Inverted left atrial appendage is an unusual complication associated with congenital cardiac surgery. Inversion of the left atrial appendage may occur during the surgical procedure or afterwards. The left atrial appendage may invert iatrogenically or as a result of the negative pressure during placement or removal of the left atrial vent or during deairing manoeuvres. This event can be life-threatening because of the mass effect of the atrial appendage within the left atrial cavity.

Summary

Background and objective: A randomized double-blind controlled trial was performed to determine if there was a difference in discomfort on injection between two preparations of propofol. A long-chain triglyceride preparation (LCT-propofol (Fresenius)) was compared against a medium- and long-chain triglyceride preparation (MCT/LCT-propofol (BBraun)). Methods: One hundred and twenty ASA I–II patients listed for elective procedures were consented and randomized to receive either induction agent. A standard rate of infusion was used for induction of anaesthesia and subjects were questioned about discomfort until contact was lost. Discomfort was recorded as none, mild, moderate or severe. Incidence of postoperative nausea and vomiting and anti-emetic requirements were recorded in the postanaesthetic care unit. Results: There was seen to be a 54% reduction in moderate/severe discomfort with MCT/LCT-propofol compared with LCT-propofol (P < 0.006). There was a 70% reduction in severe discomfort with MCT/LCT-propofol compared with LCT-propofol (P < 0.04). The term discomfort was used during the study because there is a wide array of unpleasant sensations felt by patients during propofol induction which are not always reported as pain. There was no significant difference in the incidence of postoperative nausea and vomiting or anti-emetic use between the two groups. Conclusions: There is a significant decrease in the incidence of discomfort with MCT/LCT-propofol compared with LCT-propofol. This difference is more marked in subjects reporting severe discomfort.

Summary

Background and objective: The purpose of this study was to compare the characteristics of epidural catheter insertion via the midline or the paramedian approach with regard to ease of catheter insertion, incidence of paraesthesias and efficacy of epidural block. In addition to the type of approach, the prognostic value of Patients characteristics variables with regard to the incidence of paraesthesias was assessed. Methods: Thirty patients scheduled for surgery under epidural anaesthesia were randomly assigned to one of two groups of 15 patients each. Epidural anaesthesia was performed via a midline or paramedian approach using loss of resistance to saline. Variables measured were: time needed to identify the epidural space, time needed for and ease of epidural catheter insertion and the incidence of paraesthesias. After completion of these observations, epidural anaesthesia was established with 150 mg ropivacaine 1%. Efficacy of the epidural block was assessed by the need for intraoperative analgesics and by the patient on a three-point scale (good/fair/poor). Results: Quality of sensory blockade was adequate in both groups. Catheter insertion was significantly faster using the paramedian approach. The difference between the two approaches with regard to the incidence of paraesthesias was not significant, however, there was a trend towards more paraesthesias in the midline group. In the multivariate analysis, type of approach was an independent significant predictor of paraesthesias and we found a trend towards a higher incidence of paraesthesias in female patients. Conclusions: Catheter insertion was faster in the paramedian group and we found a trend towards a higher incidence of paraesthesias with the midline approach.

Summary

Background and objectives: Increasing numbers of patients taking herbal medicine products are presenting for anaesthesia and surgery. Anaesthetists need to consider the perioperative implications of herbal medicines and should, therefore, have some knowledge of this subject. Methods: A postal questionnaire survey was sent to a random 5% of practising members of the Association of Anaesthetists of Great Britain and Ireland residing in the UK, to identify attitudes, practice and knowledge regarding herbal medicines. Results: From 341 questionnaires there were 221 replies, a 65% response rate. Ninety per cent stated that they seldom or never asked patients about herbal medicine usage, yet 65% felt that there could be potentially harmful effects of herbal medicines in the perioperative period. There was a very poor level of knowledge with respect to the current management of 10 well-known herbal medicines. However, 75% agreed that information about perioperative usage of herbal medicines is important, and 77% felt that herbal medicines should be in the undergraduate medical curriculum. Reading was the usual source of herbal medicine product information. Most (82%) felt their knowledge of herbal medicine products and the implications in patient care were inadequate. Conclusions: This sample of anaesthetists require education on herbal medicines. Suggestions for remedial action are given.

Summary

Background and objective: The timing of interscalene block in relation to general anaesthesia remains a controversial subject. We believe that the results of our study demonstrate that this block may be performed safely on anaesthetized patients, providing that certain conditions are met.

Methods: Five hundred and forty-eight cases of arthroscopic shoulder surgery were analysed retrospectively in order to identify the results of interscalene block performed after induction of general anaesthesia, but before the start of surgery. Patients were kept in hospital for 24 h and assessed before being discharged from the hospital and again in the period from 4 to 8 weeks after surgery. Duration of the block, quality of postoperative pain relief and neurological complications were recorded.

Results: Our study failed to reveal any permanent or long-term neurological complications attributable to interscalene block performed after induction of general anaesthesia.

Conclusion: It is our opinion that the primary factor for safe interscalene block is modification of the anaesthetic technique rather than the timing of regional block in relation to induction of general anaesthesia.

Summary

Background and objective: The mechanism underlying stable cuff pressure in the Brandt rediffusion endotracheal tube during anaesthesia with nitrous oxide is not fully understood. The present study assessed changes in gas concentrations in the cuff during and after nitrous oxide anaesthesia.

Methods: The pressure of an air-filled Brandt endotracheal tube cuff was measured; anaesthesia was maintained with nitrous oxide 67% and oxygen 33% for 6 h in the Continuous Group; oxygen was substituted for nitrous oxide after 3 h of nitrous oxide anaesthesia in the Discontinuous Group (n = 8 for each). In some other patients, the study was terminated at 90, 180, 270 and 360 min (n = 8 for each). Gas concentrations in the cuff were measured at the end of the study.

Results: Cuff pressures increased slightly during the first 180 min of anaesthesia (P < 0.001). Thereafter, the cuff pressure did not change significantly in the Control Group but decreased in the Discontinuous Group (P < 0.001); there was a significant difference between the two groups (P < 0.0001). Cuff pressure never exceeded 22 mmHg and there were no air leaks in either group during the 6 h anaesthesia. Nitrous oxide concentrations in the cuff were 11.3 ± 2.6% and 2.6 ± 0.8% in the Control Group and Discontinuous Groups, respectively; however, changes in carbon dioxide and oxygen concentrations in the cuff were within approximately 1%.

Conclusions: Small changes in the nitrous oxide concentration in the cuff contribute to a stable cuff pressure in the Brandt rediffusion system, but changes in carbon dioxide or oxygen concentrations have little effect.

Severe complications such as spinal epidural haematoma and an array of adverse neurological events leading to temporary or permanent disability have been ascribed to central neuraxial blocks. Infections (meningitis, abscesses), chemical injuries and very rarely cerebral ischaemia or haemorrhage, or both, have also been ascribed directly or indirectly to spinal and/or epidural anaesthesia. Some case reports, and very few retrospective studies, have focused their attention on the fact that central nerve blocks can cause, albeit rarely, permanent damage to the spinal cord or nerve roots, or both. The cause of this damage in many cases remains unclear. The attention of investigators and practitioners is focused both on understanding the causative mechanisms of such accidents and in identifying 'alarm events' that can arise during the administration of a central block, if any. We reviewed the international literature for the neurological complications of central neuraxial blocks to identify some events that, if they occurred during the block procedure, could be perceived as dangerous.

Background and objective: The epidural and subarachnoid spaces should be identified at the first attempt, since multiple punctures increase the risk of postdural puncture headache, epidural haematoma and neural trauma. The study aimed to describe the predictors of successful neuraxial blocks at the first attempt.

Methods: After institutional Review Board approval, 1481 patients undergoing spinal or epidural anaesthesia were prospectively enrolled. For each block we recorded: gender, age, height, weight, body habitus, anatomical landmarks (palpability of the spinous processes), spinal anatomy, patient positioning, premedication, needle type and gauge, approach, spinal level of the block, and the provider’s level of experience. Retrieval of cerebrospinal fluid or loss of resistance to saline or air identified the subarachnoid and epidural spaces, respectively. The outcome variable was the first attempt success or failure (whether or not the needle was correctly located with one skin puncture and produced adequate surgical anaesthesia). Backward stepwise logistic regression tested its association with the other variables.

Results: The first-attempt rate of success was 61.51%. Independent predictors (Odds ratio, 95% confidence limits) were the quality of anatomical landmarks (1.92 (1.57; 2.35)), the provider’s level of experience (1.24 (1.15; 1.33)) and the adequacy of patient positioning (3.84 (2.84; 5.19)).

Conclusions: The successful location of the subarachnoid or the epidural space at the first attempt is influenced by the quality of patients’ anatomical landmarks, the adequacy of patient positioning and the provider’s level of experience.

Patients receiving anticoagulants offer a challenge to anaesthesiologists. The issue of spinal haematoma following central neuraxial block in such patients is a contentious issue. Although rare, with an estimated incidence of <1 : 150 000 for epidural blocks and 1 : 220 000 for spinal anaesthetics in patients with normal coagulation status, this is an emergency situation with a potentially grave prognosis. The review presents cases of spinal haematomata that have occurred in the last 5 years, both spontaneously and after central neuraxial blockade. Of the 60 cases reported in the literature, 33% occurred following central neuraxial block and, of these, 55% were associated with concomitant use of anticoagulants. The pharmacology of the newer and older anticoagulants is also described. The variety of risk factors and diverse recommendations that have been described in these patients are reviewed.

Background and objective: Children are vulnerable to regurgitation with a relatively high incidence of aspiration during general anaesthesia which is attributed to the high intragastric pressure, a short oesophagus, an immature laryngeal reflex and incomplete lower oesophageal sphincter muscle function. Subcutaneous administration of epinephrine is generally used in surgery to decrease bleeding due to local vasoconstriction. The effect of epinephrine on the sphincter muscle tone was investigated during general anaesthesia in children.

Methods: Ten children scheduled for skin graft or plastic surgery of the ear were studied. A gastrointestinal pressure sensor was inserted nasally, and the intraluminal pressures of the lower oesophagus, lower oesophageal sphincter and stomach were monitored under sevoflurane, nitrous oxide anaesthesia. The effect of epinephrine on the lower oesophageal sphincter muscle tone was measured.

Results: The resting pressure of the lower oesophageal sphincter muscle tone significantly decreased from 4.56 ± 1.85 to 3.79 ± 1.11 kPa after 3 μg kg−1 epinephrine for 4 min. The barrier pressure is the difference between the lower oesophageal sphincter and intragastric pressure, and that decreased to 1.23 ± 1.17 kPa from the 2.07 ± 1.77 kPa resting level. The observations implied that epinephrine had a long-lasting relaxing effect on lower oesophageal sphincter muscle in children.

Conclusions: The observations may give some explanation about the mechanism of gastro-oesophageal reflux during general anaesthesia, especially in the participation of the adrenergic receptors.

Background and objective Epidermolysis bullosa is a rare, genetically determined disorder characterized by excessive susceptibility of the skin and mucosa to separate from the underlying tissues after mechanical trauma. Patients suffering from this disease may have multiple medical problems, but the risk of anaesthesia is attributed mainly to oropharyngeal involvement; airway management may be hazardous and preservation of mucosa and skin integrity problematical. There is a paucity of data in the literature concerning the perioperative management of children with epidermolysis bullosa. We present our experience of managing 54 general anaesthetics (and two local anaesthetics) over the past 20 years.

Methods The case notes of 16 children with epidermolysis bullosa were reviewed. The children underwent surgical procedures under local or general anaesthesia over a 20-year period.

Results Fifty-four general and two local anaesthetics were administered for 58 procedures in 10 children (mean age 12.6 years). Surgical procedures included oesophageal dilatation (24), insertion/revision of gastrostomy (16), dental procedures (10), hand surgery (2), skin biopsy (2) and others (4). Anaesthesia was induced by inhalation in 73.4% of patients and the airway was maintained with an endotracheal tube in 64.8%. Monitoring of anaesthesia was performed with pulse oximetry (89%), whereas electrocardiography and non-invasive blood pressure monitoring were used in 16.6% of cases each. The mean duration of anaesthesia was 64 min. Tracheal intubation was difficult in two of the five children who were intubated. Mucocutaneous blistering occurred in three children, otherwise there was no attributable morbidity.

Conclusion With maximal skin and mucous membrane protection, anaesthesia in children with epidermolysis bullosa may be undertaken with few sequelae.

Background and objective The main objective of this study was to assess mortality and morbidity after thoracic surgery in a medical centre, without resident chest surgeons and anaesthesiologists, and to determine specific risk factors.

Methods A prospective cohort study using a local database which includes patients’ clinical characteristics, results of preoperative investigations, surgical and anaesthesia data and all postoperative complications was undertaken. Two hundred and seventy-three consecutive patients undergoing thoracic surgery from 1992 to 1999 were studied. The referral chest medical centre was without resident thoracic surgeons or anaesthesiologists; postoperative care was led by local chest physicians according to standardized protocols and in close collaboration with university-based surgeons and anaesthesiologists.

Results The majority of patients had lung cancer (71%) and underwent resection of at least one lobe (62%). Thirty-day mortality rate was 2.2% and one or more complications occurred in 74 patients (27%). Three patients had to be transferred to a university hospital for further treatment. Univariate predictors of complications included age (> 70 years), history of smoking, body mass index, as well as the extent and duration of surgery. After multiple logistic regression analysis, smoking (current or past), prolonged surgery (>120 min) and major lung resection (pneumonectomy or bilobectomy) remained the only independent risk factors.

Conclusions Overall perioperative mortality and morbidity rates did not exceed those reported from large teaching hospitals. In selected patients, thoracic surgery can be safely performed in a specialized chest medical centre without on-site surgeons and anaesthesiologists.

Background and aim Compound A generation and accumulation in sevoflurane anaesthesia is dependent on fresh gas flow. We investigated the extent of generation of compound A.

Methods After Institutional Review Board approval and informed consent, patients with normal renal function were randomized to receive either sevoflurane (n = 33) or isoflurane (n = 43) minimal flow anaesthesia (0.5 L min−1) for at least 2 h under standardized conditions. Compound A concentrations were quantified and blood and urine samples were taken to assess renal involvement. Both groups were comparable.

Results No significant differences concerning blood chemistry and urine measurements were found. The maximum mean compound A concentration was observed 90 min after flow reduction being 40±9p.p.m. at a corresponding mean sevoflurane concentration of 2.1 ±0.5 vol%. Mean inspiratory compound A exposure was 102±l33p.p.mh−1.

Conclusion Compound A concentrations using 0.5 L min−1 fresh gas flow and a heated absorber were higher than previously published values using an inflow of 1 Lmin−1. Compound A exposure was similar to other clinical studies which did not show changes in renal and hepatic function.

We present a case of pulmonary embolism that occurred during the injection of lipiodol during transcatheter arterial chemoembolization under general anaesthesia. A 7-year-old child suffering from a large hepatoblastoma was admitted for arterial chemoembolization and carcinostatic administration. Pulmonary embolism due to lipiodol during arterial chemoembolization was evident by a sudden fall in oxyhaemoglobin saturation from 100 to 90%. This was associated with a spread of lipiodol into both lungs, particularly the middle lung zones and detected by chest fluoroscopy. Arterial blood gases returned to normal values 1 day later but pulmonary infiltration persisted for 7 days before final clearance. Pulmonary embolism caused by lipiodol during arterial chemoembolization is infrequent, but such a complication could prove fatal. Understanding the risk of pulmonary embolism in patients receiving lipiodol, during and after arterial chemoembolization, and late onset pulmonary injury is important and a close follow-up for several days after arterial chemoembolization is advisable.