Assessment of tracheal intubation in children after induction with propofol and different doses of remifentanil

Tracheal intubating conditions were assessed in 112 children after induction of anaesthesia with propofol and remifentanil 1.0, 2.0 or 3.0 micro g.kg-1. Subjects in a control group were given propofol and mivacurium 0.2 mg.kg-1. Haemodynamic and respiratory parameters were recorded. Plasma catecholamine levels were measured in a subgroup of 40 children. Intubating conditions were acceptable in 14/28 (50%), 18/26 (69%) and 22/27 (82%) in those subjects given remifentanil 1.0, 2.0 or 3.0 micro g.kg-1, respectively, and in 27/28 (96%) of the control group. Intubating conditions in subjects given remifentanil 3.0 micro g.kg-1 were better than in those given remifentanil 1.0 micro g.kg-1 (p < 0.05). There were no significant differences in intubating conditions between those given remifentanil 3.0 micro g.kg-1 and the control group. Systolic blood pressure and heart rate increased in response to tracheal intubation in subjects given remifentanil 1.0 micro g.kg-1 and in the control group (p < 0.05). Time to resumption of spontaneous respiration was prolonged in subjects given remifentanil 3.0 micro g.kg-1 (p < 0.001). In conclusion, remifentanil 2 micro g.kg-1 provides acceptable intubating conditions and haemodynamic stability without prolonging the return of spontaneous respiration.     

Effect of head posture on tracheal tube position in children

Changes in the tracheal tube tip to carina distance were measured by radiographic screening following various head postures in 45 children undergoing cardiac catheterisation under general anaesthesia who were intubated via nasal and oral routes. Extension of the head moved the tracheal tube away from the carina and flexion moved it towards the carina in both routes. Endobronchial intubation was noted during neck flexion in a significant proportion of children intubated orally but none occurred during nasal intubation. Extension produced greater upward movement of the tracheal tube tip in the oral route than the nasal route. In contrast, flexion produced greater downward movement in the nasal route in some patients. The direction of movement with lateral rotation and use of a shoulder roll was inconsistent.     

Watson and Crick 50 years on. From double helix to pharmacogenomics

The second half of the 20th century has seen quantum leaps in our understanding of molecular biology. The technological advances, which facilitated the recent successful completion of the Human Genome Project, have provided the tools for deciphering the complexity of the human condition. At present, the function of only 50% of genes is known. However, as understanding of the human genome improves, a plethora of gene targets for treating disease will be uncovered - leading to therapies which will be considered revolutionary. Genome related science has begun to impact almost every facet of medicine including anaesthesia and intensive care. Better understanding of interindividual differences will enable better prediction of illness susceptibility as well as response to treatment. These insights will permit therapies to be tailored to individuals or racial groups. At present, there is only rudimentary knowledge of factors controlling gene regulation, but in the future, better understanding of gene-environment interactions and gene expression will enable pharmaceutical companies to develop new therapies and permit clinicians to optimise their effects, without recourse to current laborious testing regimens. As genomic science progresses, new ethical, legal, social and philosophical dilemmas will also continue to emerge.     

Prevention of postoperative sore throat using capsicum plaster applied at the Korean hand acupuncture point

In a randomised, double-blind, sham-controlled study, we compared the efficacy of capsicum plaster (PAS) applied at the Korean hand acupuncture point for the prevention of postoperative sore throat in 150 patients scheduled to undergo abdominal hysterectomy. The K group had PAS applied at the K-A20 of both hands and placebo tape at both non-acupoints. The PAS was applied prior to induction of anaesthesia and removed 8 h postoperatively. The sore throat scores of Group K were significantly lower than those of other groups at 24 h following surgery (p = 0.00027). The prevalence of moderate to severe sore throat at 24 h was lower for Group K (0%) than for sham and placebo controls (16%[p = 0.038] and 19%[p = 0.032], respectively). There were no differences in the recovery room of the sore throat scores for all groups. We found that the PAS applied at the K-A20 was an alternative method for reducing postoperative sore throat.     

Dead space and paediatric anaesthetic equipment: a physical lung model study

Untested assumptions have been made with regard to functional dead space in facemasks, filters and breathing systems used in children for the administration of inhalation anaesthesia. Total functional dead space was measured in various combinations of this equipment applied to a spontaneous ventilation lung model with parameter settings appropriate for infants of 7-8 kg. We found that functional dead space was too large to allow for spontaneous ventilation of the lungs when a breathing filter was fitted. There was minimal relationship between size of the facemask and functional dead space; however, the provision of 22-mm female inlets to facemasks achieved proportionately less functional dead space than with 15-mm male inlets. Regardless of the apparatus used and the magnitude of the dead space, the leak induced when a poorly fitting facemask was used dramatically reduced the dead space of the breathing system - to near optimal conditions - by moving the alveolar gas elimination point to within the facemask itself.     

The short, tragic life of Robert M. Glover

Robert Mortimer Glover (1815-1859) was a contemporary of John Snow and James Young Simpson. Although he did not reach the standing of those two giants, his researches, writings and lectures were important contributions to the early development of British anaesthesia. Glover was the first to explore the physiological action of chloroform in the laboratory and to discover its anaesthetic effect in 1842. He helped Sir John Fife in Hannah Greener's autopsy in January 1848 and influenced Fife's conclusions on the cause of the young girl's death. His numerous and extensive articles reviewing the history, chemistry, pharmacology and clinical applications of various anaesthetics were widely read and quoted by his colleagues, including John Snow. While in Edinburgh and Newcastle, Glover was recognised as a remarkably astute physician, original researcher, prolific writer and enthusiastic lecturer with an enormous knowledge of medicine, the physical sciences, mathematics and philosophy. His brilliant career deteriorated after his arrival in London and, especially, after his return from the Crimea, although he continued to publish until the week before his death. The causes of his decline remain obscure. The last year of his life was ruined by his addiction to chloroform, to whose development he had contributed so much, and which killed him at the early age of 43.     

A partially blinded randomised controlled trial of patient-maintained propofol sedation and operator controlled midazolam sedation in third molar extractions

Patient-maintained sedation using propofol has recently been shown to be effective for dental surgery. We compared this new technique to the established technique of operator administered midazolam. The two groups were compared before, during and after sedation. The two primary outcomes were time until discharge and oxygen saturation. Vital signs, anxiety and psychomotor skills were also compared. State anxiety was reduced to a greater extent in the propofol group (mean difference 10 (SD 4) mm; p = 0.010. Propofol patients recovered quicker (mean difference 7 (SD 1.4) min; p = 0.001). Propofol patients had a smaller reduction in arterial oxygen saturation (mean difference 0.8 (SD 0.3)%; p = 0.030), and a reduced increase in heart rate (mean difference 9 (SD 2) beats.min(-1); p < 0.001). Both techniques were well tolerated and safe. Propofol sedation offered superior anxiolysis, quicker recovery, less amnesia and less depression of simple psychomotor function.     

The management of patients with ischaemic heart disease undergoing non-cardiac elective surgery: a survey of Australian and New Zealand clinical practice

Improvements in patient risk stratification and peri-operative beta-blockade have been suggested as methods which can reduce cardiovascular risk in patients with known cardiac risk factors. A postal questionnaire was sent to all Australian and New Zealand teaching hospitals to identify patterns of pre-operative cardiac risk evaluation and methods of peri-operative beta-blocker use. In all, 67 replies were evaluated (64% response rate). Specialist anaesthetists are present in the majority of pre-admission clinics (78%), with a designated peri-operative physician in 9%. Further cardiological referral was possible in almost all institutions (96%), and specific peri-operative physician referral in 54%. Waiting times for specialist consultation were < 7 days in the majority of cases. Whilst 79% of institutions used peri-operative beta-blockade, specific protocols were available in only 10%. In 60% of institutions, beta-blockers were administered to high-risk patients, and in 25% they were given to intermediate risk group patients. There was a wide range in the duration of pre- and postoperative beta-blocker administration. Whilst peri-operative risk assessment appears to be consistent, the pattern of beta-blockade, a known beneficial intervention, is variable. Reasons need to be identified, protocols developed and consistent administration targeted for further improvements to be made.     

The effects of intrathecal diamorphine on gastric emptying after elective Caesarean section

This study investigated whether intrathecal diamorphine affects gastric emptying following elective Caesarean section. Forty women were randomly allocated to receive either diamorphine 300 microg or 0.9% saline as part of a standard spinal anaesthetic. Gastric emptying was measured in the immediate postoperative period using paracetamol absorption. Paracetamol concentrations were measured by enzymatic assay method using a Beckman CX-7 automated analyser. The time to maximum concentration (Tmax) was statistically longer in the diamorphine group (control 41.8, SD 20.8 min; diamorphine 72.6 SD 41.9 min; p < 0.01). During the 2-h study period, mean morphine consumption via a patient controlled analgesia device was significantly higher in the control group (control 9.3, SD 3.6 mg; diamorphine 2.1, SD 2.1 mg; p < 0.01). We conclude that intrathecal diamorphine may contribute to the delay in gastric emptying that occurs immediately following elective spinal Caesarean section.     

Anaesthetic considerations in Kartagener's syndrome -- a case report

Kartagener's syndrome is a rare disorder characterized by the triad of situs inversus, including dextrocardia, bronchiectasis and paranasal sinusitis. We report the anaesthetic management of a patient with Kartagener's syndrome and postrenal transplant immunosuppression, presenting for repair of uterovaginal prolapse. Combined spinal epidural anaesthesia was administered to this patient. The anaesthetic considerations of this rare disorder and the relative advantages of the regional technique over general anaesthesia in this situation are discussed.