Summary

Background and objective: To survey French anaesthetic practice regarding acid aspiration prophylaxis and compare it with an earlier survey.

Methods: A confidential questionnaire was sent to all 800 maternity units in France to assess three major topics: (a) drugs used for pharmacological prophylaxis; (b) regional anaesthesia for labour and Caesarean section and (c) techniques used for general anaesthesia and endotracheal intubation.

Results: Two-hundred-and-two units responded. Pharmacological prophylaxis was regularly used for labouring women in 78% of the responding units in 1998 (compared with 63% in 1988, P < 0.05). Antacid drug use before Caesarean section had increased from 75% in 1988 to 97% in 1998 (P < 0.05). General anaesthesia was used for Caesarean section by less than 2% of responding units (vs. 21% in 1988, P < 0.05). In contrast, there was little change in the use of endotracheal intubation for instrumental delivery (53% vs. 50%) or manual removal of the placenta (15% vs. 16%) between 1988 and 1998. The use of cricoid pressure increased significantly during the 10 yr period (50% vs. 88%, P < 0.05) and the technique was correctly described by 80% of the responding units (vs. 50%, P < 0.05). Similarly, the use of succinylcholine increased significantly from 25% (1988) to 47% (1998) (P < 0.05).

Conclusions: There was a significant overall improvement of French practice regarding acid aspiration prophylaxis in obstetrics. However, the complete prophylaxis strategy is still not used in every patient emphasizing the need for continuing medical education.

Summary

Background and objective: To compare the effects of remifentanil and fentanyl on intraocular pressure during the maintenance and recovery of anaesthesia in patients undergoing elective non-ophthalmic surgery.

Methods: Thirty-two patients (ASA I–II) were randomized into two groups to receive either a continuous infusion of remifentanil (0.25–0.5 μg kg−1 min−1, n = 16, Group R) or an intermittent bolus of fentanyl (2–5 μg kg−1, n = 16, Group F) during the maintenance of anaesthesia. For the induction of anaesthesia, Group R received remifentanil 1 μg kg−1 and Group F received fentanyl 2 μg kg−1; both groups then received propofol 2 mg kg−1 with vecuronium 0.1 mg kg−1. Anaesthesia in both groups was maintained with a continuous infusion of propofol 4–8 mg kg−1 h−1. Ventilation of the lungs was controlled to a constant end-tidal PCO2 of 4.7–5.4 kPa. Blood pressure, electrocardiography, heart rate and oxygen saturation were monitored throughout anaesthesia. Intraocular pressure was determined before surgery, during the maintenance of anaesthesia, 2 min after emergence and in the recovery room using a Perkins hand-held applanation tonometer by an ophthalmologist blinded to the anaesthetic technique.

Results: After induction of anaesthesia, a significant decrease in intraocular pressure in the remifentanil group from 13.6 ± 2.6 to 7.1 ± 3.1 mmHg (P < 0.001) and in the fentanyl group from 13.7 ± 2.2 to 9.7 ± 3.4 mmHg (P < 0.001) was observed and maintained during anaesthesia. Thirty minutes after the end of anaesthesia, intraocular pressure returned to baseline values in both groups (remifentanil: 13.9 ± 2.8 mmHg, P = 0.28; fentanyl: 13.6 ± 2.3 mmHg, P = 0.59). The intraocular pressure and haemodynamic variables did not differ significantly between the two groups (intraocular pressure, P = 0.7327; blood pressure, P = 0.1295; heart rate, P = 0.8601).

Conclusions: Remifentanil maintains intraocular pressure at an equally reduced level compared with fentanyl.

Summary

Background and objective: Little has been documented about the development of pain after ophthalmic surgery. This study was designed to assess the incidence and severity of postoperative pain following ophthalmic surgery, and to identify key factors independently associated with development of such pain.

Methods: In a prospective, observational cohort study, 500 patients undergoing elective ophthalmic surgery were examined by assessing numerical analogue scales and analgesic requirements.

Results: Depending on anatomical location of surgery, operations could be classified into creating ‘more severe’ or ‘less severe pain’. Patients undergoing posterior segment, corneal and muscle surgery exhibited the highest numerical analogue scale scores (risk ratio 4.5, 95% CI 3.01–6.79, P < 0.0001). Anterior segment surgery, which per se did not create much pain, resulted in significantly more pain when performed under general anaesthesia compared to regional anaesthesia (risk ratio 6.52, 95% CI 2.33–18.2, P < 0.0001). No other factors independently associated with an increased risk of developing serious postoperative pain could be identified.

Conclusions: Patients undergoing certain ophthalmic operations, especially if performed under general anaesthesia, are more likely to experience serious postoperative pain.

Summary

Background and objective: The randomized, patient- and observer-blinded study was performed in 120 patients undergoing ear, nose and throat surgery to test the hypothesis that intravenous anaesthesia with propofol–remifentanil when compared with a balanced anaesthesia technique using isoflurane–alfentanil improves the speed of recovery, minimizes postoperative side-effects and, thus, leads to an improved quality of recovery without increasing total costs.

Methods: The total costs for each anaesthesia technique were calculated considering drug acquisition costs, personnel costs for the additional time spent in the operating room and the postanaesthesia care unit until fast-tracking eligibility, and the costs to treat the side-effects during and after operation.

Results: The times from the end of surgery to tracheal extubation and the time until leaving the operating room were not different between the two groups. However, more patients receiving intravenous anaesthesia (80 versus 49%) were eligible for fast tracking and thus could bypass the recovery room. This was associated with an average cost saving of €6.00 per patient. However, intravenous anaesthesia was associated with higher total costs (€89 versus €78) mainly because of higher acquisition costs of the anaesthetics (€34.60 versus €16.50). There was no difference in the quality of recovery as measured by a Quality of Recovery score and patient satisfaction between the two groups.

Conclusions: The higher acquisition costs of the intravenous anaesthetics propofol and remifentanil cannot be compensated for by improved speed of recovery. This anaesthesia technique is more cost intensive than balanced anaesthesia using isoflurane and alfentanil.

Summary

Background and objective: The use of propofol compared with isoflurane is associated with improved patient comfort and decreased costs. However, as the cost saving, the quicker recovery time and patient comfort may not be evident if sevoflurane is substituted for isoflurane; these two anaesthetic agents were analysed in elderly patients.

Methods: In a prospective randomized study, 96 patients undergoing elective ophthalmic surgery received either total intravenous anaesthesia with propofol (Group P), propofol for induction and sevoflurane for maintenance (Group P/S) or sevoflurane for inhalation induction and maintenance (Group S). Analyses focussed on haemodynamics, the quality of recovery, and the costs for the anaesthetic and the entire procedure.

Results: Bradycardia or hypotension, mainly registered in Groups P and P/S, did not influence patients' recovery. In Group S, postoperative nausea and vomiting occurred frequently, and 50% of patients complained of discomfort during induction. In Group P/S, the costs for anaesthetics and total costs were lower than those in Groups P and S.

Conclusions: Propofol- and sevoflurane-based maintenance of anaesthesia were similar with regard to patient comfort and recovery in the elderly. Cost analysis revealed that it was less expensive to use propofol for induction and sevoflurane for maintenance than to use either propofol or sevoflurane as sole agents for anaesthesia.

Summary

Background and objective: Unanticipated difficulty in tracheal intubation in an anaesthetized patient has always been a cause of concern to anaesthesiologists. This difficulty may lead to morbidity and mortality. This survey was carried out to determine the technique commonly favoured in centres in the Oxford region in the UK for the management of unanticipated difficult intubation.

Methods: We conducted a clinical scenario-based questionnaire survey of 181 anaesthesiologists in the Oxford region. In this scenario, difficulty in endotracheal intubation is recognized only after induction of anaesthesia. A number of options were available to deal with this situation. We used this scenario as a tool to gain insight into the training and the training needs of anaesthesiologists at various levels of training.

Results: Of the 181 questionnaires sent, we received 143 (79%) completed replies. The vast majority (141/143 (99%)) of anaesthesiologists would use a gum-elastic bougie together with head and neck positioning and optimal external laryngeal manipulation to gain the best attempt at intubation. If intubation still failed, overall 129/143 (90%) had a back-up plan, while 14/143 (10%) had no plan. Flexible fibreoptic techniques were more commonly planned by 92/143 (64%) anaesthesiologists compared to blind techniques which were less commonly planned by 37/143 (26%) anaesthesiologists. Differences in choice of technique among anaesthesiologists in teaching and district general hospitals were not significant (P = 0.87). Overall, trainees were less likely to choose fibreoptic techniques compared to consultants (P = 0.0009) and would use blind techniques or ask a more experienced colleague to take over. The main reason for the choice was previous experience with the technique.

Conclusions: Although fibreoptic techniques were most commonly planned, these were less often chosen by trainees than consultants due to lack of experience/training, while unavailability of intubating laryngeal mask airway (Intavent®) was an additional issue precluding its use as an adjunct to intubation.

Summary

Background and objective: Adverse effects associated with difficult airway management can be catastrophic and include death, brain injury and myocardial injury. Closed-malpractice claims have shown prolonged and persistent attempts at endotracheal intubation to be the most common situation leading to disastrous respiratory events. To date, there has been no evaluation of the types of difficult airway equipment currently available in Irish departments of emergency medicine. The objective of this survey was to identify the difficult airway equipment available in Irish departments of emergency medicine.

Methods: Departments of emergency medicine in the Republic of Ireland with at least one dedicated Emergency Medicine consultant were surveyed via telephone.

Results: All of the departments contacted held at least one alternative device on site for both ventilation and intubation. The most common alternative ventilation device was the laryngeal mask airway (89%). The most common alternative intubating device was the surgical airway device (100%).

Conclusions: Irish departments of emergency medicine compare well with those in the UK and USA, when surveyed concerning difficult airway equipment. However, we believe that this situation could be further improved by training inexperienced healthcare providers in the use of the laryngeal mask airway and intubating laryngeal mask airway, by placing greater emphasis on the ready availability of capnography and by the increased use of portable difficult airway storage units.

Summary

Background and objective: Our hypothesis was that stroke volume variation during mechanical ventilation of the lungs would allow accurate prediction and monitoring of changes in cardiac index in response to fluid loading in patients with severe sepsis.

Methods: This was a prospective clinical study in a university hospital. Ten mechanically ventilated patients with severe sepsis or septic shock were given fluid loading with 500 mL 10% hydroxyethylstarch 200/0.5 over 30 min. Before and after fluid loading pulmonary arterial occlusion pressure and central venous pressure were measured. Intrathoracic blood volume index, stroke volume variation and cardiac index were measured by the transpulmonary thermodilution technique. After verifying normal distribution of the data (skewness <1.0) the paired t-test was used for statistical analysis.

Results: After fluid loading stroke volume variation decreased significantly, whereas central venous pressure, pulmonary arterial occlusion pressure, intrathoracic blood volume index and cardiac index increased significantly. Changes of cardiac index in response to fluid loading were correlated to baseline values of stroke volume variation (r = 0.64, P = 0.02) and intrathoracic blood volume index (r = −0.73, P = 0.009). Changes in cardiac index were significantly correlated to percentage changes in stroke volume variation (r = −0.65, P < 0.001) and changes in intrathoracic blood volume index (r = 0.52, P = 0.002), whereas changes in cardiac index revealed no significant correlation to changes in central venous pressure (r = 0.28, P = 0.07) and changes in pulmonary arterial occlusion pressure (r = 0.29, P = 0.06).

Conclusions: Measuring stroke volume variation may be a useful way of guiding fluid therapy in ventilated patients with severe sepsis because it allows estimation of preload and prediction of cardiac index changes in response to fluid loading.

Summary

Background and objective: Xenon reduces the infarct size after regional ischaemia in the rabbit heart in vivo, but the underlying mechanisms are unknown. Since adhesion molecules on neutrophils are closely involved in the pathophysiology of ischaemia/reperfusion injury and modulation of neutrophil function, we investigated the effect of xenon on neutrophil adhesion molecule expression in vitro.

Methods: Freshly isolated neutrophils were incubated with 30% or 60% xenon for 60 min. In unstimulated and after stimulation with either N-formyl-methionyl-leucyl-phenylalanine or phorbol-12-myristate-13-acetate neutrophil surface expression of PSGL-1, L-selectin, CD11a and CD11b were measured by flow cytometry.

Results: At both concentrations, xenon reduced the surface expression of PSGL-1 by 10% (P < 0.05), and of L-selectin by 15% (P < 0.05) in the 60% xenon group. Furthermore, N-formyl-methionyl-leucyl-phenylalanine activated neutrophils showed an increased removal of L-selectin from the neutrophil surface following incubation with xenon (30% compared to controls, P < 0.05). Neutrophil β2-integrin expression was not altered by xenon.

Conclusions: Xenon increases the removal of the selectins PSGL-1 and L-selectin from the neutrophil surface in vitro. Since both selectins are involved in the initial contact between neutrophils and endothelial cells, xenon may affect neutrophil adhesion to endothelium during ischaemia/reperfusion injury. However, because the β2-integrin expression was unaffected by xenon, further investigations are required to clarify whether xenon may modulate neutrophil transmigration through endothelial cells in vivo.

Summary

Background and objective: Isoflurane is a chiral volatile anaesthetic, routinely administered as racemate. It has a low metabolic rate and is mostly eliminated via respiration. In blood samples, S(+) enantiomers are found in greater proportion in the days immediately after administration of isoflurane racemate whereas the ratio in breath samples is unknown.

Methods: Breath and blood samples were drawn immediately after recovery and daily up to 19 days after operation from patients undergoing anaesthesia with isoflurane racemate. The percentage of isoflurane enantiomer was determined by gas chromatography mass spectrometry in blood and thermodesorption gas chromatography mass spectrometry in breath samples.

Results: In breath samples, there were significant differences in S(+) enantiomers at all time points compared to the racemate. During the early postoperative phase, the percentage of S(+) enantiomers were significantly enhanced whereas 5 days after surgery predominantly R(−) enantiomers (50.41%) were detected in the breath samples. Also in blood samples a statistical significant accumulation of the S(+) enantiomer was noted between days 1 and 5 compared to isoflurane racemate blood control. S(+) enantiomers were significantly higher in blood compared to breath samples and was most evident on the third day after surgery (51.43%).

Conclusions: During the first days after application of isoflurane racemate, the percentage of S(+) enantiomers are higher in breath and blood samples of patients. We suggest that resorbtion and/or redistribution of enantiomers are responsible for the different kinetics of isoflurane enantiomers.

Summary

Background and objective: To analyse the use of standardized application of ryanodine for in vitro muscle contracture testing to define cut-off values separating malignant hyperthermia susceptible from malignant hyperthermia negative subjects. Furthermore, we compared the results of in vitro muscle-contracture tests following the halothane, caffeine and ryanodine challenges.

Methods: In 113 subjects, halothane, caffeine and ryanodine muscle-contracture tests were performed according to the protocol of the European Malignant Hyperthermia Group.

Results: Malignant hyperthermia susceptible subjects (n = 77) had significantly shorter onset times in the ryanodine in vitro muscle-contracture test (1 μmol ryanodine) compared with malignant hyperthermia negative subjects (n = 36), median 4.8 vs. 20.1 min, respectively, without any influence of age or gender. The best cut-off value was 10 min (sensitivity 0.78 and specificity 0.94, respectively). Shorter cut-off values had greater specificity, but lower sensitivity. Groups could not be separated without an overlap. In susceptible subjects, we found a correlation between onset time and threshold concentrations for halothane and caffeine (ρ = 0.47 and 0.52, respectively). In addition, muscle bundles with high susceptibility to halothane and caffeine also showed high susceptibility to ryanodine.

Conclusions: The ryanodine in vitro muscle-contracture test confirmed the malignant hyperthermia status that was determined using the halothane and caffeine in vitro muscle-contracture tests. Due to an overlap between the two groups, discrimination ability was not always perfect and short cut-off values with higher specificity had reduced sensitivity and vice versa. The correlation of contractures following the halothane, caffeine and ryanodine challenges points towards a similar individual pharmacogenetic effect rather than a specific, different pharmacological action between the three agents.