bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of Propofol and Antagonised Midazolam Anaesthesia for Day-Case Surgery
Authors: Forrest P. , Galletly D. C.
Published: January 2019

A technique of midazolam/fentanyl/isoflurane/nitrous oxide anaesthesia, in which the benzodiazepine was antagonised by the specific antagonist, flumazenil, was compared with propofol/fentanyl/nitrous oxide anaesthesia for minor outpatient urological surgery. No significant difference was found in the overall ease of anaesthesia; however, using subjective (linear analogue sedation scales) and objective (letter deletion and simple reflex time) tests, recovery was found to be significantly slower for the antagonised midazolam group. For both groups, the most frequent intraoperative problem was patient movement in response to surgical stimulation and, postoperatively, headache. The midazolam group displayed the greatest degree of residual sedation at the 4-hour time of discharge and on arrival home a significantly larger number of patients in the midazolam group slept for a period.

It is likely that the dose of flumazenil chosen (1 mg) was inadequate to completely antagonise the dose of midazolam (mean 17 mg) for the full duration of recovery.
Clinical Pharmacokinetics of Long-Term Infusion of Midazolam in Critically Ill Patients — Preliminary Results
Authors: Dirksen M. S. C. , Vree T. B. , Driessen J. J.
Published: January 2019

Seven intensive care patients were sedated with prolonged infusion of midazolam. One patient received a continuous infusion of midazolam for the treatment of status epilepticus. A bolus injection of 5 mg was administered, followed by infusion of 4–14 mg/hour depending on the required level of sedation. The length of infusion varied between 80 and 360 hours. The plasma concentrations of the midazolam during infusion were between 500–1000 ng/ml. All the patients were adequately sedated. The plasma elimination half-life of midazolam and its main metabolite, 1-OH-midazolam glucuronide, after stopping the infusion varied from 4–12 hours.
Cisternal Cerebrospinal Fluid Concentrations of Morphine following Intrathecal and Epidural Administration in the Baboon
Authors: Hampton W. A. , Lavies N. G. , Downing J. W. , Brock-Utne J. G. , Salisbury R. T. , Elson K. I.
Published: January 2019

Eleven baboons, anaesthetised with ketamine, had catheters introduced into the cisterna magna. Morphine was injected at lumbar level intrathecally in six and epidurally in five. Cisternal CSF was sampled hourly and the morphine concentration measured using a high pressure liquid chromatograph. In two cases following intrathecal injection peaks of 180 ng/ml at 4 hours, and 2,200 ng/ml at 3 hours were detected. In the latter case there was associated error in sampling therefore this baboon had a repeat injection four weeks later. The maximum level of morphine obtained then was 139 ng/ml at 4 hours. In the epidural group peaks of 113 ng/ml and 53 ng/ml at 1 hour were measured in 2 baboons and 27 ng/ml at 6 hours in a third. In all six other baboons following either procedure no morphine was detected in the cisterna. We conclude that morphine injected either intrathecally or epidurally in primates does migrate centrally in varying quantities. This finding would seem to have some bearing on the unpredictability of reported episodes of respiratory depression following intraspinal morphine.
Affective, Cognitive and Subjective Changes in Patients Undergoing Cardiac Surgery — a Preliminary Report
Authors: Adrian J. , Crankshaw D. P. , Tiller J. W. G. , Stanley R. O.
Published: January 2019

Neuropsychiatric change following open-heart surgery has been investigated and emboli proposed as a major causative factor. However, few studies have thoroughly evaluated patients’ status prior to surgery. The subjective experiences and neuropsychological status of five open-heart surgery patients was documented both pre- and postoperatively. It was found that prior to surgery patients presented with a wide range of cognitive and emotional problems, some of which were exacerbated by surgery. In particular psychomotor slowing was observed and persisted at six weeks following surgery. This report highlights the importance of conducting preoperative assessments in research which aims to evaluate the effects of different medical procedures on neuropsychiatric functioning.
Hypoxaemia following Sustained Low-Volume Venous Air Embolism in Sheep
Authors: Pfitzner J. , Petito S. P. , McLean A. G.
Published: January 2019

In six upright (head above thorax) anaesthetised sheep, serial blood gas measurements were made over a 100-minute period during which repeated small-volume air emboli were injected intravenously to lower and maintain the end-tidal CO 2 concentration approximately 0.5% below its initial baseline level. With constant volume ventilation and an inspired N 2 O:O 2 ratio of 2:1, the arterial PCO 2 progressively increased and the arterial PO 2 progressively decreased with significant arterial hypoxaemia ensuing in three out of the six animals. It is suggested that during neurosurgery performed in the sitting position and with an inspired oxygen concentration of 33%, the degree of cardio-respiratory disturbance caused by venous air embolism should be assessed by continuous monitoring not only of end-tidal CO 2 concentration but also of arterial oxygen saturation using pulse oximetry.
Epidural Anaesthesia for Caesarean Section: A Comparison of 0.5% Bupivacaine and 2% Lignocaine Both with Adrenaline
Authors: Paech M. J.
Published: January 2019

Thirty-eight women having caesarean section under epidural anaesthesia received either lignocaine 2% or bupivacaine 0.5% both with adrenaline 1:200,000 in a double-blind, randomised study. The time to establish satisfactory surgical anaesthesia, the volume required and the quality of analgesia as assessed by the anaesthetist, patient pain and discomfort scales and patient approval, were not significantly different. Motor block assessed by the Bromage and RAM-test was greater in the lignocaine group but surgical opinion of abdominal wall relaxation was not significantly different between groups. The bupivacaine group had significantly longer durations of sensory and motor block while the lignocaine group had a higher incidence of maternal shivering, other complication rates being similar. Neonatal outcomes were uniformly good. Both local anaesthetics provided satisfactory epidural anaesthesia and neither proved to have a distinct advantage in the clinical setting of this study.
A Seldinger Technique for Minitracheostomy Insertion
Authors: Corke C. , Cranswick P.
Published: January 2019

Minitracheostomy is a valuable technique in patients with sputum retention. However, insertion of a minitracheostomy tube over a dilator passed through an incision through the cricothyroid membrane (the suggested method of insertion of the Mini-trach II, [Portex]), can prove difficult. A Seldinger method is described which results in easier and more reliable placement in difficult cases.
Perioperative Hypoxaemia Detected by Intermittent Pulse Oximetry
Authors: Mckenzie A. J.
Published: January 2019

Perioperative pulse oximetry was performed on one hundred consecutive abdominal surgical patients to audit our management of perioperative oxygenation. Oximetry was performed preoperatively, in the recovery room, and daily in the ward until discharge or the sixth postoperative day, with prescribed oxygen therapy continuing during measurement. Twenty-nine patients had saturations of 90% or less on a total of fifty-one occasions. Twenty-nine patients were prescribed prophylactic oxygen therapy, but seven had oxygen therapy stopped prematurely and were found to have saturations of 90% or less.

In this group of patients, clinical assessment of oxygenation and the need for oxygen therapy was inadequate. Intermittent oximetry is rapidly and simply performed, and by detecting patients with arterial haemoglobin desaturation, could improve oxygen prescribing in the perioperative period.
Pulmonary Clearance of 99mTc-DTPA in the Diagnosis and Evolution of Increased Permeability Pulmonary Oedema
Authors: Barrowcliffe M. P. , Jones J. G.
Published: January 2019

We measured pulmonary clearance of aerosolised 99m technetium-labelled diethylenetriaminepentacetate (99mTc-DTPA) in thirty-four patients with acute respiratory dysfunction. Results were expressed as a half-time clearance from lung to blood (T½). In sixteen non-smoking patients with acute lung injury, clearance was monoexponential, median T½ 11, range 4–40 min, and in five multi-exponential, median rapid T½ 3 min, with a slower median T½ of 18 min (range 2–4 and 15–31 min respectively). Clearance was significantly (P < 0.0001) more rapid than normal non-smoking subjects previously studied (median T½ 70, range 37–182 min). Three smokers with acute lung injury had T½s of 5, 18 and 22 min, not significantly (P> 0.05) quicker than normal smokers previously studied (median T½ 20, range 6–73 min). One smoking lung-injured patient had an abnormal multi-exponential 99mTc-DTPA clearance. Four patients with cardiogenic pulmonary oedema had T½s within the normal range. Repeated measurements made on nine patients with acute lung injury showed that clearance remained abnormally rapid despite improvements in lung radiographic appearance and gas exchange. We conclude that the 99mTc-DTPA technique provides a virtually non-invasive measure of alveolar-capillary barrier dysfunction in non-smoking patients with acute lung injury.
A Comparison of the Effects of Suxamethonium, Atracurium and Vecuronium on Intracranial Haemodynamics in Swine
Authors: Ducey J. P. , Deppe S. A. , Foley K. T.
Published: January 2019

Sixteen Yorkshire swine weighing 15–20 kg were studied to compare the effects of suxamethonium, atracurim and vecuronium on intracranial pressure (ICP), heart rate (HR), arterial blood pressure (BP), and cerebral perfusion pressure (CPP) in swine with normal or elevated ICP. In each animal an intacranial pressure-volume curve was produced by the inflation of an epidural balloon. The baseline ICP (Po), the ICP at the inflection point (Pi) and on the steep portion (Pmax) of the pressure-volume curve were identified and the balloon volumes recorded. The animals were assigned to receive either suxamethonium 1.0 mg/kg, atracurium 0.6 mg/kg, vecuronium 0.2 mg/kg, or saline placebo intravenously at three conditions: First, with the epidural balloon deflated Po, next at Pi, then at Pmax. Neither atracurium, vecuronium, nor placebo produced any statisticially significant effect on HR, BP, ICP, or CPP at any baseline level of ICP. Suxamethonium produced an early fall in ICP (0.8±0.3, 2.6±1.0 and 3.5±1.3 mmHg at Po, Pi and Pmax respectively: P = .0005) followed by a rapid rise above the pre-infusion level (1.8 ± 0.6, 2.8 ±0.6 mmHg, and 2.2 ±0.5 mmHg at P0, Pi and Pmax respectively: P =.0005). A fall in BP coupled with the rise in ICP resulted in a fall in CPP (5.8 ± 2.3, 6.1 ±1.2, and 6.3 ± 1.8 mmHg at P0, Pi and Pmax respectively: P = .0005). Although the fall in CPP was not large, in the presence of elevated ICP, where CPP already is marginal, such a decrease may compromise cerebral blood flow. Atracurium and vecuronium had no effect on ICP or haemodynamics, even in the presence of an elevated ICP. These agents may be preferred in settings of suboptimal CPP or in the presence of pre-existing intracranial hypertension.
Prophylaxis against venous Thromboembolism
Authors: Goucke C. Roger
Published: January 2019

Death from venous thromboembolism occurs in the perioperative period at a rate varying between 0.1% and 7.0%. The risk factors and methods of prophylaxis are reviewed and current recommendations presented.
A New Comprehensive Anaesthetic Record
Authors: Jackson C. J. , Scott R. J.
Published: January 2019

Eternal vigilance and strict attention to detail are the ‘sine qua non’ of safe anaesthesia with the contemporaneous anaesthetic record being the documentation. As an alternative to the manifold and often inadequate forms currently in use, a new rapidly completed anaesthetic record incorporating a comprehensive checklist is presented. Guidelines of the Faculty of Anaesthetists, Royal Australasian College of Surgeons are met.

It is argued that the chart improves safety not only by its direction to attention during the preoperative visit and equipment check, but also by its demand for the ongoing attention of the anaesthetist. Reservations are expressed about ‘black box’ recording by trend printout and a perspective for computerised and automated anaesthetic records is also discussed.
The Influence of CO2 Production and Physiological Deadspace on End-Tidal CO2 During Controlled Ventilation: A Study Using a Mechanical Model
Authors: Stockwell M. A. , Bruce W. , Soni N.
Published: January 2019

A mechanical lung model was used to investigate the effect of varying carbon dioxide production and deadspace on the end-tidal carbon dioxide levels achieved during mechanical ventilation when using the Bain, Humphrey ADE, and circle systems. Both factors had significant influence on end-tidal cardon dioxide concentration and could result in values in excess of those considered acceptable in clinical practice. The implications of the results are discussed.
The Perioperative Effects of Oral Premedication in Children
Authors: van der Walt J. H. , Jacob R. , Murrell D. , Bentley M.
Published: January 2019

The pre- and postoperative effects of oral diazepam (0.5 mg/kg), trimeprazine (4 mg/kg), pentobarbitone (3 mg/kg) and a placebo were compared in a randomised double-blind clinical trial in 149 children, aged one to ten years, undergoing adenotonsillectomy. The anaesthetic was standardised and each patient received intraoperative intramuscular papaveretum (0.3 mg/kg). Preoperative sedation was assessed in the ward before transfer onto the theatre trolley, on leaving the ward, on arrival on the theatre floor, on arrival in the induction room and on induction of anaesthesia. There was no significant difference in sedation between the four drug groups except for the placebo group which had a significantly greater unsatisfactory rating at the stage of induction of anaesthesia (P = 0.001). There were no differences in waking times between the diazepam, pentobarbitone and placebo groups, but the trimeprazine group's waking times were significantly prolonged (P < 0.001). However, the trimeprazine group exhibited significantly less distress in the recovery unit (P = 0.02) and had half the incidence of vomiting (P < 0.001) than did the other premedication groups.
Double-Blind Study of the Reversal of Midazolam-Induced Sedation in the Intensive Care Unit with Flumazenil (Ro 15–1788): Effect on Weaning from Ventilation
Authors: Pepperman M. L.
Published: January 2019

Midazolam (0.1–0.2 mg/kg/hr) and morphine (2 mg/hr) were given by carefully regulated continuous intravenous infusions to thirty patients who required sedation, analgesia and ventilation for between twelve and twenty-four hours in the Intensive Care Unit. The midazolam and morphine infusions were stopped at the end of the period of sedation required and the efficacy of placebo or flumazenil in reversing the sedative effects of midazolam was compared in this double-blind randomised parallel group study.

Patients receiving flumazenil were less sedated (P < 0.05), able to obey commands (P < 0.05), weaned from ventilation (P < 0.05) and extubated (P < 0.05) significantly earlier than those receiving placebo.
Gastric Aspiration at the End of Anaesthesia Does Not Decrease Postoperative Nausea and Vomiting
Authors: Hovorka J. , Korttila K. , Erkola O.
Published: January 2019

Two hundred and one women undergoing elective abdominal hysterectomy were anaesthetised with isoflurane in nitrous oxide and oxygen. At the end of anaesthesia the stomach was aspirated in half of the patients, selected in random order. In the other half no aspiration was performed. Incidence and severity of emesis (none, nausea, retching or vomiting) was assessed during the first 24 hours after operation. Emesis was similar after the operation regardless of aspiration of the stomach (overall emesis 79% and 70% for those whose stomach had and had not been aspirated, respectively). The incidence at all times during the 24 hours was similar in both groups. The results suggest that gastric aspiration at the end of anaesthesia has no major effect on the incidence or severity of postoperative emesis in patients undergoing abdominal hysterectomy.
Neuromuscular Sensitivity to Atracurium in Humans
Authors: Torda T. A. , Graham G. G. , Tsui D.
Published: January 2019

The relation between plasma concentration and the effects of atracurium was studied in seven patients anaesthetised with thiopentone, fentanyl and nitrous oxide - oxygen. The responses to train-of-four stimulation at ten-second intervals with tetanic stimuli applied every five minutes were recorded. The first sign of transmission returning after complete blockade was usually the post-tetanic facilitated twitch, which was noted when the mean atracurium concentration was 1.15 mg 1−1 (SD 0.77). The most sensitive parameter was the train-of-four ratio, which recovered to 0.5 when the concentration was 0.217 mg 1−1 (SD 0.56), compared with a concentration of 0.271 (SD 0.85) at 50% recovery for twitch height, 0.221 (SD 0.029) for tetanic peak and 0.231 (SD 0.079) for tetanic fade. The value for the train-of-four ratio differed significantly (P < 0.05) from that for the twitch height, but other differences were not significant. Once recovery commenced, these four parameters recovered at similar rates, with recovery indices (25 to 75% responses) of 14.8 (SD 1.7), 14.0 (SD 1.0), 14.3 (SD 1.8) and 13.7 (SD 2.1) minutes respectively. Post-tetanic facilitation was most marked during severe but incomplete blockade and tetanic stimulation temporarily reversed the atracurium-induced decrease in train-of-four ratio. Clinically, the use of tetanic stimulation did not improve the sensitivity of neuromuscular monitoring, but post-tetanic count may be useful where monitoring of profound relaxation is required.
Suxamethonium and Hyperkalaemia
Authors: Yentis S. M.
Published: January 2019

Severe life-threatening hyperkalaemia may occur following administration of suxamethonium during certain periods after burns, neurological injuries, and in certain other conditions. Although this response is well-known, there is disagreement about when it may occur. This review describes the normal hyperkalaemic response to suxamethonium, the factors affecting it, the conditions in which it may be exaggerated, and the periods of high risk.
Anaesthetic Agents and the Ozone Layer
Authors: Westhorpe R. , Blutstein H.
Published: January 2019

There is an important relationship between the stratospheric ozone layer and the absorption of potentially harmful ultraviolet-B radiation from the sun. Chlorofluorocarbons and halogenated hydrocarbons are commonly used chemicals which are implicated in the depletion of the ozone layer. Of the anaesthetic agents, halothane has the greatest potential for depleting ozone although, when compared with the global use of other chlorofluorocarbons and halogenated hydrocarbons, its current contribution to the problem is relatively small.
Possible Interaction between SPPS and Enalapril
Authors: McKenzie A. J.
Published: January 2019

A patient undergoing groin lymph node dissection with spinal and general anaesthesia was receiving enalapril to control hypertension. Infusion of stable plasma protein solution (Commonwealth Serum Laboratories, Australia) was associated with significant hypotension and flushing. A brief review of stable plasma protein solution and angiotensin converting enzyme inhibitor pharmacology is presented to provide a possible mechanism for these events. This mechanism implies that angiotensin converting enzyme inhibitor therapy is a relative contraindication to rapid SPPS infusion.
Thrombocytopenia and Platelet Functional Defects in Pre-Eclampsia: Implications for Regional Anaesthesia
Authors: Schindler M. , Gatt S. , Isert P. , Morgans D. , Cheung A.
Published: January 2019

A prospective, observational study of forty pre-eclamptic patients was conducted to confirm or refute reports of a platelet functional defect superimposed on the consumptive thrombocytopenia of pre-eclampsia. Investigations included a platelet count, in vivo platelet function as assessed by a Duke bleeding time, and in vitro platelet function as assessed by thromboxane B2 and Platelet Factor 3 (PF 3).

The overall incidence of thrombocytopenia was 15%. Prolonged bleeding time and slightly decreased availability of PF 3 (evidence of possible platelet dysfunction) was present in 2.5% of patients while 21% had evidence of fibrinolysis with an elevated monoclonal D-dimer.

In the assessment of suitability for regional blockade, a platelet count is essential. If the platelet count is between 50 and 100 × 109/l a bleeding time is indicated.
The Haemodynamic Effects of Propofol and Thiopentone for Induction of Caesarean Section
Authors: Gin T. , Gregory M. A. , Oh T. E.
Published: January 2019

Forty Chinese women for elective caesarean section received either propofol 2 mg.kg−1 or thiopentone 4 mg.kg1 for induction of general anaesthesia. Systolic, mean and diastolic arterial pressures and heart rate were recorded non-invasively every minute for ten minutes. Post-induction arterial pressures were similar to pre-induction values with no differences between thiopentone and propofol. Following intubation, the rise in systolic arterial pressure was greater in the thiopentone group, 32.1 mmHg (SD 23.7) compared with the propofol group, 17.4 mmHg (SD 23.8), (P < 0.05). In the thiopentone group, arterial pressures were slower in returning to baseline values. Heart rate was initially elevated in both groups to the same degree. At caesarean section, induction with propofol causes less variation in arterial pressure than thiopentone. Hypotension is probably prevented by the coincident stimulus of rapid sequence induction. Neonatal Apgar scores were similar between the two groups.
Comparison of Two Methods of Intravenous Administration of Morphine for Postoperative Pain Relief
Authors: Zacharias M. , Pfeifer M. V. , Herbison P.
Published: January 2019

Morphine sulphate was used for the control of pain following major abdominal surgery for a period of three days either as patient-controlled or continuous infusion. The two groups of patients were comparable with regard to patient and operation details, duration of infusion, pain scores and complications. The only significant difference was a reduced dose requirement of morphine in the patient-controlled analgesia group (P < 0.005). Some possible explanations for this finding are given. It is suggested that a properly supervised continuous infusion of morphine is as good as patient-controlled administration. There was a negative correlation between the age of the patient and the dose of morphine used.
Pain Relief for Outpatient Colonoscopy: A Comparison of Alfentanil with Fentanyl
Authors: Holloway A. M. , Logan D. A.
Published: January 2019

Alfentanil was used as an adjuvant to midazolam for analgesia in thirty outpatients undergoing colonoscopy. A similar group of thirty outpatients received fentanyl. The operating conditions and recovery times of the two groups were compared. Alfentanil usage resulted in better operating conditions. Recovery time was similar. Patient acceptance was high. No patient suffered respiratory depression during or after the procedure.
Effects of Alfentanil on Induction and Recovery from Propofol Anaesthesia in Day Surgery
Authors: Wall R. J. , Zacharias M.
Published: January 2019

The influence of alfentanil on induction and recovery characteristics of propofol was examined in women presenting as day cases for minor gynaecological surgery. Alfentanil reduced the incidence of pain on injection and the induction and maintenance requirements of propofol. This was at the expense of more prolonged apnoea. Immediate recovery characteristics were similar in each group although changes in Critical Flicker Fusion Threshold as a measure of psychomotor impairment were more pronounced after alfentanil. Such differences were insignificant at three hours by which time Critical Flicker Fusion Threshold had returned to baseline and patients were ready for discharge home.
A Comparative Analysis of the Loss of Amiodarone from Small and Large Volume PVC and Non-PVC Infusion Systems
Authors: Peters P. G. , Hayball P. J.
Published: January 2019

The time-course of the adsorption of amiodarone hydrochloride onto flexible polyvinyl chloride (PVC) infusion bags and administration sets has been studied under ambient conditions similar to the intensive and coronary care units at the Repatriation General Hospital – Daw Park. When admixtures containing 900–1000 mg amiodarone hydrochloride in 500 ml PVC infusion bags containing glucose 5% were assayed, a minimal (2.7%) loss of amiodarone was detected at 24 hours compared with glass infusion bottles. There was no loss apparent when 100 ml PVC infusion bags were used compared with 100 ml glass bottles. When PVC administration sets were attached to 500 ml glass infusion bottles, maximal adsorption losses of up to 4.9% were observed in the effluent within one hour of the commencement of the simulated infusion.

In Australia, the current recommendations by the distributor of amiodarone, Reckitt & Colman Pharmaceuticals, advise that the administration of amiodarone should be via glass infusion bottles or rigid PVC plastic containers without plasticisers together with non-PVC administration lines. These results do not support this recommendation.
Anaesthesia and the Sick Foetus
Authors: Lah F.
Published: January 2019

The primary cause of foetal illness is placental pathology. The use of diagnostic ultrasound allows for a better understanding of how the foetus may be compromised by inadequate placental function.

Anaesthesia affects placental function by changing uteroplacental and umbilical placental perfusion. Regional anaesthesia may have a beneficial effect on these circulations although general anaesthesia may be adapted to produce minimal disturbance of placental circulatory dynamics.

The advantages and disadvantages of particular anaesthetic techniques in the delivery of the sick foetus are discussed.
Management of Failed Endotracheal Intubation at Caesarean Section
Authors: Hewett E. , Livingstone P.
Published: January 2019

A review of the history of endotracheal intubation and endotracheal tubes is presented and a plan of management of failed endotracheal intubation at caesarean section is described. The importance of preparation for such an event by incorporation of certain features into anaesthesia training programs is emphasised.
The Melbourne Chart – A Logical Guide to Neonatal Resuscitation
Authors: Roy R. N. , Betheras F. R.
Published: January 2019

Resuscitation of the asphyxiated infant is one of the great emergencies in medical practice. Properly done, it can save many lives and greatly reduce the morbidity resulting from hypoxic-ischaemic encephalopathy, but if it is ineptly performed, the effects of hypoxic-ischaemic encephalopathy may be accentuated, with resultant increased morbidity and even mortality.

Other than paediatricians, few practitioners have regular experience in neonatal resuscitation: indeed many, including obstetricians, anaesthetists, general practitioners and midwives may only rarely face the problem of severe asphyxia.

It is therefore essential for the occasional practitioner to have ready reference to a logical guide to resuscitation. We have designed such a guide which is widely distributed in delivery suites and operating theatres in Victoria. Its basic form has been in use for over a decade and it has recently been revised.

Use of the chart assists the resuscitator to judge the level of resuscitation required. It is our experience that much unnecessary intervention occurs at resuscitation, and we believe the methods outlined in this schematic chart represent a more conservative but logical approach to neonatal resuscitation.

The chart is based on the pathophysiological changes that occur in perinatal asphyxia, directing the user to the appropriate manoeuvres required to correct those changes, depending on the degree of asphyxia which is determined by clinical signs and by use of the Apgar score.
Drug Dependence and Pregnancy: Antenatal and Intrapartum Problems
Authors: Kliman L.
Published: January 2019

The last decade has seen an increase in the use of illicit drugs and alcohol in the community including an increase in the use of these agents by women in the reproductive age group.

With this in mind, health-care workers need to avoid being complacent in caring for these women – they are a high-risk obstetric population with a significant incidence of medical, obstetric and paediatric complications.

This paper concentrates on the antenatal and intrapartum problems, and outlines their management. An overview of the problem is presented as well as an illustrative case report.
Pulmonary Hypertension and Pregnancy – A Lethal Combination
Authors: Roberts N. V. , Keast P. J.
Published: January 2019

Pulmonary hypertension may be either primary of unknown aetiology or secondary to existing cardio-respiratory disease. As a single entity the prognosis is poor but superimposition of the physiological changes of pregnancy and labour produces a lethal condition. This paper sets out two clinical cases of primary pulmonary hypertension as background for discussion to highlight the issues involved. Whatever this discussion does, let it be clearly spelt out that prevention is better than any proposed cure.
Role of Repeated Doses of Oral Activated Charcoal in the Treatment of Acute Intoxications
Authors: McLuckie A. , Forbes A. M. , Ilett K. F.
Published: January 2019

While single dose activated charcoal is effective in preventing drug absorption, repeated doses not only prevent absorption but also can increase systemic drug clearance. The mechanism for the latter effect may involve interruption of enterohepatic recycling and/or promotion of drug exsorption from the systemic circulation into the gut lumen. A comprehensive review of reported studies in volunteer subjects and overdose patients showed that repeated dose activated charcoal markedly decreased the half life and/or increased the clearance of a wide range of drugs. Side-effects of the treatment were infrequent, but included aspiration pneumonia, diarrhoea and constipation. The addition of laxatives to repeated dose charcoal treatment did not offer any significant increase in drug clearance and is not recommended. It is suggested that the optimal regimen for the use of repeat dose activated charcoal in acute drug intoxications is an initial dose of 75–100 g followed by 50 g every 4 hours until the risks of systemic drug toxicity are reduced to an acceptable level.
Predictors of Mortality in Children with Respiratory Failure: Possible Indications for ECMO
Authors: Rivera R. A. , Burr W. , Shann F.
Published: January 2019

There are many unproven methods of ventilation and oxygenation that have been used in children dying from respiratory failure, including extracorporeal devices and high frequency ventilation. However, no objective predictors of death have been developed that enable clinicians to decide when it is reasonable to use these therapies in children over one month of age with acute respiratory failure. To determine predictors of death, we evaluated the charts of all 42 children aged one month to eighteen years admitted to the intensive care unit who were ventilated for more than twelve hours, received greater than 90% oxygen, received a peak inspiratory pressure greater than 25 cmH2O and had no pre-existing neurodevelopmental handicap. A combination of a variable reflecting ventilation and a variable reflecting oxygenation reliably predicted death: a combination of ventilation index > 40 and oxygenation index > 0.4 was associated with a 77% chance of mortality (sensitivity 65% and specificity 74%); a combination of peak inspiratory pressure > 40 cmH2O and A-aDO2 > 580 was associated with an 81% chance of mortality (sensitivity 74% and specificity 79%). These criteria may be useful in predicting death from respiratory failure in children.
Neuromuscular Blocking Agents in Paediatric Patients: Influence of Age on the Response
Authors: Meretoja O. A.
Published: January 2019

This paper reviews the studies in which neuromuscular blocking drugs were comapred in at least two different age groups of patients. Most recent studies have lead to a uniform concept of the variation of the effect of these drugs in different age groups.

In general, the dose of a nondepolarizing agent required to produce a particular degree of relaxation is similar in neonates (less than one month), infants (one to twelve months) and adolescents (more than thirteen years). However, in children from three to ten years the dose is significantly greater. The maximal effect is reached more quickly in neonates and infants than in the older children and adolescents. These results can be explained by changes in sensitivity, distribution volume and muscle mass.

The duration of effect of a nondepolarizing agent is significantly altered by age only in the case of vecuronium, which has a prolonged action in neonates and infants. Suxamethonium remains as the agent with the most rapid onset.
Dose Response of Alcuronium and d-Tubocurarine in Infants, Children and Adolescents
Authors: Meretoja O. A. , Brown T. C. K. , Clare D.
Published: January 2019

Seventy neonatal to adolescent general surgical patients were studied to create an individual dose-response curve for the long-acting neuromuscular blocking agents, alcuronium and d-tubocurarine. The mean (SEM) ED95 of alcuronium was 196 (9), 271 (13) and 243 (8) μg/kg in infants, children and adolescents, respectively (P < 0.01). d-tubocurarine showed a similar age dependent dose-response relationship. ED95 doses were 414 (40), 499 (41) and 445 (31) μg/kg, respectively. The onset time (time from intravenous administration to maximal effect) following equipotent dosages was 40–50% shorter in infants than in children or adolescents (1.5 vs 2.7 minutes, P < 0.05).
Maintenance Requirement of Alcuronium in Paediatric Patients
Authors: Meretoja O. A. , Brown T. C. K.
Published: January 2019

Seventeen paediatric patients from 0.3 to 19 years old were studied to determine the individual dose-response curves and the maintenance requirements of alcuronium during N2O-O2-opioid anaesthesia. Alcuronium 300 μg/kg maintained the mean (SD) neuromuscular block at 90–95% for 62 (34 min). This time was longest in patients of < 1 year of age (92 min). The hourly maintenance requirement of alcuronium was 0.41 (0.12) times the individual ED95 dose. This value was comparable in infants, children and adolescents and indicates similar duration of effect of alcuronium in all paediatric age groups.
Myasthenia Gravis in Children and its Anaesthetic Implications
Authors: Brown T. C. K. , Gebert R. , Meretoja O. A. , Shield L. K.
Published: January 2019

Myasthenia gravis, a rare disease in children, occurs in a variety of forms. The aetiology and clinical presentations are reviewed. Eight patients who were studied with electromyography are presented. The results show that, in general, patients with the usual pattern of disease are resistant to suxamethonium (ED95 3–4 times normal) and are sensitive to nondepolarizing relaxants. When the latter are used it is advisable to administer small increments with neuromuscular monitoring. One patient with the disease localised to the eyelid had normal EMG responses when monitored on the hand with ulnar nerve stimulation.
Suxamethonium – Electromyographic Studies in Children
Authors: Brown T. C. K. , Meretoja O. A. , Bell B. , Clare D.
Published: January 2019

Suxamethonium was administered to 225 children aged from one to sixteen years, in doses varying from 0.1 to 0.5 mg/kg. Dose responses were determined. ED95 was 445 μg/kg in one to four year olds, 454 μg/kg in the five to ten years group and 270 μg/kg in eleven to fifteen year olds (P < 0.05). There is a wider variability in patient responses to 0.1 and 0.2 mg/kg than to the higher doses.

Sixty-two children in the three age groups were given suxamethonium 1 mg/kg. The time from injection to maximum block and to 50% recovery increased with increasing age (P< 0.05).
Simultaneous Monitoring of Force, Acceleration and Electromyogram during Computer-Controlled Infusion of Atracurium in Sheep
Authors: Meretoja O. A. , Brown W. A. , Cass N. M.
Published: January 2019

Five sheep were anaesthetised with sodium thiopentone, nitrous oxide and oxygen, and the lungs ventilated artificially. A computer-controlled infusion of atracurium employing feedback from isometric force measurement was set to maintain 15, 50 and 85% depth of neuromuscular block. Each was held constant for 30 minutes, while isometric force and electromyogram were measured on the left forelimb and acceleration on the right. The acceleration transducer records at the three levels of block were practically identical with those from force measurements: mean differences (SD) between simultaneous measurements being 3.6(5.4)%. EMG value was 10.1 (12.0)% different from force measurement. Correlation between simultaneous force and either acceleration or EMG was excellent (r = 0.986 and 0.938 respectively). In clinical practice all three techniques measure block comparably. In the sheep forelimb, EMG was a less reliable method of measuring block.
The Addition of Fentanyl to Epidural Bupivacaine in First Stage Labour
Authors: Yau G. , Gregory M. A. , Gin T. , Bogod D. G. , Oh T. E.
Published: January 2019

Epidural analgesia was studied in 100 healthy Chinese women with uncomplicated pregnancies in first stage labour. Patients were randomly allocated to receive 8 ml of one of the following five solutions: bupivacaine 0.125% with fentanyl 50 μg or fentanyl 100 μg, bupivacaine 0.25% plain, bupivacaine 0.25% with fentanyl 50 μg or fentanyl 100 μg. There was no difference in quality of analgesia among groups as measured by the reduction of visual analogue pain scores 20 minutes after the epidural dose. The duration of analgesia was similar among groups with the overall median duration being 105 minutes. There was no difference in method of delivery or neonatal Apgar scores. The least concentrated mixture providing good quality analgesia for the first stage of labour was the combination of bupivacaine 0.125% with fentanyl 50 μg.
A Comparison of Intravenous Cannulae Available in New Zealand
Authors: Treuren B. C. , Galletly D. C.
Published: January 2019

This study examined physical and clinical features of eleven models of disposable intravenous cannulae available in New Zealand: Angiocath, Braunule, Insyte, Jelco, J.M.S., Medicut, Nipro, Quikcath, Surflo, Venflon and Wallace. Dimensions of external and internal diameter and wall thickness varied greatly among the models of the same gauge size. As a result, flow rates also varied greatly, but linearly with internal diameter. Anaesthetists were randomly given a range of 16 and 22 gauge cannulae for routine clinical use (forty of each model) and completed a questionnaire on features of cannula performance relating to success of cannulation, ease of insertion, ease of handling, kinking, and packaging. The results of this questionnaire are presented and discussed. The 22 gauge cannula tips were assessed microscopically for distortion after clinical use. Jelco cannulae were found to have the highest incidence of catheter tip distortion (54%).
Rate-Controlled Analgesia: A Laboratory Evaluation of a New Infusion Device
Authors: Currie J. , Owen H. , Ilsley A. H.
Published: January 2019

We report an evaluation of the Bard Harvard Mini Infuser, one of a new generation of agent-specific intraoperative infusion pumps which are designed for use by the anaesthetist. This pump permits potent intravenous anaesthetic agents to be used in pharmacokinetically designed dosage regimens. The controls are calibrated directly in kg body weight and micrograms per minute rather than the usual settings of ml of solution per hour. The performance was assessed by measuring the volume delivered over given time intervals and all safety functions were tested at least three times. This device was found to be acceptably safe and accurate. Two points to note are that it must be purged every time before it is connected to the intravenous infusion and if an occlusion is suddenly relieved, the patient can receive an ‘accidental bolus’ of up to 1.18 ml of drug.

The main advantage of this pump is that it uses undiluted drug direct from the ampoule and does not require any calculations or dilutions prior to use. However, this restricts its use to drugs with a concentration of 500 mcg/ml and in effect means that it is suitable mainly for infusion of alfentanil.
Liver Dysfunction in Critical Illness
Authors: Hawker F.
Published: January 2019

Abnormal liver function commonly accompanies critical illness. Ischaemic hepatitis occurs with shock and is characterised by elevated plasma aminotransferase concentrations. ‘ICU jaundice’ occurs later in critical illness, especially after trauma and sepsis. The major biochemical abnormality is conjugated hyperbilirubinaemia.

The clinical setting suggests that hepatic ischaemia and hepatotoxic actions of inflammatory mediators are the major aetiological factors. Massive blood transfusion, effects of nutritional support and drug toxicity may contribute.

Both the presence and degree of jaundice are associated with increased mortality in several nonhepatic diseases. It is proposed that Kupffer cell phagocytic depression associated with liver dysfunction permits systemic spread of endotoxin and inflammatory mediators and thus predisposes to multiple organ failure. Immunosuppression, metabolic abnormalities, impaired drug oxidation and myocardial depression may contribute to the poor prognosis.

There is no specific treatment, but prompt resuscitation, definitive treatment of sepsis and meticulous supportive care will likely reduce the incidence and severity.
Is Propofol Cost-Effective for Day-Surgery Patients?
Authors: Cade L. , Morley P. T. , Ross A. W.
Published: January 2019

To attempt to justify the expense of using propofol for day-surgery, we have compared propofol with methohexitone for induction of anaesthesia for elective minor gynaecological procedures. Seventy healthy patients were randomised to receive either induction agent and postoperatively they were compared for recovery times, side-effects and patient appraisal the following day. The results showed that propofol was superior to methohexitone for most parameters, with small but statistically significant differences in response time, ambulation time, vomiting and drowsiness during recovery. There were minor differences in patient appraisal the next day. However, it is doubtful whether the advantages of propofol are sufficiently substantial to justify the expense of its routine use in preference to methohexitone and its place is a matter for individual judgement.
Prediction of Difficult Laryngoscopy: An Assessment of the Thyromental Distance and Mallampati Predictive Tests
Authors: Butler P. J. , Dhara S. S.
Published: January 2019

Two hundred and fifty patients were assessed preoperatively using the Mallampati classification and by measuring their thyromental distances.

The ease or difficulty of direct laryngoscopy was assessed at the time of induction of anaesthesia. Retrognathia was seen in 15.6% of patients and the incidence of difficult laryngoscopy without external laryngeal pressure was 8.2%.

It was found that both assessments predicted less than two in three difficult laryngoscopies and had high false positive rates. It was found that external laryngeal pressure often improved the view of the glottis in difficult laryngoscopies.
Effect of Myocardial Ischaemia-reperfusion on Granulocyte Elastase Release
Authors: Ceriana P.
Published: January 2019

During extracorporeal circulation, activation and degranulation of neutrophil granulocytes occur, with subsequent massive release of elastase, a neutral protease stored in the azurophil granules. Neutrophil granulocytes and oxygen-derived free radicals are intimately involved in the occurrence of reperfusion injury, which affects especially the lungs and the myocardium. In this study we evaluated changes in the leucocyte count and of the plasma elastase levels in the coronary circulation during open heart surgery. We collected blood samples from the radial artery and the coronary sinus before skin incision, after onset of cardiopulmonary bypass and 5, 15, 30, 60, 120 minutes after the release of the aortic cross-clamp. The leucocyte count did not change significantly during the operation and no difference in leucocyte count was found between the radial artery and the coronary sinus. Plasma elastase levels significantly increased after the onset of cardiopulmonary bypass (P = 0.007) and after the release of the aortic cross-clamp (P = 0.001). Moreover, significantly higher values were found in the coronary sinus than in the radial artery 5 (P = 0.04), 15 (P = 0.02) and 30 (P = 0.02) minutes after the release of the aortic cross-clamp. We assume, therefore, that during the early phase of reperfusion, degranulation of neutrophil granulocytes occurs in the coronary circulation.
Efficacy of Lignocaine in Alleviating Potassium Chloride Infusion Pain
Authors: Lim E. T. M. , Kloo S. T. , Tweed W. A.
Published: January 2019

A double-blind study was set up to investigate the effect of pretreatment with lignocaine on the incidence of potassium chloride infusion pain. Twenty-eight patients were randomly allocated into two equal groups. Patients in both groups were hypokalaemic and were scheduled for replacement consisting of potassium chloride 20 mmol diluted to 100 ml in dextrose 5% solution administered over two hours. Group A (lignocaine) patients were pretreated with a bolus dose lignocaine 3 ml 1%, Group B (control) received isotonic saline 3 ml. The incidence of potassium chloride infusion pain was significantly reduced in Group A. There was no adverse effect reported. This study demonstrates the efficacy of bolus dose of lignocaine in alleviating injection pain for the duration of a two-hour continuous infusion.
A Survey of Fellows of the Faculty of Anaesthetists of the Royal Australasian College of Surgeons Endorsed in Intensive Care by Examination in the First 10 Years of Final Examinations in Intensive Care
Authors: Harrison G. A. , Byth P. L.
Published: January 2019

Fifty-nine of the 70 Fellows of the Faculty of Anaesthetists who had passed the Final Examination in Intensive Care including that of October 1989, responded to a questionnaire on the pattern of their intensive care and anaesthetic practice and their perception of the training and examination. Responses came predominantly from Fellows who had passed the examination more than two years previously. Forty-eight (81%) were practising intensive care at least 50% of the time and 51% had become Director or Deputy Director of an Intensive Care Unit. However, 51% maintained some anaesthetic practice. Although individuals had changed the intensive care/anaesthetic distribution of their practice, the group overall had not. With one exception all Fellows were practising in public hospitals but 26% in private hospitals also. Only eight had sought intensive care as their first vocational qualification. Training and examination were generally regarded favourably except for training in research methods and experience in internal medicine.

The results suggest that the intensive care specialist is not likely to leave such practice in the long term, but there has been a reluctance to abandon altogether training and some subsequent practice in anaesthetics.