bluuebunny/crossref_metadata_2025 huggingface dataset:
Tidal Volume, Lung Hyperinflation and Arterial Oxygenation during General Anaesthesia
Authors: Tweed W. A. , Phua W. T. , Chong K. Y. , Lim E. , Lee T. L.
Published: January 2019

Impaired pulmonary oxygen (O2) exchange is common during general anaesthesia but there is no clinical unanimity as to methods of prevention or treatment. We studied 14 patients at risk for pulmonary dysfunction because of increased age, obesity, cigarette smoking, or chronic lung disease. Pulmonary O2 exchange was measured during four conditions of ventilation: awake spontaneous, conventional tidal volume (CVT, 7 ml.kg-1) or high tidal volume (HVT, 12 ml.kg-1) controlled ventilation, and five min after manual hyperinflation (H1) of the lungs. The F1O2 was controlled at 0.5, and FETCO2 was kept constant by adding dead space during HVT. Eight patients were ventilated with N2O/O2 and six with air/O2. Arterial blood gases were used to calculate the (A-a)DO2.

In seven patients (A-a)DO2 worsened after induction of anaesthesia, while in seven there was no change or an improvement. Manual HI significantly reduced (A-a)DO2, but changing tidal volume (VT) had no effect. Using a multivariate model to predict O2 exchange, obesity and type of surgery were significantly associated with worsening, while level of VT and inspiratory gas (N2O or N2) were not significant predictors. Thus patient and surgical factors were more important determinants of pulmonary gas exchange during anaesthesia than were tidal volume or inspiratory gas. Manual HI is a simple and effective manoeuvre to improve gas exchange.
Arterial Desaturation during Induction with and without Preoxygenation: Evaluation of Four Techniques
Authors: Kashyap L. , Yaddanapudi L. N. , Sandhya
Published: January 2019

The incidence and degree of hypoxaemia during induction of balanced anaesthesia and endotracheal intubation were studied prospectively in 80 healthy adults undergoing elective surgery randomly divided into four equal groups of 20. Group I was preoxygenated for three minutes. The other three groups were not preoxygenated. Groups 1 and 2 were ventilated with 100% oxygen, while Groups 3 and 4 were ventilated with 50% and 33% oxygen respectively. Anaesthesia was induced with thiopentone 3-5 mg/kg and endotracheal intubation was done after ventilating for one minute with the chosen gas. Arterial desaturation was measured by pulse oximetry. In Groups 1-3 there was a significant increase and in Group 4 a significant decrease in saturation from the preinduction value. The arterial oxygen saturation was similar in Groups 1 and 2. Two patients in Group 3 and four in Group 4 had hypoxaemia. This incidence was not statistically significant. We conclude that ventilation with 100% oxygen for one minute prior to intubation and preoxygenation for three minutes are equally effective in preventing hypoxaemia during induction.
A Survey of Cardiopulmonary Bypass Perfusion Practices in Australia in 1992
Authors: Wajon P. R. , Walsh R. G. , Symons N. L. P.
Published: January 2019

Twenty-four cardiopulmonary bypass (CPB) perfusion units around Australia were surveyed to determine the characteristics of CPB perfusion as practised in Australia in 1992. Twenty completed survey forms were received. Findings were compared with those of a similar study performed by one of the authors for the year 1986. The field of CPB perfusion continues to expand both in terms of numbers of cases and increasing technological complexity. The major technological changes evident are the now clear dominance of membrane over bubble oxygenators and the proliferation of inline SvO2 monitoring devices. The greatest change in practice has been to the virtually universal use of cardioplegia. There remains considerable variation in the composition of the cardioplegia solutions used in the responding units. A range of minimum perfusion pressures for CPB is noted, whereas most units employ similar minimum perfusion flows. Methods of central nervous system and renal protection are mainly hypothermia and diuretics, respectively, with a scattering of other techniques. Staffing of CPB perfusion units is essentially unchanged since 1986 and at least five units had no medical perfusionist appointed in 1992.
The Training/Examination Programme in Intensive Care, Australian and New Zealand College of Anaesthetists: 2. Examination
Authors: Harrison G. A. , Clarke G. M.
Published: January 2019

The structure of the Final Examination in Intensive Care for the award of Diploma of Fellow of the Australian and New Zealand College of Anaesthetists is based on a model explicated in the College's Objectives of Training in Intensive Care. There are five sections in the examination: short answer questions, essay questions, investigations, orals and a clinical.

The first examination was held in October 1979. Up to and including the examination of October 1992, 94 of the 136 attempts by 107 candidates had been successful. Eighty-three per cent of the candidates passed at the first attempt. The failure rate has been highest in the clinical section.

The examination is regarded as a hard examination but one which is helpful in training and subsequent practice.
Humidity of Anaesthetic Gases with Respect to Low Flow Anaesthesia
Authors: Kleemann P. P.
Published: January 2019

It has been demonstrated in an experimental study in swine using the scanning electron microscope that a rebreathing technique utilising minimal fresh gas flowrates significantly improves climatization of anaesthetic gases. Consequently, effects of various anaesthetic techniques on airway climate must be assessed, which covers the need for suitable measuring devices. Basic principles and methods of humidity measurement in flowing anaesthetic gases include gravimetric hygrometry, dew point hygrometry, wet-dry bulb psychrometry, mass spectrometry, spectroscopic hygrometry and electrical hygrometry. A custom-made apparatus for continuous measurement of humidity and temperature in the inspired and expired gas mixtures of a breathing circuit (separated by a valve system, integrated between the endotracheal tube and the Y-piece) is described. Comparative evaluation of this apparatus and the psychrometer was carried out. It could be demonstrated that the apparatus, measuring with capacitive humidity sensors, is more suitable for prolonged use under clinical conditions than the psychrometer. In the second part of the study, climatisation of anaesthetic gases under clinical conditions was investigated using fresh gas flowrates of 0.6, 1.5, 3.0 and 6.0 l/min. In the inspiratory limb of the circuit an absolute humidity of 21.3 mg H2O/l and a temperature of 31.5 °C were obtained after 120 minutes of minimal flow. Humidity and temperature of inspired air obtained with fresh gas flowrates of 6.0 and 3.0 l/min were found to be inadequate for prolonged anaesthesia. Reducing the fresh gas flow to 1.5 l/min increases heat and moisture content in the respired gases, but conditions are still inadequate for prolonged anaesthesia. Sufficient moisture (≥20 mg H2O/l) and temperature are obtained under minimal flow conditions after one hour.
Comparison of Patient-Controlled Analgesia and Nurse-Controlled Infusion Analgesia after Cardiac Surgery
Authors: Myles Paul S. , Buckland Mark R. , Cannon Graham B. , Bujor Michael A. , Langley Mark , Breaden Allison , Salamonsen Robert F. , Davis Bruce B.
Published: January 2019

A randomized, controlled clinical trial was conducted on 72 patients undergoing elective cardiac surgery to compare patient-controlled analgesia (PCA) to nurse-titrated infusion of morphine. Pain and nausea scores were assessed at 5, 20, 32 and 44 hours after cardiopulmonary bypass. Serum cortisol estimations were performed at 24 and 48 hours, and morphine consumption was measured at 0-24 and 24-48 hours. There was no difference between pain scores (P=0.72), nausea scores (P=0.52), serum cortisol at 24 and 48 hours (P=0.32 and P=0.34), and morphine consumption at 0-24 and 24-48 hours (P=0.16 and P=0.12). There was also no difference in the time to tracheal extubation (P=0.79) and discharge from ICU (P=0.64). There was a significant association between pain and serum cortisol at 48 hours (P=0.023). This study also found a tenfold difference in the amount of morphine used (range = 11 to 108 mg), with no significant association with patient age or sex. We could find no significant benefit from the routine use of PCA in cardiac surgical patients.
Clinical Comparison of Spontaneous Respiration versus Controlled Ventilation General Anaesthesia using Isoflurane for Intraocular Surgery: Intraoperative, Recovery and Postoperative Effects
Authors: Van Den Berg A. A. , Honjol N. M.
Published: January 2019

A prospective randomized study was undertaken on elderly patients undergoing intraocular, predominantly cataract, surgery to compare the intraoperative, recovery and postoperative features associated with general anaesthesia employing either the spontaneous (SV) or controlled ventilation (IPPV) techniques of respiration using isoflurane, nitrous oxide and a constant FiO2 of 0.33. SV patients received isoflurane 0.97% (mean). IPPV patients were intubated with atracurium alone, and received isoflurane 0.60% (mean). Heart rates were lower intraoperatively with IPPV, and blood pressures were lower with SV. Intraocular pressure measurement identified three subgroups of patients within each respiratory group: a large subgroup (70% of SV, 64% of IPPV patients) with a high-normal initial mean intraocular pressure which fell intraoperatively; a small subgroup (25% of SV, 24% of IPPV patients) with a low normal initial mean intraocular pressure which rose intraoperatively and a small subgroup (5% of SV and 11% of IPPV patients) in whom the intraocular pressure remained unchanged. A satisfactory operative field was reported by surgeons in 87% of SV and in 86% of IPPV patients. SV patients had a lower mean end-operative SaO2 than IPPV patients (SV 95.0%; IPPV 96.7%), and were extubated sooner at the end of anaesthesia. In the recovery ward the times to awakening, vomiting incidences, analgesic usages and recovery times were similar, and patients were similarly restful. Postoperatively, the incidences of vomiting, headache, fever, sore throat and myalgia were similar, but SV patients required more analgesia for headache. We conclude that both techniques properly performed are similarly satisfactory for cataract surgery in elderly patients.
Training, Skills and Approach to Potentially Difficult Anaesthesia in General Practitioner Anaesthetists
Authors: Watts R. W. , Bassham M.
Published: January 2019

Seventy-six of the 92 practising South Australian rural general practitioner anaesthetists responded to a questionnaire on anaesthetic training, skills and approach to potentially difficult anaesthesia.

The mean training period in anaesthesia was 7.5 months, 24% at registrar level. Eight per cent had no training, and 40% had 3 months or less. Thirty-three per cent trained exclusively overseas and 13% hold a Diploma in Anaesthesia.

A total of 11,400 anaesthetics were performed by 76 general practitioners in 1992 at an average of 152 (range 2 to 1500). The mean visual analog “comfort score” in performing anaesthesia was 6.6 and correlated best with the number of procedures per year (r = 0.32, P = 0.03).

Forty-six per cent of general practitioners provided anaesthesia for the 0 to 12 month age group, and only 35% had regional skills to use in obstetric anaesthesia. Patients classified as ASA grade 3 to 5, disease states such as unstable angina, severe asthma, and risk factors such as skeletal myopathy, were avoided by most general practitioners. The failed intubation rate was 50/10,000.

The conclusion is that South Australian general practitioner anaesthetists exhibit a generally safe approach to selection of patients for anaesthesia, although in some instances the approach to potentially difficult anaesthesia should be more conservative.
Changes in Oxygen Saturation in the 72 Hours after Hip Surgery: The Effect of Oxygen Therapy
Authors: Fugere F. , Owen H. , Ilsley A. H. , Plummer J. L. , Hawkins D. J.
Published: January 2019

The aim of this study was to investigate changes in oxygen saturation (SpO2) occurring during the three days following hip surgery in patients in this hospital and to determine to what extent SpO2 might be improved by oxygen therapy for 24 or 72 hours.

Eighty-three patients (aged 43-96 years) scheduled for elective total hip replacement or emergency surgery for hip fractures were studied. Forty-four patients had 24 hour postoperative oxygen prescribed by their anaesthetist or surgeon; we randomized these to either continue oxygen for a total of three days (Group 1) or to discontinue oxygen after Day 1 (Group 2). Patients not prescribed oxygen by the surgeon or anaesthetist (n = 39) were randomly assigned either to receive oxygen for three days (Group 3) or not to receive oxygen (Group 4). Oxygen was administered through nasal cannulae at a flow of 2 l.min−1. SpO2 was measured every 10 seconds for three days and stored on computer disc. Percentage of time spent with SpO2 below 90% was used as an idex of desaturation.

Patients receiving oxygen had significantly improved SpO2. In patients not receiving oxygen, desaturation was most severe on Days 1 and 2, improving somewhat on Day 3. On Day 2 desaturation was similar in Groups 2 and 4. When oxygen was not being administered males were significantly more desaturated than females.

Our investigations indicate that following hip surgery poor saturation continues for at least two days and can be improved by oxygen therapy.
The Physiological Changes Associated with Brain Death-Current Concepts and Implications for Treatment of the Brain Dead Organ Donor
Authors: Power B. M. , Van Heerden P. V.
Published: January 2019

The profound physiological disturbances associated with severe intracerebral pathology have long been recognized. These changes have also been described in the brain dead potential organ donor but have only been studied since the early 1980s Physiological disturbances in the brain dead organ donor result in a diffuse vascular regulatory injury and a diffuse metabolic cellular injury. The net result of these changes is an inexorable deterioration of all organs and eventual “cardiovascular death” of the patient. This paper reviews these physiological changes and the effect they may have on solid transplantable tissues and discusses the management of brain dead organ donor with regard to these changes. Current concepts of brain death and how they may affect the interpretation of the observed physiological changes are also reviewed.
Rocuronium Bromide in Dental Day Case Anaesthesia—A Comparison with Atracurium and Vecuronium
Authors: Chetty M. S. , Pollard B. L. , Wilson A. , Healy T. E. J.
Published: January 2019

We have compared intubating conditions at 60 seconds, onset times and reversal characteristics of the new steroidal nondepolarizing muscle relaxant rocuronium with atracurium and vecuronium. A dose of approximately 1.75 × ED90 of each agent was used to assess their relative suitability for brief day case dental procedures requiring intubation. The anaesthetic technique included propofol, fentanyl, nitrous oxide/oxygen and isoflurane. Electromyography was used to assess neuromuscular blockade. The percentage of good or excellent intubating conditions at 60 seconds was 80% for rocuronium but only 12.5% each for atracurium and vecuronium. The mean percentage bleck at 60 seconds was 55.1% for rocuronium, compared to 9.2% for atracurium and 8.3% for vecuronium. Rocuronium had the fastest onset time to maximum block (mean 313 sec) compared to atracurium (mean 391.9 sec) and vecuronium (mean 331.9 sec). The duration of action of rocuronium was shorter than either atracurium or vecuronium, times for spontaneous recovery to 75% block being 22.2 min, 29.6 min and 26.3 min respectively. The neostigmine evoked recovery indices were. rocuronium 4.2 min, atracurium 6.6 min and vecuronium 3.7 min. Maximum blockade of greater than 97% was achieved with all three relaxants.
The Identification of Potential Cadaveric Organ Donors
Authors: Thompson J. F. , Mccosker C. J. , Hibberd A. D. , Chapman J. R. , Compton J. S. , Mahony J. F. , Mohacsi P. J. , Macdonald G. J. , Spratt P. M.
Published: January 2019

Most Australian transplantation programs are severely restricted in their activities by a limited availability of cadaveric donor organs. To investigate possible reasons for this problem, an audit was undertaken over three 12-month periods of all deaths in 13 hospitals in New South Wales and the Australian Capital Territory. From 7406 deaths, 271 patients were classified as having been realistic, medically suitable potential donors. Of these, only 60 (22%) became actual donors. In the other 211 patients, donation did not occur because of unsuccessful resuscitation (30%), permission refusal by relatives (34%), and failure to identify or support the potential donors (36%). If the impediments to organ donation which were identified in this study could be overcome, allowing a greater number of potential donors to become actual donors, the chronic shortage of cadaveric donor organs for transplantation could be at least partly relieved.
A Survey of Families of Brain Dead Patients: Their Experiences, Attitudes to Organ Donation and Transplantation
Authors: Pearson I. Y. , Bazeley P. , Spencer-Plane T. , Chapman J. R. , Robertson P.
Published: January 2019

A questionnaire survey of 69 families of brain dead patients is reported. The study population included those who had been asked about organ donation as well as those who had not, those who had agreed to organ donation and those who had declined. Their experiences and their perceptions of treatment and explanations of underlying disease, brain death and organ donation were examined. Their own knowledge of and attitudes towards organ donation as well as the prior knowledge and wishes of their deceased relative were also explored.

Statistical analysis did not show any differences between the three groups of families with regard to their experiences, their perceptions of the treatment they received, or in the resolution of their grief.

Family members who had agreed to organ donation were significantly more likely to donate their own organs and to be more resolved in their grief. There was a strong correspondence between the attitudes of respondents and their agreement or otherwise to donate their relatives’ organs. One quarter, however, made the opposite choice for their relative, where their relative's wishes were known. There was a highly significant relationship between those who had previously discussed organ donation to have expected to be asked or to raise the subject themselves.

Hospital treatment in general did not appear to have any effect on the decision to donate. Involvement in organ donation was felt by most of the donor families to have been helpful to the grieving process.
Correction of Splanchnic Oxygen Deficit in the Intensive Care Unit: Dopexamine and Colloid versus Placebo
Authors: Trinder T. J. , Lavery G. G. , Fee J. P. H. , Lowry K. G.
Published: January 2019

Correction of the splanchnic oxygen deficit indicated by low gastric intramucosal pH (pHi < 7.35) appears to reduce ICU mortality. Dopexamine hydrochloride is in clinical use for this purpose but its efficacy has not been fully investigated. We report the results of a prospective, randomized, placebo-controlled study with a crossover design to assess the efficacy of dopexamine in correcting low pHi. Twelve patients in whom pHi < 7.32 was detected during eight-hourly monitoring were randomized to receive either incremental dopexamine (4-6 μg/kg/min) with colloid or 5% dextrose for three hours prior to crossover. There was no difference in pHi between treatments despite cardiovascular effects during dopexamine infusion. There was, however, a time-related increase in pHi suggesting a beneficial effect of conventional therapy. Dopexamine hydrochloride at 4-6 μg/kg/min in conjunction with colloid is not a clinically useful therapy to correct the splanchnic oxygen deficit indicated by low pHi.
The Medical Emergency Team
Authors: Lee A. , Bishop G. , Hillman K. M. , Daffurn K.
Published: January 2019

The concept of a Medical Emergency Team was developed in order to rapidly identify and manage seriously ill patients at risk of cardiopulmonary arrest and other high-risk conditions. The aim of this study was to describe the utilization and outcome of Medical Emergency Team interventions over a one-year period at a teaching hospital in South Western Sydney. Data was collected prospectively using a standardized form. Cardiopulmonary resuscitation occurred in 148/522 (28%) calls. Alerting the team using the specific condition criteria occurred in 253/522 (48%) calls and on physiological/pathological abnormality criteria in 121/522 (23%) calls. Survival rate to hospital discharge following cardiopulmonary arrest was low (29%), compared with other medical emergencies (76%).
An Enclosed Efferent Afferent Reservoir System: The Maxima
Authors: Miller D. M.
Published: January 2019

A single, lightweight, valveless, non-absorber breathing system, which functions with near maximal efficiency (hence the name Maxima) in spontaneous and controlled ventilation is described. It may be classified as an enclosed efferent afferent reservoir (EEAR) breathing system and is characterised by the selective elimination of alveolar gas in all modes of ventilation. A functional description explains how this is achieved in the system in spontaneous and controlled ventilation.

The potential for error which arises in combination systems for different switch positions with different modes of ventilation is avoided, as it is a single universal system. With no moving parts, mechanical reliability is guaranteed. The apparatus deadspace is negligible making the system usable even in neonates.

Finally, the characteristics of the theoretical ideal non-absorber circuit are discussed as this illustrates the objective of the circuit design and important physical principles surrounding its function.
EMLA Cream Prior to Insertion of Elective Epidurals
Authors: Elson J. A. , Paech M. J.
Published: January 2019

A randomized double-blind study was conducted in 83 women scheduled for elective caesarean section to determine the efficacy of EMLA and lignocaine infiltration for epidural insertion. The patients were randomly allocated to one of three groups: Group A (EM/LIG) received EMLA and intradermal and subdermal 1% lignocaine infiltration, Group B (EM/SAL) EMLA and saline while Group C (PL/LIG) received placebo cream and 1% lignocaine.

Assessments using a 100 mm pain score were performed on skin infiltration and after subsequent insertion of a 16 gauge Tuohy needle into the supraspinous ligament. Skin changes under the applied cream and nursing rating of patients’ response were also noted. Statistical analyses were performed using Kruskal-Wallis and Fisher's Exact Tests.

Groups were comparable for age, weight, parity and EMLA application time (interquartile range 105-150 minutes) There were significantly higher pain scores for skin infiltration in Group C (PL/LIG) (P<0.01) and for epidural needle insertion in Group B (EM/SAL) (P<0.05).

We concluded that in this patient population, the application of EMLA cream for at least 90 minutes plus 1% lignocaine infiltration optimized patient comfort for epidural insertion.
Pain and Vomiting after Vitreoretinal Surgery: A Potential Role for Local Anaesthesia
Authors: Williams N. , Strunin A. , Heriot W.
Published: January 2019

Periconal local anaesthesia with subtenon supplementation was used to provide anaesthesia for 94 patients having vitreoretinal surgery. Of these, 44 patients also received general anaesthesia with neuromuscular block. None of these patients received opioid or antiemetic before or during surgery. In comparison with a retrospective control group, patients who had received local anaesthesia as part of their anaesthetic technique were less likely to be given a parenteral opioid (P< 0.001) or to vomit (P<0.001) within six hours of the completion of surgery. They also experienced significantly fewer bradycardic episodes during surgery (P=0 001). For patients having general anaesthesia, administration of an intraoperative antiemetic reduced the incidence of vomiting within six hours of the completion of surgery (P=0.008). For patients who did not receive local anaesthetic, shorter operating time was a factor associated with both reduced postoperative vomiting (P=0.0015) and administration of parenteral opioid (P=0.0014). It is suggested that the use of local anaesthesia as part of the anaesthetic technique for vitreoretinal surgery is associated with improved patient comfort.
A Double-Blind Randomized Controlled Trial of Ginger for the Prevention of Postoperative Nausea and Vomiting
Authors: Arfeen Z. , Owen H. , Plummer J. L. , Ilsley A. H. , Sorby-Adams R. A. C. , Doecke C. J.
Published: January 2019

The efficacy of ginger for the prevention of postoperative nausea and vomiting was studied in a double-blind, randomized, controlled trial in 108 ASA 1 or 2 patients undergoing gynaecological laparoscopic surgery under general anaesthesia. Patients received oral placebo, ginger BP 0.5g or ginger BP 1.0g, all with oral diazepam premedication, one hour prior to surgery. Patients were assessed at three hours postoperatively. The incidence of nausea and vomiting increased slightly but nonsignificantly with increasing dose of ginger. The incidence of moderate or severe nausea was 22, 33 and 36%, while the incidence of vomiting was 17, 14 and 31% in groups receiving 0, 0.5 and 1.0g ginger, respectively (odds ratio per 0.5g ginger 1.39 for nausea and 1.55 for vomiting). These results were essentially unchanged when adjustment was made for concomitant risk factors. We conclude that ginger BP in doses of 0.5 or 1.0 gram is ineffective in reducing the incidence of postoperative nausea and vomiting.
The Role of Autologous Blood Transfusion in Joint Replacement Surgery
Authors: Mah E. T. , Davis R. , Seshadri P. , Nyman T. L. M. , Seshadri R.
Published: January 2019

The efficacy of predeposited autologous blood transfusion (PABT) with and without intra/postoperative blood salvage to reduce or eliminate the need for homologous blood transfusion (HBT) in primary total hip or knee replacement surgery was investigated by retrospective and prospective studies. Depending on the type of surgery, one to three units of PABT eliminated the need for HBT in 50 to 78% of patients, but, intra/postoperative blood salvage alone reduced the need only in 11 to 29%. In contrast, blood salvage, when combined with three units of PABT, eliminated the need for HBT in all patients undergoing primary joint replacement surgery. A cost comparison analysis showed that blood salvage was more expensive than PABT, and therefore it should be limited to patients who had predeposited fewer than three units of autologous blood.
A Comparison of the Efficacy of Dopexamine and Dobutamine for Increasing Oxygen Delivery in High-Risk Surgical Patients
Authors: Boyd O. , Lamb G. , Mackay C. J. , Grounds R. M. , Bennett E. D.
Published: January 2019

Peri-operative increase of oxygen delivery has been shown to reduce mortality in high-risk surgical patients. This study compares the effectiveness of dopexamine and dobutamine when used to increase cardiac output as part of a regimen to increase oxygen delivery. Sixteen surgical patients were randomly allocated to receive either dopexamine or dobutamine, which was increased to a stable dose defined as either oxygen delivery index >600 ml/min/m2, or tachycardia >20% above baseline, other dysrhythmias or angina. At this “stable” dose there were significant increases in cardiac index (2.4±0.2 vs3.7± 0.3 l/min/m2) and oxygen delivery (380±73 vs 579±40 ml/min/m2) in the dopexamine group (P< 0.05); but not the dobutamine group. Five out of eight patients receiving dopexamine and three out of eight receiving dobutamine reached target oxygen delivery Three dobutamine patients, but no dopexamine patients, had angina or dysrhythmias. In preoperative high-risk surgical patients, dopexamine can allow greater increases in oxygen delivery than dobutamine, due to cardiac effects that limit the dobutamine infusion rate.
Single-Dose Prophylaxis for Postoperative Nausea and Vomiting after Major Abdominal Surgery: Ondansetron versus Droperidol
Authors: Paech M. J. , Pavy T. J. G. , Evans S. F.
Published: January 2019

The new antiemetic ondansetron is effective for the prophylaxis and treatment of postoperative nausea and vomiting (PONV), but has been subject to limited comparative evaluation in surgical inpatients. Two hundred and seventy women having abdominal gynaecological surgery were investigated for 24 hours postoperatively in a randomized, double-blind, placebo-controlled study of intraoperative intravenous ondansetron 8 mg (n=83), droperidol 2.5 mg (n = 89) or saline placebo (n=87). Patients receiving either ondansetron or droperidol remained likely to vomit, although the incidence was significantly reduced compared with placebo (72% and 83% versus 91%, P<0.01). Both drugs also resulted in significantly fewer vomiting episodes (P<0.001), lower nausea scores (P<0.05) and a lower incidence of patients requiring treatment for PONV (P<0.01). Compared with droperidol, the risk of vomiting after ondansetron was less (odds ratio 0.5, CI 0.3–1.0). Ondansetron resulted in fewer vomiting episodes (P<0.05) and a higher percentage of patients free of nausea after six hours postoperatively (P<0.05). In patients with a past history of PONV, both drugs had a similar short-lived antiemetic effect, reducing the incidence of vomiting and the need for treatment while in the recovery room, but not thereafter. Droperidol was associated with significantly less headache (P<0.05), but higher early sedation scores (P<0.05).

Although, compared to placebo, both droperidol and ondansetron administered intraoperatively reduced vomiting after major abdominal gynaecological surgery, the incidence during the first 24 postoperative hours was very high in all groups. Ondansetron reduced the risk of experiencing nausea after six hours postoperatively and the risk of vomiting, with respect to the total number of episodes, in the first 24 hours. It was no better than droperidol, however, in reducing the incidence of vomiting or the need for antiemetic treatment during the first postoperative day, whether or not patients had a past history of PONV.
Rectal Indomethacin Potentiates Spinal Morphine Analgesia after Caesarean Delivery
Authors: Pavy T. J. G. , Gambling D. R. , Merrick P. M. , Douglas M. J.
Published: January 2019

This double-blind, randomized study was designed to evaluate the use of indomethacin (Indocid®, MSD) following caesarean delivery performed under spinal anaesthesia. Thirty ASA I-II women presenting for elective caesarean were recruited. Spinal anaesthesia was performed in a standard manner using hyperbaric bupivacaine, fentanyl and morphine. At the completion of surgery, subjects were administered two rectal suppositories, followed by 12-hourly suppositories for six doses (three days). The study group received 100 mg indomethacin suppositories and controls were given placebo (Anusol®).

Data collected included Visual Analog Scale (VAS) pain scores at rest and with movement, VAS scores for nausea and itch, and analgesic use.

Demographic data were similar in the two groups. Median time to first analgesia (TTFA) was nine hours in the control group v. 39.5 hours in the indomethacin group (P<0.003). Additional analgesic requests throughout the postoperative period were less in women who received indomethacin: 4 v 11 (P<0.001). Women who received indomethacin had significantly less pain on the first postoperative day, especially on movement: mean VAS 1.4 v. 5.1 (P<0.00001). There were no reported adverse neonatal or maternal effects from the use of indomethacin.

Rectal indomethacin use following caesarean delivery leads to significantly improved pain relief compared with placebo. The combination of spinal morphine and rectal indomethacin leads to high-quality postoperative analgesia.
Postspinal Headache in Taylor's Approach: A Comparison between 21- and 25-Gauge Needles in Orthopaedic Patients
Authors: Pippa P. , Barbagli R. , Rabassini M. , Doni L. , Rucci F. S.
Published: January 2019

A randomized study was carried out on 160 patients aged 30–60 years with the aim of finding a method of preventing postdural puncture headache (PDPH). In Taylor's lumbosacral approach to the subarachnoid space, two different needle sizes were used (21-gauge versus 25-gauge) for injecting the anaesthetic solution. Our results show an overall incidence of PDPH in nearly 8% of patients, with no significant difference related to the size of the needle employed. Patients with PDPH showed mild symptoms which disappeared in a short time and none needed epidural blood patching. The possibility of using larger needles, facilitating the execution of the block without increasing PDPH incidence, renders this technique particularly attractive in patients where the midline approach is not feasible, or when pencil-point needles are not available.
Comparison of Total Intravenous, Balanced Inhalational and Combined Intravenous-Inhalational Anaesthesia for Tympanoplasty, Septorhinoplasty and Adenotonsillectomy
Authors: Van Den Berg A. A. , Savva D. , Honjol N. M. , Prabhu N. V. Rama
Published: January 2019

Two hundred and thirty-five consecutive Saudi patients aged between two and fifty-three years undergoing elective tympanoplasty (n = 32), septorhinoplasty (n = 68) or adenotonsillectomy (n=135) were studied. They were randomized to receive either a total intravenous anaesthetic (10 ears, 23 noses, 44 throats) consisting of propofol for induction of anaesthesia followed by a propofol infusion, a combined intravenous-inhalational anaesthetic (11 ears, 22 noses, 46 throats) consisting of the above with isoflurane in oxygen-enriched air, or a balanced inhalational anaesthetic (11 ears, 23 noses, 45 throats) consisting of thiopentone for induction of anaesthesia and oxygen in nitrous oxide with isoflurane for maintenance.

During tympanoplasty, all three anaesthetic techniques produced stable heart rates and arterial pressures. During septorhinoplasty, blood pressure rose in patients who received total intravenous anaesthesia, while combined and balanced techniques produced haemodynamic stability. During adenotonsillectomy, total intravenous anaesthesia produced a rise in both heart rate and blood pressure, the combined technique produced a rise in heart rate alone while balanced anaesthesia produced haemodynamic stability. Postoperatively, vomiting, pain scores and analgesic requirements were similar following all three types of anaesthetic within each surgical site subgroup.

Our findings support the choice of balanced inhalational anaesthesia for all three types of ENT surgery and, where cost and facilities permit, total intravenous anaesthesia for tympanoplasty and combined intravenous-inhalational anaesthesia for septorhinoplasty.
Gastro-Oesophageal Reflux and Adverse Respiratory Events in Children under Anaesthesia
Authors: Milross J. G. , Negus B. H. , Street N. E. , Gaskin K. J.
Published: January 2019

The incidence of gastro-oesophageal reflux in children undergoing general anaesthesia has not previously been studied. One-hundred-and-twenty children (ASA Class 1–2) were studied intraoperatively using continuous oesophageal pH monitoring. The incidence of reflux was 2.5% (3 of 120). None of these three patients had an adverse respiratory event. There was no correlation between reflux and adverse respiratory events. Thirteen patients had minor respiratory events without evidence of acid reflux. Gastro-oesophageal reflux does occur in healthy paediatric patients having minor surgery, but was not a significant cause of the adverse respiratory events that occurred in our study.
Prospective Clinical Evaluation of Two Combined Spinal-Epidural Kits
Authors: Paech M. J. , Evans S. F.
Published: January 2019

One hundred combined spinal-epidural kits (Portex, n = 51, Mallinckrodt, n=49) were evaluated clinically by twelve anaesthetists with respect to performance of the loss-of-resistance syringe, epidural needle and spinal needle, and success in establishing single-segment combined spinal-epidural anaesthesia for caesarean section. Similar components included a plastic loss-of-resistance device, a Tuohy epidural needle, 26 or 27 gauge pencil-point spinal needle and closed end, three-lateral-eye epidural catheter. The Mallinckrodt kit incorporated a “back-eye” design for exit of the spinal needle from the epidural needle.

The epidural and subarachnoid spaces were satisfactorily identified on 98 occasions. Most anaesthetists preferred the Mallinckrodt kit packaging and the Portex loss-of-resistance syringe, although the latter may have been biased by familiarity with this device. The Portex spinal needle was more likely to be felt penetrating the dura (P=0.02) and aspiration of cerebrospinal fluid was more frequently described as easy (P=0.01). The most common criticisms of both kits were difficulty controlling the spinal needle position after entry into the subarachnoid space and subjectively, a high degree of resistance to injection through the spinal needle.
Flow Continuity of Infusion Systems at Low Flow Rates
Authors: Dunster K. R. , Colditz P. B.
Published: January 2019

Infusion of fluids and drugs at very low rates may be necessary in neonatal intensive care. Marked haemodynamic fluctuations occurring during the infusion of inotropes have been shown to be due to the sticking of the plunger in the barrel of syringes used in syringe drivers. The Australian Therapeutic Goods Administration has recommended the use of volumetric or peristaltic pumps in these circumstances. We tested a number of infusion systems and found that 1. some syringes give continuous flow at low rates, and would be suitable for the delivery of inotropes, and 2. some infusion pumps provide non-continuous flow at low rates, and would not be satisfactory for the infusion of inotropes.
Perioperative Changes of Plasma Endothelin-1 Concentrations in Patients Undergoing Cardiac Valve Surgery
Authors: Huang C. H. , Huang H. H. , Chen T. L. , Wang M. J.
Published: January 2019

Twenty-one patients who underwent cardiac valvular replacement procedures were studied to determine the peri-operative changes of plasma endothelin-1 (ET-1) concentration and disposition of ET-1 in the pulmonary and systemic vasculature between patients with elevated (over 20 mmHg) mean pulmonary artery pressure and patients with normal pulmonary artery pressure. The overall profile alterations of plasma ET- 1 concentration did not differ between the two groups of patients. The plasma ET- 1 levels in the pulmonary artery and right atrium were significantly higher in patients with high pulmonary artery pressure than in patients with normal pulmonary artery pressure. Before cardiopulmonary bypass, significant pulmonary extraction of the plasma ET- 1 existed in patients with high pulmonary artery pressure but the pulmonary extraction was not seen after bypass. There was no transpulmonary difference of the plasma ET- 1 concentration in patients with normal pulmonary artery pressure either before or after bypass. The high levels of ET- 1 in the pulmonary circuit and the pulmonary extraction of the ET- 1 in patients with high pulmonary artery pressure might be a protective mechanism for rheumatic valvular patients with elevated pulmonary artery pressure.
Postoperative Nausea and Vomiting. Propofol or Thiopentone: Does Choice of Induction Agent Affect Outcome?
Authors: Myles P. S. , Hendrata M. , Bennett A. M. , Langley M. , Buckland M. R.
Published: January 2019

Postoperative nausea and vomiting (PONV) has many causes, including anaesthetic drugs. Choice of induction agent may affect the incidence of PONV, though the evidence is conflicting. We have analysed our database of outcome after surgery. Data on 4173 patients were analysed using multivariate logistic regression, with an overall incidence of PONV 21.3%. Propofol, when compared to thiopentone for induction of anaesthesia, resulted in an 18% reduction in PONV (OR=0.82, P=0.03). The likely postoperative benefits of propofol may outweigh concerns about its additional cost.
Comparison of Subcutaneous Ring Block of the Penis with Caudal Epidural Block for Post-Circumcision Analgesia in Children
Authors: Irwin M. G. , Cheng W.
Published: January 2019

A randomized, prospective, blind trial was conducted comparing caudal epidural blockade (caudal block) with subcutaneous ring block of the penis (penile ring block) in fifty healthy boys between two and twelve years of age undergoing elective circumcision. Subjects receiving caudal block had a longer duration of analgesia (P=0.003), and took longer to first micturition (P=0.04) but there was no difference in time taken to awaken from anaesthesia or spontaneously walk unaided. There was an 8% failure rate with the penile ring block but no local or systemic complications related to either block and a very low incidence of vomiting. It is concluded that both techniques are effective. Caudal block is more reliable and produces a longer duration of analgesia but penile ring block is inherently safer and has a lower incidence of adverse effects.
Efficacy and Potency of Antivenoms in Neutralizing the Procoagulant Effects of Australian Snake Venoms in Dog and Human Plasma
Authors: Sprivulis P. , Jelinek G. A. , Marshall L.
Published: January 2019

The efficacy and potency of Commonwealth Serum Laboratories (CSL) snake antivenoms in neutralizing the procoagulant action of Australian snake venoms was studied in vitro. The procoagulant action of venoms from Tiger, Brown and Taipan Snakes were measured in pooled canine or pooled human plasma. Mixtures of the venoms and their appropriate antivenoms, ranging from 0.1 to 15 times the recommended neutralizing dose of antivenom were then added to pooled canine or pooled human plasma and the efficacy and potency of the antivenoms in preventing the procoagulant action was measured. Neutralization was achieved by the addition of the appropriate antivenom in concentrations of 0.5 (Taipan), 10 (Tiger), 10 (Gwardar), 15 (Dugite) and an estimated 20 (Common Brown) times the dose expected. Similar results were obtained in canine and human plasma. The potency of Tiger and especially Brown Snake antivenom is substantially lower (10–20 times) than that predicted by CSL. These findings support an increase in the dose of antivenom to be used for the treatment of Tiger and especially Brown Snake envenomation complicated by coagulopathy. The in vitro canine model may be suitable for studying the procoagulant effects of Australian snake venoms.
Haemodynamic and Renal Effects of Dopexamine after Cardiac Surgery in Children
Authors: Habre W. , Beghetti M. , Roduit C. , Girardin E. , Vallotton M. , Friedli B. , Berner M.
Published: January 2019

Dopexamine hydrochloride, a synthetic dopamine analog with predominantly beta and delta agonist properties, has been shown to improve cardiac performance and renal function in adults with heart failure. This study was designed to investigate the haemodynamic and renal effects of dopexamine in children after cardiac surgery. Seven children were selected in whom a need for postoperative vasodilation after cardiac surgery was anticipated. Haemodynamics and renal function were determined under baseline conditions and during a continuous infusion of dopexamine at 2 and 6 μg.kg-1.min-1 for 90 minutes, the sequence being randomized for the initial dose. Cardiac output was measured by thermodilution and glomerular filtration rate (GFR) and renal plasma flow (RPF) by the clearances of inulin and para-aminohippurate respectively. Dopexamine induced a dose-related increase in cardiac index (CI) expressed as mean (SD) from 3.5 (0.7) to 3.9 (0.76) and 4.5 (0.8) l.min.-1m-2 (both P<0.05), and in heart rate (HR) from 107 (17) to 122 (17) and 136 (17) beats.min-1 (P<0.05). Stroke volume index (SVI) and mean systemic pressure were unchanged, but pulmonary wedge pressure decreased from 14 (3) to 11 (4) and 12 (3) mmHg (both P<0.05). Systemic vascular resistances (SVR) decreased from 24 (7) to 20 (5) mmHg.l-1.min-1.m-2 (P<0.05), with dopexamine 6 μg.kg-1.min-1. Renal blood flow (RBF) increased from 319 (113) to 441 (230) and 410 (138) ml.min-1.m-2 (both P<0.05), GFR from 115 (32) to 142 (34) and 146 (29) ml.min-1.1.73m-2 (both P<0.05), urine output and fractional excretion of sodium respectively from 3.12 (2) to 7.16 (8) and 7.21 (6) ml.kg-1 (both P<0.05) and from 2.24 (1) to 4.25 (3.4) (P<0.05) and 3.15 (3.1)% (n.s.). The fraction of CI delivered to the kidneys, the fraction of RBF filtered in the kidneys, plasma renin activity and aldosterone levels remained unchanged. In children after cardiac surgery, dopexamine increases CI at the expense of a concomitant increase in heart rate and demonstrates few selective vascular systemic or intrinsic renal actions.
Axillary Brachial Plexus Block in Two Hundred Consecutive Patients
Authors: Pearce H. , Lindsay D. , Leslie K.
Published: January 2019

Two hundred consecutive, minimally-sedated patients presenting for upper limb surgery were audited prospectively to determine the overall clinical success rate, extent of cutaneous neural blockade, reliability and complication rate of each indicator of axillary sheath entry, and degree of patient satisfaction. The axillary sheath was identified, using a 22 gauge, short-bevelled needle, by one of four indicators, whichever was elicited first (paraesthesia, arterial or venous puncture, or tethering by the axillary sheath). Alkalinized mepivacaine 1.2%, 50 ml then was injected. The cutaneous distribution of the block was mapped in the presence of minimal sedation. Anaesthesia was supplemented with peripheral nerve blocks where necessary. Patients were followed up with a mailed questionnaire and surgeon interview. The overall clinical success rate was 92.5%, improving to 99% with supplementary nerve blocks. Complete anaesthesia distal to the elbow was achieved in 85% of patients. Complications were common, but generally mild and transient: mild acute local anaesthetic toxicity, 3.5%; axillary tenderness and bruising, 12%; and dysaesthesias, 12.5%. Despite this, patient satisfaction was high (97%).