Showing papers in "Acta Anaesthesiologica Scandinavica in 1993"

Pharmacokinetics and related pharmacodynamics of anticholinergic drugs.

Abstract: The pharmacokinetics and some pharmacodynamic properties of atropine, glycopyrrolate and scopolamine are reviewed. With the development of new analytical methods for drug determination, it is now possible to measure relatively low concentrations of these drugs in biological fluids and, consequently, some new kinetic data have been collected. Following intravenous administration, a fast disappearance from the circulation is observed and due to a high total clearance value their elimination phase half-lives vary from 1 to 4 h. All these agents are nonselective muscarinic receptor antagonists, but their actions on various organ systems with cholinergic innervation show considerable diversity. The cardiovascular effects are of short duration; other peripheral muscarinic effects and CNS effects can last up to 8 h or even longer. Differing from atropine and scopolamine, glycopyrrolate as a quaternary amine penetrates the biological membranes (blood-CNS, placental barriers) slowly and incompletely, making it the drug of choice for elderly patients with coexisting diseases and for obstetric use. Similarly, its oral absorption is slow and erratic, and hence it cannot be used as an oral premedicant. Atropine, scopolamine and glycopyrrolate have a definitely faster absorption rate, when injected into the deltoid muscle compared with administration into the gluteal or vastus lateralis muscles. There appear to be significant differences in the metabolism and renal excretion of these agents. Scopolamine is apparently excreted into the urine mainly as inactive metabolites, nearly half of the atropine dose administered is recovered in the urine as the parent drug or as active metabolites and about 80% of glycopyrrolate is excreted as unchanged drug or active metabolites.(ABSTRACT TRUNCATED AT 250 WORDS)

Cervical epidural steroid injection for cervicobrachialgia.

Abstract: Fifty patients with chronic resistant cervicobrachialgia were randomly divided into two groups. Twenty-five patients (group A) were treated with cervical epidural steroid/lidocaine injections and 17 patients (group B) were treated with steroid/lidocaine injections into the posterior neck muscles. Another eight patients from group B were excluded from the study because they had started the process of litigation of insurance claims and their subjective analysis of pain relief might therefore not be trustworthy. One to three injections were administered at 2-week intervals according to the clinical response. All patients continued their various pre-study treatments: non-steroidal anti-inflammatory drugs, non-opioid analgesics and physiotherapy. Pain relief was evaluated by the visual analogue scale 1 week after the last injection and then 1 year later. One week after the last injection we rated pain relief as very good and good in 76% of the patients in group A, as compared to 35.5% of the patients in group B. One year after the treatment 68% of the group A patients still had very good and good pain relief, whereas only 11.8% of group B patients reported this degree of pain relief. These differences were statistically significant. We failed to achieve significant improvement of tendon reflexes or of sensory loss in both groups, but the increase in the range of motion, the fraction of patients who were able to decrease their daily dose of analgesics, and recovery of the capacity for work were significantly better in group A. We encountered no complications in either group of patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Alpha2-adrenergic agents in anaesthesia

Abstract: 1 . INTRODUCTION Clonidine, a centrally acting antihypertensive agent which relatively selectively activates a,-adrenergic receptors ( a,-adrenoceptors), has attracted increasing interest as an adjunct to anaesthesia. Clinical studies with clonidine have demonstrated, among other effects, reduced anaesthetic requirements and improved cardiovascular and adrenergic stability during surgery (1-3). O n the other hand, veterinary anaesthetists have already for a long time employed xylazine and detomidine, two a,-adrenergic agents, to induce sedation and analgesia in their patients. It has recently become evident that it is possible to induce complete anaesthesia in animals by employing new, more potent a,-agonists, such as medetomidine and its stereoisomer, dexmedetomidine (4). The prospect of using specific antagonists to reverse the effects induced by a,-agonists adds to the attractiveness of this approach (5, 6). Another important development has been the demonstration of potent analgesic activity of a,-adrenergic agonists after intrathecal and epidural application (7,

Inhibitory effects of amide local anaesthetics on stimulus‐induced human leukocyte metabolic activation, LTB4 release and IL‐1 secretion in vitro

Abstract: The anti-inflammatory effects of the amide local anaesthetics lidocaine and bupivacaine were evaluated in vitro by examination of the metabolic activation and secretory responses of human polymorphonuclear granulocytes (PMNGs) and mononuclear cells. Pretreatment with lidocaine or bupivacaine had a dose-dependent inhibitory effect on PMNG luminol-amplified chemiluminescence stimulated by bovine serum albumin (BSA)/anti-BSA immune complexes (IC) or by serum-opsonized zymosan (SOZ) particles. Both lidocaine and bupivacaine inhibited the release of the inflammatory mediators leukotriene B4 (LTB4) and interleukin-1 (IL-1) evaluated by radioimmunoassay (RIA). Pretreatment of suspended PMNGs and monocytes with the anaesthetics caused a marked inhibition of LTB4 release when the cells were stimulated with SOZ. In short-term (24 h) cultures of mononuclear cells the addition of lidocaine or bupivacaine reduced, in a dose-dependent manner, the level of IL-1 detected after stimulation with lipopolysaccharide (LPS). In all three assays (chemiluminescence, LTB4 and IL-1 RIA) bupivacaine was found to be more potent than lidocaine. The present results show that amide local anaesthetics have marked suppressive effects on the metabolic activation and secretory functions of leukocytes stimulated by different agonists. Although the detailed mechanisms for these effects are not known, they may explain part of the potent anti-inflammatory actions of local anaesthetics previously described in vivo.

Efficacy of epidural blood patch for postdural puncture headache

Abstract: This prospective investigation was conducted to evaluate the efficacy of different volumes of epidural blood patch (EBP) for treatment of postdural puncture headache (PDPH) in 81 consecutive patients. In the first part of the investigation (Study part I), 10 ml of blood was injected for EBP in 28 patients. In the second randomized part of the investigation (Study part II), the patients were allocated to receive for EBP either 10 ml (27 patients) or 10-15 ml (26 patients), according to the height of the patient. The procedure was considered initially successful if PDPH disappeared completely during the 2-h recovery room follow-up. To evaluate the long-term success, a questionnaire was mailed to all patients. The EBP performed 3.7 +/- 2.9 days following the dural puncture was initially successful in 88-96% of the patients in the different study groups. In the questionnaire, only 50-68% of the patients reported that PDPH had disappeared immediately without recurrence. In 16-36% of the patients the PDPH returned at lesser intensity and in 14-17% PDPH was reported to have continued, disappearing gradually in all patients. Despite this, 87% of all patients were satisfied with the EBP treatment. There were no statistically significant differences between the groups. The results indicate that a larger, height-adjusted volume of blood for EBP in adults does not produce a better effect on PDPH compared to a standard 10-ml volume. Despite the excellent initial effect (91%) seen in our patients, a permanent effect of the blood patch was only achieved in 61%.

Effective concentration 50 for propofol with and without 67% nitrous oxide.

Abstract: The Effective Blood Concentration (EC) of propofol required to prevent response to surgical incision was determined in 65 ASA I or II female patients breathing either 100% oxygen or 67% N2O in oxygen. Propofol was administered via a microcomputer-controlled infusion system programmed to maintain the blood propofol concentration at predetermined target values. The blood propofol concentrations predicted by the micro-computer were validated by measurement of whole blood propofol concentration. Predicted and measured concentrations differed during infusion of propofol, but became similar after discontinuing the infusion for at least 90 s, suggesting that equilibration within the central compartment was incomplete during infusion. The response to the initial incision was observed and probit analysis used to determine the predicted blood concentration at which 50% of patients responded. The predicted EC50 for propofol/N2O/O2 and propofol/O2 was 4.5 micrograms ml-1 and 6.0 micrograms ml-1 respectively, and the measured EC50 propofol/N2O/O2 and propofol/O2 was 5.36 micrograms ml-1 and 8.1 micrograms ml-1, 67% nitrous oxide in oxygen reducing the predicted EC50 by 25% and the measured EC50 of propofol by 33%. The predicted EC may be more representative of the equilibrated concentration in the central compartment and thus reflective of tissue propofol concentrations.

Nausea: the most important factor determining length of stay after ambulatory anaesthesia. A comparative study of isoflurane and/or propofol techniques.

Abstract: Speed of recovery and length of stay in hospital were studied in 95 ambulatory patients undergoing laparoscopy or arthroscopy. The patients were divided into three groups regarding maintenance of anaesthesia. Group A (n = 32) received isoflurane 0.7% end-tidally, group B (n = 31) propofol infusion for 25 min and thereafter isoflurane, and group C (n = 32) received an infusion of propofol throughout the procedure. Recovery was assessed by a combination of the Maddox-Wing, the Choice Reaction Time test and p-deletion. The awakening period was somewhat shorter in group A, but psychomotor recovery was somewhat slower compared to groups B and C. The length of stay in hospital depended on whether the patient was nauseated or not. In group A, 44% suffered from nausea requiring medical intervention compared to 13% and 19% in groups B and C, respectively. The stay in hospital was 235 +/- 90 min (mean +/- standard deviation) in group A compared to 184 +/- 56 min and 197 +/- 55 min in groups B and C, respectively. The non-nauseated patients in group A had a stay in hospital of 188 +/- 55 min compared to 184 +/- 52 and 184 +/- 37 in the non-nauseated patients in groups B and C, respectively. In total, the nauseated patients (n = 24) stayed 267 +/- 95 min compared to 185 +/- 47 min for the non-nauseated patients (n = 71), P < 0.001. We found nausea to be the most important factor determining length of stay after ambulatory anaesthesia.(ABSTRACT TRUNCATED AT 250 WORDS)

Complications related to thoracic epidural analgesia: a prospective study in 1071 surgical patients.

Abstract: In a prospective study, the complications of 1071 patients scheduled for thoracic epidural catheterization for postoperative analgesia (TEA) were studied. All catheters were inserted preoperatively between segment Th 2/3 and Th 11/12 under local anesthesia. Balanced anesthesia with endotracheal intubation and TEA were combined. Postoperatively 389 patients (36.9%) were monitored on a normal surgical ward. Buprenorphine, 0.15 to 0.3 mg, and if needed bupivacaine 0.375% 3-5 ml h-1 were given epidurally. Primary perforation of the dura occurred in 13 patients (1.23%). Radicular pain syndromes were observed in six patients (0.56%). In one patient (0.09%) respiratory depression was seen in close connection with the epidural administration of 0.3 mg buprenorphine. Although 116 patients (10.83%) showed one abnormal clotting parameter but no clinical signs of hemorrhage, there was no complication related to this group. No persisting neurological sequelae caused by the thoracic epidural catheters were found. In conclusion, continuous TEA with buprenorphine for postoperative pain relief after major abdominal surgery is a safe method without too high a risk of catheter-related or drug-induced complications, even on a normal surgical ward and when one clotting parameter is abnormal.

Evaluation of a new system for ventilatory administration of nitric oxide

Abstract: A new system for delivery of nitric oxide (NO) to inspiratory gas consisting of two mass flow regulators and a soda-lime absorber for scavenging of nitrogen dioxide (NO2) is described. The system was evaluated using three different techniques for NO analysis (infrared, chemiluminescence and electro-chemical fuel cell technique). The electro-chemical fuel cell was less sensitive to humidity in the sample and is suitable for clinical routine use. The infrared analyser was very sensitive to humidity and the gas sample must be dried by silica gel, which absorbs NO2 and will cause falsely low NO2 values. NO2 was analysed with ultra-violet methodology. NO2 is highly toxic and the highest recommended occupational health and safety level for inhalation is 5 ppm. The highest values of NO2 in our system were detected before the absorber in the inspiratory limb of the breathing system, being 5 ppm at 100% oxygen and 100 ppm NO using "infant" respiratory settings (3 l/min in ventilation, frequency of 30/min). The corresponding value for "adult" respiratory settings (10 l/min in ventilation, frequency of 15/min) was 3.2 ppm. The absorber reduced these levels to well below 1 ppm. When clinically relevant levels of NO were used (20 ppm), no NO2 could be detected after the absorber, irrespective of oxygen concentration in the breathing gas. It was observed that gas cylinders with NO mixed in nitrogen may initially have a high NO2 concentration (around 12 ppm) and should be flushed thoroughly before use.

Propofol induces bronchodilation in mechanically ventilated chronic obstructive pulmonary disease (COPD) patients

Abstract: The aim of this study was to evaluate the effects of propofol administration (2 mg.kg-1 i.v.) on the airways resistances and respiratory mechanics of patients affected by COPD exacerbation, requiring mechanical ventilation. Twenty patients required anaesthesia for diagnostic or therapeutic procedures. Fourteen consecutive patients were divided at random into two groups: Group P received propofol and Group C (control) received only Intralipid 10%; an additional group of six patients received i.v. flunitrazepam (0.03 mg.kg-1). Lung mechanics (dynamic and static compliance, peak inspiratory pressure, intrinsic positive and expiratory pressure, minimal and maximal resistances of the respiratory system) were evaluated in basal conditions and 3 and 6 min after propofol, Intralipid or flunitrazepam administration. We did not observe significant variations of the evaluated variables after Intralipid or flunitrazepam (Groups C and F), while in patients who received propofol (Group P), we observed the following modifications: dynamic compliance increased from 2.3 +/- 0.3 to 2.8 +/- 0.4 ml.kPa-1 (P < 0.05), peak inspiratory pressure decreased from 3.3 +/- 0.7 to 2.8 +/- 0.4 kPa (P < 0.05), minimal resistances of the respiratory system (that mainly reflect airways resistances) decreased from 1 +/- 0.2 to 0.7 +/- 0.2 kPa.l-1 x s-1 (P < 0.01). Our results suggest that propofol induces bronchodilation in mechanically ventilated COPD patients, and that this effect is not related specifically to the induction of general anesthesia.

Mivacurium‐induced neuromuscular blockade in patients with atypical plasma cholinesterase

Abstract: The duration of action of mivacurium was evaluated during a modified neurolept anaesthesia in 17 patients heterozygous for the usual and the atypical plasma cholinesterase (pChe) gene (E1uE1a) and in five patients homozygous for the atypical gene (E1aE1a). The response to train-of-four nerve stimulation was recorded using a Myograph 2000. Five heterozygous patients were given a small dose of mivacurium 0.03 mg kg bw-1 intravenously (Group 1). The mean (range) suppression of the first twitch in the train-of-four response (T1) was 91% (69-100%). The time to 90% T1 recovery was 23.9 min (14.0-31.3 min). Twelve other heterozygous patients (Group 2) received mivacurium 0.2 mg kg bw-1 (2.5 x ED95). In these patients the time to 100% T1 suppression was 1.4 min (1.1-2.0 min). The time to reappearance of the T1 response, to 90% T1 recovery, and the recovery index (25.3 min (14.5-34.5), 45.5 min (30.9-59.2), and 9.8 min (6.8-19.6), respectively) were significantly longer than reported in phenotypically normal patients. Five patients homozygous for the atypical gene (Group 3) were given 0.03 mg kg bw-1 mivacurium. The time to reappearance of T1 response following this low dose of mivacurium ranged from 26-128 min. In all five patients the neuromuscular block was successfully antagonized with neostigmine preceded by atropine. In conclusion, mivacurium-induced neuromuscular blockade was moderately prolonged in patients heterozygous for the usual and the atypical gene for plasma cholinesterase. Patients homozygous for the atypical plasma cholinesterase gene appear to be markedly sensitive to mivacurium.

Redistribution of lymphocytes after major surgical stress

Abstract: Major surgery evokes an endocrine stress response, characterized by increased serum cortisol, plasma adrenaline and noradrenaline. Furthermore, surgical stress is accompanied by lymphopenia and granulocytosis in peripheral blood. The changes in peripheral white blood cells have been demonstrated after surgery as well as after cortisol infusion. The aim of the present study was to investigate to which tissues/organs peripheral blood lymphocytes are redistributed after major surgery. From 20 rabbits lymphocytes were isolated from peripheral blood, labelled with indium-111-tropolene and reinjected intravenously into the rabbits. Ten of the rabbits underwent major surgery (upper laparatomy) during general anaesthesia, while the control group (n = 10) was anaesthetized without surgery. The endocrine stress response to surgery was measured as serum cortisol, plasma adrenaline and noradrenaline. The redistribution of lymphocytes was imaged with a gamma camera and calculated with a connected computer before, 2, 4, and 7 h after the skin incision. Compared to preoperative values, laparotomy resulted in an increase in serum cortisol from 116.6 to 461.9 nmol/l (mean) and a decrease in the fraction/percentage of lymphocytes in peripheral blood from 43.8% to 14.7% 7 h after surgery. Simultaneously, the activity of the heart and lungs together decreased to 76.1% of initial values, while the spleen activity was unaffected. The radioactivity of the lymphatic tissue increased to 137.8% and 134.7%, respectively, 4 and 7 h after the start of surgery. The results indicate that major surgery induces a redistribution of lymphocytes from peripheral blood to lymphatic tissue. It is suggested that the endocrine stress response may be of major importance.

Myoclonic spasms during treatment with high doses of intravenous morphine in renal failure

Abstract: Myoclonic spasms occurred in a patient suffering from renal failure after high doses of continuous intravenous morphine (100 mg/h). The concentrations of morphine, morphine-6-glucuronide and morphine-3-glucuronide (mumol/l) in plasma were: 1.93, 52.06 and 381.8, and in cerebrospinal fluid were: 1.02, 5.86 and 61.82, respectively. The role of morphine and morphine glucuronides in myoclonic spasms is discussed.

QT interval, heart rate and arterial pressures using propofol, thiopentone or methohexitone for induction of anaesthesia in children

Abstract: The effects on corrected QT interval (QTc), heart rate and arterial pressure were studied after induction with propofol 1.5, 2 or 2.5 mg.kg-1, thiopentone 5 mg.kg-1 or methohexitone 2 mg.kg-1 in 123 ASA class I or II children undergoing outpatient otolaryngological surgery. Premedication consisted of oral midazolam and atropine. The children were randomly allocated to one of the three propofol groups or to the thiopentone or methohexitone group. After injection of the intravenous anaesthetic, the QTc interval was significantly prolonged after propofol 2.5 mg.kg-1. Thirty seconds after suxamethonium 1.5 mg.kg-1, a significant prolongation of the QTc interval occurred in the thiopentone and propofol 1.5 and 2 mg.kg-1 groups. After intubation, no further prolongation of the QTc interval occurred in any of the groups. Heart rate increased significantly after the barbiturates but not after propofol. Systolic arterial pressure decreased significantly after propofol 1.5 and 2.5 mg.kg-1. In all groups a cardiovascular intubation response occurred. Bradycardia and junctional rhythm occurred in 4% of the children in both barbiturate groups and in 19-29% in the propofol groups. It is concluded that propofol causes prolongation of the QT interval and results in a higher incidence of bradycardia and junctional rhythm than the barbiturates.

Effects of PEEP on splanchnic hemodynamics and blood volume

Abstract: The effects of intermittent positive pressure ventilation with PEEP on splanchnic circulation and hepatic oxygen supply were studied in six beagles. PEEP of 0, 0.5 and 1.0 kPa (0, 5, 10 cmH2O, PEEP0, PEEP5 and PEEP10, respectively) of 30 min duration was applied in a random sequence. Hepatic arterial blood flow and portal venous blood flow were measured by electromagnetic flow meters. Blood volume changes in the splanchnic area were assessed from hepatic and splenic dimensions determined by sonomicrometry. PEEP5 and PEEP10 were associated with proportional decreases in both hepatic blood flow and cardiac output, while mean arterial pressure remained unchanged. Reflecting the decrease in hepatic blood flow, the hepatic oxygen supply decreased with the level of PEEP, and hepatic venous hemoglobin oxygen saturation was significantly less during PEEP10 (55.1 +/- 14.3%) than during PEEP5 (62.6 +/- 17.4%) and PEEP0 (62.3 +/- 11.9%). Hepatic venous and portal venous pressure increased with the level of PEEP. Hepatic dimensions increased by 7-8% and 16-19% during PEEP5 and PEEP10, respectively, but no significant changes in splenic dimension were observed. We conclude that PEEP5 and PEEP10 are accompanied by a decrease in hepatic blood flow and oxygen supply along with hepatic congestion.

Direct vascular effect of ropivacaine in femoral artery and vein of the dog

Abstract: A study was conducted to examine the direct vascular effect of ropivacaine, in comparison with the effect of bupivacaine and lidocaine. Changes in tension induced by ropivacaine (10-5-3 × mol 1-1), bupivacaine (10-5-3 times 10-3 mol 1-1) and lidocaine (10-5-10-2 mol 1-1) were examined cumulatively in vascular rings of dog femoral artery and vein under basal tension, or in those which had been precontracted with phenylephrine submaximally in Krebs' bicarbonate solution at 37°C aerated with 95% O2 and 5% CO2 (pH 7.4). The change in tension induced by lo-2 moll-1 ropivacaine was tested under basal tension in vascular rings bathed in HEPES buffer (pH 6.8). Ropivacaine induced greater constriction than bupivacaine at concentrations over 10-5 mol 1-1 in vascular rings under basal tension (P<0.01). The maximal contraction was induced by ropivacaine at mol 1-1, averaging 51.5± 2.8% (n = 11) and 27.0± 3.7% (n= 12) of the maximal contraction induced by epinephrine in the artery and vein, respectively, and the contractions induced by ropivacaine at 10-3 mol 1-1 were 16.3± 2.0% (n=11)and 5.5± 1.1% (n=9), respectively. Phenylephrine (10-6mol 1-1)-precontracted artery was contracted significantly by ropivacaine at 3 times 10-4 mol 1-1 and mol 1-1, and by bupivacaine at 3 times 10-3 mol 1-1, whereas the phenylephrine 10-6mol 1-1)-precontracted vein was relaxed by these anesthetics. Lidocaine did not exert constricting effects. It is concluded that ropivacaine is a potent vasoconstrictor, although its constrictive effect is slight at 10-2 mol 1-1, which may be relevant to the clinical local concentration.

Beclomethasone prevents postoperative sore throat.

Abstract: The effects of a dose of beclomethasone inhaler (50 micrograms) or lidocaine 10% spray on postoperative sore throat were studied in 120 patients undergoing tracheal intubation for elective surgical procedures. Fifty-four patients (90%) in the beclomethasone group scored no postoperative sore throat compared with 27 (45%) in the lidocaine group (P < 0.001). Beclomethasone inhaler seems to be highly effective in the prevention of postoperative sore throat and is therefore to be recommended before tracheal intubation for general anaesthesia.

Hydroxyethyl starch as a prime for cardiopulmonary bypass: effects of two different solutions on haemostasis

Abstract: Hydroxyethyl starch (HES) is efficacious as a volume expander in cardiac surgical patients, but it may impair the haemostatic mechanisms. However, this latter effect may be less conspicuous with low molecular weight (LMW) solutions than with high molecular weight (HMW) solutions. Therefore, LMW– and HMW–HES solutions were evaluated as priming solutions for cardiopulmonary bypass (CPB) with respect to their effect on haemostasis. Forty–five patients undergoing coronary bypass grafting were prospectively randomised to three groups and in a double–blind manner as their CPB prime either 20 ml kg-1 LMW–HES (Mw 120 000), 20 ml kg-1 HMW–HES (Mw 400000) or Ringer's acetate 2000 ml. The final volume of the prime was completed to 2000 ml with Ringer's acetate in the HES groups. Anaesthesia and CPB management were standardised. Plasma levels of von Willebrand factor antigen and factor VIII procoagulant activity were significantly more depressed after CPB in both HES–groups as compared with the crystalloid prime group. In addition, APTT was more prolonged and the maximal amplitude of thromboelastographic tracing was more decreased in the HES–groups. It is concluded that it may be advisable to avoid HES solutions in the CPB prime, especially in patients with an increased risk for bleeding after cardiac operations.

Enhanced pneumonia resolution by inhalation of nitric oxide

Abstract: We present a patient with severe bacteraemic pneumococcal pneumonia associated with severe hypoxaemia, where nitric oxide (NO) 15-40 ppm was added to the inspired gas. Nitric oxide therapy improved gas exchange, reduced pulmonary vasoconstriction and peak airway pressure. The patient survived. We observed an unexpected rapid and complete disappearance of bilateral pulmonary infiltrates during the first 120 h of the 7-day NO inhalation period.

Postoperative pain relief, from the patients' and the nurses' point of view.

Abstract: UNLABELLED In this prospective, consecutive study, 191 patients were interviewed before and after surgery (orthopaedic, gynaecological, abdominal and urological operations) about their attitude to and the quality of received pain relief, respectively. In addition, nurses working in the surgical units involved in the study were asked to answer a questionnaire covering attitudes to postoperative pain and pain treatment. Of the patients, 47% were in pain at the time of the postsurgical interview, 10% had not any analgesic prescribed at all and 15% had received less than prescribed. In 36% of the cases there was a discrepancy between the amount of analgesic prescribed by the surgeon and the amount prescribed by the anaesthetist. In 80% of the patients the pain outlasted the first postoperative day, but only 64% would always tell the staff if they had pain. Seventeen per cent of the patients had never been asked about their postoperative pain status. Preoperative pain had a significant correlation to postoperative pain. Although the results are not impressive, they do constitute some improvement compared to previously published studies. Fifty-one nurses (71% of the total nursing staff) answered the questionnaire. Of these, 63% were sometimes in doubt about the physicians' prescriptions, 55% would occasionally refuse to give analgesics for various reasons, and 37% were not satisfied with the routines of pain control in their ward. CONCLUSION Knowledge of pain treatment and communication between surgeons, anaesthesiologists, nurses and patients must be improved to make postsurgical pain relief adequate.

Cerebral pharmacodynamics of anaesthetic and subanaesthetic doses of ketamine in the normoventilated pig

Abstract: There are still divergent opinions regarding the pharmacodynamic effects of ketamine on the brain. In this study, the cerebral blood flow (CBF), cerebral metabolic rate for oxygen (CMRO2) and electroencephalographic (EEG) activity were sequentially assessed over 80 min in 17 normoventilated pigs following rapid i.v. infusions of anaesthetic (10.0 mg.kg-1; n = 7) or subanaesthetic (2.0 mg.kg-1; n = 7) doses of ketamine or of its major metabolite norketamine (10.0 mg.kg-1; n = 3). The animals were continuously anaesthetized with fentanyl, nitrous oxide and pancuronium. CBF was determined by the intra-arterial 133Xe technique. Ketamine (10.0 mg.kg-1) induced an instant, gradually reverting decrease in CBF, amounting to -26% (P < 0.01) at 1 min and -13% (P < 0.05) at 10 min, a delayed increase in CMRO2 by 42% (P < 0.01) at 10 min and a sustained rise in low- and intermediate-frequency EEG voltage by 87% at 1 and 97% at 10 min (P < 0.0001). It is concluded that metabolically formed norketamine does not contribute to these effects. Considering the dissociation of CBF from CMRO2 found 10-20 min after ketamine (10.0 mg.kg-1) administration, it is suggested that ketamine should be used with caution for anaesthesia in patients with suspected cerebral ischaemia in order not to increase the vulnerability of brain tissue to hypoxic injury. Ketamine (2.0 mg.kg-1) had no significant effects on CBF, CMRO2 or EEG. It therefore seems that up to one fifth of the minimal anaesthetic i.v. dose can be used safely for analgesia, provided that normocapnaemia is preserved.

Colloid osmotic pressure of plasma replacement fluids

Abstract: Colloid osmotic pressure (COP) of some of the most frequently used plasma replacement fluids was measured with a colloid osmometer. COP of 4% human albumin solutions was only half that of normal human serum (13.6 +/- 0.6 vs. 27.5 +/- 2.7 mmHg (1.8 +/- 0.1 vs. 3.7 +/- 0.4 kPa)) (mean +/- s.d.), whereas COP of 20% human albumin solutions was eight times higher (196.0 +/- 12.3 mmHg (26.1 +/- 1.6 kPa)). Enhancing the protein concentration from 4% to 20% in the human albumin solutions increased COP 14-fold, reflecting the exponential relationship between protein concentration and COP of a solution. Fresh donor plasma furnished by the hospital blood-bank had a COP about 30% below normal human serum (18.1 +/- 1.3 mmHg (2.4 +/- 0.2 kPa)), due to dilution during preparation. Dextran 70 (6%) had a COP more than twice, and Ringer-Dextran 60 (3%) about 75% of that of normal human serum. Dextran 40 (10%) and gelatin (3.5%, Haemaccel) leaked markedly through the membrane of the colloid osmometer, making acceptable measurements impossible. Seven different hydroxyethyl starch (HES) solutions were measured, and the COP varied between half and 3 times that of normal human serum, depending on molecular weight and concentration of the HES.

Influence of high thoracic epidural anesthesia on left ventricular contractility assessed using the end-systolic pressure-length relationship.

Abstract: The effect of high thoracic epidural anesthesia (TEA on left ventricular contractility was studied in a prospective clinical trial. Forty-eight patients with ASA physical status 1 and 2 and without cardiovascular disease were included in the study. Thirty-six patients scheduled for elective upper abdominal surgery were randomly assigned to Group 1 (TEA, bupivacaine 0.25%, n = 12), Group 2 (TEA, bupivacaine 0.5%, n = 12) or to Group 3 (control without TEA, n = 12). TEA induced a sensory block which extended over all cardiac segments. In order to assess the effect of systemically absorbed bupivacaine, we studied a separate group of patients who received lumbar epidural anesthesia without involvement of the cardiac segments: Group 4 (LEA, bupivacaine 0.5%, n = 10). Left ventricular contractility was assessed using the end-systolic pressure-length relationship. Left ventricular dimensions were measured by transesophageal echocardiography. All hemodynamic measurements were performed under general anesthesia. There was no significant difference in systolic or diastolic arterial pressure, heart rate, left ventricular end-systolic and end-diastolic cross-sectional areas and left ventricular wall stress between the four groups. Left ventricular maximum elastance as a measure of left ventricular contractility was significantly (P < 0.001) reduced in Groups 1 and 2 [8.1 (+/- 3.5) and 9.6 (+/- 4.4) kPa.cm-1, respectively] as compared to Groups 3 and 4 [18.4 (+/- 8.8) and 17.7 (+/- 7.7) kPa.cm-1, respectively]. No significant difference could be demonstrated between Groups 1 and 2 or between Groups 3 and 4. It is concluded that high TEA severely alters left ventricular contractility even in subjects without pre-existing cardiac disease.

Effects of 2‐, 4‐ and 12‐hour fasting intervals on preoperative gastric fluid pH and volume, and plasma glucose and lipid homeostasis in children

Abstract: We evaluated 105 randomly-selected unpremedicated children aged 1-14 years to determine the effects of a 2-, 4- and 12-h preoperative fasting interval on the preoperative gastric fluid pH and volume, and plasma glucose and lipid homeostasis. Each child undergoing elective surgery ingested a large volume (approximately 10 ml/kg b.w.) of apple juice and then fasted for 2, 4 or 12 h before the estimated induction of anaesthesia. After induction of anaesthesia, gastric fluid was aspirated through a large-bore, multiorifice orogastric tube. Plasma concentrations of glucose, total ketone bodies, non-esterified fatty acid (NEFA), triglycerides, and cortisol were measured at the time of induction to evaluate the fasting interval effects on preoperative plasma glucose and lipid homeostasis. There were no significant differences between the three groups in either gastric fluid volume or pH. In addition, there were no significant differences between the groups with respect to the proportion with a pH 0.4 ml/kg b.w. Neither plasma concentrations of glucose, triglycerides, nor cortisol at the time of anaesthetic induction differed between the three groups. Both 4 and 12 h nil per os (NPO) caused an increase in lipolysis, which was presumably a compensatory mechanism to maintain normoglycaemia. The plasma NEFA and total ketone bodies concentrations were therefore significantly higher in these two fasting intervals than in 2 h NPO. These data suggest that a 2-h NPO, after a large volume of ingested apple juice, may offer additional benefits by preventing an increase in lipolysis during the fasting interval without either increasing the volume of gastric fluid or decreasing the gastric pH.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of P6 acupoint injection with 50% glucose in water and intravenous droperidol for prevention of vomiting after gynecological laparoscopy.

Abstract: Postoperative vomiting causes patients distress and delays discharge after outpatient surgery. Although P6 electroacupuncture is recognized as having an antiemetic effect, its inconvenient instrumentation may limit its clinical applicability. The purpose of this study was to explore a simple and effective alternative method for control of postoperative vomiting in outpatient surgery. We prospectively compared the effect of P6 acupoint injection with 0.2 ml 50% glucose in water (G/W) and intravenous injection of 20 micrograms/kg droperidol for prevention of vomiting in 120 consecutive outpatients undergoing gynecological laparoscopy with general anesthesia. Patients were randomly allocated to receive P6 acupoint injection, i.v. droperidol, or nothing as control group. Both P6 acupoint injection and i.v. droperidol 20 micrograms/kg were found to have a significant antiemetic effect when compared with the control group. We conclude that P6 acupoint injection with 50% G/W is a simple and effective method for reducing the incidence of postoperative emesis in outpatient surgery.

Intrathecal morphine for the relief of post-hysterectomy pain - a double-blind, dose-response study

Abstract: Eighty patients undergoing total abdominal hysterectomy under general anaesthesia were randomly divided into four groups to study the dose-response relationship of intrathecal morphine (0, 0.1, 0.3 and 0.5 mg) for postoperative pain relief. Pain scores, as assessed by using the visual analogue scale, revealed that intrathecal morphine provided long-lasting pain relief, was most effective after 0.3 mg and significantly reduced the need for supplementary analgesics (P < 0.05). There was no difference as regards the quality of analgesia or the use of supplementary analgesics between the 0.3 and 0.5 mg groups. Adequate pain relief was not evident after a 0.1 mg dose. There was no incidence of respiratory depression in any of the patients in this study. The incidence of side effects was least following 0.3 mg intrathecal morphine, which we consider to be the optimum dose.

Analysis of lung density by computed tomography before and during general anaesthesia.

Abstract: Pulmonary structure was analysed by means of computed tomography (CT) in 20 lung-healthy patients, relating tissue density to the attenuation value (AV) of a picture element. Regional density of pulmonary tissue (rlung) was determined using mean lung density in five regions of interest (ROI1-5) (sector method). Vertical and horizontal distributions of x-ray attenuation were analysed by density profiles, relating AV values to evenly distributed and normalised length scales. In group I (n = 12), CT-densitometry was obtained in awake, supine patients and after induction of general anaesthesia. In group II (n = 8), the effect of mechanical ventilation with positive end-expiratory pressure (PEEP, 1.0 kPa [10 cmH2O]) was studied. In the awake state, a vertical tissue density difference between the top and bottom of the lung was found in all patients, accounting for a mean of 0.235 g.cm-3 (right lung) and 0.199 g.cm-3 (left lung). Only minor changes were seen in the horizontal lung density profiles. After induction of anaesthesia, x-ray attenuation of ROI1-4 showed no significant differences when compared with the awake state. The basal lung areas (ROI5) revealed a significantly increased tissue density (P < or = 0.01), reaching mean values of 0.94 g.cm-3 (right lung) and 0.814 g.cm-3 (left lung). Similarly, vertical density profiles showed a markedly enhanced rlung of the bottom of the lung in all patients, interpreted as atelectasis. The amount of atelectasis accounted for 4.8 +/- 2.6% (right lung) and 4.7 +/- 2.1% (left lung) of the intrapulmonary area.(ABSTRACT TRUNCATED AT 250 WORDS)

Laboratory methods for detecting disseminated intravascular coagulation (DIC): new aspects.

Abstract: The objective was to diagnose a hypercoagulative state or "pre-DIC" with new laboratory tests. APACHE II score was used as a measure of primary illness. Ventilator time was used as a reflexion of secondary complications. Twenty-three ICU patients were divided into two groups depending on time on the ventilator: Group 1 > 7 days and Group II < or = 7 days. If, after admittance patients deteriorated or complications occurred, new quantitative coagulation tests were done: soluble fibrin, prothrombin fragment 1 + 2, thrombin-antithrombin complex, D-dimer and elastase. We found a positive correlation between SF levels, the APACHE II score and the ventilator time. Diagnostic efficacy for SF was 87%, sensitivity 91%, specificity 83%, the predictive value of a positive result was 87% and the predictive value of a negative result 91%. The levels of the other new tests were also generally higher in the clinically worse group, although not significantly. Prothrombin complex, APTT, platelet count and AT III were pathologic to the same extent in both groups. The patients who developed most secondary complications, resulting in longer ventilator treatment (Group I), were also hypercoagulative. Soluble fibrin, in particular, seems to be valuable in the diagnosis of "pre-DIC" and possibly of predictive value for organ system complications.

Analgesic action of metoclopramide in prosthetic hip surgery.

Abstract: Prosthetic hip surgery was performed under subarachnoidal anaesthesia with bupivacaine 16–20 mg and morphine 0.2 mg. Preoperatively, metoclopramide 1 mg · kg-1 was given i.v., followed by an infusion of 1.5 mg · kg-1 over 9 h (n= 17). Control patients received corresponding volumes of solvent (n = 23). The design of the study was double blind. The characteristics of the spinal block (level of analgesia to pinprick and muscular block) and postoperative VAS pain scores were similar in both groups. During the 24 h following the start of the infusion, four patients receiving metoclopramide required i.v. opioids, compared to 15 in the control group (P<0.05). The pain-free period was longer (P<0.05) in the metoclopramide group. Arterial PcO2-levels were increased, reaching a maximum within 6 h of infusion, with no significant difference between the groups. The study suggests an analgesic action of metoclopramide.

Tracheal intubation after induction of anaesthesia with propofol, alfentanil and lidocaine without neuromuscular blocking drugs in children

Abstract: In a double-blind study, intubating conditions and haemodynamic responses were assessed in two age-groups of 45 ASA I-II children, with mean ages of 2.4 and 6.3 years, premedicated with oral midazolam and atropine. The children were randomly allocated to one of three groups: alfentanil 20 micrograms.kg-1 + lidocaine 1 mg.kg-1 (Alf20 + Lign); alfentanil 20 micrograms.kg-1 (Alf20); or alfentanil 40 micrograms.kg-1 (Alf40), followed by propofol 3.5 mg.kg-1 in the children aged 1-3 years and 3.0 mg.kg-1 in the older children. Intubating conditions, 40 s after the administration of propofol, were assessed as good, moderate or impossible on the basis of jaw relaxation, ease of insertion of the endotracheal tube and coughing during intubation. In the younger age group the frequencies of good, moderate or impossible intubating conditions were 87, 13 and 0% in the Alf40, 40, 60 and 0% in the Alf20 (P < 0.05 compared to the Alf40 group) and 53, 47 and 0% in the Alf20 + Lign group. In the older age group the corresponding frequencies were 60, 33 and 7% in the Alf20 + Lign, 47, 53 and 0% in the Alf20 and 47, 40 and 13% in the Alf40 group. All the drugs prevented any increase in arterial pressure and heart rate after tracheal intubation. The QTc interval of the ECG was always in the normal range. Clinically important bradycardia did not occur. In conclusion, the best intubating conditions occurred after propofol 3.5 mg.kg-1 and alfentanil 40 micrograms.kg-1 in the younger age group.(ABSTRACT TRUNCATED AT 250 WORDS)