Summary

The treatment of critically ill patients has advanced markedly over the last decade. However, non-surgical bleeding of a diffuse nature from numerous tiny capillaries still remains a challenge. Once initiated, this type of bleeding may be troublesome and a vicious circle develops since it is not a single vessel contributing to this blood loss. The description ‘non-surgical blood loss’ is often given to this. This review describes a step-by-step approach for the treatment of non-surgical bleeding and includes various measures, such as desmopressin, blood components, antifibrinolytics, antithrombin III, prothrombin complex concentrates and factor XIII. While most non-surgical bleedings can be managed using the approach described here, a number of patients still continue to bleed. In these cases, the surgeon should re-evaluate the bleeding in terms of its surgical origin. If this can positively be excluded and if all of measures described fail to reduce or stop the bleeding, further treatment of such uncontrolled bleeding remains symptomatic.

Summary

Background and objective: The advantages of albumin over less costly alternative fluids continue to be debated. Meta-analyses focusing on survival have been inconclusive, and other clinically relevant end-points have not been systematically addressed. We sought to determine whether albumin confers significant clinical benefit in acute illness compared with other fluid regimens.

Methods: Database searches (MEDLINE, EMBASE, Cochrane Library) and other methods were used to identify randomized controlled trials comparing albumin with crystalloid, artificial colloid, no albumin or lower-dose albumin. Major findings for all end-points were extracted and summarized. A quantitative meta-analysis was not attempted.

Results: Seventy-nine randomized trials with a total of 4755 patients were included. No significant treatment effects were detectable in 20/79 (25%) trials. In cardiac surgery, albumin administration resulted in lower fluid requirements, higher colloid oncotic pressure, reduced pulmonary oedema with respiratory impairment and greater haemodilution compared with crystalloid and hydroxyethylstarch increased postoperative bleeding. In non-cardiac surgery, fluid requirements, and pulmonary and intestinal oedema were decreased by albumin compared with crystalloid. In hypoalbuminaemia, higher doses of albumin reduced morbidity. In ascites, albumin reduced haemodynamic derangements, morbidity and length of stay and improved survival after spontaneous bacterial peritonitis. In sepsis, albumin decreased pulmonary oedema and respiratory dysfunction compared with crystalloid, while hydroxyethylstarch induced abnormalities of haemostasis. Complications were lowered by albumin compared with crystalloid in burn patients. Albumin-containing therapeutic regimens improved outcomes after brain injury.

Conclusions: Albumin can bestow benefit in diverse clinical settings. Further trials are warranted to delineate optimal fluid regimens, in particular indications.

Summary

Background and objective: It has recently been suggested that recruitment proceeds far above the lower inflection point of the elastic pressure–volume (Pel/V) curve of the respiratory system. Accordingly, the value of the lower inflection point as a guide to set the positive end-expiratory pressure (PEEP) has been challenged. Our aim was to evaluate the derecruitment induced by stepwise decreasing PEEP levels.

Methods: Seven consecutive sedated and paralysed patients with acute respiratory distress syndrome were studied. Multiple Pel/V curves of the respiratory system were recorded at PEEP levels progressively decreasing in steps of 3.75 cmH2O from +15 to zero according to the principles of the low flow inflation method.

Results: Multiple Pel/V curves shifted towards lower volumes at decreasing PEEP. Dynamic compliance was higher for Pel/V curves recorded from lower PEEP levels. A high correlation (r = 0.99) was found between dynamic compliance and PEEP. The lower inflection point was on average 9.2 cmH2O. However, the transition between the lower segment and the linear part of the Pel/V curve was in general smooth to the eye. The upper inflection point was on average 23.8 cmH2O. A high correlation (r = 0.98) between the upper inflection point and PEEP was found.

Conclusions: The lower inflection point is a poor indicator of alveolar closure. The evaluation of derecruitment induced by a stepwise reduction in PEEP seems to be more useful than individual titration of PEEP and tidal volume in patients with adult respiratory distress syndrome.

Summary

Background and objective: Previous studies have shown existence of inconsistent data concerning the use of auditory-evoked potential (AEP) and electroencephalogram (EEG) changes to measure the depth of anaesthesia in regimens involving the use of opioids. The present studies characterize the effects of fentanyl on those responses in rats.

Methods: The effects of a bolus of fentanyl (6–10 μg kg−1 intravenously) alone or following naloxone (100 μg kg−1 intravenously) were examined using brain responses in rats during light anaesthesia with either propofol (20–30 mg kg−1 h−1) or isoflurane (0.8%). Electrophysiological data were recorded using silver ball electrodes. The rats' tracheas were intubated and a femoral artery cannula was inserted to monitor blood pressure. Body temperature, respiratory and pulse rate, and pedal withdrawal data were also collected. Parameters measured before and following administration of naloxone and fentanyl or of fentanyl alone were compared using repeated-measures ANOVA.

Results: Fentanyl significantly increased the latency of the major peak from the AEP during propofol and isoflurane anaesthesia (F = 13.2 and 13.5, respectively; P < 0.05) and the amplitude differential between two waveform complexes, and the second differential index (F = 28.3 and 57.2, respectively; P < 0.01). The spectral edge frequency and median frequency from the EEG tended to increase. These effects were abolished by the prior administration of naloxone.

Conclusions: These excitatory effects were inconsistent with the classical concept of brain activity depression indicating a deepening of anaesthesia.

Summary

Background and objective: Previous studies have shown that L-type voltage-sensitive Ca2+ channel blocking agents increased and the L-type Ca2+ channel activator Bay K 8644 reduced the general anaesthetic potency in animals. As the bispectral index correlates with the depth of sedation, we examined whether L-type Ca2+ channel blocking agents affect the bispectral index.

Methods: Thirty hypertensive patients (systolic arterial pressure >160 mmHg) presenting for total intravenous anaesthesia with propofol, fentanyl and ketamine were recruited. Bispectral index monitoring was commenced directly the patients arrived in the operating theatre. All patients were given either nicardipine or diltiazem intravenously at the discretion of the anaesthesiologist in charge.

Results: Twenty-three and seven patients received nicardipine or diltiazem, respectively. The bispectral index level (mean (95% confidence interval)) did not change with either drug. In the nicardipine group, the bispectral index at 0, 5, 10 and 15 min was 55 (52–58), 55 (51–59), 55 (52–59) and 56 (53–59), respectively. In the diltiazem group, values were 59 (48–71), 60 (51–70), 61 (52–71) and 61 (50–72), respectively. Both L-type Ca2+ channel blocking agents significantly decreased arterial pressure.

Conclusions: Clinical doses of nicardipine and diltiazem do not alter the bispectral index during general anaesthesia.

Summary

Background and objective: Remifentanil has unique pharmacokinetics that might allow faster recovery after neurosurgery. We investigated the effects of a propofol/sufentanil versus a remifentanil/propofol regimen on the primary end-point tracheal extubation time.

Methods: In the Neurosurgery Department of a University Hospital, 36 patients awaiting craniotomy for supratentorial tumour resection were randomly assigned to one of two study groups. In the sufentanil/propofol group, anaesthesia was induced with 0.5 μg kg−1 sufentanil and 1–2 mg kg−1 propofol. Propofol infusion and boluses of sufentanil were administered for maintenance. In the remifentanil/propofol group, anaesthesia was started with an infusion of remifentanil (0.2–0.35 μg kg−1 min−1) and a bolus of propofol (1.5–2 mg kg−1). Patients received a propofol infusion and a remifentanil infusion for maintenance of anaesthesia. Recovery times were taken from cessation of the propofol infusion. In addition, data about self-reported nausea and vomiting, pain and analgesic requirements were collected.

Results: Patients in the remifentanil/propofol group were extubated earlier (mean times 6.4 (±SD 4.7) versus 14.3 (±9.2) min; P = 0.003). The two groups were similar with respect to postoperative nausea and vomiting, and patient-reported pain scores. Fifty per cent of the remifentanil/propofol patients and 88% of the sufentanil/propofol patients required no analgesics within 1 h after operation (P= 0.03).

Conclusions: The remifentanil/propofol regimen provided quicker recovery. The two regimens were similar in terms of postoperative nausea and vomiting and patient-reported pain scores, but patients in the remifentanil/propofol group required more analgesics within 1 h postoperatively.

Summary

Background and objective: The augmentation of the effect of neuromuscular blocking drugs with volatile anaesthetics is well documented, but the mechanism remains unclear. The pharmacological interaction and relative plasma concentrations of mivacurium isomers were investigated during either propofol- or isoflurane-maintained anaesthesia.

Methods: Forty-four patients were randomly assigned to one of two groups: isoflurane or propofol. All patients received an initial dose of mivacurium 0.1 mg kg−1. After recovery of the first twitch (T1) response measured by acceleromyography to 5%, a T1 depression of 90–99% was maintained by infusion. After a steady state was reached, blood samples were taken after 10 and 30 min for analysis of mivacurium isomers. Recovery times for T1 to 25/50/75/90% (TW25–90), train-of-four ratio 25/70% and recovery index (time TW25–75) were recorded after stop of infusion.

Results: In the isoflurane group, lower infusion rates were needed (3.0 ± 1.6 versus 3.6 ± 1.6 μg kg−1 min−1) and there was a slower recovery (significant for train-of-four ratio 70%: 21.9 versus 17.9 min). The plasma concentrations of mivacurium and its trans–trans isomer (in percentage of the total) were significantly higher in the isoflurane group (10 min: 52.6 versus 25.8%; 30 min: 49.6 versus 23.2%).

Conclusions: For mivacurium, the phenomenon of ‘potentiation’ of the effect of muscle relaxants by volatile anaesthetics could be due to an increase in the plasma concentration of the potent trans–trans isomer.

Summary

Background and objective: Levobupivacaine is the most recently introduced local anaesthetic into clinical practice. In a randomized double-blinded study, the onset, intraoperative tolerance, postoperative analgesic effect, motor blockade and any adverse reactions produced by levobupivacaine were compared with ropivacaine.

Methods: Sixty children, ASA I–II, 2–6 yr old, undergoing elective minor surgery, received a single caudal injection of 1 mL kg−1 of either levobupivacaine 0.25% or ropivacaine 0.25%. Caudal blocks were performed after induction of inhalation general anaesthesia using sevoflurane; anaesthesia was maintained via a laryngeal mask airway using a mixture of sevoflurane, oxygen and air.

Results: Onset time, intraoperative tolerance, postoperative analgesic effect and motor blockade were comparable between the two groups. The mean onset of the block was 8.2 ± 2.2 min for levobupivacaine and 8.5 ± 3.0 min for ropivacaine (P = 0.66). Additional analgesics during operation were not required in any of the children. No significant difference was found for mean time to requirement of additional analgesia with rectal acetaminophen (paracetamol) (302 ± 29 min for the levobupivacaine group and 230 ± 38 min for the ropivacaine group (P = 0.32)). During the first 4 h after placement of caudal block, the pain assessment score (according to the Children Hospital Eastern Ontario Pain Scale) was comparable for the two groups. No motor block was observed in any group on awakening, nor during the observation period.

Conclusions: We conclude that levobupivacaine 0.25% 1 mL kg−1 provides caudal block of comparable onset and duration, as produced by the same volume and concentration of ropivacaine.

Summary

Background and objective: In a randomized, placebo-controlled, double-blind trial, we compared the efficacy of oral dolasetron and ondansetron in preventing postoperative nausea and vomiting in children after various surgical operations.

Methods: Children were assigned randomly to one of three groups (each contained 50 children) to receive dolasetron 1.8 mg kg−1 or ondansetron 0.15 mg kg−1 orally, or a placebo. All children received methylene blue capsules (10 mg) orally as an indicator before the induction of anaesthesia. Postoperatively, contamination of the mouth and the endotracheal tube by methylene blue was recorded, and postoperative nausea and vomiting was recorded for 0–1, 1–24 and 0–24 h. Metoclopramide (0.1 mg kg−1) intravenously was used as the rescue antiemetic.

Results: In the 0–1 h period after operation, there were no differences between the groups. In the 1–24 h period, dolasetron was significantly better than placebo (nausea 8 versus 24%; vomiting 4 versus 20%; total nausea and vomiting scores 16 versus 48%). Over the 0–24 h period, both dolasetron and ondansetron were significantly better than placebo (nausea 16 versus 26 versus 40%), vomiting (8 versus 16 versus 30%), and total nausea and vomiting scores (32 versus 48 versus 78%). There were no significant differences between dolasetron and ondansetron. There was no important methylene blue contamination, and little use of rescue metoclopramide. There were no important adverse events.

Conclusions: Prophylactic oral dolasetron and ondansetron were effective in reducing postoperative nausea and vomiting in children.