Summary

The ‘wet vs. dry’ philosophy in patients undergoing abdominal surgery is a subject of substantial debate. It has been suggested that restricting fluid input would significantly reduce complications and improve outcome following abdominal surgery. Keeping the patients dry may be a two-edged sword because the resulting hypovolaemia may result in compromised organ perfusion and poor tissue oxygenation. A review of the literature from 1990 to 2004 revealed that only very few studies on this subject have been published. Unfortunately, most of the ‘dry’-supporting studies used fixed amounts of volume instead of a fluid concept adapted to the patients' need (‘goal-directed’) and there is no generally accepted definition of ‘restricted’, ‘dry’ or ‘overload’. Not only the amount but also the kind of administered fluid appears to be important. Current evidence indicates that using crystalloids exclusively may cause overloading of the interstitial compartment with considerable negative sequelae, whereas using colloids may improve microperfusion and tissue oxygenation. This review shows that the meagre literature on a restricted volume replacement strategy in abdominal surgery patients cannot clearly support the ‘dry’ approach. Further well-performed studies are necessary to elucidate the ideal amount and type of fluid replacement and determine how to guide fluid therapy.

Summary

Cardiac complications are the major cause of perioperative morbidity and mortality of patients undergoing non-cardiac surgery. This is related to the frequent presence of underlying coronary artery disease. In the last few decades, attention has focused on preoperative cardiac risk assessment that may help to identify patients at increased cardiac risk for whom cardioprotective medication and, when indicated, coronary revascularization may improve perioperative outcome. On the other hand, less attention was given to the role of anaesthesia and monitoring techniques in the cardiac risk management of high-risk patients undergoing non-cardiac surgery. The aim of this review was to summarize the current evidence from published studies on the effect of the type of anaesthesia and monitoring techniques on perioperative cardiac outcome in non-cardiac surgery.

Summary

Background and objective: Sedation is commonly required by critically ill patients and inadequate sedation may be hazardous. Traditionally, subjective scales have been used for monitoring sedation. Bispectral index has been proposed, although its utility in the intensive care unit is debated. Our aim was to evaluate the depth of sedation in intubated surgical critically ill patients by means of two sedation scales (Ramsay and Observer's Assessment of Alertness and Sedation) and bispectral index. Methods: Sedation was assessed prospectively in 50 postoperative intubated patients requiring at least 24 h of sedation (35 propofol, 15 midazolam/fentanyl), every 8 h for a 24 -h period. The bispectral index value recorded was the mean value obtained during a 10-min observation period, whenever the quality signal index was above 75% and the electromyographic signal was below 25%. Results: Most of the patients (78%) were oversedated (bispectral index < 60). The three sedation scores (global data) correlated significantly (P < 0.001). This correlation was lost in the midazolam group in which the patients were also significantly more sedated than the propofol group (P = 0.001). The correlation between the bispectral index and the scales in the midazolam group reappeared when the measurements with a Ramsay = 6 or an Observer's Assessment of Alertness and Sedation = 1 were excluded. Conclusions: Sedation should be monitored routinely in intensive care units. The Ramsay and the Observer's Assessment of Alertness and Sedation scales showed equal efficacy. Bispectral index might prove useful for discriminating between deeper levels of sedation.

Summary

Backgrounds: The purpose of this study was to evaluate the effect of ephedrine and phenylephrine on propofol concentrations and bispectral index during propofol anesthesia. Methods: General anaesthesia was induced with propofol and was maintained with propofol (4 mg kg−1 h−1) and fentanyl. Vecuronium was used to facilitate the artificial ventilation of the lungs. Patients with systolic blood pressure > 90 mmHg were defined as the control group (n = 16). Patients who had to be treated for larger decreases in arterial blood pressure (systolic blood pressure <90 mmHg) were randomly assigned to receive ephedrine 0.1 mg kg−1 (n = 20) or phenylephrine 2 μg kg−1 (n = 20). Propofol concentrations were determined before (baseline) and at 3 and 10 min after the administration of ephedrine or phenylephrine. Bispectral index was monitored continuously. Cardiac output was determined using a pulmonary arterial catheter. Results: Ten minutes after drug injection, bispectral index in the ephedrine group increased significantly compared with the baseline and was significantly larger than that in the control or phenylephrine group. Eight patients in the ephedrine group had bispectral index >60, whereas no patient in the control or phenylephrine groups had bispectral index >60. There were no significant differences in propofol concentrations or cardiac output relative to baseline at 3 or 10 min after the administration of ephedrine or phenylephrine. Conclusions: Ephedrine increases bispectral index values without decreasing propofol concentrations during general anesthesia.

Summary

Background and objective: No clinical trials comparing the characteristics of sensory blockade caused by various local anaesthetics in thoracic paravertebral blockade have been published. The aim of this prospective study was a clinical assessment of sensory blockade after paravertebral injection of ropivacaine or bupivacaine in patients undergoing modified radical mastectomy. Methods: Seventy ASA I–II patients were randomized to receive a single injection of ropivacaine 0.5% (n = 35) or bupivacaine 0.5% (n = 35) at the T4 level. General anaesthesia with propofol and fentanyl was provided during the procedure and patients were not intubated. The following parameters were analysed: duration and dynamics of the sensory blockade and the patient's and surgeon's assessment. Results: Both ropivacaine and bupivacaine provided a similar level of analgesia. Ropivacaine was characterized by more rapid onset – after only 5 min 53% of patients in this group had the extent of sensory blockade wide enough to perform modified radical mastectomy in comparison to only 20% after bupivacaine (P < 0.01). The initial spread of sensory blockade (>9 segments blocked) was noted more often in the ropivacaine group (88% vs. 65%, P < 0.05), lasted longer and appeared to be wider than sensory blockade produced by bupivacaine. Regression of sensory blockade was initially similar, but after 24 h sensory blockade in the ropivacaine group still had a potential to provide analgesia for modified radical mastectomy in 81% of patients in comparison to only 50% of such patients in the bupivacaine group (P < 0.05). Degree of postoperative pain, performance of the cardiovascular system, consumption of medications and complications were all similar between the study groups. Conclusions: Both agents provide satisfactory conditions for mastectomy, but ropivacaine seems to be superior to bupivacaine for thoracic paravertebral blockade during breast cancer surgery.

Summary

Background and objectives: This study was designed to quantify the additional postoperative analgesic efficacy of a single dose of ketoprofen in patients undergoing thyroid surgery using two different intraoperative analgesic regimens. Methods: One hundred and twenty patients were randomly assigned to one of four groups: intraoperative fentanyl or remifentanil with or without ketoprofen (n = 30 for each group). Intravenous ketoprofen (1.5 mg kg−1) or saline was administered 45 min before the end of surgery. Pain scores, opioid demand and length of stay in the postanaesthesia care unit were assessed in a blinded manner. Results: Patients receiving intraoperative fentanyl with saline had significantly lower visual analogue scale pain scores in the postanaesthesia care unit compared with those receiving intraoperative remifentanil with saline (55 ± 10 mm vs. 80 ± 18 mm, P < 0.05) and they stayed shorter in the postanaesthesia care unit (86 ± 24 min vs. 126 ± 37 min). In conjunction with intraoperative fentanyl, ketoprofen significantly decreased postoperative pain scores (40 ± 10 mm, P < 0.05 compared with fentanyl alone) and opioid demand (4 of 30 patients vs. 14 of 30 patients compared with fentanyl alone, P < 0.05). Patients receiving intraoperative remifentanil had no additional analgesic benefit with ketoprofen. Conclusion: After thyroid surgery, patients receiving intraoperative fentanyl had lower pain scores and needed less rescue analgesia compared with patients receiving intraoperative remifentanil. The adjunction of ketoprofen further improved analgesia in patients who received intraoperative fentanyl only.

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: 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 objective: Following the discovery of the feasibility of assessing the adequacy of the splanchnic perfusion by means of gastrotonometry, this technique became extensively used in clinical practice and in research. At present, high-technology instruments are available for the purpose. However, there is still a need for a simple, cheap tool that is easily applicable for patients of all ages. The present article describes such a tool and presents the results of in vitro and in vivo validation measurements with it. Methods: Balloon-free tonometric probes consisting of silicone rubber tubes were developed. In vitro measurements of the uptake of CO2 inside the probes and for comparison in a conventional ballooned intestinal tonometer were made in a closed container maintained at 37°C. In in vivo studies in anaesthetized dogs, the tonometric PCO2 values were determined with a tonometric probe and catheter introduced simultaneously into the ileum of the animals and the results were analysed by the Bland–Altman method. Results: The in vitro equilibration studies revealed that the filling media inside the probes equilibrated rapidly with the PCO2 content of the chamber. The data obtained from the in vivo investigations with the two different methods demonstrated a statistically significant linear association (correlation coefficient: 0.778, significance: P < 0.001). Conclusion: The new simple tonometric probe described appears to be a reliable tool with certain advantages for gastric tonometry. However, further studies are warranted before its general clinical use.

Summary

Background and objective: We have compared the effects of gabapentin on arterial pressure and heart rate at induction of anaesthesia and tracheal intubation in a randomized double-blind study. Methods: Ninety normotensive patients (ASA I) undergoing elective surgery were divided into three groups of 30 patients each. Patients received oral placebo (Group I), 400 mg of gabapentin (Group II) or 800 mg of gabapentin (Group III) 1 h prior to surgery in the operating theatre. After induction of anaesthesia heart rate and mean arterial pressure were recorded at baseline 1, 3, 5, 10 and 15 min after intubation. Results: Patients receiving placebo and 400 mg gabapentin showed a significant increase in blood pressure and heart rate associated with tracheal intubation compared to baseline levels and Group III. There was significant decrease in heart rate and arterial pressure in Group III after intubation 1, 3, 5 and 10 min (P < 0.001, P < 0.001, P < 0.05 and P < 0.05, respectively) compared to Groups I and II. Conclusion: Given 1 h before operation gabapentin 800 mg blunted the arterial pressure and heart rate increase in first 10 min due to endotracheal intubation. Oral administration of gabapentin 800 mg before induction of anaesthesia is a simple and practical method for attenuating pressor response to laryngoscopy and tracheal intubation after standard elective induction.

Summary

Background: Short-acting agents for neuromuscular block (NMB) require frequent dosing adjustments for individual patient's needs. In this study, we verified a new closed-loop controller for mivacurium dosing in clinical trials. Methods: Fifteen patients were studied. T1% measured with electromyography was used as input signal for the model-based controller. After induction of propofol/opiate anaesthesia, stabilization of baseline electromyography signal was awaited and a bolus of 0.3 mg kg−1 mivacurium was then administered to facilitate endotracheal intubation. Closed-loop infusion was started thereafter, targeting a neuromuscular block of 90%. Setpoint deviation, the number of manual interventions and surgeon's complaints were recorded. Drug use and its variability between and within patients were evaluated. Results: Median time of closed-loop control for the 11 patients included in the data processing was 135 [89–336] min (median [range]). Four patients had to be excluded because of sensor problems. Mean absolute deviation from setpoint was 1.8 ± 0.9 T1%. Neither manual interventions nor complaints from the surgeons were recorded. Mean necessary mivacurium infusion rate was 7.0 ± 2.2 μg kg−1 min−1. Intrapatient variability of mean infusion rates over 30-min interval showed high differences up to a factor of 1.8 between highest and lowest requirement in the same patient. Conclusions: Neuromuscular block can precisely be controlled with mivacurium using our model-based controller. The amount of mivacurium needed to maintain T1% at defined constant levels differed largely between and within patients. Closed-loop control seems therefore advantageous to automatically maintain neuromuscular block at constant levels.

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

Objective: Intensive insulin therapy reduced mortality in patients admitted to an intensive care unit following mainly cardiac surgery. The aim of this prospective study was to evaluate, if intensive insulin therapy could reduce mortality in medical and non-cardiac surgical patients admitted to a multidisciplinary intensive care unit. Patients and methods: For 6 months all adult patients, admitted to the intensive care unit, were included. Insulin was administered, if blood glucose 12 mmol L−1. For the next 6 months blood glucose level was reduced with intensive insulin therapy (aim 4.4 < BG < 6.1 mmol L−1); 271 patients were included. Patient characteristics data, APACHE II score, morbidity and mortality were recorded. Results: At admission the two groups were comparable. The overall relative mortality was reduced 20% in the intensive insulin treated group (n.s.). In the intensive insulin treated group mortality was 13.1% in the medical patients and 11.2% in the surgical patients compared to 15.8% and 14.4%, respectively, in the conventional treated group (n.s.). The frequency of secondary infections was 21.5% in the intensive insulin treated group and 16.0% in the conventional treated group (n.s.). The proportion of hypoglycaemia increased from 4% to 14% (P < 0.05). Conclusions: Following intensive insulin therapy there was a trend towards reduced mortality in medical and non-cardiac surgical patients but less pronounced as in cardiac surgical patients. Intensive insulin therapy increased the frequency of hypoglycaemia. Around 4400 patients would have to be included in any future randomized study to reach significance.