving conventional treatment, while no important differences were observed after cessation of the epidural regimen. However, the achieved pain relief had no impact on postoperative convalescence parameters, such as ambulation, patient activity including need for nursing care, fatigue or hospital stay. Late postoperative pain, fatigue and conservative attitudes and routines in the postoperative care, were the most important reasons limiting mobilization and activity. We conclude that effective early (48 h) postoperative pain relief with balanced analgesia does not per se lead to important improvements in convalescence and hospital stay.
107 citations
TL;DR: Signs of marked haemodynamic changes and sedation may limit the usefulness of intrathecal clonidine in patients undergoing knee arthroscopy under spinal anaesthesia.
Abstract: Clonidine, an alpha-2-adrenergic agonist, may have a clinically relevant analgesic action but also a hypotensive action, when administered spinally. In this study, therefore, the analgesic and circulatory effects of intrathecal clonidine were studied in patients undergoing knee arthroscopy under spinal anaesthesia. Forty ASA I-II patients were randomly divided to two groups. One group received clonidine 3 micrograms.kg-1 mixed with 15 mg 0.5% bupivacaine and the other group an identical saline volume mixed with bupivacaine as above, in a double-blind fashion. Sensory analgesia, blood pressure, heart rate and sedation were followed during and after the operation. Oxycodone 0.14 mg.kg-1 i.m. or ketoprofen 100 mg p.o. was administered when needed. The duration of sensory analgesia (until regression of the block to L2) was longer in the clonidine group (mean 217 min) than in the control group (mean 160 min) (P < 0.05). Duration of motor blockade was also longer in the clonidine group (mean 215 min) compared to the control group (161 min) (P < 0.05). Mean arterial pressure and heart rate were significantly lower in the clonidine group compared to the control group. The clonidine patients needed fewer supplemental doses of oxycodone (8 doses) than those in the control group (16 doses) (P < 0.05). More patients in the clonidine group were sedated 3-6 h after the injection (P < 0.05). Addition of clonidine prolonged the bupivacaine spinal block. However, marked haemodynamic changes and sedation may limit the usefulness of intrathecal clonidine.
97 citations
TL;DR: This study demonstrated a simple, efficient and safe way to reduce pain perception following a thyroidectomy using bupivacaine 0.5% wound infiltration for postoperative pain management following thyroid surgery.
Abstract: Control of postoperative pain is an important element in preventing the modification of the excitability of the dorsal horn neurons. We studied the efficacy of bupivacaine 0.5% wound infiltration for postoperative pain management following thyroid surgery. Forty consecutive ASA I-II patients, scheduled for thyroidectomy, were assigned randomly to two groups. Group I (n = 20) consisted of patients receiving bupivacaine 0.5% (10 ml) wound infiltration at the end of surgery and group II (n = 20 included patients without infiltration. The patients did not know whether the wound had been anaesthetized or not. All patients received balanced inhalational anaesthesia, including fentanyl (a total dose of up to 4 micrograms.kg-1). Postoperative pain medication included morphine IV or IM, as needed. Twenty-four hours after surgery the worst pain was recorded using a visual analogue scoring system, from 0 to 10. Twenty-four hour postoperative morphine requirement was recorded. Groups did not differ in demographic data. Pain scores significantly different in the two groups. In group I, the mean pain score was 3.7 +/- 1.6 compared with 6.9 +/- 1.7 in group II (P < 0.05). Only six patients (30%) in group I received opioids and only one of these (5%) had a pain score above 5. In comparison, 18 patients (90%) in group II received morphine during the first postoperative day. The local injection of bupivacaine corresponds to a block of the superficial branches of the cervical plexus. This study demonstrated a simple, efficient and safe way to reduce pain perception following a thyroidectomy.
TL;DR: Indwelling spinal catheterization > 24 h with continuous intrathecal analgesia following accidental dural puncture in parturients may for some patients be a suitable method for providing PDPH prophylaxis and postoperative analgesia.
Abstract: To examine the effects of prolonged (> 24 h) intrathecal catheterization with the use of postoperative analgesia on the incidence of post-dural puncture headache (PDPH), charts of 45 obstetric patients who had accidental dural puncture following attempts at epidural block were reviewed retrospectively. Three groups were identified: Group I (n = 15) patients had a dural puncture on the first attempt at epidural block, but successful epidural block on a repeated attempt; Group II (n = 17) patients had a dural puncture with immediate conversion to continuous spinal anaesthesia with catheterization lasting only for the duration of caesarean delivery; Group III (n = 13) patients had an immediate conversion to spinal anaesthesia and received post-caesarean section continuous intrathecal patient-controlled analgesia consisting of fentanyl 5 micrograms.ml-1 with bupivacaine 0.25 mg.ml-1 and epinephrine 2 micrograms.ml-1 with catheterization lasting > 24 h. No parturient in group III developed a PDPH. This was substantially lower (P 24 h with continuous intrathecal analgesia following accidental dural puncture in parturients may for some patients be a suitable method for providing PDPH prophylaxis and postoperative analgesia.
TL;DR: This work studied the effect of 40 ppm inhaled nitric oxide on PCP and longitudinal distribution of pulmonary vascular resistance (PVR) in 18 patients with ALI and found that in the presence of intrapulmonary vasoconstriction pulmonary capillary pressure may increase thereby promoting transvascular fluid filtration and lung oedema formation.
Abstract: In acute lung injury (ALI), where pulmonary microvascular permeability is increased, transvascular fluid filtration depends mainly on the hydrostatic capillary pressure. In the presence of intrapulmonary vasoconstriction pulmonary capillary pressure (PCP) may increase thereby promoting transvascular fluid filtration and lung oedema formation. We studied the effect of 40 ppm inhaled nitric oxide (NO) on PCP and longitudinal distribution of pulmonary vascular resistance (PVR) in 18 patients with ALI. PCP was estimated by visual analysis of the pressure decay profile following pulmonary artery balloon inflation. Contribution of venous pulmonary resistance to total PVR was calculated as the percentage of the pressure gradient in the pulmonary venous system to the total pressure gradient across the lung. Inhalation of 40 ppm NO produced a prompt decrease in mean pulmonary artery pressure (PAP) from 34.1 +/- 6.8 to 29.6 +/- 5.7 (s.d.) mmHg; (P < 0.0001). PCP declined from 24.8 +/- 6.2 to 21.6 +/- 5.2 mmHg; (P < 0.0001) while pulmonary artery wedge pressure (PAWP) did not change. PVR decreased from 166 +/- 73 to 128 +/- 50 dyn.sec.cm-5; (P < 0.0001). Pulmonary venous resistance (PVRven) decreased to a greater extent (from 76 +/- 41 to 50 +/- 28 dyn.sec.cm-5; (P < 0.001) than pulmonary arterial resistance (PVRart) (from 90 +/- 36 to 79 +/- 29 dyn.sec.cm-5; (P < 0.01). The contribution of PVRven to PVR fell from 44.3 +/- 10.8 to 37.8 +/- 11.9%; (P < 0.01). Cardiac output (CO) remained constant. The findings demonstrate that NO has a predominant vasodilating effect on pulmonary venous vasculature thereby lowering PCP in patients with ALI.
TL;DR: Thoracic epidural analgesia (TEA) has been reported to be beneficial in patients with coronary heart disease going through major surgery withachycardia and hypertension.
Abstract: Tachycardia and hypertension may cause myocardial ischaemia in patients with coronary heart disease going through major surgery. Thoracic epidural analgesia (TEA) has been reported to be beneficial in this situation.
The haemodynamic effects of TEA in aortocoronary bypass surgery were investigated in 30 male patients 0.5. They were randomized into 3 groups: the high dose fentanyl (HF) group receiving high–dose fentanyl (55 μg kg-1) anaesthesia, the HF + TEA group receiving the same fentanyl dose + TEA with 10 ml bupivacaine 5 mg ml-1 followed by 4 ml every hour, and the low dose fentanyl (LF) + TEA group receiving low–dose fentanyl (15 μg kg-1) anaesthesia + TEA. Haemodynamic parameters, the use of vasoactive and inotropic drugs and fluid balance were followed during the operation and for 20 h postoperatively.
Before bypass the only significant difference between groups was a higher mean pulmonary arterial pressure in the HF + TEA group and a lower systemic vascular resistance (SVR) in the LF + TEA group, both compared to the HF group. 89% of epidural group patients needed small doses of ephedrine whereas more HF group patients were given nitroglycerine. During bypass SVR and mean arterial pressure (MAP) were significantly higher and pump flow lower in the HF group compared to the LF + TEA group. More ketanserin to HF group patients and methoxamine to epidural group patients were given. After bypass heart rate increased in all groups. Lower MAP 0.5 h after bypass and higher filling pressures in the early post bypass period in the epidural groups, most pronounced in the HF + TEA group, were noted. More propranolol, nitroglycerine and sodium nitroprusside were given to patients in the HF group. No difference in intraoperative fluid balance between groups was seen.
Our results suggest more easy control of perioperative hypertension and tachycardia with TEA. This was achieved without haemodynamic side effects of clinical importance.
TL;DR: Every second patient experienced nausea or vomiting after breast surgery, the majority of these emetic symptoms occurring after leaving the postoperative unit.
Abstract: Nausea and vomiting during the first 24 postoperative hours after breast surgery were studied. Ninety patients scheduled for elective breast surgery were randomly assigned to one of three anaesthetic methods: total intravenous anaesthesia with propofol, or propofol or thiopental for induction followed by isoflurane anaesthesia. All three groups received fentanyl for peroperative analgesia. A total of 46 (51%) patients experienced emetic sequelae: 19 (21%) complained about nausea and another 27 (30%) vomited once or more during the postoperative course. More than 50% of the patients with nausea and 70% with vomiting first suffered from these symptoms in the surgical wards after leaving the postoperative unit. Nausea and vomiting were seen in 18 (60%), 13 (43%) and 15 (50%) for the groups propofol-propofol, propofol-isoflurane and thiopental-isoflurane, respectively. In conclusion, every second patient experienced nausea or vomiting after breast surgery, the majority of these emetic symptoms occurring after leaving the postoperative unit. Propofol for induction or as a main anaesthetic did not make any major difference with regard to postoperative nausea or vomiting.
TL;DR: Auscultation of the epigastrium, right and left axilla is more reliable than auscultations of the chest, and the anaesthetist's feeling when he squeezes the bag.
Abstract: Prompt detection of oesophageal intubation is a primary concern in anaesthetic practice. This blind, randomised study evaluates three widely used tests of intubation. Forty patients had both their trachea and oesophagus intubated, each patient was studied twice. Auscultation of the epigastrium, right and left axilla is more reliable than auscultation of the chest, and the anaesthetist's feeling when he squeezes the bag. P = 0.001 and P = 0.048, respectively. The tests were carried out after gastric distension with gas had occurred. We conclude that auscultation of epigastrium, right and left axilla, are recommended.
TL;DR: PVB may possess a potential for postoperative analgesia equal to or maybe even superior to conventional lumbar EDA in pediatric patients undergoing renal surgery, and further prospective studies investigating the analgesic efficacy of this novel technique are warranted.
Abstract: Continuous thoracic paravertebral blockade (PVB) has only recently been reported in pediatric patients. The aim of the present study was to compare retrospectively the postoperative analgesic efficacy of PVB vs conventional lumbar epidural blockade (EDA) in children. Thirty-five consecutive pediatric patients undergoing renal surgery, receiving either PVB (n = 15) or EDA (n = 20), were reviewed. The need for supplemental morphine administration during the first 24 postoperative hours was used to assess the postoperative analgesic efficacy of the two different regional techniques. Both the total amount of supplemental morphine and the number of patients with no need for supplemental morphine administration, were compared between the two groups. The need for supplemental morphine administration was significantly lower (P = 0.046) and the number of patients with no need for supplemental morphine administration postoperatively was significantly higher (P = 0.019) in patients treated with PVB vs EDA. The present study indicates that PVB may possess a potential for postoperative analgesia equal to or maybe even superior to conventional lumbar EDA in pediatric patients undergoing renal surgery. Further prospective studies investigating the analgesic efficacy of this novel technique are warranted.
TL;DR: Patients receiving intramuscular premedication with midazolam about 45 minutes prior to induction of anaesthesia showed a delta dominated EEG with a reduced alpha peak and an average median of 4 Hz as the baseline findings of the EEG power spectrum.
Abstract: Changes in the EEG power spectrum were studied in 50 patients (ASA status I or II), receiving either 2 mg.kg-1 of racemic ketamine or 1 mg.kg-1 of S-(+) ketamine in a randomized and double-blind manner after prior administration of 0.1 mg.kg-1 of midazolam. The patients receiving intramuscular premedication with midazolam about 45 minutes prior to induction of anaesthesia showed, in a deliberately quiet environment and mostly in the early morning, a delta dominated EEG (56% delta power) with a reduced alpha peak (17% alpha power) and an average median of 4 Hz as the baseline findings of the EEG power spectrum. The intravenous administration of midazolam led to activation of the lower beta range (13-18 Hz) and the subsequent injection of ketamine caused an increase in activity in the fast beta range (21-30 Hz), both being accompanied by a reduction of delta power from 56% to 40%. Correspondingly, an increase in the median frequency was noted. Causing nearly the same changes in EEG, S-(+) ketamine was confirmed to be twice as potent as racemic ketamine.
TL;DR: It is concluded that postoperative analgesia in patients undergoing knee arthroscopy under local anaesthetic, but not under bupivacaine spinal anaesthesia, can be improved with a single intraarticular injection of 1 mg morphine.
Abstract: Eighty patients scheduled to undergo knee arthroscopy were studied in random and double blind fashion. Spinal anaesthesia with hyperbaric 0.5% bupivacaine was selected for 40 overnight-in-patients. At the end of arthroscopy, 1 mg morphine or saline was injected intraarticularly. Local anaesthesia with 1% lidocaine plus adrenaline, was selected for another 40 out-patients. At the end of the arthroscopy either 1 mg morphine or saline was injected intraarticularly. As a rescue medication the spinal anaesthesia patients received oxycodone 0.14 mg kg-1 i.m. or ketoprofen 100 mg p.o. and the local anaesthesia patients received ketoprofen 100 mg p.o. The need for additional postoperative analgesic was almost similar in both spinal anaesthesia groups. The patients having local anaesthesia and given intraarticular morphine needed fewer doses of ketoprofen (22 doses) postoperatively than the control group (39 doses) (P < 0.05). Duration of analgesia was slightly longer after morphine than in the control group (ns). There was no difference between the morphine patients and the control patients in the two studies regarding the incidence of side effects. We conclude that postoperative analgesia in patients undergoing knee arthroscopy under local anaesthesia, but not under bupivacaine spinal anaesthesia, can be improved with a single intraarticular injection of 1 mg morphine.
TL;DR: Plain solutions of ropivacaine produced significantly longer durations of dermal analgesia than did plain solutions of bupvacaine, in all tested concentrations, and a significant increase in duration was seen for both local anaesthetics when adding adrenaline.
Abstract: Ropivacaine, a new long-acting amino-amide local anaesthetic agent, and bupivacaine, in various concentrations with or without addition of adrenaline, were tested in a randomized, double-blind study using intradermal wheals. Ten non-smoking, healthy, young male volunteers participated. In series I plain solutions of ropivacaine (0.25%, 0.5%, 0.75% and 1%) and bupivacaine (0.25%, 0.5% and 0.75%) were injected intradermally and in series II the same concentrations, with the addition of adrenaline 5 ug.ml-1 (1:200,000), were used. The same volunteers took part in both series, with an interval of at least three weeks between the experiments. Saline was included as control in both series. Pin-pricking was used to assess the dermal analgesia. Plain solutions of ropivacaine produced significantly longer durations of dermal analgesia than did plain solutions of bupivacaine, in all tested concentrations. A significant increase in duration was seen for both local anaesthetics when adding adrenaline. Local vascular effects at the injected areas were determined by visual inspection (nil, pink, pale). Local blanching (pale) was significantly more frequent for plain solutions of ropivacaine, in all tested concentrations. Local redness (pink) was significantly more frequent with plain bupivacaine, in a dose-dependent relation. An initial redness was frequently observed for both local anaesthetics containing adrenaline, followed by blanching at most sites.
TL;DR: The rapid onset obtained after intranasal midazolam and ketamine offers advantages over orally or rectally administered drugs and the absence of respiratory depression and oxygen desaturation suggests that this technique is safe and efficient in the CT room with its particular working conditions.
Abstract: We have studied the sedation achieved with a mixture of midazolam (0.56 mg/kg-1) and ketamine (5 mg/kg-1) administered nasally in 30 children weighing less than 16 kg undergoing computerised tomography. Assessment was two fold using a visual analogue scale; the radiologist/radiographer rated the exam from "failed examination" to "perfect working conditions" while the anesthetist's assessment ranged from "poor sedation" to "perfect sedation with clinical well being". This new method proved to be effective alone in 83% of the cases and there were no complications. The rapid onset obtained after intranasal midazolam and ketamine offers advantages over orally or rectally administered drugs. The absence of respiratory depression and oxygen desaturation suggests that this technique is safe and efficient in the CT room with its particular working conditions.
TL;DR: Extended exposure to nitrous oxide seems to produce haematological and central nervous effects resembling those observed in cobalamin deficiency, and this possibility and its biochemical basis have been substantiated by both experimental and clinical studies.
Abstract: Nitrous oxide (N,O) has been extensively used as an anaesthetic agent since the middle of the nineteenth century. It has been regarded as an ideal drug with few side effects (1). In 1956, Lassen et al. (2) reported that nitrous oxide inhalation for five to six days to control spasms in tetanus patients produced severe bone marrow depression. Twelve years later, Amess and colleagues (3) more directly demonstrated interference with DNA synthesis in bone marrow from patients exposed to nitrous oxide for 24 hours, and they correctly suggested that nitrous oxide may oxidise cobalamin required by methionine synthase (Fig. 1). This mechanism was confirmed by Deacon et al. (4) shortly afterwards. The same year Layzer (5) reported on myeloneuropathy in 15 dentists who had abused nitrous oxide for months to years. Thus, prolonged exposure to nitrous oxide seems to produce haematological and central nervous effects resembling those observed in cobalamin deficiency. This possibility and its biochemical basis have been substantiated by both experimental and clinical studies which are briefly reviewed in this article.
TL;DR: Analysis revealed that only one reaction in three was likely to be due to IgE‐mediated anaphylaxis (Type 1), and suxamethonium was the most frequently reported drug, but in this study 11 reactions were identified as Type 1 response.
Abstract: A survey is presented of neuromuscular drug involvement in 590 clinically severe anaphylactoid reactions (grades II-IV) reported to a Sheffield laboratory from 1988 to the end of 1992 from hospitals throughout the UK. Despite advances in patient monitoring and newer drugs, the reporting frequency and individual drug involvement were remarkably similar to those of a previous report from the laboratory in 1988. The highly immunogenic drug suxamethonium still predominated (48% of reports), but there was now much reduced use of the similarly immunogenic drug, alcuronium. The incidence of reactions to vecuronium and atracurium remained similar (12% and 18% reports, respectively) and acceptable to the anaesthetist. However, in choosing drugs for individual patients, the anaesthetist may wish to note that vecuronium reactors mainly showed bronchospasm, and atracurium reactors hypotension. By a systematic laboratory investigation, based on measurement of plasma tryptase and urinary methylhistamine, reaction mechanisms were assessed in 53 reactions. Despite their overall clinical similarity, analysis revealed that only one reaction in three was likely to be due to IgE-mediated anaphylaxis (Type 1). Not only was suxamethonium the most frequently reported drug, but in this study 11 reactions were identified as Type 1 response: no allergic reactions were identified for either vecuronium or atracurium, although single cases were identified for alcuronium, gallamine, and tubocurarine, with two unidentified. The remaining reactions were judged to be non-immune, although most involved mast cell degranulation. These reactions were no less hazardous than Type 1 reactions (one death), and two deaths were recorded. The importance of laboratory investigation as a feature of postreaction care is emphasized.
TL;DR: Pain at rest, during mobilisation and during cough was significantly decreased in patients receiving bupivacaine compared to placebo, and the consumption of supplementary morphine during the 24 h study period reduced from four to two doses of 0.1 mg· kg‐1 iv or 0.125 mg·kg‐1 im.
Abstract: In a prospective, double-blind, placebo-controlled study, twenty-eight healthy, male patients, aged 20-69 years, scheduled for unilateral elective inguinal herniorrhaphy ad modum Bassini were randomized to receive postoperative infiltration of the surgical wound with either bupivacaine 0.25%, or isotonic saline. General anaesthesia was induced with thiopentone 3-5 mg.kg-1 and alfentanyl 10 micrograms.kg-1, and maintained with alfentanyl 5 micrograms.kg-1 15 min and N2O/O2. After herniorrhaphy, the internal fascia was infiltrated with bupivacaine 0.25% or saline, 10 ml. After closure of the external fascia, the subcutaneous tissue was infiltrated with bupivacaine 0.25% or saline, 15 ml on both sides of the surgical wound. Pain at rest, during mobilisation and during cough was significantly decreased in patients receiving bupivacaine compared to placebo. Median time to first request for morphine was increased from 25 min to 135 min, and the consumption of supplementary morphine during the 24 h study period reduced from four to two doses of 0.1 mg.kg-1 iv or 0.125 mg.kg-1 im, in patients who received bupivacaine compared to placebo.
TL;DR: Six patients undergoing cholecystectomy, hernia repair, or mammoplasty were studied and xenon appeared to be satisfactory, and the patients woke up rapidly after xenon was discontinued.
Abstract: Xenon is a more potent anesthetic than nitrous oxide, and give more profound analgesia This investigation was performed to assess the potential of xenon for becoming an anesthetic inspite of its high manufacturing cost Seven ASA I-II patients undergoing cholecystectomy (n = 4), hernia repair (n = 2), or mammoplasty (n = 1) were studied Denitrogenation by 15-20 min of oxygen breathing under propofol anesthesia was followed by fentanyl-supplemented xenon anesthesia administered via an automatic minimal flow system which held the oxygen concentration at 30% Xenon anesthesia lasted 76-228 min and 8-14 l of xenon (ATPD) was used, of which 56-81 l was expended during the first 15 min Anesthesia appeared to be satisfactory, and the patients woke up rapidly after xenon was discontinued The automatic system made minimal flow xenon anesthesia easy to administer, but nitrogen accumulation is still a problem Assuming a xenon price of 10 US$ per litre, the average cost for xenon was about 65 US$ for the first 15 min and then about 25 US$ for each subsequent hour of anesthesia
TL;DR: Harmful effects of nitrous oxide were first observed in patients and measures were taken to reduce the level of exposure in the operating theatres, including carrying the gases to the outdoor environment.
Abstract: Harmful effects of nitrous oxide were first observed in patients (1). Later, in the 1970s and 1980s, occupational hazards related to waste anaesthetic gases were recognized. Measures were taken to reduce the level of exposure in the operating theatres, including carrying the gases to the outdoor environment. In this last decade world society has focused on problems related to those called ozone depletion and the greenhouse effect, resulting from emission of manmade compounds to the atmosphere.
TL;DR: CPAP therapy was well tolerated, and minimized the decrease in Pao2 after extubation, but could not prevent the poor oxygenation or the late development of atelectatic areas on the second postoperative day.
Abstract: Thirty patients who underwent coronary artery bypass grafting were randomized to receive 30% oxygen by mask either with an ambient airway pressure or with 7.4 mmHg (1 kPa) continuous positive airway pressure (CPAP) for 8 h after extubation. Arterial blood oxygen tension (PaO2) decreased remarkably in the control group after extubation (from 19.2 +/- 5.3 kPa to 12.4 +/- 2.7 kPa) but less in the CPAP group (from 16.4 +/- 3.3 kPa to 14.0 +/- 2.1 kPa). On the second postoperative morning PaO2 was equally low in both groups (control: 8.4 +/- 1.5 kPa, CPAP: 8.9 +/- 1.9 kPa). Atelectatic areas were seen with similar frequency in both groups, 17% (whole material) on the first and 50% on the second postoperative morning. Atelectasis was more common in patients with internal thoracic artery grafting and/or pleural drainage. In conclusion, CPAP therapy was well tolerated, and minimized the decrease in PaO2 after extubation, but could not prevent the poor oxygenation or the late development of atelectatic areas on the second postoperative day.
TL;DR: It is with humility that I assume the editorship of Acta Anaesthesiologica Scandinavica, and it is my conviction, that this system improves quality and enhances safety for patients, and I take this challenge seriously.
Abstract: It is with humility that I assume the editorship of Acta Anaesthesiologica Scandinavica. When Jan Eklund took over in 1986, he had already been coeditor for no less than 12 years. Thus, he can look back on almost 20 years of service to our journal. During these years, Acta has become a leading journal. Jan Eklund has done a great service to Acta and to the promotion of Scandinavian anaesthesiology. Future challenges are many. The days are over when a journal sold itself. Today there is strong competition not only from an increasing number of journals, but also from abstract services and electronic data bases offering “instant satisfaction” to the busy reader. The only reliable weapon in this situation is quality, quality of the work published and quality of editorial effort. This is our challenge, and we take i t seriously. We feel strongly that we have quality to offer from the Scandinavian countries. However, Acta Anaesthesiologica is also an international journal. In 1992 55% of our articles came from other countries. This is a most welcome trend. Anaesthesiology as a speciality is rapidly expanding. The trend in Scandinavia is for anaesthesiology to include postoperative and intensive care as well as pain therapy and emergency medicine. We welcome articles from all these disciplines. When looking at our standards of care ( l ) , we work on the same lines and principles in the five countries. The well-educated anaesthesia nurse is an important element in our operating rooms, in contrast to some other countries. It is my conviction, that this system improves quality and enhances safety for our patients. Anaesthesiology as a speciality has played a leading role internationally when it comes to developing standards of care.
TL;DR: This review highlights the most recent experimental and clinical studies on nitrous oxide and its action on the cardiovascular system.
Abstract: In a textbook of the 1970’s (l), nitrous oxide is claimed to leave “the heart unaffected in rate, rhythm and output”. The author thus concludes “that N 2 0 does not possess any direct myocardial depressant action”. In the early 19805, Hickey and Eger in their chapter in Miller’s Anesthesia (2) summarized the cardiac effects of nitrous oxide as follows: “nitrous oxide alone or in combination with potent inhaled anesthetics produces sympathetic stimulation. Such stimulation may obscure any cardiac depressant effects”. Thanks to the development of new technology for the study of the circulation over the past decade, much new knowledge of the circulatory effects of nitrous oxide has become available. This review highlights the most recent experimental and clinical studies on nitrous oxide and its action on the cardiovascular system.
TL;DR: Thoracic epidural fentanyl/bupivacaine results in significantly better analgesia than patient–controlled intravenous morphine and this was associated with significantly greater pulmonary ventilation compared with the PCA series.
Abstract: Twenty-one ASA I or II patients undergoing upper abdominal surgery were studied for 24 hours after operation. They were entered into a prospective, randomised study of patient-controlled intravenous morphine compared with continuous thoracic epidural fentanyl combined with 0.2% bupivacaine. Pain relief was superior in the bupivacaine series (P < 0.05) throughout the 24 hour study period and this was associated with significantly greater pulmonary ventilation compared with the PCA series. Forced expiratory parameters were reduced in both series after the operation but significantly less so in the epidural group. There was a reduced incidence of emetic symptoms in the epidural group (P < 0.05) but the incidence of other minor side effects did not differ significantly. Thoracic epidural fentanyl/bupivacaine results in significantly better analgesia than patient-controlled intravenous morphine.