Summary

Background and objectives: Postoperative confusion and delirium is a common complication in the elderly with a poorly understood pathophysiology. The aim of this study was to examine whether the type of anaesthesia (general or regional) plays a role in the development of cognitive impairment in elderly patients during the immediate postoperative period. Methods: Forty-seven patients >60 yr of age and undergoing major surgery were randomly allocated to receive either regional or general anaesthesia. The mental status of the patients was assessed preoperatively and during the first three postoperative days with the Mini Mental State Examination. The incidence of delirium was also examined during the same period with the use of DSM III criteria. Results: Overall, during the first three postoperative days, the mean Mini Mental State Examination score decreased significantly (P < 0.001). However, this decline was very significant only in patients assigned to receive general anaesthesia (P < 0.001) compared to regional anaesthesia. Nine patients developed delirium but the type of anaesthesia did not affect its incidence. The only important factor for the development of delirium was pre-existing cardiovascular disease irrespective of anaesthesia type (P < 0.025). Conclusions: Elderly patients subjected to general anaesthesia displayed more frequent cognitive impairment during the immediate postoperative period in comparison to those who received a regional technique.

Summary

Background and objective: To compare the onset of action, and quality of block, of lidocaine 2% with levobupivacaine 0.75% for sub-Tenon's block in patients undergoing cataract surgery. Methods: We performed a two-centre trial in 91 patients who were randomized to receive 4 mL of lidocaine 2% (n = 44) or levobupivacaine 0.75% (n = 47) for sub-Tenon's block, both with hyaluronidase 15 IU mL−1. Onset of akinesia was assessed every 2 min for 10 min. Numbers of patients requiring supplementary injections to achieve clinically satisfactory akinesia or rescue analgesia were recorded. Data were analyzed with Fisher's exact test, U-test and t-test where appropriate. Results were considered significant when P < 0.05. Results: The speed of onset was statistically significantly faster for lidocaine compared to levobupivacaine (3.02 vs. 5.06 min, P < 0.001). There was no statistical difference in number of patients requiring a supplementary injection of local anaesthetic (levobupivacaine 3 vs. lidocaine 0, P = 0.24), rescue analgesia with topical tetracaine (levobupivacaine 0 vs. lidocaine 2, P = 0.5), or ocular akinesia scores at the completion of surgery (lidocaine 1.4 vs. levobupivacaine 1.6, P = 0.12). Pain scores measured by a verbal analogue scale were not significantly different for injection, perioperatively or postoperatively. Conclusions: Both agents produce a rapid onset of anaesthesia when used for sub-Tenon's block. The difference between the two agents, although statistically significant, is not clinically important.

Summary

Background and objective: Patients undergoing total abdominal hysterectomy under general anaesthesia have a high risk of developing postoperative nausea and vomiting (PONV). The aim of this study was to evaluate the incidence of PONV in patients undergoing total abdominal hysterectomy under spinal anaesthesia with intravenous patient-controlled analgesia (PCA) using morphine and to compare its incidence with and without antiemetic prophylaxis. Methods: Thirty-four patients undergoing total abdominal hysterectomy under spinal anaesthesia with i.v. PCA morphine postoperatively were divided into two groups. The first (n = 17) received ondansetron prophylaxis near the end of surgery while the second (n = 17) received no prophylaxis. Morphine consumption, emetic episodes (on a 3-point scale), patient satisfaction (visual analogue score), sedation and pruritus were evaluated 2, 4, 6, 9, 12, 18 and 24 h postoperatively. Results: Patient characteristics, postoperative morphine consumption (43.3 ± 7.6 vs. 40.3 ± 12.3 mg) and peristaltic recovery time (16.9 ± 5 vs. 18.4 ± 5.2 h) were similar in both groups. Overall nausea and vomiting were significantly lower in the ondansetron prophylaxis group than in the group without prophylaxis (52.9% vs. 88.2%, P < 0.05). Though nausea alone was higher in the prophylaxis group (41.2% vs. 29.4%), nausea with vomiting was significantly lower in the prophylaxis group (11.8% vs. 58.8%, P < 0.01). Patients' satisfaction scores were higher in the ondansetron group at all times and the difference was significant (P < 0.05) 4 h postoperatively. Conclusions: The incidence of PONV in patients undergoing total abdominal hysterectomy under spinal anaesthesia with i.v. PCA morphine is very high (88.2%). Antiemetic prophylaxis with ondansetron is highly recommended in this patients group resulting in a lower incidence of nausea and vomiting, and significantly improves patient' satisfaction and life quality in the early postoperative period.

Summary

Objective: This retrospective study aims to describe the airway management and benefits of nasotracheal intubation over tracheostomy in 260 patients with oral cancer undergoing surgery. Methods and Results: The medical records of 260 patients undergoing surgery for oral cancer were reviewed for airway management during the perioperative period. Eighteen patients had previous surgery for oral cancer and were scheduled for flap reconstruction, recurrence or other complications. In 28 cases neck movement was restricted and decreased mouth opening was found in 50% of all patients because of a large growth or fixation of tissues of head and neck, oral cavity, pharynx or larynx by tumour, or radiation fibrosis. In 53 patients intubation was undertaken under spontaneous ventilation. In 20 cases the trachea was extubated in the immediate postoperative period. In 220 cases patients were extubated next morning in the intensive care unit. In none of the cases was elective tracheostomy under local anaesthesia performed before surgery for the maintenance of the airway for anaesthesia. Elective tracheostomies were done in 17 cases. Three patients remained intubated for 24–48 h because of a high suspicion of airway obstruction following extubation due to a large pectoralis major flap. These three patients received a tracheostomy because of increased oropharyngeal and laryngeal oedema. In three cases emergency tracheostomies were performed due to upper airway obstruction after extubation and in one case prolonged elective ventilation was required due to severe chest infection. Conclusion: Oral cancer patients have a potentially difficult airway but, if managed properly during perioperative period, morbidity and mortality can be reduced or avoided. Oral cancer patients can be managed safely without the routine use of a tracheostomy. Nasotracheal intubation is a safe alternative to tracheostomy in oral cancer patients except in some selected patients.

Summary

Introduction: We tested the hypothesis that repeated autoclaving removes protein deposits from the classic laryngeal mask airway (LMA). Methods: Twenty previously used LMAs were hand washed, machine washed, dried, autoclaved and randomly allocated into four equal-sized groups for repeat autoclaving on 0 (control), 1, 2 and 3 occasions. After the final autoclave cycle, the LMAs were immersed in a protein-staining solution, rinsed, dried and a high-resolution digital image taken of the dorsal and ventral surfaces. The severity of staining was scored by two blinded observers. Results: All LMAs were stained. There was no reduction in staining with repeat autoclaving. Conclusions: Repeat autoclaving does not remove protein deposits from the LMA.

Summary

Background and objectives: To compare the analgesic effects of intrathecal fentanyl and low-dose intravenous ketamine as adjuvants to intrathecal bupivacaine for Caesarean section. Methods: Ninety elective Caesarean section patients were randomized into three groups. Spinal anaesthesia was performed with 15 mg hyperbaric bupivacaine in all groups. Ketamine (0.15 mg kg−1) or an equal volume of normal saline was given intravenously immediately after initiating spinal anaesthesia in the ketamine and control group, respectively. In the fentanyl group, 10 μg fentanyl was added to the intrathecal bupivacaine. Arterial pressures, heart rate values, adverse effects, the time of first request for postoperative analgesia, visual analogue pain scores, total analgesic consumptions at 24 and 48 h were recorded in all patients. Results: The time to first request for analgesia was significantly longer in the ketamine (197 min) and fentanyl (165 min) groups compared to the control group (144 min). Postoperative pain scores were significantly lower in the ketamine group than in both other groups. Although the analgesic requirements during first 24 h were significantly lower in the ketamine group, there was no significant difference between the groups during the following 24 h. Conclusion: Intravenous low-dose ketamine combined with intrathecal bupivacaine for Caesarean section provides longer postoperative analgesia and lower postoperative analgesic consumption than bupivacaine alone suggesting a pre-emptive effect.

Summary

Background and objective: Even moderate hyperglycaemia increases mortality/morbidity after coronary artery bypass grafting, stroke and myocardial infarction. The goal of this prospective study was to determine if using thoracic epidural analgesia from start of surgery until the end of the third postoperative day would blunt postoperative hyperglycaemia. Methods: Forty-four patients had diabetes mellitus, 60 did not; half of each group had an epidural with continuous local anaesthetics. All patients received continuous insulin infusions during the initial 24 h period beginning with surgery. Blood glucose was measured four times daily (fasting or 2–3 h post-prandial) until end of the third postoperative day. Results: For patients without diabetes, the epidural group had lower mean blood glucose and insulin requirements (P < 0.02) than controls during the initial 24 h period beginning with surgery. For patients with diabetes mellitus, thoracic epidural analgesia reduced mean blood glucose (P = 0.017) with unchanged insulin requirements. Epidural did not diminish the increase (vs. preoperative) in fasting blood glucose on the third postoperative day (32% vs. 22%, P < 0.001) for non-diabetics. Epidural analgesia was not able to attenuate hyperglycaemia during the first 3 postoperative days. Conclusions: Epidural analgesia improved glucose homeostasis minimally during the initial 24 postoperative hours but did not attenuate hyperglycaemia during the subsequent 3 postoperative days.

Summary

Background and objective: Non-depolarizing neuromuscular blocking agents have differential effects on the diaphragm and skeletal muscles. We employed a new method to study the effects of mivacurium on the diaphragm and compared the results obtained with this method with published data. Methods: Anaesthesia was induced and maintained with propofol and alfentanil and the trachea was intubated after topical anaesthesia. Contractions of the diaphragm were induced by cervical magnetic stimulation of the phrenic nerves and quantified by measuring airway pressure responses. The neuromuscular effects on skeletal muscles were measured by acceleromyography of the adductor pollicis muscle. Mivacurium (0.15 mg kg−1) was injected and neuromuscular responses were recorded until the effects had waned. Results: Eleven male and 10 female patients (ASA I–II; 57 ± 16 yr; 78 ± 13 kg; mean ± standard deviation) participated. Median maximal reduction of twitch response was less (P < 0.05) for the diaphragm (89%) than for the adductor pollicis (100%). Time to 25% recovery was shorter for the diaphragm than for the adductor pollicis (8.8 ± 2.2 min vs. 22.6 ± 5.0 min, P < 0.05). The difference between the recovery index of the diaphragm (7.3 min (3.6–18.4)) and the adductor pollicis (8.2 min (4.4–20.9) (median (range)) just missed our chosen level of statistical significance (P = 0.06). The recovery time to train-of-four 0.8 was shorter for the diaphragm (median and 95% confidence interval 25.1 ± 10.2 min) than for the adductor pollicis (median and 95% confidence interval 37.5 ± 9.4 min, P < 0.05). Conclusions: The duration of the clinical effect of mivacurium on the diaphragm is markedly shorter than on the adductor pollicis muscles but there was only a small difference in the recovery index of the two muscles. These effects and the time courses determined with the new method closely resemble the results obtained with different methods in other studies.

Summary

Background and objectives: Salt-water aspiration results in pulmonary oedema and hypoxia. We tested the hypothesis that partial liquid ventilation has beneficial effects on gas exchange and rate of survival in acute and extended salt water-induced lung injury. Methods: Anaesthetized, ventilated rats (tidal volume 6 mL kg−1, PEEP 5 cmH2O) received a tracheal salt-water instillation (3%, 8 mL kg−1 body weight) and were randomly assigned to three groups (n = 10 per group). While lungs of Group 1 were gas-ventilated, lungs of Group 2 received a single perfluorocarbon instillation (30 min after the injury, 5 mL kg−1 perfluorocarbon) and lungs of Group 3 received an additional continuous perfluorocarbon application into the treachea (5 mL kg−1 h−1). Arterial blood gases were measured with an intravascular blood gas sensor. Results: Salt-water instillation resulted in a marked decrease in PaO2 values within 30 min (from 432 ± 65 to 83 ± 40 mmHg, FiO2 = 1.0, P < 0.01). Arterial oxygenation improved in all three groups irrespective of treatment. We observed no significant differences between groups in peak PaO2 and PaCO2 values. Conclusions: Our results suggest that partial liquid ventilation has no additional beneficial effects on gas exchange after life-threatening salt water-induced lung injury when compared to conventional gas ventilation with positive end-expiratory pressure.

Summary

Background and objective: The aim of this study was to evaluate the value of terminal complement complex (C5b-9) plasma levels as a marker for complement activation in septic shock with concomitant capillary leak syndrome. Methods: In a prospective animal study 10 fasted, anaesthetized, mechanically ventilated and multi-catheterized pigs (20.6 ± 1.3 kg) were investigated over a period of 8 h. Sepsis was induced by faecal peritonitis (1 g kg−1 body weight faeces, n = 5) and compared to controls (n = 5). The animals received 6% hydroxyethyl starch 200/0.5 to maintain a central venous pressure of 12 mmHg. To quantify capillary leak syndrome, albumin escape rate was measured using 99mTc-labelled human serum albumin. Plasma levels of terminal complement complex were measured in a double antibody immunoassay (neoepitope-specific MoAb aE11 as catching antibody). Immunohistological studies of renal specimens were performed to detect terminal complement complex deposition. Results: Albumen escape rate increased in septic animals (+52%) compared to controls (+3%, P < 0.05). Plasma levels of terminal complement complex decreased during the study period in both groups. In septic animals this finding was accompanied by a significant deposition of terminal complement complex in renal specimens (P < 0.05). Conclusion: We found an activation of the complement system proven by marked deposition of terminal complement complex in renal specimen, while its plasma levels decreased during the study period in septic and control animals. These results suggest that in septic shock with capillary leak syndrome plasma level of terminal complement complex may not be a reliable marker of complement activation.