bluuebunny/crossref_metadata_2025 huggingface dataset:
Midazolam in Paediatric Anaesthesia
Authors: Cole W. H. J.
Published: January 2019

Midazolam was given intravenously to 100 children over the age of 8 years to induce anaesthesia and a similar control group was anaesthetised with diazepam. The actions of midazolam in children were found to be similar to those of diazepam. Midazolam acted more quickly in children than has been reported in adults. The effects on the circulation and respiration, and the incidence of postoperative amnesia were similar in children to that which has been reported in adults. The incidence of postoperative vomiting after midazolam was 1% in the recovery room and 32% during the first two postoperative days. Laboratory investigations did not demonstrate any adverse effects. Midazolam has a considerable advantage over diazepam being water soluble and injectable safely without dilution.

This clinical trial suggests that midazolam is a satisfactory induction agent for children.
The Prolonged Q-T Syndrome. A Review with Anaesthetic Implications and a Report of Two Cases
Authors: O'Callaghan A. C. , Normandale J. P. , Morgan M.
Published: January 2019

Inherited prolongation of the Q-T interval is associated with syncopal attacks due to ventricular arrhythmias, which, if untreated, are often fatal at an early age. The condition is reviewed and the anaesthetic management of two patients with the syndrome presented. The importance of recognition of the syndrome and its treatment with β-blockers is stressed.
Sodium Citrate: An Alternative Antacid for Prophylaxis against Aspiration Pneumonitis
Authors: Wrobel J. , Koh T. C. , Saunders J. M.
Published: January 2019

In a double-blind study, 107 patients undergoing elective and emergency surgical procedures were given 15 ml of either sodium citrate 0ṁ3 M or placebo 10 minutes before induction of anaesthesia. Gastric contents were sampled immediately after induction and the pH was measured.

The mean pH of the gastric contents of patients given sodium citrate was 5ṁ67, whereas for those given the placebo it was 3ṁ21 (p < 0ṁ001). Of patients given sodium citrate 92% had a gastric pH above 3ṁ0 compared with only 37% in the placebo group (p < 0ṁ001).

At the end of surgery gastric contents were emptied as completely as possible and the volume and pH measured. There was no significant difference in the mean volume of gastric contents in the two groups. In neither group was the mean pH at the end of surgery significantly different from that after induction.
Blind Nasal Intubation in an Awake Patient for Caesarian Section
Authors: Edwards R. M. , Hunt T. L.
Published: January 2019

Failure to intubate the trachea continues to claim the lives of women undergoing caesarian section. Obstetric anaesthetists have been advised to desist from prolonged attempts to intubate, and to provide either inhalational anaesthesia via a face mask, or regional anaesthesia. A case is described in which neither of these options was considered appropriate.
The Scope for Computerisation in Anaesthesia
Authors: Holland R.
Published: January 2019

It is possible for computers to substitute for, add to, and enhance the function of the anaesthetic apparatus. Already computerised accounting is available. To have the computer print out the anaesthetic record with input derived from manual input and on-line monitors is a logical extension of this technology. Computerisation can assist in such administrative tasks as theatre and anaesthetic staff allocation. Regret ably health authorities tend to regard computer technology as a specialised area, only capable of being applied by experts. This is slowing down the application of computer technology in the field of anaesthesia.
Selecting a Computer for your Needs
Authors: Crankshaw David , Paull John
Published: January 2019

Realistic goals and adequate information about equipment and program capabilities are essential prerequisites when selecting a computer system. Problems of equipment selection are dealt with by discussing a range of microcomputers emphasising the need to consider expansion and compatibility with standards such as the S. 100 bus. The importance of ready availability of word processing and management programs is emphasised.
The Computer in Anaesthesia — A Cautionary Note
Authors: Hill D. W.
Published: January 2019

A brief outline is given of the various factors which need to be considered when contemplating the use of computers in a hospital environment in terms of hardware, software, staff and financial implications. However advanced the technology, there is no escape from the requirement for detailed planning, both short and long term.
Computer-based Monitoring and Data Analysis in Anaesthesia and Intensive Care
Authors: Phillips Garry D. , Gordon Phillip J. , Cousins Michael J.
Published: January 2019

A computer with a software package for physiological monitoring at the bedside has been set up, modified and used in a Department of Anaesthesia and Intensive Care over the last three and a half years. Many difficulties have been experienced in implementing a useful computer-based program for monitoring physiological data. The cost of further development to overcome these difficulties could not be justified, and demands for computer time to allow storage and analysis of other data was increasing. A decision was therefore made to eliminate the monitoring role of the computer, and it is now used for storage and analysis of administrative and clinical data from the Intensive Care Unit, Operating Theatres and Pain Management Unit.
A Clinical Evaluation of Safflower Oil Emulsion in Total Parenteral Nutrition
Authors: Tabrett D. G. , Phillips G. D.
Published: January 2019

A new intravenous safflower oil emulsion (Liposyn, Abbott) was administered to 23 patients receiving total parenteral nutrition. In a prospective clinical trial, 500 ml of the 10% emulsion was administered each day for a minimum of 10 days. Plasma fatty acid estimations showed a rise in linoleic acid in 22 patients, and a fall in triene/tetraene ratio (a guide to the presence of essential fatty acid deficiency), in 17 patients within four days of commencement of the infusion. Administration of Liposyn prevented the development of biochemical evidence of essential fatty acid deficiency. There were no clinical side effects attributable to the emulsion. Elevation of serum triglyceride and liver enzyme concentrations occurred in some patients.
Effect of Lateral Posture on Epidural Blockade for Surgery
Authors: Seow L. T. , Lips F. J. , Cousins M. J.
Published: January 2019

In a prospective double-blind study, single-dose lumbar epidural blockade was administered to 60 healthy patients undergoing lower abdominal surgery, the patients lying in the lateral position only during the time of injection of the local anaesthetic. Solutions used were bupivacaine HCl 0.5%, lignocaine HCl 2% and lignocaine-bupivacaine mixtures in the ratios of 1:3, 1:1 and 3:1 by volume. Data were pooled and analysed for the effects of posture on epidural blockade. Using skin temperature as a criterion of sympathetic blockade, onset of blockade was more rapid and there was more prolonged blockade on the dependent side. Initial onset of sensory blockade was faster on the dependent side by I minute and 3.1 minutes for partial and complete blockade, respectively. Mean duration of sensory blockade was longer in the dependent dermatomes for partial (14, SD 7, minutes, T6-L4) and complete blockade (20, SD 6, minutes, T8-L3) respectively. Initial onset of complete motor blockade was 5 minutes more rapid on the dependent side, with mean myotome score consistently greater at all time intervals on the dependent side. Our study therefore suggests that a more efficacious sensory and motor blockade could be achieved by lying the patient on the operative side during the administration of the epidural and injection of the local anaesthestic solution close to the operative dermatomes.
Clinical Trial of Continuous Infusion of Alphaxalone/Alphadolone in Intensive Care Patients
Authors: Stewart G. O. , Dobb G. J. , Craib I. A.
Published: January 2019

The safety and efficacy of prolonged infusion of alphaxalone/alphadolone (Alfathesin: Glaxo) was assessed in 20 critically ill patients needing sedation during intermittent positive pressure ventilation in a general intensive care unit. The mean dose of Alfathesin infused was 1542 ml (range: 225 to 4820 ml) over 6.9 days (3 to 16 days) at rates between 5 and 15 ml/hour. Significant increases in plasma urea, creatinine, bilirubin, alkaline phosphatase and white cell count occurred during the infusion, but these were expected from each patient's clinical course. Lipoprotein electrophoresis invariably showed loss of the alpha band and appearance of a densely staining pre-beta band. Four patients had involuntary movements during the infusion and two patients fitted when the infusion stopped. Both had cerebral injuries. Subjective assessment of the quality of sedation was “very good” or “good” in 15 patients and “fair” in five.
Intravenous Access: A Comparison of two Methods
Authors: Duffy B. L. , Lee J. S.
Published: January 2019

The reliability in providing a continued venous route to the circulation is compared between a winged needle (Abbott “Butterfly — 23 INT”) and a plastic catheter (Jelco Teflon “Catheter Placement Unit”, 22 gauge). The catheter remained within the vein in all cases and had a much lower incidence of total obstruction during the study period. Where an intravenous infusion is not in place, a plastic catheter provides a more reliable access route to the circulation than does a winged needle.
Protection against Acid Pulmonary Aspiration with Cimetidine
Authors: Brock-Utne J. G. , Downing J. W. , O'Keefe S. J. D. , Gjessing J.
Published: January 2019

Gastric pH values were studied prior to, and up to, ninety minutes after an intravenous injection of cimetidine 200 mg given before general anaesthesia, in twenty surgical patients, all with a gastric pH < 3.5. At thirty, sixty and ninety minutes, sixteen, eighteen and twenty patients had a gastric pH>3.5 respectively. In conclusion, the results of the present study indicate that cimetidine 200 mg given intravenously 90 minutes before surgery will reduce the hazard of chemical pneumonitis should stomach content be aspirated.
pH Testing Paper for Measurement of Intragastric Acidity: An Assessment
Authors: More David G. , Boutagy John , Shenfield Gillian M.
Published: January 2019

Regular evaluation of the pH of aspirated gastric juice is an important part of the routine prevention of the stress ulceration syndrome. This study has examined the use of commercially available pH paper for this purpose. Both clear buffer solutions and samples of gastric aspirate were used to assess the reliability of four products, Merck Universal pH Indicator strips (Art. 9535), Lyphan Universal pH Indicator paper, Whatman Wide Range pH paper and Macherey-Nagel Universal pH paper. The results show that the Merck strips and Lyphan paper are very reliable for measuring gastric aspirate pH and that intensive care nursing staff can make accurate observations when using these papers.
Detection of Serum IgE Antibodies that React with Alcuronium and Tubocurarine after Lifethreatening Reactions to Muscle-relaxant Drugs
Authors: Baldo B. A. , Fisher M. McD.
Published: January 2019

Although anaphylactoid reactions to muscle-relaxant drugs are now well recognised, there has been no general agreement on the mechanism(s) underlying the responses.

By covalently coupling alcuronium and tubocurarine to a solid phase carrier and using the resultant complexes in radioimmunoassay experiments with patients’ sera and 125I-anti-human IgE, we have found high levels of drug-specific IgE antibodies in the sera of some subjects who reacted to these muscle relaxants.

These results provide important supporting evidence that, in some patients at least, lifethreatening anaphylactoid reactions to muscle-relaxant drugs are mediated by drug-specific IgE antibodies.
Anaesthesia and the Mucopolysaccharidoses: A Survey of Techniques and Problems
Authors: Kempthorne P. M. , Brown T. C. K.
Published: January 2019

Mucopolysaccharide infiltration of tissues in Hurler, Hunter, San Filippo, Maroteaux-Lamy, Morquio and Scheie syndromes causes problems to anaesthetists in the management of the airway and in myocardial function. Recent experience at the Royal Children's Hospital, Melbourne, is presented with illustrations highlighting these problems.
Pancuronium Requirements during Hypothermic Cardiopulmonary Bypass in Man
Authors: Futter Malcolm E. , Whalley David G. , Wynands J. Earl , Bevan David R.
Published: January 2019

Eight patients were studied to determine the changes in pancuronium requirements during hypothermic cardiopulmonary bypass. They were anaesthetised with fentanyl as the principal agent, ventilated with oxygen and the neuromuscular junction was monitored using train-of-four stimulation. After a bolus dose of pancuronium an infusion was used to maintain the first twitch of the train-of-four at 5-15 per cent of control. Before bypass the mean pancuronium infusion rate was 0.52 (SD 0.16) μg/kg/min. There was a small, brief increase in requirement with the initiation of bypass to 0.62 (SD 0.38) μg/kg/min, which was followed by a decrease of more than 80 per cent during hypothermia to 0.08 (SD 0.03) μg/kg/min. Rewarming was associated with a rapid increase in requirement to 0.64 (SD 0.17) μg/kg/min, which decreased to 0.33 (SD 0.23) μg/kg/min when normothermia was re-established.
Cerebral Perfusion and Cerebral Protection during Carotid Endarterectomy
Authors: McMeniman W. J. , Kam P. C. A.
Published: January 2019

The relative safety of carotid endarterectomy depends upon surgical expertise combined with appropriate monitoring of cerebral perfusion and the ability to intervene either surgically or pharmacologically to match cerebral perfusion to cerebral oxygen requirement.

Methods of monitoring adequacy of cerebral perfusion are reviewed and include regional cerebral blood flow measurements, electroencephalographic monitoring, carotid stump pressure measurements, jugular venous oxygen partial pressure, neurological assessment and plethysmographic techniques.

When cerebral perfusion is inadequate, such procedures as insertion of a temporary bypass shunt and maintenance of normocarbia may improve cerebral perfusion. Anticoagulants along with pharmacologic intervention to either increase cerebral perfusion pressure or reduce cerebral oxygen requirement may be used to preserve cerebral function.
A Quadruple-Lumen Intravenous Infusion Catheter
Authors: Gatt Stephen P. , Lawrence John C.
Published: January 2019

A 5 French gauge, 30 cm usable length, radio-opaque, colour-coded quadruple-lumen catheter has been designed for simultaneous multiple central drug infusion and central venous pressure measurement. Concentrated drug infusions can be administered without interruption for pressure measurements. It eliminates the risk of inadvertent bolus administration of concentrated drug solutions during flushing of lines or administration of “push-doses” of other injections into the same infusion line. The problems of chemical incompatibilities and drug interactions are reduced. The system may help reduce complications in patients requiring complex intravenous therapy and pressure measurement.
A Multiple-purpose Automatic Pressure Regulator
Authors: Cameron P. D. , Oh T. E. , Jack I.
Published: January 2019

The Gairdner Hospital Automatic Pressure Regulator was developed to deliver a constant preset gas pressure for the continuous inflation of infusion pump cuffs or pneumatic tourniquets. It has been found to be economical, safe, reliable and easy to use. The device facilitates both continuous flushing of catheters and rapid intravenous infusions especially during emergency situations. It may also be used in other clinical situations where a continuous gas supply at a preset constant pressure is required.
Anaesthesia and the Kidney
Authors: Cousins Michael J. , Skowronski George , Plummer John L.
Published: January 2019

Applied anatomy and physiology of the kidney are briefly reviewed. This includes an account of renal blood flow, glomerular filtration rate, juxtaglomerular apparatus, renal autoregulation and intra-renal blood flow distribution, tubular transport mechanisms, solute handling in proximal tubule, function of loop of Henle and distal tubule system. This section concludes with a summary of changes in tubule fluid along the length of the nephron.

Acute effects of anaesthesia are reviewed in detail. Indirect effects include those on circulatory and sympathetic nervous systems, autoregulation, endocrine systems such as those involving antidiuretic hormone, adrenaline and noradrenaline, renin-angiotensin and aldosterone. Direct effects of anaesthesia on renal function have now been confirmed both in vitro and in vivo.

Delayed direct nephrotoxicity of anaesthetics relates predominantly to methoxyflurane (MOF) and its metabolism to inorganic fluoride. Other factors are MOF dose, genetics, age, enzyme induction, obesity, other nephrotoxic drugs. Clinical implications are presented. Enflurane nephrotoxicity is rare but aetiologic factors are similar to the foregoing. Isoflurane and halothane are not nephrotoxic.

A consideration of the influence of anaesthetic management on the incidence and severity of postoperative acute renal failure concludes the review.
Anaesthesia for the Patient with Impaired Renal Function
Authors: Maddern Peter J.
Published: January 2019

Patients with renal disease are at risk of further deterioration of renal function and acute tubular necrosis when subjected to anaesthesia and surgery. Optimal fluid loading and careful selection of anaesthetic techniques and agents, appropriate monitoring and the use of mannitol and dopamine assist in the maintenance of renal blood flow and help preserve renal function in these patients. In association with renal failure, physiological changes in other systems result in reduced oxygen supply to the tissues, metabolic disturbances, impairment of the coagulation and immune defence mechanisms and an increased risk of cardiac and cerebrovascular catastrophe. Although many anaesthetic techniques including regional analgesia may be used successfully in these patients caution with most drugs, especially pethidine, phenoperidine, suxamethonium and all non-depolarising neuromuscular relaxants is recommended. Of the volatile anaesthetics currently available, halothane is the agent of choice. Oxygen therapy and close monitoring of cardiorespiratory function are necessary postoperatively.
Pharmacokinetics in Renal Failure
Authors: Nancarrow C. , Mather L. E.
Published: January 2019

A knowledge of pharmacokinetic principles is essential to understand dosage modification for drugs used in patients in renal failure. Dosage modification is indicated either where drugs have a low therapeutic index, or where renal mechanisms play a major role in drug elimination. Drug renal clearance can be indexed to creatinine clearance in order to gauge the degree of drug elimination impairment. Two schemes of dosage modification have been proposed; dosage interval extension or dosage size reduction. In addition to effects on drug elimination, renal failure may also alter drug absorption, distribution, protein binding and metabolism. Dialysis regimens, by eliminating drugs to a greater or lesser degree, have implications for drug therapy.
The Renin Angiotensin System — Its Physiology and Role in Disease States
Authors: Stokes G. S.
Published: January 2019

The renin-angiotensin system is one of a number of interlinked mechanisms regulating vascular resistance and blood volume. Under certain conditions it may become a predominant factor in maintaining vascular tone. Knowledge about these conditions (sodium depletion, mineralocorticoid deficiency, renovascular hypertension and iatrogenic hyperreninaemic states) is important for the safe and effective use of drugs which inhibit the renin-angiotensin system. Measurements of plasma renin activity are useful in the diagnostic assessment of hypertensive patients with hypokalaemia or evidence of renal artery stenosis. They may also have a place in the management of refractory or dialysis-resistant hypertension. Their use in the selection of antihypertensive therapy for the individual patient is controversial. Sequential measurements of plasma renin are helpful in analysing states of electrolyte depletion, and in titrating therapy for Addison's disease.
Pharmacology of Agents Acting on the Renin-Angiotensin System
Authors: Johnston C. I. , Jackson B.
Published: January 2019

The renin-angiotensin system is the most important hormonal system in the control of blood pressure. It can be blocked at several steps in its reaction pathway. Angiotensin-converting enzyme, or kininase II, is responsible for catalysing the formation of vasoconstrictor angiotensin II as well as for the breakdown of the vasodilator bradykinin. With the advent of specific orally active angiotensin-converting enzyme inhibitors (captopril and enalapril) a practical and effective means of blocking angiotensin formation is now clinically available.

ACE inhibitors are effective long-term therapy in patients with essential hypertension. They are particularly useful in the treatment of severe accelerated drug-resistant hypertension and renovascular hypertension, and the agents of choice for afterload reduction in severe congestive cardiac failure. They have several pharmacological advantages, important in anaesthetic practice, over other hypotensive agents. They have no central nervous or autonomic nervous system effects. Thus, patients being treated with ACE inhibitors retain normal sympathetic cardiovascular responses.
Lorazepam in Open-Heart Surgery — Plasma concentrations before, during and after bypass following different dose regimens
Authors: Boscoe M. J. , Dawling S. , Thompson M. A. , Jones R. M.
Published: January 2019

Thirty-six patients (29 males and 7 females) undergoing open-heart surgery received one of three different dose regimens of lorazepam. All received a weight-related oral dose (2 mg, 3 mg or 4 mg) pre-operatively for night sedation. Twenty-four patients had an additional weight-related dose (2 mg, 3 mg or 4 mg intravenously) either as part of the induction (12 patients) or just prior to connection of the heart-lung machine (12 patients).

Plasma concentrations of lorazepam were measured 20 minutes after induction, immediately before bypass, 30 and 60 on bypass and 30 minutes after bypass. Only when additional intravenous lorazepam was given prior to connection to the heart-lung machine were plasma lorazepam concentrations obtained compatible with complete amnesia.
Use of a Pharyngeal Guide to Aid Intubation with the Fibreoptic Laryngoscope
Authors: Hogan K. , Harpur M. H. , Pollard B. J.
Published: January 2019

The fibreoptic laryngoscope is a difficult instrument to master in anaesthetised patients, and reasons for this are discussed. The use of a pharyngeal guide was shown to provide an acceptable success rate in patients without anatomical deformity. These guides may also be beneficial to those with such deformities.
The Effects of Gallamine and a Mixture of Pancuronium and Alcuronium on the Pressor and Plasma Catecholamine Responses to Tracheal Intubation
Authors: Cummings Mary F. , Russell W. J. , Frewin D. B. , Miller Wendy A.
Published: January 2019

Tracheal intubation can be accompanied by significant increases in arterial pressure, heart rate and the plasma levels of noradrenaline and adrenaline. The drugs used at induction can enhance or attenuate these responses. In nine patients who had received gallamine, intubation was associated with a 45% rise in mean arterial pressure, a twofold rise in plasma adrenaline and a 49% rise in plasma noradrenaline concentration. When a mixture of pancuronium and alcuronium (in a ratio of 4:10 by weight) was used in ten patients, blood pressure fell 24% after induction and rose 49% after intubation. A 24% rise in plasma noradrenaline in response to intubation was also observed. Compared with pancuronium alone, the use of the mixture attentuates the rise in blood pressure and noradrenaline concentration associated with intubation but does not abolish them. In addition, the mixture was associated with a significant fall in blood pressure between induction and intubation, whereas this was not found with gallamine.
A Disposable Double-lumen Tracheostomy Tube — A Prototype
Authors: Taylor S. , Walford A. , McLellan I.
Published: January 2019

A prototype disposal double-lumen tracheostomy tube made of plastic has been developed and used successfully in two cases. It has definite advantages over a conventional double-lumen tube in facilitating suction and minimising the risk of kinking by virtue of its shorter length.
A Comparative Study of Techniques of Postoperative Analgesia following Caesarean Section and Lower Abdominal Surgery
Authors: Brownridge P. , Frewin D. B.
Published: January 2019

A double-blind, within-patient trial was carried out to compare intramuscular pethidine 100 mg, epidural pethidine 50 mg and epidural bupivacaine 25 mg for pain relief on the day after caesarean section or lower abdominal gynaecological surgery. Analgesia was assessed on a visual analogue pain scale. Forced expiratory volume in one second (FEV1.0) and venous plasma catecholamine levels were measured immediately before and approximately thirty minutes after each treatment. At the completion of the study the treatments were ranked in order of patient preference. Nineteen patients completed the trial.

Analgesia provided by epidural pethidine 50 mg was superior to intramuscular pethidine 100 mg (p <0.05) but not statistically better than epidural bupivacaine. There was no significant difference in the duration of analgesia between the active treatments. A mean increase in FEV1.0 of 18% occurred after both of the epidural treatments, but this did not achieve statistical significance. There was no significant change in catecholamine levels after any of the treatments. Epidural pethidine was preferred by patients over and above intramuscular pethidine and epidural bupivacaine (p <0.05).
A Comparison of Different Concentrations of Lignocaine Hydrochloride used for Topical Anaesthesia of the Larynx of the Cat
Authors: Robinson E. P. , Rex M. A. E. , Brown T. C. K.
Published: January 2019

Electromyographic (EMG) recordings were made from the intrinsic laryngeal muscles (cricothyroid, thyroarytenoid) and the diaphragm of the cat to compare the effect of the same dose of different concentrations of lignocaine hydrocholoride applied topically to the laryngeal mucosa. All concentrations of lignocaine hydrochloride tested, two, five and ten per cent, produced desensitisation of the larynx, as demonstrated by a loss of response of the crocothyroid and thyroarytenoid to mechanical stimulation of the mucosa. Desensitisation was produced in a mean of 1.80 minutes in the thirty experiments performed. Return of baseline response took significantly longer when 5 or 10% lignocaine was used compared with that when 2% was used (p <0.05). The usefulness of lignocaine hydrochloride as a topical anaesthetic for the larynx is reviewed.
2. A Study during Spontaneous Ventilation in Awake Volunteers using the Mapleson a Mode
Authors: Bradley J. P. , Marsland A. R. , Massang J. R.
Published: January 2019

Mapleson's A and D are the most efficient semiclosed nonabsorbing circuits used for spontaneous and controlled ventilation. A new device, the Multicircuit System, allows single-lever selection of Mapleson A or D functions, when used with the conventional two hoses or Mera F coaxial circuit attached. In the A mode, in a study performed on awake volunteers, the Multicircuit System with two hoses performed comparably to the Magill attachment. When coupled with the Mera F circuit as a coaxial system, the Multicircuit System was less efficient than the Magill, and had a resistance to expiration exceeding 2cm H2O pressure at a gas flow of 30 l/minute.
A Comparison of Continuous Flush Devices
Authors: Gibbs N. , Hart G. , Cameron P. D. , Thompson W. R. , Oh T. E.
Published: January 2019

Six different makes of continuous flush device were compared for reliability of flow rate and ease of use. All of the devices tested were considered suitable for flushing of vascular pressure monitoring catheters. However, flow rates were considered too variable for control of drug infusions or flushing of intracranial pressure monitoring systems.
Diazepam Mixed Micelle — Comparison with Diazepam in Propylene Glycol and Midazolam
Authors: Galletly D. C. , Wilson L. F. , Treuren B. C. , Boon B. P.
Published: January 2019

A mixed micelle formulation of diazepam was compared with midazolam and diazepam in propylene glycol for evidence of venous intolerance following IV injection. The overall incidence of venous morbidity was 17% for diazepam mixed micelle, 26% for midazolam and 90% for diazepam in propylene glycol. Diazepam mixed micelle is suggested as a preferable alternative to the standard formulation.
Factors Affecting Outcome after Chest Injury
Authors: Moore Peter G. , James Owen F. , Byth Philip L. , Simpson Ian J.
Published: January 2019

From 1978 to 1983 a total of 328 patients was admitted to Royal Newcastle Hospital Intensive Care Unit with chest injuries; 255 had other injuries as well. Of the 328, 171 developed acute respiratory failure, 174 received mechanical ventilation (159 for acute respiratory failure) and 46 died. The commonest causes of death were head injury (19), sepsis (10) and uncontrollable haemorrhage (10). Associated head (131) and/or abdominal (89) injuries tripled mortality. Those without respiratory, cardiac, renal or hepatic failure (155) had a mortality rate of 5.8% while the remainder had mortality rates of 21.6%, 12.5%, 37.5% and 100%, for respiratory (171), cardiac (8), renal (8) and hepatic (5) failures, respectively.

Shock was present on admission in 55, of whom 19 died. Sepsis developed in 59 and 14 with this complication died. Sepsis remains a potentially avoidable late cause of death and attention needs to be directed towards limiting invasive techniques of management to those which are necessary, and towards early diagnosis of abdominal injuries with early exploratory surgery.

The best chance of survival in the initial phase of injury may lie in the establishment of an integrated regional trauma centre system together with improved pre-hospital and retrieval systems.
Congenital Diaphragmatic Hernia and the Management of Persistent Foetal Circulation
Authors: Fong L. V. , Pemberton P. J.
Published: January 2019

Twenty-two cases of diaphragmatic hernia, presenting from 1978 to 1982, were reviewed. Sixteen patients presented before 24 hours of life, of whom nine survived (56%). Six were late presenters who all did well. Seven babies had ten documented episodes of persistent foetal circulation (PFC) occurring as early as three hours postoperatively, although three babies had episodes in their second week. Hyperventilation, with hand bagging, was successful in treating five out of six episodes of PFC (83%), without complication. Tolazoline caused improvement in two out of four episodes of PFC but was associated with significant complications. We recommend early and sometimes persistent use of hyperventilation by hand bagging as a means of managing PFC in diaphragmatic hernia.
The Power Spectrum Analyser as an Indicator of Cerebral Ischaemia during Carotid Endarterectomy
Authors: Ashburn M. A. , Mitchell L. B. , Dean D. F. , String S. T. , Callahan A.
Published: January 2019

Stroke is a potential major compliction of carotid endarterectomy and may be caused by cerebral ischaemia or embolisation from the operative site. Conventional EEC monitoring has been used intraoperatively to identify periods of cerebral ischaemia, but this monitoring technique can be difficult to operate and interpret in the operating room. This study reports the use of a new signal analyser, the power spectrum analyser (PSA-1, Neurologics, Inc., Nashville, Tennessee), and its impact on active patient management. Thirty-six patients undergoing carotid endarterectomies were monitored with the PSA-1 in conjunction with routine EEG. Eight patients (22%) showed evidence of ischaemia 22 times on both PSA-1 and routine EEG. At no time did the routine EEG show evidence of ischaemia when the PSA-1 did not. The PSA-1 has proven to be a reliable neurophysiologic monitor for the identification of periods of cerebral ischaemia. Use of this small, easily operated and interpreted machine could enhance safety in operating rooms lacking sufficient resources to use conventional EEG machines.
A Computer Program to Prepare and Answer Multiple Choice Questions
Authors: Worthley L. I. G.
Published: January 2019

A computer program to develop files of multiple choice questions for examination and teaching purposes is described. The program enables an examiner to prepare and modify up to 50 short answer questions with either a single or multiple correct answer format, and allows one to review the students answers individually or collectively, updating the item discrimination and difficulty indices each time a student performs the test. It also provides the option of answering the question file with or without review of the correct answer and reference.
Janet Lindsay Greig: A Pioneer
Authors: Wilson Gwen
Published: January 2019

Janet Lindsay Greig was the first women Anaesthetist in Australia; she was also the first Resident Medical Officer who later became an anaesthetist to be trained by E. H. Embley at the Royal Melbourne Hospital. Janet Greig played a pioneering role among medical women in Australia. She was a founder of the Queen Victoria Hospital, Melbourne. A brief resume is given of the history of the entry of women into the Faculty of Medicine at the University of Melbourne; of the first appointments of women as Resident Medical Officers, and of the foundation of the Queen Victoria Hospital.
The Relationship of Duration of Fast to the Volume and pH of Gastric Contents
Authors: Hutchinson B. R. , Merry A. F. , Wild C. J.
Published: January 2019

Volume and pH of gastric contents were measured after anaesthetic induction in 99 in-patients undergoing general and vascular surgery scheduled for either morning (50) or afternoon (49) lists. Significantly fewer patients in the morning group had pH values below 2.5. The mean pH value of the morning group was significantly higher than that of the afternoon group. There was a positive correlation between duration of fast and pH (the longer the more alkaline) for the groups combined. No significant relationship could be shown for any factor with volume.
Plasma Bupivacaine Concentrations following Lumbar Epidural Anaesthesia in Children
Authors: Eyres R. L. , Hastings C. , Brown T. C. K. , Oppenheim R. C.
Published: January 2019

Plasma levels of bupivacaine were measured following lumbar epidural administration of 3 mg/kg of 0.5% plain solution in sixteen children. The peak levels were generally between 1.0 and 2 μg/ml, the highest being 2.9 μg/ml. No manifestations of toxicity were observed. There was a significant positive correlation between peak plasma levels and increasing age.
A Closed Loop Microprocessor Controller for Treatment of Hypertension after Cardiac Surgery
Authors: Rosenfeldt F. L. , Chang V. , Grigg M. , Parker S. , Cearns R. , Rabinov M. , Xu W. G.
Published: January 2019

Hypertension after cardiac surgery is common and requires accurate control by carefully regulated infusions of drugs such as sodium nitroprusside. A microprocessor-based controller has been designed to close the loop between the blood pressure response and the infusion rate of a hypotensive drug. This system has been refined by computer simulation of the blood pressure response to sodium nitroprusside and by experience gained in using the controller in eleven patients in the early recovery period after cardiac surgery. The controller was able automatically to maintain blood pressure within 10% of a specified value. Provision of sophisticated safety features in automatic drug infusion controllers is essential for patient protection.
An Evaluation of Ventilator Monitoring Alarms
Authors: Myerson K. R. , Ilsley A. H. , Runciman W. B.
Published: January 2019

Thirteen commercially available ventilator monitoring alarms supplied by the distributors were evaluated. It was decided that devices with no power failure precautions or unprotected variable controls could not be recommended for general use. By these criteria only two devices could be recommended for general use as ventilator alarms and a further three as disconnect alarms; in each instance these recommendations are subject to certain reservations and suggested modifications. A ventilator alarm should be regularly serviced and checked before use and should be not used by anyone unfamiliar with the applications or limitations of that particular device.
An Approach to Posterior Femoral Cutaneous Nerve Block
Authors: Hughes P. J. , Brown T. C. K.
Published: January 2019

An approach to blocking the posterior femoral cutaneous nerve at the point where its branches emerge from below the medial border of gluteus maximus is described. This is located by inserting the needle at a point one quarter of the distance from the ischial tuberosity to the greater trochanter in the gluteal fold and then feeling two distinct losses of resistance as superficial and deep fascia are penetrated with a short-bevelled needle.
A Prospective Randomised Trial Comparing Spinal Anaesthesia using Hyperbaric Cinchocaine with General Anaesthesia for Lower Limb Vascular Surgery
Authors: Cook P. T. , davies M. J. , Cronin K. D. , Moran P.
Published: January 2019

One hundred and one patients were randomly allocated to have their peripheral vascular surgery performed under general anaesthesia (51 patients) or spinal anaesthesia (50 patients). Intraoperative haemodynamic changes were markedly different between the two groups with a higher incidence of hypotension in the spinal group (72% vs 31%) and a higher incidence of hypertension in the general anaesthesia group (22% vs 0%). Blood loss was significantly less in the spinal group (560, SD 340, ml vs 792, SD 440, ml). Postoperatively three patients from the general anaesthesia group died from causes unrelated to the anaesthesia, and one had a myocardial infarct. Two patients in the spinal group had myocardial infarcts, both had been treated for bradycardia and hypotension intraoperatively, and one died. There was a significantly higher incidence of postoperative chest infection in the general anaesthesia group (33% vs 16%). There was no significant difference between the groups in the incidence of postoperative confusion, or lower limb amputation rate or need for further surgery prior to hospital discharge.
Radial Artery Cannulation — The influence of method on blood flow after decannulation
Authors: Cronin K. D. , Davies M. J. , Domaingue C. M. , Worner M. J. , Koumoundouros E.
Published: January 2019

A prospective randomised study of two hundred patients undergoing open-heart surgery was carried out to determine if the method of radial artery cannulation (direct threading or transfixion) had any influence on the incidence of abnormal flow after decannulation. A standard 20-gauge non-tapered teflon-coated cannula was used and the groups were well matched for age, sex, wrist circumference, duration of cannulation and haematoma formation, all of which have been postulated to influence thrombosis rate. We were unable to demonstrate a statistically significant difference between the two methods of cannulation. The overall abnormal flow rate at five days assessed by Doppler ultrasound was low at 5%.
An Evaluation of Fourteen Oxygen Analysers for Use in Patient Breathing Circuits
Authors: Ilsley A. H. , Runciman W. B.
Published: January 2019

Fourteen in-line oxygen monitors designed for use in patient breathing circuits were assessed to determine the lifespans of their sensors when exposed to oxygen, their response times to a sudden change in oxygen concentration from 30% to 0%, the effects of exposure to nitrous oxide, and the effects of some agents and conditions commonly encountered in anaesthetic breathing systems by exposing the sensors repeatedly for three two-hour periods to 1% halo thane, 2% enflurane, saturated water vapour at 37 °C, 5 % carbon dioxide, or a continuous pressure of 40 mmHg. Under the conditions of this study all sensors but one exceeded the manufacturers’ claimed lifespans, and all had clinically adequate response times to sudden hypoxic changes. None had significantly altered responses when repeatedly exposed to nitrous oxide. Water vapour was the most common cause of error for both polarographic and galvanic cell sensors, although some errors occurred with each of the test conditions; errors from all causes occurred evenly throughout the lifespans of both types of sensor. The incidence of over-read errors was approximately equal to that of under-read errors. However, clinically potentially dangerous over-read errors of greater than 6% oxygen did not occur in any of the sensors, with the exception, on some occasions, of the Datex Oxygen Analyser when exposed to saturated water vapour at 37°C.
Autologous Blood Transfusion for Major Vascular Surgery Using the Sorenson Receptal Device
Authors: Davies M. J. , Cronin K. C. , Moran P. , Mears L. , Booth R. J.
Published: January 2019

Twenty-five patients having aortic surgery had blood scavenged using the Sorenson Receptal Device (Group A) and were compared with twenty-five patients having homologous blood transfusion (Group H). Mean intraoperative blood loss was similar in both groups, Group A 3224 (SD 2392) ml, Group H 2999 (SD 1579) ml, but the mean homologous blood replacement was significantly different intraoperatively, Group A 1.2 (SD 1.7) units, Group H 2.7 (SD 1.8) units. Total intra-hospital homologous blood replacement was not significantly different, Group A 4.0 (SD 3.4) units, Group H 5.5 (SD 5.8) units. Mean haemoglobin concentration in the scavenged blood was 8.5 (SD 2.1) g/dl compared to 10.8 (SD 2.4) g/dl in the median aged homologous blood units crossmatched for Group H. Mean red cell half life in the scavenged blood was the same as that for the homologous blood, 24 (SD 5) days, but plasma-free haemoglobin and bacterial contamination was greater in the scavenged blood. There was no difference in the incidence of postoperative renal dysfunction, coagulopathy or mortality between the two groups of patients.
An Evaluation of Six Disposable Heat and Moisture Exchangers
Authors: Turtle M. J. , Ilsley A. H. , Rutten A. J. , Runciman W. B.
Published: January 2019

Six disposable heat and moisture exchangers were tested on patients undergoing anaesthesia requiring mechanical ventilation. Inspiratory humidity and temperature were monitored to find the steady-state values reached with each device together with the times taken for these to be achieved. The exchangers were tested in a non-rebreathing T-piece circuit and in a conventional circle system with a fresh gas flow of 6 l/min: the Siemens 150 provided 28 and 32 mg of water/litre of inspired gas (at about 30°C) in 10 and 5 min respectively, but is rather heavy and bulky. The Portex Humidvent provided 25 and 30 mg/l, and although taking longer to reach steady state (27 and 15 min respectively) is small, light and cheap. The Siemens 151 provided 25 and 27 mg/l in 18 and 10 min respectively, but is heavier than the Portex exchanger. The performances of these three devices were not significantly different from each other in either study (P < 0.05). For the T-piece system the Pall and Engstrom exchangers were the next most efficient. The Pall device provided 18 and 23 mg/l (in 18 and 8 min respectively) and the Engstrom provided 20 and 23 mg/l (in 19 and 10 min respectively). In the circle system, there were no significant differences between the peformances of the Portex, Siemens 151, Pall and Engstrom exchangers. The Pall is also a very effective bacterial filter and has been found to be satisfactory in the intensive care setting. The Terumo appeared to perform no better than a circle system with catheter mount (13 mg/l at 27°C). It would seem that more complex humidification equipment is not necessary during anaesthesia if an efficient heat and moisture exchanger is used.
Physical Characteristics and Clinical Evaluation of a New Disposable Fibreoptic Transducer-Tipped Catheter System
Authors: Barin E. S. , Cejnar M. , Nelson G. I. C. , Hunyor S. N.
Published: January 2019

A new disposable fibreoptic transducer-tipped catheter manometer system was evaluated to assess its accuracy, stability of accuracy under prolonged simulated intra-arterial conditions, and dynamic characteristics. Maximum errors observed in the measurement of static pressure using a sample of five catheters (with one display unit) were 2 mmHg at 0 mmHg reference pressure, 2 at 20 mmHg, 4 at 40 mmHg, 4 at 100 mmHg and 9 at 200 mmHg. An immersion artifact caused a shift in baseline of up to 2 mmHg. Exposure of the transducer to 24 hours of simulated intra-arterial conditions (pulsatile pressure at 40°C) resulted in errors of up to 7 mmHg for pressures up to 100 mmHg, and 11 mmHg for 200 mmHg, which were largely attributable to a drift in baseline pressure (up 6 mmHg by 24 hours). Consistent overestimation by the system suggested inappropriate gain setting within the display unit which, however, is not user-adjustable. The system exhibited uniform frequency response up to 33 Hz.
The Position of the Larynx in Children and its Relationship to the Ease of Intubation
Authors: Westhorpe R. N.
Published: January 2019

Lateral radiographs of the upper airway of children aged from birth to puberty were used to determine the changes in position, with growth, of the tip of the epiglottis, the hyoid, the glottis, and the inferior margin of the cricoid cartilage.

There is a marked descent of these structures relative to the cervical spine during the first two years of life. Their position then remains fairly static until puberty, when further descent of laryngeal structures occurs.

Using the same methods to determine ease of laryngoscopy with the head and neck in different positions it was shown that in infants the best view is obtained with the atlanto-occipital joint fully extended and the head and shoulders on a flat surface. In adults the best view is obtained with the atlanto-occipital joint fully extended and the head resting on a low pillow. Anatomical explanations for these observations are presented.
Comparison of Propofol and Thiopentone Anaesthesia (with Special Reference to Recovery Characteristics)
Authors: Weightman W. M. , Zacharias M.
Published: January 2019

Thiopentone and propofol were used for the induction and maintenance of anaesthesia in unpremedicated patients undergoing minor gynaecological procedures. There were no significant differences in the induction and maintenance characteristics except for a high incidence of pain on injection and a greater fall in the mean systolic blood pressure associated with propofol in comparison with thiopentone. Propofol was associated with a quicker early recovery as well as a faster psychomotor recovery, as tested by a peg-board. However, complete psychomotor recovery was not achieved for up to three hours in some patients receiving propofol and so caution is advised regarding the early street fitness of patients receiving repeated doses of the drug for day case surgery.