Summary

Background: Leucocytes are a pivotal component of the inflammatory cascade that results in tissue injury in a large group of disorders. Free radical production and endothelial activation promote leucocyte–endothelium interactions via endothelial expression of vascular cell adhesion molecule 1 (VCAM-1) and intercellular adhesion molecule 1 (ICAM-1) which augment these processes, particularly in the setting of reperfusion injury. Propofol has antioxidant properties which may attenuate the increased expression of these molecules that is observed. Methods: Cultured human umbilical vein endothelial cells were exposed to 20 h of hypoxia, then returned to normoxic conditions. Cells were treated with saline, Diprivan® 5 μg mL−1 or propofol 5 μg mL−1, for 4 h after reoxygenation and were examined for ICAM-1 and VCAM-1 expression. Results: Hypoxia did not increase the expression of ICAM-1/VCAM-1. ICAM-1 expression peaked 12 h after reoxygenation (21.75(0.6) vs. 9.6(1.3), P = 0.02). Propofol, but not Diprivan®, prevented this increase (8.2(2.9) vs. 21.75(0.6), P = 0.009). VCAM-1 expression peaked 24 h after reoxygenation (9.8(0.9) vs. 6.6(0.6), P = 0.03). Propofol and Diprivan® prevented this increase, with no difference between the two treatments observed (4.3(0.3) and 6.4(0.5) vs. 9.8(0.9), P = 0.001, 0.02, respectively). Conclusion: These effects are likely to be attributable to the antioxidant properties of propofol, and suggest that propofol may have a protective role in disorders where free radical mediated injury promotes leucocyte–endothelium adhesive interactions.

Summary

Background and objectives: This study was designed to investigate the role of nitric oxide on catalepsy induced by fentanyl and haloperidol. Methods: Male albino mice were treated either with fentanyl (0.1–0.2 mg kg−1, s.c.) or haloperidol (0.5–2 mg kg−1, i.p.). The non-selective nitric oxide synthase inhibitor, NG-nitro-l-arginine (10 mg kg−1, i.p.), selective neuronal nitric oxide synthase inhibitor, 7-nitroindazole (3 mg kg−1, i.p.), and nitric oxide donors, l-arginine (30–300 mg kg−1, i.p.) and d-arginine (30 mg kg−1, i.p.), were applied 20 min prior to fentanyl or haloperidol injection. A μ-opioid receptor antagonist naloxone (1 mg kg−1, i.p.) was also given in some groups. The cataleptic status of mice was assessed by placing animals in a rearing position in the cage. If the mouse maintained cataleptic posture for more than 20 s, it was scored as cataleptic and duration of catalepsy was expressed in terms of minutes. Results: Both NG-nitro-l-arginine and 7-nitroindazole prolonged fentanyl-induced catalepsy (fentanyl: 3.6 ± 0.8 min; fentanyl + NG-nitro-l-arginine: 77.4 ± 14.6 min, fentanyl + 7-nitroindazole: 56.0 ± 10.4 min; n = 6; P < 0.01). This effect was reversed by l-arginine and naloxone, but not by d-arginine. Nitric oxide synthase inhibitors also prolonged the cataleptic action of haloperidol but to a lesser extent (haloperidol: 72.0 ± 6.3 min; haloperidol + NG-nitro-l-arginine: 98.5 ± 6.3 min, haloperidol + 7-nitroindazole: 89.6 ± 2.2 min; n = 6; P < 0.05). The prolongation of haloperidol-induced catalepsy with nitric oxide synthase inhibitors was not reversed by l-arginine. Conclusion: These results suggest a common mechanism between μ-opioid receptors and the nitric oxide system in the development of fentanyl-induced catalepsy in mice different from haloperidol-induced catalepsy.

Summary

Background and objective: Remifentanil boluses are used in different clinical situations and the effects on bispectral index monitoring are unclear. We analysed the effect of a remifentanil bolus on the bispectral index of the electroencephalogram (bispectral index) under total intravenous anaesthesia with propofol and remifentanil. Methods: ASA I–III patients were included in this study. All patients received a 2 μg k g−1 remifentanil bolus in a period free from stimuli. Bispectral index and haemodynamic data were collected from an A-2000XP bispectral index monitor (every second) and an AS/3 Datex monitor (every 5 s). Bispectral index data were analysed using the area under the curve. Mean arterial pressure and heart rate were averaged at each 30-s period and analysed using analysis of variance. Results: A total of 240 bispectral index values were obtained per patient. The area under the curve between 90 and 120 s after the bolus was significantly lower than the basal area under the curve (average of all areas before the bolus, P < 0.05). Mean arterial pressure and heart rate were significantly reduced from 96.4 ± 19.9 mmHg at the time of the bolus to 74.2 ± 16.6 mmHg 120 s after, and from 70 ± 16.4 bpm at the time of the bolus to 61 ± 13.6 bpm after (P < 0.001), respectively. Conclusions: There was a significant reduction in the areas under the curve between 90–120 s following the bolus. Heart rate and blood pressure also showed significant reductions. Thus, remifentanil bolus given under total intravenous anaesthesia with propofol and remifentanil decreases bispectral index, an effect independent of intubation and surgical stimuli.

Summary

Background and objective: There is a controversy regarding the best drug for prevention of nausea and vomiting in patients receiving intrathecal morphine. The aim of this study was to examine efficacy and tolerability of droperidol compared with ondansetron for the prevention of morphine-induced nausea and vomiting. Methods: In a randomized, placebo-controlled trial, 120 women undergoing Caesarean section under spinal anaesthesia with intrathecal morphine 0.1 mg received intravenous ondansetron 4 mg (n = 40), droperidol 1.25 mg (n = 40) or saline (n = 40) immediately after umbilical-cord clamping. Nausea and vomiting were graded according to intensity at 1, 2, 4, 6, 12 and 24 h. Results: Nausea or vomiting occurred in 14 patients (35%) in the placebo group, 4 (10%) in the ondansetron group and 10 (25%) in the droperidol group; the difference between ondansetron and placebo was statistically significant (P = 0.007). Eleven of the 14 placebo patients (27.5%) vomited, compared with none of the 4 ondansetron patients (vs. placebo, P = 0.0004) and 5 of the droperidol patients (vs. placebo, P = 0.18). Three of the 14 placebo patients (7.5%) were nauseous, compared with 4 (10%) receiving ondansetron and 5 (12.5%) receiving droperidol. Conclusions: Ondansetron was effective in reducing the incidence of nausea and vomiting in patients receiving intrathecal morphine for Caesarean section.

Summary

Background and objective: The use of a pneumatic tourniquet can induce muscular and neurological complications in the operated limb. The genesis of these injuries could involve an ischaemia/reperfusion phenomenon and a compression under the cuff. We evaluated effects of an antioxidant, acetylcysteine and ischaemic preconditioning on the rhabdomyolysis and postoperative pain following a knee ligamentoplasty using a pneumatic tourniquet. Methods: We included 31 patients scheduled for a knee ligamentoplasty randomly assigned in three groups (control, acetylcysteine 1200 mg the day before and 600 mg at the operative day, ischaemic preconditioning). Results: There was a moderate rise in myoglobin and creatinine phosphokinase with no significant difference between the three groups. The muscular functional parameters were similar in all the groups. However, the morphine consumption within the first 48 h was smaller in the treatment groups (0.22 ± 0.31 mg kg−1 and 0.22 ± 0.23 mg kg−1 in the preconditioning and antioxidant groups, respectively) than in the control group (0.47 ± 0.33 mg kg−1, P <0.05). Conclusions: Acetylcysteine and ischaemic preconditioning do not decrease the extent of rhabdomyolysis related to the use of a pneumatic tourniquet and do not improve the postoperative muscle recovery. On the other hand, they allow a significant reduction in the postoperative morphine consumption.

Summary

Background and objectives: Positive end-expiratory pressure may alter cardiac function and systemic haemodynamics. As transplanted livers may be sensitive to liver congestion, the aim of our study was to evaluate the effect of positive end-expiratory pressure on the cardiovascular system and in particular on central venous and iliac venous pressure in liver transplanted patients. Patients and methods: Seventy-two liver transplant patients were enrolled in this prospective, interventional study. On admission to our Intensive Care Unit all patients were ventilated in a biphasic positive airway pressure mode. Haemodynamic effects of three randomly set levels of end-expiratory pressures (0, 5 and 10 mbar) were studied in the immediate postoperative period in all patients. Mean arterial pressure, central venous pressure, pulmonary capillary wedge pressure, central iliac venous pressure and cardiac index were recorded and analysed at each of the three end-expiratory pressure levels. Results: The values of central- and wedge-pressure significantly increased with increased end-expiratory pressure. Central venous pressure increased by 24% and wedge pressure showed a 6% increase at 10 mbar in comparison to 0 mbar. The values for cardiac index and mean arterial pressure showed no statistically significant difference at 10 mbar as compared to 0 and 5 mbar. The mean pulmonary arterial and common iliac venous pressure were unaffected by different positive end-expiratory pressure levels. Conclusions: Short-term pressure controlled ventilation with end-expiratory pressure up to 10 mbar does not significantly impair systemic haemodynamics in liver-transplanted patients. Further studies are needed to determine whether these findings could be confirmed with higher pressure levels and/or over a longer period of ventilation time.

Summary

Background and objectives: A difficult issue in anaesthesia is its titration for an individual patient to avoid over- and underdosage. Common practice is to use an initial dose and increase it subsequently if the defined end-point is not reached. This assumes that the end-point is reached after a similar interval of time in all patients given a similar dose. In order to test this hypothesis we measured the time to reach end-points such as loss of consciousness (LOC), a bispectral index (BIS®) value of 60, the minimal BIS and the minimal mean arterial pressure (MAP) values. Methods: Thirty patients aged 18–60 yr scheduled for general surgery were included in this observational study. After preoxygenation, induction was performed with 6% inspired concentration of sevoflurane in 6 Lmin−1 oxygen using the SiBI® connector and the tidal volume technique. Remifentanil was administered when the BIS value was 60 and tracheal intubation was performed 4 min later. Results: Time (median, minimum–maximum) to LOC, a BIS value of 60, the minimal BIS and MAP values were, respectively, 75 (45–135), 120 (75–270), 300 (120–720) and 450 (120–1200) seconds. The time to the minimal BIS value was significantly (P < 0.05) shorter than the time to reach the minimal MAP value. Conclusions: These results demonstrate large inter-patient variability for the time necessary to reach defined end-points of depth of anaesthesia when a similar dose of anaesthetic is given. Measuring the time to reach a predefined BIS value would allow application of nociceptive stimuli only at adequate levels of hypnosis and would facilitate titration.

Summary

Background and objective: We examined the efficacy of intraoperative propofol administration to prevent pruritus induced by epidural morphine. Methods: Seventy patients ASA I–II undergoing combined epidural and general anaesthesia for hysterectomy were randomly assigned to two groups, Group P where anaesthesia was induced with propofol and fentanyl and maintained with propofol-nitrous oxide and Group S in which anaesthesia was induced with thiopental and fentanyl and maintained with sevoflurane-nitrous oxide. All patients received a ropivacaine epidural bolus with 3 mg morphine 1 h before the end of surgery. The incidence and severity of pruritus were evaluated every 4 h for the first 12 h postoperatively by blinded observers. Results: The total incidence of pruritus was significantly higher (P = 0.024) in Group S (65.6%) compared to Group P (29%) between 4 and 8 h postoperatively. There were also significantly more patients (P = 0.03) reporting severe pruritus in Group S (22%) compared to Group P (0). Conclusion: Propofol-based general anaesthesia compared to thiopental–sevoflurane-based anaesthesia reduces the incidence and severity of pruritus induced by a single injection of 3 mg epidural morphine with ropivacaine.

Summary

Background and objective: The low cardiovascular and neurological toxicity of levobupivacaine has led to its application as a local anaesthetic in a wide variety of specialist applications including peribulbar block for cataract surgery. The aim of this study was to evaluate the efficacy of levobupivacaine 0.5% and to compare block quality vs. ropivacaine 0.75% in peribulbar anaesthesia. Methods: We examined 208 patients subjected to cataract surgery by phacoemulsification who were randomized into two groups according to the anaesthetic used for peribulbar block, namely levobupivacaine 0.5% or ropivacaine 0.75%, both with the addition of hyaluronidase. Nerve block was carried out by injection of 6 mL of the anaesthetic mixture equally distributed between the inferotemporal and superonasal areas. The success of the block was evaluated by determining the time of motor and sensory onset, akinesia score, times of motor and sensory offset and satisfaction of the patient and surgeon after 24 h. Pre-block, post-block and postoperative intraocular pressure as well as the duration of surgical intervention was also determined. Results: With respect to ropivacaine, levobupivacaine showed a significant reduction (P < 0.001) in the average motor and sensory onset. Both the akinesia score (P < 0.01) and mean motor and sensory offset times were also higher (P < 0.001). Neither the average intervention times nor the satisfaction of the patient/surgeon showed any significant differences between the two groups. Conclusions: Levobupivacaine (0.5%) has better anaesthetic properties with respect to 0.75% ropivacaine and is well-suited for peribulbar block in cataract surgery.

Summary

Background and objective: We evaluated the effect of two different preload solutions: (i) Ringer's lactate (compound sodium lactate intravenous infusion BP) and (ii) 0.9% sodium chloride solution on the neonatal acid–base status of the newborn infants. The two standard regimens were compared to detect a possible difference. Methods: A 2 L crystalloid fluid bolus was administered immediately before spinal anaesthesia for elective Caesarean section in two groups of 20 healthy parturients, while rigorously maintaining maternal normotension. Results: No significant differences in the Apgar scores at 1 and 5 min, or infant well-being were demonstrated in either of the two groups. The data show that umbilical artery PCO2 is lower in the Ringer's lactate group and that pH is insignificantly higher by 0.03. Conclusions: The choice of Ringer's lactate or saline for fluid preload does not have any effect on neonatal well-being.

Summary

Background and objectives: This was a prospective audit to assess the incidence and characteristics of early postoperative complications in the recovery room in extubated patients after elective neurosurgical procedures using propofol and remifentanil-based total intravenous anaesthesia. Methods: Vital signs (temperature, conscious level, respiratory rate, oxygen saturation, pulse and blood pressure) and postoperative complications (shivering, nausea, vomiting and cardiorespiratory) were analysed in 145 adult patients over a 1-yr period. Results: The overall shivering, postoperative nausea and vomiting and postoperative hypertension (systolic blood pressure more than 25% of the preoperative value) incidences were 30.3%, 16.6% and 35.2%, respectively. Fifty-one percent of the patients had at least one of the above complications. The complication rates were found to be widely different among various types of neurosurgery. The surgical procedures were divided into five groups: supratentorial craniotomy, posterior fossa craniotomy, intracranial vascular procedures, transphenoidal hypophysectomy and extracranial procedures. Median extubation time was similar in all groups and patients were fully conscious with no hypoxia in the recovery room. The intracranial vascular group had the highest shivering and postoperative nausea and vomiting rates (58.8% and 29.4%, respectively). In the supratentorial craniotomy group, 46% of the patients had hypertension. The overall complication rate (presence of any complications) was highest in the supratentfial craniotomy (55.4%), posterior fossa craniotomy (75%) and intracranial vascular (76.5%) groups. Shivering and overall complication rate was significantly related to the anaesthetic time (P ≤ 0.001 and 0.02, respectively). Conclusions: Despite the potential advantages of total intravenous anaesthesia in titratability, rapid return of consciousness and reduced respiratory complications, making it suitable for planned extubation at the end of neurosurgery, the postoperative complications of shivering, postoperative nausea and vomiting and hypertension were still high.

Summary

Background and objective: Propofol has been shown to inhibit a variety of functions of neutrophils in vitro, but there is a lack of in vivo data. To analyse the effects of propofol on neutrophil function in vivo we chose to investigate cataract surgery since it represents a small surgical procedure with minimal immunomodulatory effects induced by surgery. We sought to analyse any immunosuppressive effects of propofol after short-term administration in vivo in comparison to local anaesthesia as well as to in vitro effects of propofol. Methods: The study was designed as an open randomized trial enrolling 20 patients undergoing general or local anaesthesia. The neutrophil oxidative response and propofol plasma concentration were assessed prior, during and after anaesthesia. Neutrophil function was determined flow cytometrically based on dihydrorhodamine 123 oxidation. Results: Propofol concentrations which yielded a marked suppression in vitro did not alter the neutrophil oxidative response during cataract surgery in vivo. However, after local anaesthesia the neutrophil oxidative response declined to 37%, compared to the control response prior to anaesthesia. Conclusions: Although we could detect the well established suppression of neutrophil function by propofol in vitro it was not evident in vivo. This may be due to compensating effects on neutrophil function during surgery in vivo. The decline in the neutrophil oxidative response in the local anaesthesia group might be due to increased stress and catecholamine concentrations or a direct interaction of local anaesthetics with neutrophil intracellular signalling.

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: Patients have the right to be informed about the expected benefits and risks of medical and surgical procedures. Ideally this information should be scientifically based and presented to the patient in time. In morbidly obese patient undergoing general anaesthesia, postoperative pulmonary complications are an important cause of postoperative morbidity and mortality. A 46-yr-old female with a body mass index of 89.8 kg m−2 was scheduled to undergo radical abdominal surgery for cervix carcinoma. In order to inform her accurately on the risk of developing postoperative pulmonary complications, we undertook to answer the following question: What is the risk to develop postoperative pulmonary complications in a morbidly obese patient about to undergo abdominal surgery under general anaesthesia? Methods: A Medline search was conducted from 1966 to 2004 with respect to postoperative pulmonary complications in abdominal surgery of morbidly obese patients. Altogether, 213 articles were found, of which seven were selected. Additionally, seven cross-references and or related articles were used. Results: For obese patients who undergo abdominal surgery under general anaesthesia, the likelihood to develop atelectasis is 10.4 ± 4.8% (P < 0.001) with a correlation coefficient of 0.28–0.34 (P < 0.05). The likelihood to develop atelectasis and pneumonia taken together is 29.3% with an adjusted odds ratio of 2.82 (95% confidence interval 1.66–4.78; P = 0.0001). Conclusion: Considering the positive correlation coefficient and the high body mass index of this patient she has a risk of at least 29.3% to develop pneumonia and/or atelectasis, which should affect the anaesthetic strategy in this patient.

Summary

Background and objective: A prospective crossover randomized trial was conducted to compare the performance of three commonly used anaesthetic facemasks: a clear plastic ‘Anaesthetic Facemask’ with pre-inflated air cushion, no inflation valve, and for single use (Intersurgical Limited, Wokingham, UK), a clear plastic ‘Air Cushion Mask’ with inflatable air cushion and inflation valve, and for single use (Proact Medical Limited, Kettering, UK), and a black antistatic reusable rubber facemask with pre-inflated air cushion, and no inflation valve (Datex Ohmeda Limited, Hatfield, UK). Methods: After local Ethics Committee approval, written consent was taken from 60 ASA 1 or 2 patients undergoing elective ENT procedures. Following routine intravenous anaesthetic induction and muscle relaxation, a Guedel's oropharyngeal airway was inserted and each of the facemasks tried in a crossover fashion. The degree of chest expansion, the feel on the reservoir bag, the degree of leak around the mask and the overall satisfaction of the anaesthetist were graded and recorded for each facemask. Results: Both the plastic facemasks performed similarly in all the four criteria. The antistatic rubber facemask performed significantly better than the plastic facemasks in these criteria (P < 0.05). Conclusions: This study has shown that the antistatic rubber facemask outperformed the two plastic facemasks during routine induction of general anaesthesia. We hope this will encourage manufacturers to improve disposable facemask design to simulate the antistatic rubber facemask.

Summary

Background and objective: Different types of polymer surfaces affect the activation of platelets and coagulation pathway containers depending on their surface qualities. Importantly, this could produce variability of coagulation results obtained with thrombelastographical analysis. We assessed the effects of blood storage on thrombelastograph, TEG®, variables using polypropylene and polycarbonate containers. Methods: An in vitro experiment was performed, with eight volunteers in each limb. Fresh whole blood was stored in polypropylene or polycarbonate tubes prior to TEG® analysis, to assess the role of these plastics in the TEG® results obtained. Results: The polycarbonate tubes displayed slower onset of coagulation and greater variability of data for all four basic TEG variables (r-time, k-time, α-angle and maximum amplitude, P < 0.05). Polycarbonate results fell outside manufacturer reference ranges. Conclusions: It is likely that this is due to the altered surface properties and charge effects of the containers affecting proteins and platelets differently. Caution should be used in choosing which containers are used for storage of fresh blood prior to coagulation assessment, as variable results will follow where different types of plastic containers are employed.

Summary

Background and objectives: To analyse the prevalence of positive prick-tests to all medicaments normally checked in allergy units when a patient is suspected of being allergic to anaesthetics. To establish the degree of agreement between the antecedents of a previous history of an allergic reaction to a medicament and the positive result, or not, to the specific prick-test for the said medicament. Methods: This was a prospective study, during 2003 and 2004, which analysed 473 patients referred by their doctors to allergy units to make retrospective diagnoses of an allergy to a drug. The prick-test was done using the undiluted drug. All patients were tested for 41 drugs. These include antibiotics, trimethoprim–sulphamethoxazole, non-steroidal anti-inflammatory drugs (NSAIDs) and perioperative drugs (PD): neuromuscular blocking drugs, latex, iodine, local anaesthetics, hypnotics, opioids and coadjuvants. Cohen's Kappa Index was used to determine the degree of agreement. Results: 71.5% of patients studied presented a positive prick-test. The largest number of positive cases was found in antibiotics (56.4%), followed by PD (15.6%), NSAIDs (14.4%) and trimethoprim–sulphamethoxazole (12.7%). Among PD, the highest prevalence of positive prick-tests was found for neuromuscular blocking drugs (5.3%). Agreement between the substance suspected of causing the allergic reaction and the positive prick-test was excellent for penicillin (Kappa = 0.74) and other antibiotics (Kappa = 0.721) and good for NSAIDs (Kappa = 0.47) and iodine (Kappa = 0.54). Conclusions: The prevalence of patients with positive prick-tests to PD occurred in 15.6% in this prospective cohort. Neuromuscular blocking drugs were found to have the highest prevalence of positive prick-tests. There is positive agreement when the substance responsible for the allergic reaction is suspected, otherwise agreement is low.

Summary

Background and objective: Recent studies emphasize a positive correlation between (cardiac) surgical interventions and increased risk for developing Alzheimer's disease in the late postoperative period. Since amyloid precursor protein and its neurotoxic derivatives play key roles in the development of Alzheimer's dementia, the impact of several agents used in the intra- and perioperative period is examined. Method: Amyloid precursor protein concentrations were assessed by semi-quantitative Western-immunoblot in brains of rats following intraperitoneal treatment with diazepam and midazolam. Results: There were no significant changes in the amyloid precursor protein concentrations. Conclusion: Both diazepam and midazolam are considered to be relatively safe with respect to amyloid precursor protein metabolism.

Summary

Background and objectives: The aim of our study was to investigate the antimicrobial effects of dexmedetomidine and etomidate-lipuro, and to compare these effects with those of midazolam and propofol on Staphylococcus aureus, Escherichia coli, Pseudomonas aeroginosa, Acinetobacter baumannii and extended-spectrum beta-lactamase Escherichia coli ( E. coli ESBL). Methods: All hypnotic dilutions were exposed to micro-organisms for 0, 30, 60, 120 and 240 min at room temperature in vitro. The inoculums taken from diluted suspensions were re-inoculated on blood agar and incubated for 18–24 h at 35°C after which a count of the colonies was compared. Results: Midazolam reduced the viable cells of S. aureus at 30, 60, 120 and 240 min, and also completely inhibited the growth of E. coli, P. aeroginosa, A. baumannii and E. coli ESBL. Dexmedetomidine, etomidate-lipuro and propofol, however, did not inhibit any of the micro-organisms tested. Conclusion:In vitro, midazolam had an antimicrobial effect on E. coli, P. aeroginosa, A. baumannii and E. coli ESBL. Like propofol and dexmedetomidine, etomidate-lipuro had no antimicrobial effect on any of the micro-organisms tested.

Summary

Background and objective: Whereas the protective effect of anaesthetic and ischaemic preconditioning has been described for several organs, it is uncertain whether this mechanism is also effective in the kidney. We compared the effect of preconditioning with sevoflurane and preconditioning with short episodes of ischaemia on renal ischaemia/reperfusion injury in the rat in vivo. Methods: Fourteen days after right-sided nephrectomy, anaesthetized male Wistar rats were randomly assigned to a sham-operated group (no arterial occlusion, n = 5) or underwent 45 min of left renal artery occlusion (control group, n = 9) followed by 3 days of reperfusion. Two further experimental groups of animals were preconditioned prior to ischaemia either by administering 1 MAC sevoflurane for 15 min followed by 10 min of washout (sevoflurane group, n = 10) or by subjecting the animals to three short episodes of renal ischaemia (ischaemia-preconditioned group, n = 8). Blood creatinine was measured during reperfusion and morphological damage was assessed by histological examination. Results: Baseline creatinine values were similar in all four groups (0.7 ± 0.2 mg dL−1; mean ± SD) and remained unchanged in the sham-operated animals after 3 days (0.8 ± 0.2 mg dL−1). Creatinine levels increased in the ischaemic preconditioning group (3.3 ± 1.2 mg dL−1) and sevoflurane preconditioning group (4.0 ± 1.1 mg dL−1) compared to the control group (1.6 ± 0.6 mg dL−1). Morphological damage was less severe in the control group, i.e. in animals without preconditioning, than in both preconditioning groups. Conclusion: Neither sevoflurane nor ischaemic preconditioning preserves renal function or attenuates cell damage in the rat in vivo.