bluuebunny/crossref_metadata_2025 huggingface dataset:
The Scientific Basis of Patient-Controlled Analgesia
Authors: Mather L. E. , Owen H.
Published: January 2019

The current practice of patient-controlled analgesia has grown from empirical observations. Although several variants of patient-controlled analgesia, bolus doses, infusions, or combinations of both, have been suggested, a scientific basis for advocating one variant over the others has been lacking. Most systems have been based on the simplest system, bolus demand, although the use of a combined bolus and background infusion method has theoretical merit. Similarly, a scientific basis for setting the variables of patient-controlled analgesia, drug choice, incremental dose, maximum dose and lockout interval, also has been lacking. Settings for these variables may be rationalised post hoc on the basis of the physicochemical properties and global pharmacokinetic properties of the opioids used but knowledge of these properties has not helped in setting the variables a priori. Foremost, the drug choice should be based on therapeutic index. Knowledge of the regional kinetics of drug (influx and efflux) from brain may provide a more logical basis for setting the patient-controlled analgesia variables but such information can only come from animal experiments. More research is required if patient-controlled analgesia is to become anything but an empirical tool in the quest for improved analgesia in patients.
Education in Anaesthesia in Australia: A Centenary
Authors: Wilson Gwen
Published: January 2019

This year marks the centenary of the beginning of teaching in anaesthesia in Australia. Until 1888 there were no appointments in anaesthesia at any hospital, but in that year two were made. A brief review of the events leading to this change is given, with an even briefer review of the main steps in the transformation of education in anaesthesia in Australia on which the present-day system is based.
A Review of the Final F.F.A.R.A.C.S. Examination 1980–1987
Authors: Paget N. S.
Published: January 2019

The Final Examination for Fellowship of the Faculty of Anaesthetists, Royal Australasian College of Surgeons has been functioning since 1956. A description of its development and an analysis carried out on the examinations in 1969 and 1970 are contained in the paper by Fisk et al. 1 Since that time the examination process has been continually monitored and refined, although the basic structure has remained much the same for the last twenty years. This report presents an analysis and interpretation of data for 1025 candidates who presented themselves for the examinations from May 1980 until October 1987. Recent development within the Faculty is described to indicate the influence these events have had upon the training and examination of candidates for the Fellowship, and statistical data is provided to illustrate the effectiveness of the examination process. Recommendations include possible directions that could be taken to enhance both the training and examination of candidates for the Fellowship examination in the future.
An Evaluation of Eight Peripheral Nerve Stimulators for Monitoring Neuromuscular Blockade
Authors: Beemer G. H. , Reeves J. H.
Published: January 2019

The features of eight commercially available peripheral nerve stimulators were compared with those evolved as ideal for monitoring neuromuscular blockade. The pulse waveforms were satisfactory except for that delivered by the CIG series 80 nerve/muscle stimulator. The error in timing of the stimulation patterns was up to 60% in the Professional Instruments NS-2C compared with 8% or less in the other devices. All of the stimulators had maximum current outputs suitable for monitoring with surface stimulating electrodes. The current delivered by the CIG series 80 nerve/muscle stimulator and the Stimlocator SL1.4 sagged by 21% and 25% respectively during a tetanus. The Digistim III, Bard Biomedical 750 digital and the Professional Instruments NS-2C had accurate digital readouts of delivered current.
Dopamine and Renal Salvage in the Critically Ill Patient
Authors: Duke G. J. , Bersten A. D.
Published: January 2019

Dopamine is a catecholamine used widely in critically ill patients and those undergoing major surgery, often as a ‘renal protective’ agent. Direct renal vasodilatation with ‘low-dose’ dopamine is the widely accepted basis for its use – hence the term ‘renal dose’ dopamine.

However, recent evidence has revealed that the renal effects of this agent are far more complex. Moreover, some of these effects may be undesirable in the ‘at-risk’ kidney.

The increased renal blood flow (RBF) of dopamine may be largely attributable to its inotropic (myocardial) action, even with low doses (i.e. < 5 μg/kg/min). Similar increases in RBF can also be demonstrated with other (non-dopaminergic) inotropes. The early evidence for direct renal vasodilatation in response to dopamine has been brought into question by more recent research.

The diuresis and natriuresis commonly seen following dopamine administration is now known to be due to a direct renal tubular (or ‘diuretic’) action.

Furthermore, increasing knowledge regarding the pathophysiology of acute (ischaemic) renal failure, including RBF and the concept of ‘oxygen supply and demand’ in relation to tubular function, suggests that dopamine may mask important signs of renal ischaemia. Whether or not dopamine is truly beneficial to renal function currently remains unanswered. As it stands however, there is sufficient evidence to question its routine use in the setting of renal dysfunction in the critically ill patient.
An Evaluation of Prolonged Oximetric Data Acquisition
Authors: Jones R. D. M. , Lawson A. D. , Gunawardene W. M. S. , Roulson C. J. , Brown A. G. , Smith I. D.
Published: January 2019

Data derived from pulse oximetry has inherent limitations, one of which is artifactual desaturation caused by patient movement. Perioperative patterns of oxygen desaturation were studied for a mean duration of 67 hours in eight young patients following corrective spinal surgery. Pulse oximetry data were relayed to a computer using Satmaster, a program which permits storage, retrieval, signal evaluation and statistical analysis of oximetry data. Desaturation episodes were mild, of short duration and their infrequent occurrence was not increased during intravenous morphine infusion. Retrospective identification of contemporaneous artifactual changes in signal amplitude permitted the removal of artifactual desaturations from our statistical data analysis. This decreased the average time desaturated from 5.4% (220 minutes) to 4.2% (162 minutes) of the monitored period representing a 25% reduction in absolute incidence and a 35% reduction in episodic incidence of desaturation. Acquired data should be validated and inferences drawn from non-validated data must be assessed with caution.
Contamination of Anaesthetic Tubing – a Real Hazard?
Authors: Ibrahim J. J. , Perceval A. K.
Published: January 2019

This study aimed to find whether a patient placed on an anaesthetic machine could contaminate the tubing resulting in possible cross-infection to subsequent patients. Twenty randomly chosen anaesthetic circuits were collected after use during operations and cultured for bacteria and fungi. These were compared with ten circuits which had been washed and dried. Another ten washed circuits were attached to an anaesthetic machine and each circulated with air for four hours before similar cultures were performed. No accepted respiratory pathogens were found contaminating the tubing in any of the above situations. Cleaned circuits purposely seeded with either ‘viridans streptococci’ or staphylococcal bacteriophage were attached to an anaesthetic machine, the other end being held over an air sampler to collect organisms which might be blown out. Seeded tubing did not contaminate the air passing through it, demonstrating that dry anaesthetic gases do not facilitate pick-up and carriage of microorganisms.
Accuracy of the BoMED NCCOM3 Bioimpedance Cardiac Output Monitor during Induced Hypotension: An Experimental Study in Dogs
Authors: Tibballs J. , Hochmann M. , Osborne A. , Carter B.
Published: January 2019

Changes in thoracic electrical bioimpedance during the cardiac cycle are utilised by the BoMed NCCOM3 monitor to measure cardiac output (COTEB). The technique provides a continuous noninvasive measurement but it has not been widely accepted. To determine the accuracy of the monitor, we compared its measurement with cardiac output measured by dye dilution (COdd) during induced hypotension and recovery in 23 dogs. After calibration of the NCCOM3 monitor during a resting state in each dog [mean blood pressure 112 ± 17 (SD), mean CODD 3.22 ± 0.99 l/min], the mean difference (COTEB-CODD) between paired measurements at the nadir of hypotension (bloodpressure 55 ± 24 mmHg) was 0.29 ± 0.47 l/min whose limits of agreement (mean difference ± 2 SD) were + 111.8% and -59.1% of the mean hypotensive COdd (110 ± 0.66 l/min). Upon recovery from hypotension (mean blood pressue 102 ± 20 mmHg), the mean difference between paired measurements was -0.28 ± 0.66 l/min, whose limits of agreement were +44.1% and -67.8% of the mean CODD (2.36 ± 1.01 l/min). The mean difference between the two techniques is too variable and excessive to permit substitution of one technique for the other. These results do not support the accuracy and reliability of the BoMed NCCOM3 cardiac output monitor.
Obstetric Epidural Services in Rural South Australia
Authors: Watts R. W.
Published: January 2019

A survey of sixty South Australian country hospitals found that 35 units had more than 25 deliveries per year (total deliveries 4,247, which is 21.5% of total live births in South Australia during 1989). Twenty-five of these units had an epidural service (71%) and the overall epidural rate was 16.7%, 9.5% provided by general practitioner anaesthetists and 7.2% by specialists.

General practitioner anaesthetists were involved more in the medium-sized units (50–200 deliveries per year), whereas specialists provided more services in the larger regional units and the small units as visitors. The epidural rate varied between 6–20% depending on the size of the unit.

Most country regions in South Australia have reasonable access to an epidural service. The more geographically isolated areas are being serviced by general practitioner anaesthetists.
Hazards of Bacterial Contamination of Blood Products
Authors: Gottlieb T.
Published: January 2019

Post-transfusion bacterial sepsis is infrequent. It is, however, associated with a high mortality due to septic shock. This reflects the release of endotoxin from gram negative bacteria. Lesser transfusion reactions are usually under-reported. These are frequently caused by gram positive bacteria. Gram positive species such as staphylococci and other skin surface organisms may be cultured from platelets stored at room temperature. Typically, gram negative “psychrophyllic” species which survive storage at 4°C are cultured from stored refrigerated blood implicated in transfusion reactions. These include Yersinia enterocolitica, Pseudomonas fluorescens etc. Bacterial contamination of the blood supply can occur via an endogenous or an exogenous source. Endogenous donor bacteraemia due to Y.enterocolitica may be asymptomatic or may follow an episode of gastroenteritis. Exogenous infections occur through some defect in the usual collection practice. Transfusion-acquired syphilis is now extremely uncommon. In the third world, beside the need for effective screening for viral pathogens, infections with protozoa, in particular plasmodia, trypanosoma and leishmania remain a major obstacle to ensuring safe blood supplies. Prevention of transfusion reactions demands rigorous attention to details of collection, storage, reissuing and infusion of blood products, as well as prompt treatment, testing and reporting of suspected reactions.
Transfusion Transmitted Infection: Viral and Exotic Diseases
Authors: Wylie B. R.
Published: January 2019

Viral and other exotic diseases may be transmitted by blood transfusion. These infections include human immunodeficiency virus (HIV), hepatitis viruses (A, B, C, D and E), syphilis, malaria, retrovirus HTLV-1, and cytomegalovirus. Other more exotic diseases which may be transmitted by transfusion of blood or blood components include Chagas’ disease (Trypanosomiasis cruzi), Lyme disease (Borrelia burgdorferi), and Jakob-Creutzfeldt disease.

Screening procedures currently used in Australian blood banks minimise transfusion-transmitted infection. The risk of acquiring any infection in this manner may be less than 0.1%.
Blood Transfusion Related Adult Respiratory Distress Syndrome
Authors: Malouf M. , Glanville A. R.
Published: January 2019

Adult respiratory distress syndrome (ARDS) is a rare but important complication of blood transfusion because it has a mortality rate of 50–60%. ARDS is characterised by noncardiogenic pulmonary oedema and is often associated with major trauma and/or sepsis. Clinical features include dyspnoea, tachypnoea, chills and extensive crepitations. The pathogenesis has not been elucidated completely and a number of hypotheses have been proposed. Factors which have been implicated include neutrophil sequestration and complement activation, macrophages, metabolites of the arachidonic acid cascade and cytokines, all of which contribute to the amplification of the inflammatory process. In particular, leucoagglutinins have been implicated with blood transfusions. Treatment is generally supportive as specific therapeutic strategies remain largely unproven.
Noninvasive Monitoring of Tidal Volume with an Extensometer: Laboratory and Clinical Studies
Authors: Brimacombe J.
Published: January 2019

The extensometer or “rubbery ruler” (RR) is a new torso transducer with potential application in the field of respiratory pattern analysis. This paper determines whether the RR can measure tidal volume over a clinically useful timeframe following spirometric calibration. Laboratory testing identified no error or baseline drift during 774,000 controlled stretches. Clinical testing in a variety of patients demonstrated that 96.6% of derived spirometric values were contained within an error range of +15.2% to -16.9% of spirometrically measured tidal volume and that accuracy did not change over a period of one hour. These results are encouraging and suggest that this device merits further investigation.
Vecuronium-Thiopentone Induction for Emergency Caesarean Section under General Anaesthesia
Authors: Teviotdale B. M.
Published: January 2019

Induction of general anaesthesia for emergency caesarean section has always been hazardous. Acid aspiration syndrome1 and adverse reactions to suxamethonium1- are well recognised problems, in spite of which “crash” induction using thiopentone and suxamethonium remains a common induction technique.4

Recent case reports-1 suggest that the use of medium duration nondepolarising relaxants in place of suxamethonium achieves satisfactory intubating conditions in the emergency caesarean section patient.

This study was undertaken to investigate the following aspects of rapid-sequence vecuronium-thiopentone induction for emergency caesarean section.

1. To establish whether 8 mg of vecuronium provides effective intubating conditions. 2. To establish whether placental transfer of vecuronium used in the above dosage has any clinically detectable effect upon the newborn. 3. To establish the limit of lead time by which vecuronium may precede thiopentone to minimise the dangerous period between loss of consciousness and intubation. 4. To detect instances of acid regurgitation or aspiration. 5. To confirm that relaxant reversal is clinically effective at the completion of surgery.

In this series of thirty cases, vecuronium 8 mg preceding thiopentone 250 mg and atropine 0.6 mg by 20 seconds provided effective induction and easy intubating conditions without clinical effects on the newborn, maternal acid aspiration, or clinical signs of persistent paralysis after reversal.
A Comparison of Effects of Fixed and Tailored Cardiopulmonary Bypass Flowrates on Renal Function
Authors: Valentine S. , Barrowcliffe M. , Peacock J.
Published: January 2019

Cardiopulmonary bypass may result in renal impairment but there is little investigative data on the effect of differing flowrates on postoperative renal function. One hundred and twenty-two patients presenting for cardiac surgery were randomly assigned to receive either a fixed CPB flow of 2.4 l.m-2 or a bypass flow tailored to maintain a venous return oxygen saturation of 75–80%. Vasoactive drugs were given to maintain a perfusion pressure of 50 to 80 mmHg. Patients were assessed by serum creatinine, creatinine clearance, arterial blood gases, serum lactates and electrolytes. The results show an overall decline in postoperative renal function compared with preoperative levels, with no significant differences between the two groups.
“Don't Turn the Needle!”
Authors: Duffy B. L.
Published: January 2019

Accidental dural puncture is a well-recognised complication of epidural anaesthesia. The technique of inserting the epidural needle with the bevel parallel to the spinal ligaments is still taught in some centres. Evidence is presented that the subsequent turning of the needle to allow passage of the epidural catheter may increase the likelihood of dural puncture. There would also appear to be a greater chance of subdural catheterisation. The epidural needle should be introduced with the bevel in the direction in which the catheter is to go and not moved once the epidural space is located.
Errors, Incidents and Accidents in Anaesthetic Practice
Authors: Runciman W. B. , Sellen A. , Webb R. K. , Williamson J. A. , Currie M. , Morgan C. , Russell W. J.
Published: January 2019

Human error is a pervasive and normal part of everyday life and is of interest to the anaesthetist because errors may lead to accidents. Definitions of, and the relationships between, errors, incidents and accidents are provided as the basis to this introduction to the psychology of human error in the context of the work of the anaesthetist. Examples are drawn from the Australian Incident Monitoring Study (AIMS). An argument is put forward for the use of contemporaneous incident reporting (eliciting relevant contextual information as well as details of use to cognitive psychologists), rather than the use of accident investigation after the event (with the inherent problems of scant information, altered perception and outcome bias). A classification of errors is provided. “Active” errors may be classified into knowledge-based, rule-based, skill-based and technical errors. Different strategies are required for the prevention of each type and it may now be useful to place more emphasis in anaesthetic practice on categories to which little attention has been directed in the past. “Latent” errors make an enormous contribution to problems in anaesthesia and several categories are discussed (e.g. environment, physiological state, equipment, work practices, personnel training, social and cultural factors). An approach is provided for the prevention and management of errors, incidents and accidents which allows clinical problems to be categorized, the relative importance of various contributing factors to be established, and appropriate preventative strategies to be devised and implemented on the basis of priorities determined from the AIMS data. Accidents cannot be abolished; however, an understanding of the factors underlying them can lead to the rational direction of resources and effort to prevent them and minimise their effects.
Which Monitor? An Analysis of 2000 Incident Reports
Authors: Webb R. K. , Van Der Walt J. H. , Runciman W. B. , Williamson J. A. , Cockings J. , Russell W. J. , Helps S.
Published: January 2019

The role of monitors in patients undergoing general anaesthesia was studied by analysing the first 2000 incidents reported to the Australian Incident Monitoring Study; 1256 (63%) were considered applicable to this study. In 52% of these a monitor detected the incident first; oximetry (27%) and capnography (24%) detected over half of the monitor detected incidents, the electrocardiograph 19%, blood pressure monitors 12%, a low pressure (circuit) alarm 8%, and the oxygen analyser 4%. Of the other monitors used, 5 first detected 1–2% of incidents, and the remaining 8 less than 0.5% each. The oximeter would have detected over 40% of the monitor detected incidents had its more informative modulated pulse tone always been relied upon instead of the “bleep” of the ECG.

A theoretical analysis was then carried out to determine which of an array of 17 monitors would reliably have detected each incident had each monitor been used on its own and had the incident been allowed to evolve. To facilitate “scoring” of monitors, the incidents were categorized empirically into 60 clinical situations; 40% of applicable incidents were accounted for by only 5 clinical situations, 60% by 10 and nearly 80% by 20. 98% were accounted for by the 60 situations. A pulse oximeter, used on its own, would theoretically have detected 82% of applicable incidents (nearly 60% before any potential for organ damage). These figures for capnography are 55% and 43 % and for oximetry and capnography combined are 88% and 65%, respectively. With the addition of blood pressure monitoring these become 93% and 65%, and of an oxygen analyser, 95 and 67%. Other monitors, including the ECG, each increase the yield by by less than 0.5%.

The international monitoring recommendations and those of the Australian and New Zealand College of Anaesthetists are thoroughly vindicated by the patterns revealed in this study. The priority sequence of monitor acquisition for those with limited resources should be stethoscope, sphygmomanometer, oxygen analyser if nitrous oxide is to be used, pulse oximeter, capnograph, high pressure alarm, and, if patients are to be mechanically ventilated, a low pressure alarm (or spirometer with alarm); an ECG, a defibrillator, a spirometer and a thermometer should be available.
The Pulse Oximeter: Applications and Limitations—An Analysis of 2000 Incident Reports
Authors: Runciman W. B. , Webb R. K. , Barker L. , Currie M.
Published: January 2019

The first 2000 incidents reported to the Australian Incident Monitoring Study were analysed with respect to the role of the pulse oximeter. Of these 184 (9%) were first detected by a pulse oximeter and there were a further 177 (9%) in which desaturation was recorded.

Of the 1256 incidents which occurred in association with general anaesthesia 48% were “human detected” and 52% “monitor detected”. The pulse oximeter was ranked first and detected 27% of these monitor detected incidents; this figure would have been over 40% if an oximeter had always been used and its more informative modulated pulse tone relied upon instead of that of the “bleep” of the ECG. The pulse oximeter is the “front-line” monitor for endobronchial intubation, the fourth most common incident in association with general anaesthesia (it detected 87% of the 76 cases in which it was in use). It also played an invaluable role as a “back-up” monitor in 40 life-threatening situations in which “front-line” monitors (e.g. oxygen analyser, low pressure alarm, capnograph) were either not in use, were being used incorrectly or failed. Other situations detected, in order of frequency of detection, were: circuit disconnection, circuit leak, desaturation (severe shunt), oesophageal intubation, aspiration and/or regurgitation, pulmonary oedema, endotracheal tube obstruction, severe hypotension, failure of oxygen delivery, hypoxic gas mixture, hypoventilation, anaphylaxis, air embolism, bronchospasm, malignant hyperthermia, and tension pneumothorax.

There were 15 reports of “failure”; four because the model in use had no modulated tone or alarm, four in which performance was in fact adequate, three were probe problems, two involved “over-reading”, one “under-reading” and in one new device the alarm failed.

In the theoretical analysis of the 1256 general anaesthesia incidents it was concluded that pulse oximetry, used on its own, would have detected 82% of these incidents, had they been allowed to evolve (nearly 60% before any potential for organ damage).

It is highly recommended that a suitable pulse oximeter be used on all patients from the time of arrival in the induction room until return of protective reflexes and demonstration of adequate saturation when breathing room air.
Blood Pressure Monitoring—Applications and Limitations: An Analysis of 2000 Incident Reports
Authors: Cockings J. G. L. , Webb R. K. , Klepper I. D. , Currie M. , Morgan C.
Published: January 2019

Of the first 2000 incidents reported to the Australian Incident Monitoring Study, 1256 occurred in relation to general anaesthesia and 81 of the latter were first detected by blood pressure (BP) monitoring. A further 25 incidents not associated with general anaesthesia were first detected by blood pressure monitoring, giving a total of 106.

In the monitor detection of incidents in relation to general anaesthesia, BP monitoring ranked fourth after oximetry, capnography and low pressure alarms. On the other hand, 38 incidents in which the problem was primarily one of significant change in BP were first detected by means other than the BP monitor (20 clinically, 12 by pulse oximetry and 6 by ECG).

Early detection rates of hypotension were 60% for invasive methods, 40% for automated non-invasive (NIBP) devices and 30% for manual sphygmomanometry.

There were 21 reports of BP monitor “failure”; the 11 of these which occurred with NIBPs involved unexplained false “low” or “high” readings and failure to detect profound hypotension, and led to considerable morbidity and at least one death. The 10 cases of invasive monitoring failure were predominantly due to mains power loss, hardware breakage or operator error.

In a theoretical analysis of the 1256 GA incidents, it was considered that on its own, BP monitoring would have detected 919 (73%), but in the vast majority, by the time this detection has occurred, potential organ damage could not be excluded.

It is recommended that BP be measured at regular intervals dictated by clinical requirements (usually at least every five minutes). BP monitoring should be supplemented by other modalities in accordance with the College of Anaesthetists guidelines and when immediate and reliable detection of change in BP is critical, invasive monitoring should be used.
The Oxygen Analyser: Applications and Limitations – An Analysis of 2000 Incident Reports
Authors: Barker L. , Webb R. K. , Runciman W. B. , Van Der Walt J. H.
Published: January 2019

The first 2000 incidents reported to the Australian Incident Monitoring Study were analysed with respect to the role of the oxygen analyser; 27 (1%) were first detected by the oxygen analyser. All of these were amongst the 1256 incidents which occurred in association with general anaesthesia, of which 48% were “human detected” and 52% “monitor detected”. The oxygen analyser was ranked 7th and detected 4% of these monitor detected incidents. This figure would have been much higher had the oxygen analyser been correctly used on more occasions.

The oxygen analyser detected 10 ventilator-driving-gas leaks into the circuit, 6 hypoxic mixtures due to rotameter settings, 3 inappropriate nitrous oxide concentrations, 2 disconnections and 1 leak at the common gas outlet, and 2 partial and 1 total failure of ventilation. In a theoretical analysis of these 1256 incidents it was considered that the oxygen analyser, used on its own, would have detected 114 (9%), had they been allowed to evolve (3% before any potential for organ damage).

In 4 incidents an oxygen analyser gave faulty readings, in 3 caused a leak and in one a total circuit obstruction; 5 incidents were not detected because the alarm had been disabled. Despite the advent of piped gas supplies, failure of gas delivery or delivery of a “wrong” gas mixture still occurs surprisingly frequently in current anaesthetic practice; hypoxic mixtures were supplied on 16 occasions, other “wrong” mixtures on 23 and the oxygen supply failed on 7 occasions. Failure to use and improper use of the oxygen analyser is also surprisingly common; this is mainly due to a rule-based error encouraged by the poor design of the high alarm. It is highly recommended that a suitable, correctly sited, calibrated, tested oxygen analyser be used from before pre-oxygenation until the patient is no longer breathing gas from the anaesthetic machine or circuit.
Crisis Management—Validation of an Algorithm by Analysis of 2000 Incident Reports
Authors: Runciman W. B. , Webb R. K. , Klepper I. D. , Lee R. , Williamson J. A. , Barker L.
Published: January 2019

Anaesthetists are called upon to manage complex life-threatening crises at a moment's notice. As there is evidence that this may require cognitive tasking beyond the information-processing capacity of the human brain, it was decided to try and develop a generic crisis management algorithm analogous to the “Phase I” immediate response routine used by airline pilots. Such an algorithm, based on the mnemonic “COVER ABCD, A SWIFT CHECK”, was developed and refined over 3 meetings, each attended by 60–100 anaesthetists and aviation psychologists. It was validated against 1301 relevant incidents among the first 2000 incidents reported to the Australian Incident Monitoring Study. It proved sufficiently robust and safe to recommend its general use as an initial response to any incident or crisis which occurs when a patient is breathing gas from an anaesthetic machine. It requires a limited knowledge base and is easily learnt and rehearsed during the anaesthetist's working day. It will provide a functional diagnosis in over 99% of cases and will correct 62% of the problems in 40–60 seconds. In the remaining 37% it will allow the anaesthetist to proceed with a “sub-algorithm”, confident in the knowledge that some important step has not been missed. In just over 30% of incidents this will be for a problem familiar to all anaesthetists (e.g. laryngospasm, bradycardia); in just over 6% it will be for a less common, more complex, but finite, set of problems (3% cardiac arrest, 1% air embolism, 1% anaphylaxis, 1% for the remaining desaturations); in less than 1% diagnosis and correction will require a more complex checklist (e.g. for malignant hyperthermia, pneumothorax). The next stage, the development of specific sub-algorithms and a structured team approach for ongoing problems, is in progress.
Problems before Induction of Anaesthesia: An Analysis of 2000 Incident Reports
Authors: Ludbrook G. L. , Webb R. K. , Fox M. A. , Singleton R. J.
Published: January 2019

The first 2000 incidents reported to the Australian Incident Monitoring study (AIMS) were examined to identify those incidents which occurred preoperatively (defined as occurring prior to the commencement of general or regional anaesthesia). The 35 incidents, representing 1.7% of the total, which occurred in this time period were analysed with a view to identifying areas in which current practice could be improved.

Almost all incidents led to significant delays in operating lists, and 9 resulted in cancellation of surgery. A number of areas of concern specific to the preoperative period were identified. Inadequate coordination between surgical and anaesthetic staff in patient preparation was a frequent cause of preoperative incidents. Improvement in this area may reduce surgical delays and patient morbidity.

Problems with premedication drugs resulted in 8 of the 35 incidents, and care must be taken in the prescription and administration of these drugs to minimise adverse effects on patients.

Only 2 cases of incorrect patient identification were reported. However, in view of its disastrous consequences, vigilance in patient identification by all members of the operating team, including the anaesthetist, is essential.
The ‘'Wrong Drug” Problem in Anaesthesia: An Analysis of 2000 Incident Reports
Authors: Currie M. , Mackay P. , Morgan C. , Runciman W. B. , Russell W. J. , Sellen A. , Webb R. K. , Williamson J. A.
Published: January 2019

Amongst the first 2000 incidents reported to the Australian Incident Monitoring Study, there were 144 incidents in which the “wrong drug” was nearly or actually administered to a patient. Thirty-three percent of the incidents involved ampoules and just over 40% syringes; in over half of the latter the syringes were of the same size, and also, in over half, they were correctly labelled. In 81% of the 144 incidents the “wrong drug” was actually given. This was more common with syringes (93%) than ampoules (58%). Thus the most common error was actually giving the wrong drug from a correctly labelled syringe. The most common drug involved was a muscle relaxant in both ampoule and syringe incidents. In 74% of all reports, there was the potential for serious harm to the patient; however no deaths were reported.

Factors which contributed significantly to the incidents were similar appearance, inattention and haste. “Failure of communication” was a significant factor in syringe incidents when two or more staff were involved. The only significant factor which minimised the outcome was rechecking of the syringe or drug ampoule before giving the drug.

Strategies suggested to address the “wrong drug” problem include education of staff about the nature of the problem and the mechanisms involved; colour coding of selected drug classes for both ampoules and syringes; the use of standardised drug storage, layout and selection protocols; having a drawing up and labelling convention; and the use of checking protocols.
Problems Related to the Endotracheal Tube: An Analysis of 2000 Incident Reports
Authors: Szekely S. M. , Webb R. K. , Williamson J. A. , Russell W. J.
Published: January 2019

The first 2000 incidents reported to the Australian Incident Monitoring Study were analysed with respect to problems with the endotracheal tube; 189 (9%) were reported. The most common problem was endobronchial intubation which accounted for 42% of these 189 reports; endobronchial intubation was the most common cause of arterial desaturation in the 2000 incidents. Obstructions and oesophageal intubation each accounted for 18% of the 189 problems with tubes. The remainder was made up of disconnections and leaks (7% each), misplacements other than endobronchial or oesophageal (4%), inappropriate choice of tube (3%), cuff herniation (1%), failure to deflate the cuff and foreign body in the tube (0.5% each).

The pulse oximeter and capnograph first detected 58% of these incidents; a further 25% were detected clinically. The pulse oximeter is the “front-line” monitor for endobronchial intubation, and the capnograph the “front-line” monitor for oesophageal intubation, disconnection and obstruction.

Recommendations are made for how to prevent problems and how to determine the nature of those that do occur.
Clinical Anaphylaxis: An Analysis of 2000 Incident Reports
Authors: Currie M. , Webb R. K. , Williamson J. A. , Russell W. J. , Mackay P.
Published: January 2019

There were 57 reports of possible allergic reactions in the perioperative period in the first 2000 incidents reported to the Australian Incident Monitoring Study. These were examined and classified with respect to presentation, clinical course, agents implicated and management strategies employed. Reactions were graded as to probability of allergic aetiology and severity of systemic disturbance. Two deaths were reported. A method of determining an “allergy score” was devised as an indication of which reactions may be most deserving of further investigation.
Cardiac Arrest—An Analysis of 2000 Incident Reports
Authors: Morgan C. A. , Webb R. K. , Cockings J. , Williamson J. A.
Published: January 2019

Eighty-seven cases of cardiac arrest from the first 2000 incidents reported to the Australian Incident Monitoring Study were reviewed. “Cardiac arrest” was taken to include patients who were either pulseless or had electrocardiographic asystole or ventricular fibrillation. Cases were grouped by primary cause—drug administration (19), vagal stimulation (16), hypoventilation (15), bleeding (13), anaphylaxis (6), direct cardiac stimulation (4) and miscellaneous (14). Overall, 20 patients died (23% of the 87 cases); all of these were in the hypoventilation, bleeding, or miscellaneous groups (4, 9 and 7 patients, respectively). Cardiac compression was performed in 66% of patients; 20% were defibrillated; adrenaline was given to 42% and bicarbonate to 3%. There was a clear anaesthetic cause for 46% of this series of arrests, and with hindsight, a preventable factor was present in over half (58%) of these. Preventative strategies regarding staffing, equipment, policy and procedures are suggested.
Air Embolism—An Analysis of 2000 Incident Reports
Authors: Williamson J. A. , Webb R. K. , Russell W. J. , Runciman W. B.
Published: January 2019

There were 19 cases of air embolism (1%) among the first 2000 incidents reported to the Australian Incident Monitoring Study. No embolism-induced fatalities were reported. Serious acute systemic effects occurred in 14 incidents; one circulatory arrest required electrical counter-shock.

The surgical field was the entry route for the air in 63% of the incidents; 47% of the cases occurred during head and neck surgery. Capnography was the most successful first detector (26%) and it confirmed the diagnosis in another 26%. Invasive blood pressure monitoring, the electrocardiograph and the pulse oximeter played a useful role in detecting and/or confirming air embolism. Doppler monitoring was not reported in this series.

A successful first response for management included head-down posture, manual ventilation, 100% oxygen and control of the air entry site. Cerebral arterial gas embolism may induce vascular endothelial damage and possible delayed neurological sequelae; hyperbaric oxygen therapy should be considered.
Patient Awareness during Anaesthesia: An Analysis of 2000 Incident Reports
Authors: Osborne G. A. , Webb R. K. , Runciman W. B.
Published: January 2019

Amongst the first 2000 incidents reported to the Australian Incident Monitoring Study there were 16 cases in which patient recall of perioperative events was consistent with awareness. Awareness that occurred in 3 of 10 cases during anaesthesia was attributed to low concentrations of volatile anaesthetic agent; the conduct of anaesthesia appeared to be unremarkable in the other 7. The remaining 6 cases involved the inadvertent paralysis of patients prior to induction of anaesthesia, most commonly by “syringe swap” when suxamethonium was given instead of fentanyl. Some of these patients were significantly distressed. These preliminary findings suggest that incident monitoring should be useful in the study of awareness associated with anaesthesia and the development of strategies to prevent it.
Paediatric Incidents in Anaesthesia: An Analysis of 2000 Incident Reports
Authors: Van Der Walt J. H. , Sweeney D. B. , Runciman W. B. , Webb R. K.
Published: January 2019

The first 2000 incidents reported to the Australian Incident Monitoring Study (AIMS) were analysed to compare anaesthetic incidents in infants and children with those in adults. Of the 2000, 1790 (90%) involved adults, 151 (7%) children and 56 (3%) infants. Healthy children (ASA I) generated a greater proportion of incidents in this group than adults and infants, emphasizing the need for maintaining the same standards for children in this group as for infants and higher risk groups. The AIMS results are similar to those of the United States (US) paediatric “closed claims” studies; the paediatric subset in both the US study and AIMS made up 10% of the total. Also, in both studies, incidents involving the respiratory and breathing circuit systems accounted for nearly half the problems, and cardiovascular problems and problems with the anaesthetic machine each accounted for 10–14% of incidents. In the AIMS study procedures on the head and neck yielded proportionately more incidents in the infant/child group than in the adult group, as did incidents involving the respiratory and breathing circuit systems. Incidents in the child group were often detected clinically; however, there were no differences between the three age groups in the way monitors were used or performed; hence the same monitoring recommendations apply to all groups. Combined oximetry and capnography would have detected nearly 90% of all applicable problems in the AIMS study and could have prevented nearly 90% of the claims arising from inadequate ventilation in the US “closed claims” study. AIMS reporters cited skilled assistance as a major factor in minimising the outcome of incidents in infants and recommended specific protocol development to cope with problems in both the infant and child groups. Other aspects analysed showed no differences between infants, children and adults and conclusions drawn from AIMS elsewhere in this symposium apply also to infants and children.
Problems Associated with Vascular Access: An Analysis of 2000 Incident Reports
Authors: Singleton R. J. , Webb R. K. , Ludbrook G. L. , Fox M. A. L.
Published: January 2019

There were 65 incidents involving access to the vascular system amongst the first 2000 reported to the Australian Incident Monitoring Study. Thirty-three involved peripheral venous access (14 cases of extravascular extravasation, 8 of unintended arterial cannulation, 6 of disruptions to intravenous lines, and 5 of problems with infusion lines, taps, pumps and connectors). Eighteen cases involved central venous access (9 cases of arterial puncture with haematomas, 5 with morbidity and/or prolonged admission), 5 of catheter misplacement and pneumo- or hydro-thorax and 4 of problems arising from operator inexperience. Thirteen cases involved peripheral arterial acces (5 involved equipment problems (3 with possible air embolism), 3 of mistaking an arterial for a venous line (drugs were injected in 2), 3 of losing arterial lines or signals, and 2 in which the presence of an arterial line placed the patient at risk). The anaesthetist should always question the continued integrity of any vascular access system, even when it has recently been shown to be functioning, and the possibility of later “migration” and misplacement should always be borne in mind. Whenever possible, correct placement of the tip should be checked (e.g. by visual inspection of the site, use of test doses, aspiration of blood, pressure measurement, X-rays). When there is more than one line, all lines and sites of access (e.g. 3-way taps) should be clearly labelled and checked before anything is injected or infused.
Equipment Failure: An Analysis of 2000 Incident Reports
Authors: Webb R. K. , Russell W. J. , Klepper I. , Runciman W. B.
Published: January 2019

Of the first 2000 incidents reported to the Australian Incident Monitoring Study, 177 (9%) were due to “pure” equipment failure according to pre-defined criteria. Of these 107 (60%) involved anaesthetic equipment, 42 (24%) involved monitors, 17 (10%) other theatre equipment and 11 (6%) the gas or electricity supply. Ninety-seven (55% of the 177) were potentially life-threatening; of these two-thirds would be detected by the array of monitors recommended by the Australian and New Zealand College of Anaesthetists and all but 9 of the remainder would be handled by application of the crisis management algorithm recommended elsewhere in this symposium. Of the 9 remaining, 2 were electrical shock, 3 overheating of a humidifier or blood warmer, 2 the unavailability of a spare laryngoscope and 1 the consequence of a power failure. Meticulous adherence to the equipment checking and monitoring guidelines of the Australian and New Zealand College of Anaesthetists and application of a suitable crisis management algorithm should protect the patient from potentially life-threatening equipment failure in virtually all cases except electric shock, power failure and overheating of warming devices.
Towards Optimal Analgesia after Caesarean Section: Comparison of Epidural and Intravenous Patient-controlled Opioid Analgesia
Authors: Cade L. , Ashley J.
Published: January 2019

The provision of optimal analgesia after caesarean section remains a challenge as satisfactory pain relief must be combined with patient satisfaction, including the ability to care for the newborn. In a prospective study of 132 patients, we have compared epidural analgesia with intravenous patient-controlled analgesia (IVPCA) after either epidural or general anaesthesia. Different bolus doses of opioid (pethidine 10 mg and 20 mg) in the IVPCA group were also compared. Although epidural morphine provided the greatest efficacy (average pain score out of 10 was 1.8 v. 2.9–3.4 for the other groups), IVPCA, especially with a bolus dose of 20 mg, and especially after epidural anaesthesia, provided the greatest patient satisfaction with the least side-effects.
Combined Epidural and General Anaesthesia versus General Anaesthesia for Abdominal Aortic Surgery: A Prospective Randomised Trial
Authors: Davies M. J. , Silbert B. S. , Mooney P. J. , Dysart R. H. , Meads A. C.
Published: January 2019

Fifty patients undergoing elective abdominal aortic surgery were randomised to receive either combined epidural and general anaesthesia and postoperative epidural analgesia (CEGA) or general anaesthesia and postoperative intravenous morphine infusion (GA). Prospective data was collected in order to compare the two groups. This included intraoperative cardiovascular changes and postoperative complications. The use of intraoperative vasopressors was significantly higher in the CEGA group (P <0.01) but the use of intravenous glyceryl trinitrate was significantly lower (P <0.01). There was no significant difference between groups in regard to blood loss, volume replacement or in the number of patients requiring postoperative ventilation. Two patients in the CEGA group died postoperatively compared to one in the GA group (not significant). There was no significant difference between groups in the total number or type of postoperative complications. Combining epidural anaesthesia with general anaesthesia altered intraoperative cardiovascular management but did not affect postoperative outcome.
Warm Local Anaesthetic—Effect on Latency of Onset of Axillary Brachial Plexus Block
Authors: Chilvers C. R.
Published: January 2019

A double-blind, controlled trial was conducted to determine whether warming local anaesthetic reduces the onset time of axillary brachial plexus block. Forty patients were randomised into two groups. The control group received local anaesthetic solution at room temperature (22±1°C), while the experimental group received the solution at body temperature (37±1°C). A solution of 40 ml of lignocaine 1.5% with adrenaline 1:200,000 was used for all patients. Warming the local anaesthetic was not demonstrated to reduce the latency of onset of blockade.