Summary

Background and objective: We compared the laryngeal mask airway (LMA™) and the laryngeal tube (LT®) with the newly introduced perilaryngeal airway (CobraPLA®, PLA) with regard to haemodynamic responses induced by airway insertion, clinical performance and occurrence of postoperative sore throat after short surgical procedures. Methods: After premedication, 90 ASA I–II patients awaiting short surgical procedures were randomized to receive, LMA, LT or PLA. Anaesthesia was induced with intravenous propofol (2.5 mg kg−1) and mivacurium (0.2 mg kg−1). Number of attempts, time of insertion of the device, any other unwanted effect, mean aterial pressure, heart rate, oxygen saturation and end-tidal carbon dioxide were recorded. At the end of surgery, the cuff of the device was immediately deflated and the airway device was removed. The device was examined and noted for the presence of visible blood. Patients were asked to rate their throat soreness, dysphonia and dysphagia 1 and 24 h postoperatively. Results: There were no differences in haemodynamic variables. Insertion times for the devices were similar (LMA: 20 ± 11 s, LT: 19 ± 14 s and PLA: 21 ± 12 s.) The success rates at first insertion were lower in the (LMA group (57%) when compared with the PLA (97%, P < 0.05). The number and type of airway interventions for achieving an effective airway were similar. When the airways were removed 50% of the PLA devices had positive blood traces, while only 17% of the LMA and LT devices had positive blood traces (P < 0.01). Fifty percent of the patients suffered from a sore throat in the PLA group, which was significantly higher than in the LMA and LT groups (P < 0.05). Conclusion: We conclude that haemodynamic, ventilation and oxygenation variables throughout the surgery were similar with, LMA, LT and PLA, but LT and PLA were easier to insert; LMA and LT caused less mucosal trauma.

Summary

Background and objective: To determine the optimal concentration of ropivacaine for bolus-only patient-controlled epidural labour analgesia, three different doses of ropivacaine were evaluated in comparison with bupivacaine in a double-blinded multicentre study.

Methods: Four hundred-and-fifty labouring parturients at term in three different academic institutions were randomized to four groups receiving bupivacaine 0.125% with sufentanil 0.75 μg mL−1, ropivacaine 0.125% or 0.175% with sufentanil 0.75 μg mL−1, or ropivacaine 0.2%. After an initial bolus of 10 mL of the study solution, and once visual analogue scores (VAS) were below 30 mm, patient-controlled epidural analgesia was initiated with a bolus of 4 mL, a lockout interval of 15 min and without a background infusion. Variables studied were the quality of analgesia, incidence of side-effects, the degree of motor blockade, and the mode of delivery.

Results: Bupivacaine 0.125% and ropivacaine 0.125% with sufentanil proved equally effective in providing labour analgesia without a difference in local anaesthetic consumption (48.6 ± 23 mg bupivacaine vs. 52.1 ± 38 mg ropivacaine), motor blockade or mode of delivery. Ropivacaine 0.175% plus sufentanil enhanced the quality of analgesia of the initial loading dose, whereas ropivacaine 0.2% without sufentanil increased the consumption of local anaesthetics (80.2 ± 34 mg; P < 0.05) and the degree of motor blockade.

Conclusion: Despite recent studies indicating that bupivacaine and ropivacaine may not be equipotent, both local anaesthetics provided equi-effective analgesia at equal doses without a difference in side-effects.

A prospective, double-blind, randomized, controlled study was undertaken to compare the perioperative analgesic and recovery characteristics of equipotent doses of tramadol, pethidine and nalbuphine (3.0 mg kg−1, 1.5 mg kg−1 and 0.3 mg kg−1 respectively) with placebo (saline 0.02 ml kg−1) given at induction of anaesthesia in 152 ASA I children and young adults undergoing tonsillo-adenoidectomy. Premedication (temazepam and diclofenac), induction and maintenance of anaesthesia (thiopentone, atracurium, nitrous oxide and isoflurane), with controlled ventilation, were standardized. Variables monitored were heart rate (HR) and systolic arterial pressure (SAP) during surgery, time to recovery of spontaneous respiration at the termination of anaesthesia and restlessness, time to awakening, sedation and emesis in the recovery unit. Increases in HR or SAP >33% of baseline during surgery were treated with esmolol 2.0 mg kg−1 intravenously (i.v.) and restlessness during recovery was treated with the same opioid i.v. given with anaesthesia, or pethidine i.v. in the placebo group. With placebo, there was a high requirement for esmolol during surgery and for pethidine in the recovery ward. Tramadol did not reduce the rate of intra-operative treatment with esmolol, but reduced the tramadol requirement during recovery (P<0.05). Pethidine and nalbuphine reduced the intra-operative esmolol requirement more significantly (P<0.025 and P<0.005 respectively) and the need for treatment during recovery with opioids (P<0.005 each). The time to recovery of spontaneous respiration at the end of anaesthesia was only delayed by pethidine. Other recovery variables were similar, except that restlessness–pain scores were reduced by tramadol (P<0.02), pethidine (P<0.005) and nalbuphine (P<0.005). These results suggest that pethidine 1.5 mg kg−1 and nalbuphine 0.3 mg kg−1 given with induction of anaesthesia provide better analgesia during and after tonsillo-adenoidectomy than does tramadol 3.0 mg kg−1. The delay to recovery of spontaneous respiration with pethidine suggests a greater safety profile of nalbuphine and tramadol.

Summary

Background: This study was designed to investigate the impact of patient age on propofol consumption and recovery time using a propofol–remifentanil anaesthetic standardized with Narcotrend™ EEG monitoring. The Narcotrend is a monitor for measuring the depth of anaesthesia based upon a six-letter classification from A (awake) to F (increasing burst suppression) including 14 substages.

Methods: In 200 patients scheduled for minor orthopaedic surgery Narcotrend EEG electrodes were positioned on the patient's forehead as recommended by the manufacturer. Anaesthesia was induced with remifentanil 0.4 μg kg−1 min−1 and 2 mg kg−1 propofol. Immediately after intubation remifentanil was reduced to a constant rate of 0.2 μg kg−1 min−1 whereas a propofol infusion was now started at 3 mg kg−1 h−1 and then adjusted accordingly to achieve a target Narcotrend stages of D0–2 indicating general anaesthesia. At the end of surgery the propofol and remifentanil infusions were stopped without tapering, the time to unstimulated opening of eyes was determined, and the propofol consumption (given as mg kg−1 h−1) was calculated from the total amount of infused propofol but without the induction bolus, from the actual body weight and the duration of propofol infusion. Furthermore, a linear regression analysis was applied for propofol consumption vs. age.

Results: The ages of the patients studied ranged from 16 to 83 yr old and patients were classified as ASA I–III. Propofol consumption significantly decreased with the patients' age: 30 yr of age or below the propofol consumption was calculated as 5.9 ± 1.7 mg kg−1 h−1, for 31–50 yr as 5.4 ± 1.8 mg kg−1 h−1, for 51–70 yr as 4.5 ± 1.7 mg kg−1 h−1 and above 70 yr as 3.5 ± 1.4 mg kg−1 h−1. Linear regression analysis revealed propofol (mg kg−1 h−1) = 9.136 − (0.0597 × age (yr)); R = 0.53. Concomitantly, the recovery time to opening of eyes increased with the patients' age: ≤30 yr, 7.4 ± 3.7 min; 31–50 yr, 9.5 ± 4.0 min; 51–70 yr, 9.8 ± 4.1 min; and ≥71 yr, 14.9 ± 12.1 min.

Conclusions: We conclude that with Narcotrend guidance, mean propofol consumption and recovery times are age dependent. However, as a result of large inter-individual variability, age per se does not allow a prediction of individual propofol need or recovery time.

Background and objective To assess retrospectively the complications and morbidity of electroconvulsive therapy.

Methods Complications occurring in 75 patients during 612 electroconvulsive therapy procedures under propofol anaesthesia were reviewed by data analysis.

Results At least one complication occurred in 51 patients (68%) during the course of their treatment. Among these complications, 12 were potentially life-threatening: one patient developed angina pectoris, another aspiration pneumopathy, there were two incidences of bronchospasm, three hypoxic episodes (SpO2 < 92% with FiO2 = 1) and five severe episodes of laryngospasm which caused hypoxia. Twenty-five patients (33%) were confused for more than 2 h after the electroconvulsive therapy. Confusion recurred in 10 patients (13%) after several sessions of electroconvulsive treatment. Six patients had a traumatic complication, with one requiring surgery.

Conclusion Our results, compared with other studies, suggest that electroconvulsive therapy is not a low-risk procedure, with a particularly high rate of respiratory complications that may have been previously overlooked. Therefore, ambulatory anaesthesia may not be appropriate on a regular basis for most of these patients.

Summary

Background: Propofol and dexmedetomidine are widely used for sedation in the intensive care unit yet there are limited data on its effects on gastric motility. In our preliminary study, we examined whether or not any effect of propofol and dexmedetomidine on gastric emptying is preserved in critically ill patients. Methods: Twenty-four critically ill, enterally fed adult patients each received enteral feeding via a nasogastric tube at 50 mL h−1 throughout the 5-h study period. Either propofol 2 mg kg−1 h−1 (n = 12, Group P) or dexmedetomidine 0.2 μg kg−1 h− (n = 12, Group D) was given intravenously over 5 h. Gastric motility was measured indirectly by analysis of the absorption over time of 1.5 g of paracetamol administered into the stomach at the start of the study period. At the beginning and end of the study, residual gastric volume and pH of residual gastric fluid were measured. Results: Gastric residual volume measured at the end of propofol infusion (19.33 ± 11.33) was found to be higher when compared with the volume measured before infusion (11.33 ± 4.84) and after dexmedetomidine infusion (9.17 ± 4.54). But, there was no difference between groups in gastric emptying time (AUC120 894.53 ± 499.39 vs. 1113.46 ± 598.09 propofol and dexmedetomidine groups, respectively). Conclusion: In our study, gastric residual volume measured at the end of propofol infusion was found to be higher when compared with the volume measured before infusion and after dexmedetomidine infusion. There was no difference between groups in gastric emptying time.

Summary

Background and objective: Extremity surgery with tourniquet to provide a bloodless field may be a good human model for ischaemia reperfusion (IR) injury. The aim of this study was to investigate the effects of three different modes of propofol use on tourniquet induced IR injury in lower extremity operations. Methods: Thirty-three consecutive ASA Grade I and II patients were randomized into three groups of 11 patients each. In the spinal group (Group S), after intrathecal anaesthesia, sedation was given with a propofol infusion at 2 mg kg−1 h−1 after a 0.2 mg kg−1 bolus dose and fentanyl 100 μg. In the general (Group G) and TIVA (Group T) groups, general anaesthesia was induced with propofol 2 mg kg−1 with fentanyl 100 μg and maintained with inhalation of halothane or infusion of propofol respectively. Venous blood samples were obtained at different time points for measurements of plasma malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) levels. Results: Plasma MDA levels were increased significantly in the Group G at 1 min before tourniquet release and 5 and 20 min after tourniquet release compared with before induction of general anaesthesia (baseline). Before intrathecal anaesthesia and before induction of general anaesthesia significantly decreased levels of MDA were observed both before and after tourniquet release compared to baseline. Plasma SOD and CAT concentrations were decreased significantly only at tourniquet release in the Group G compared with baseline. In the Groups S and T these enzymes were not changed significantly. Plasma GPx levels were not altered in any groups. Conclusion: Propofol administration may inhibit lipid peroxidation and restore antioxidant enzyme levels in extremity surgery requiring tourniquet application.

Summary

Background and objective: Preoperative anxiety is a challenging concept in the preoperative care of patients. The hypothesis of this study was that the doctors are able to estimate their patients' preoperative anxiety. Methods: A prospective clinical trial was performed on 67 adult patients and 26 paired anaesthetists and surgeons. The patients filled out two separate visual analogue scales for anxiety for the planned anaesthesia and surgery. After that the ‘anxiety subscale’ of the Hospital Anxiety and Depression's Scale was completed and a list of fearsome items was presented as the patients were asked to choose two conditions they considered the most frightening. Finally the patients were asked to select one or more items from a list of things, which they considered likely to relieve their preoperative anxiety. Similarly, the participating doctors were asked to estimate their patients' anxiety, guess their fearful conditions and their anxiety-relieving requests. Results: Median scores for anxiety as estimated with visual analogue scales by anaesthetists, surgeons and patients for anaesthesia were 34, 36 and 6, respectively; and for surgery 53, 47 and 9, respectively. The anxiety subscale of the Hospital Anxiety and Depression's Scale 8.9 ± 4.2, 8.6 ± 4.6 and 6.5 ± 4.5 (mean ± SD), respectively. Doctors' scores were significantly higher than the patients' scores (P < 0.05). Thus, the anaesthetists and the surgeons were unable to estimate their patients anxiety on any of the scales used (Kendall's τ < 0.25; P < 0.05). The proportion of correct estimation of the fearsome items was 20% for both the anaesthetists and the surgeons. Conclusions: Both anaesthetists and surgeons overestimated their patients' preoperative anxiety by a wide margin and poorly predicted their patients' feared conditions and their desire for relief of anxiety.

Summary

Background and objective: Postoperative nausea and vomiting (PONV) is a frequent and unpleasant experience that may increase postoperative complications and costs. For surgical procedures with a high risk of PONV, prevention is preferable to treatment. In this study, the authors explore the dose–response relationship between granisetron administered just prior to the end of surgery and post-operative nausea and vomiting in patients undergoing abdominal hysterectomy. Methods: This was a randomized, double-blind, placebo-controlled, pilot study of post-operative nausea and vomiting prevention. Patients undergoing elective open abdominal hysterectomy requiring general anaesthesia received a single dose of granisetron 0.1, 0.2 or 0.3 mg or placebo administered approximately 15 min prior to the end of surgery. The primary efficacy end-point was the proportion of patients with no vomiting in the 0–6 h interval following medication administration. No inferential statistics were planned. Results: The proportion of patients with no vomiting episode in the 0–6 h interval after administration of study medication was higher in each granisetron treatment group (>90%) than in the placebo group (77%). Proportions of patients with no vomiting episodes in the 0–24 h interval were similar across treatment groups. Results of analyses of proportions of patients with no moderate or severe nausea episodes, proportions of those requiring rescue medication and times to first use of rescue medication suggested a treatment effect of granisetron relative to placebo in both the 0–6 and 0–24 h intervals. Similar proportions of patients in each treatment group reported at least one adverse event. Conclusions: Granisetron at doses of 0.1, 0.2 and 0.3 mg administered just prior to the end of surgery suggested a trend of improved efficacy compared to placebo in preventing postoperative nausea and vomiting in the first 6 h after abdominal hysterectomy. This pilot study did not identify a dose–response relationship.

Despite the high frequency of sickle cell disease in Europe, the disease is poorly managed. Critical periods are the hospital stays during which the anaesthe-siologist plays an important role. Understanding the molecular basis of polymerization processes of haemoglobin S can help to avoid triggering a crisis. Differentiation of the various haemoglobin phenotypes helps to estimate the individual perioperative risk. Knowledge of the patient's history and the actual haemoglobin S level facilitates general anaesthesia, surgery and postoperative care. Damage to liver, spleen, eyes, bones, lung and central nervous system increases the perioperative risk. Preoperative preparation includes early admission, intravenous volume substitution, continuing pain therapy and prophylactic antibiotic medication. General anaesthesia seems to be better for patients with a high-risk profile rather than regional anaesthesia. Careful perioperative and postoperative monitoring should allow hypoxaemia, hypovolaemia, hypothermia, acidosis and overtrans-fusion to be avoided. Effective pain therapy includes a combination of opioids with peripherally acting analgesia.

We present a case of a patient submitted for extirpation of a neoplasm of the larynx, by means of carbon dioxide laser surgery. High frequency jet ventilation was applied by means of orotracheal intubation with two Teflon catheters, 2mm in external diameter and 30cm in length, attached with three equally placed strips of adhesive paper tape. One catheter was used to inject the jet volume and the other used to measure the airway pressure. The adhesive strips were moistened and FiO2 was lower than 50%. After 30 min using the laser, an airway fire was noticed. Ventilation was interrupted and the catheters were removed. The patient was reintubated with an endotracheal tube of 6mm ID and the surgical procedure was continued until the tumour was removed. Two factors contributed to the airway fire: the ignition of the lowest adhesive strip that had dried and the use of the laser in the mode of continuous pulsation.

Summary

Background: The local anaesthetic prilocaine has a low systemic toxicity mainly because of a high absorption in the lung and a large volume of distribution and thus is associated with a lower risk of neurological or cardiac side-effects. However, the major disadvantage is the formation of methaemoglobin by its metabolite o-toluidine. This prospective observational study was performed to identify factors that are associated with increased prilocaine-induced methaemoglobinaemia. Patients and methods: One Hundred and sixty two patients undergoing major knee surgery under general anaesthesia combined with peripheral nerve blocks (femoral nerve block, combined femoral/sciatic nerve block or lumbar plexus block) received a single bolus injection of 300 or 400 mg prilocaine about 30 min before surgery via a catheter. The proper placement was verified using nerve stimulation via a stimulating catheter. Three hours after prilocaine injection, venous blood samples were drawn and methaemoglobin levels were measured by standard photometric technique. Data was subjected to a stepwise multiple regression analysis. Results: The mean methaemoglobin for all patients was 2.7% (range: 0.9–15.4%). A higher dose of prilocaine and younger age were the most important predictive factors for higher methaemoglobin formation. Female sex and to a lesser extent the use of high-concentration/low-volume prilocaine also increased methaemoglobin levels. These four factors of the model explain 36% of the total variance. Other investigated factors, including the patient’s height, weight, body mass index, the site of catheter insertion, the anaesthetist’s judgement concerning the difficulty of catheter placement, duration of catheter placement or an inadvertent puncture of a venous or arterial vessel, had no significant impact on the concentration of methaemoglobin. Conclusion: The use of prilocaine for regional block is safe, since the older patients who might be more susceptible to suffer from clinical symptoms of methaemoglobinaemia usually form less methaemoglobin. However, since prediction of high methaemoglobin levels is difficult, anaesthesiologists performing regional blocks in patients who might be jeopardized by a decreased oxygen transport capacity should avoid high doses of prilocaine.

Background and objective Assessment of cardiac preload is of major importance in the management of critically ill patients. Echocardiographic determined left ventricular end-diastolic area and indicator dilution derived intrathoracic blood volume are used as surrogates for cardiac preload. However, no controlled comparison studies on the relationship between induced changes in end-diastolic area and intrathoracic blood volume and concomitant changes in stroke volume index are available.

Methods The effects of a change in body position on these variables were investigated in 10 anaesthetized patients.

Results Intrathoracic blood volume and end-diastolic area decreased by 18 ± 11% and 27 ± 13% respectively. Stroke volume index concomitantly decreased by 19 ± 11%. Correlation analysis revealed a close relation between stroke volume index and intrathoracic blood volume (r = 0.75) and end-diastolic area (r = 0.76).

Conclusions Within the observed range of data, intrathoracic blood volume and end-diastolic area are equivalent indices of cardiac preload.

Summary

Background and objective: We have investigated the concentrations of epinephrine, norepinephrine, vasopressin and angiotensin converting enzyme activity to explore the role of these mediators in the neuroendocrine response to laryngoscopy and tracheal intubation. Methods: One hundred (50 male, 50 female) ASA I patients aged 20–50 yr (mean ± SEM; 35.59 ± 0.99) were included in the study. They were undergoing elective surgery under standard anaesthesia induction and maintenance using tracheal intubation. Plasma concentrations of epinephrine, norepinephrine and vasopressin as well as plasma angiotensin converting enzyme activity were determined at four time points, before (T1) and after (T2) induction, and 2 (T3) and 5 min (T4) after intubation. Blood pressure and heart rate were recorded at corresponding times to reveal if any correlation existed between haemodynamic parameters and neuroendocrine response. Results: Heart rate increased after induction and intubation (P < 0.05) and decreased significantly at T4 (P < 0.05). Systolic blood pressure decreased significantly (P < 0.05) after induction and increased slightly after intubation decreasing to below baseline value (P < 0.05) at T4. Diastolic blood pressure increased slightly after intubation and decreased significantly (P < 0.05) at T4. Plasma epinephrine and norepinephrine concentrations decreased after induction and increased at T3 and T4 without reaching significance. Vasopressin concentrations increased slightly at T2 and T3 and decreased significantly at T4 (P < 0.05). Angiotensin converting enzyme activity was unaffected when compared with baseline values. Conclusions: Blood pressure, heart rate, plasma epinephrine, norepinephrine and vasopressin concentrations increased slightly in response to laryngoscopy and intubation, all returning to or below baseline 5 min later with no change in angiotensin converting enzyme activity in normotensive patients.

Summary

Background and objective: In order to identify parameters predicting intensive care unit mortality in patients transferred to a specialized tertiary centre because of progressive acute respiratory distress syndrome, an observational pilot study was carried out involving 94 patients. Methods and Results: Forty-one patients (43.6%) died. Survival was defined as intensive care unit discharge. Survivors were younger (32.0 ± 11.8 vs. 39.1 ± 12.4 yr, P = 0.008), at admission they had a lower acute physiology and chronic health evaluation (APACHE) II score (21.7 ± 5.4 vs. 25.4 ± 5.2, P = 0.0009), higher PaO2/FiO2 (122 ± 79 vs. 79 ± 42 mmHg, P = 0.002), lower positive end-expiratory pressure (10.6 ± 3.1 vs. 12.5 ± 3.7 cmH2O, P = 0.02) and a lower Murray score (2.8 ± 0.63 vs. 3.0 ± 0.62, P = 0.04). No differences were observed for tidal volumes and peak inspiratory pressures. Days of hospitalization and mechanical ventilation prior to transferral were not related to survival. Multivariate analysis of variables assessed on admission detected only differences for age (P = 0.014) and APACHE II (P = 0.005). Odds ratio was 1.06 (95% confidence interval (CI): 1.013–1.119) for age and 1.21 (CI: 1.059–1.381) for APACHE II. Multivariate analysis of changes in respiratory parameters, APACHE II and Murray score during the first 3 days after transferral revealed a significant difference only for positive end-expiratory pressure (P < 0.008). Corresponding odds ratio was 2.40 (CI: 1.25–4.58) for an increase of 1 cmH2O/24 h. Conclusion: Age-related mortality in this small, but highly selected group of patients with established ARDS increased early in life even in a population with an overall mean age of 35.1 yr. APACHE II was the only clinical predictor for mortality on admission. The need for a substantial increase in positive end-expiratory pressure after transferral markedly reduced the chance to survive.

Background and objective Late postoperative hypoxaemia after upper abdominal surgery is common even among cardiopulmonary healthy patients. Atelectasis may develop after intubation and persist into or reveal a disposition for atelectasis in the postoperative period. Positive end–expiratory pressure (PEEP) eliminates peroperative atelectasis but the effect on perioperative oxygenation is controversial. This study evaluated the effect of peroperative PEEP optimized pulmonary compliance on perioperative oxygenation and complications.

Methods Forty patients assessed by electrocardiography, spirometry, functional residual capacity and diffusion capacity were randomly assigned to receive positive end–expiratory pressure (PEEP) or zero endexpiratory pressure (ZEEP) during surgery. PaO2, SPO2 and complications in the postoperative period were evaluated without knowledge of peroperative PEEP or ZEEP application.

Results Peroperative arterial oxygenation improved for all patients receiving PEEP, mean 2.1 kPa (0.7–3.5 kPa). There was no difference in postoperative median PaO2 between the groups. The differences in the incidence of late prolonged postoperative hypoxaemia and complications were 25% (−5% to 55%) and −1% (−31% to 29%) between the ZEEP and the PEEP group, but were not statistically significant.

Gamma-hydroxybutyrate (GHB) may well be developed as an alternative for optional sedation during spinal anaesthesia. As in the case of propofol (PRO), GHB has good sedative properties associated with cardiovascular and respiratory stability. When used as a narcotic agent, recovery times are variable (e.g. > 30 min); in contrast, sedative dosages, as used in intensive care patients (e.g. 10–20 mg kg−1 h−1), result in adequate clinical recovery. The goal of the present study was to compare the clinical properties of GHB and PRO after continuous administration during spinal anaesthesia (SPA). Thirty patients (ASA I and II) received either GHB (n=15) or PRO (n=15) at random. Patients refusing sedation (n=15) received 0.9% saline (control). At eight defined time points, haemodynamic (BP, HR), respiratory (RR, RMV, Pao2, Spo2, Peto2, Petco2, ̇Vo2, ̇Vco2) and endocrinological parameters (plasma concentrations of noradrenaline and adrenaline) as well as the clinical side-effects were assessed simultaneously. With both sedatives, the desired level of sedation was achieved. Recovery times ranged between 1.7±0.9 min with PRO and 6.1±4.9 min with GHB. GHB provided stable haemodynamic conditions without clinically relevant respiratory depression. In contrast, PRO caused a decrease in mean arterial pressue (MAP) of 15%, whereas respiratory minute volume was decreased by 53% (with periods of apnoea, Spo2<90%). ̇Vo2 and ̇Vco2 correlated with respiratory minute volume (GHB, PRO, control). Plasma noradrenaline and adrenaline concentrations remained nearly constant in the GHB and control groups and declined during sedation with PRO. Both GHB and PRO are suitable for optional sedation during spinal anaesthesia. Control and recovery are acceptable for clinical purposes. It seems that GHB and PRO have similar haemodynamic, respiratory and endocrinological characteristics. Therefore, GHB may serve as an alternative for the established management of continuous sedation during SPA with PRO.

Summary

Background and objective: The analgesic potency of non-steroidal anti-inflammatory drugs and acetaminophen are still being debated. We have assessed the relative analgesic effect of ibuprofen, acetaminophen or the combination of both after orthopaedic surgery.

Methods: Sixty-one ASA I patients, scheduled for an elective anterior cruciate ligament reconstruction under general anaesthesia were randomized, in a double blind fashion, into one of three groups. The ibuprofen group (n = 17) received ibuprofen 800 mg orally 1 h before operation and again at 6 and 12 h after the initial dose. The acetaminophen group (n = 20) received of acetaminophen 1 g orally at the same time intervals. The combination group (n = 24) received both ibuprofen 800 mg and acetaminophen 1 g. Surgery was performed under general anaesthesia with propofol and fentanyl for induction and maintenance with propofol and nitrous oxide in oxygen. The patients were monitored for 24 h thereafter, and the following variables were assessed: pain by visual analogue and verbal scales, need for rescue intravenous opioid analgesia (i.e. ketobemidone) and adverse events.

Results: The ibuprofen group and the combination group experienced significantly less pain during the first 6 h after surgery than the acetaminophen group using the visual analogue and the verbal scales. The acetaminophen group also had a significantly higher average consumption of opioids during the first 6 and 24 h. There were no significant differences between the ibuprofen group and the combination group in respect of experienced pain or consumption of rescue analgesia. The incidence of side-effects, postoperative haemoglobin concentration and renal function, judged by creatinine clearance, were identical between the groups.

Conclusion: Ibuprofen 800 mg thrice daily reduced pain to a greater degree than acetaminophen 1 g thrice daily, after anterior cruciate ligament reconstruction under general anaesthesia. The combination of acetaminophen and ibuprofen did not provide any superior analgesic effect.