bluuebunny/crossref_metadata_2025 huggingface dataset:
Chemical Dependence in Anaesthetic Registrars in Australia and New Zealand
Authors: Weeks A. M. , Buckland M. R. , Morgan E. B. , Myles P. S.
Published: January 2019

The Supervisors of Anaesthetic Training in Australia and New Zealand were surveyed and asked to report any cases of chemical dependence from anaesthetic registrars at their hospital from 1981 to 1991. From 83 questionnaires there were 65 (78%) returned. There were 14 departments (22%) with experience of one or more cases during this interval. Only five (7%) reported conducting a lecture or tutorial on the problem. The departmental reports covered 4425 registrar years of training and there were 17 cases reported. Of these, 13 were complete and are considered in detail. It is estimated that 1.3 % of those who entered anaesthetic training during the interval were recognised to become chemically dependent during their training. Follow-up was available on only six of the 13 registrars and only one was reported to have completed training. The results of this survey indicate that chemical dependence is already a major health problem amongst anaesthetic registrars in Australia and New Zealand.
Anaesthesia for Laparoscopic General Surgery
Authors: Chui P. T. , Gin T. , Oh T. E.
Published: January 2019

Laparoscopic surgery minimises postoperative morbidity. Patient benefits include reduction in postoperative pain, better cosmetic result and quicker return to normal activities. Hospital stay is shortened resulting in a reduction in overall medical cost. The intraoperative requirements of laparoscopic surgery however can lead to serious physiological changes and complications. While there is a low but definite perioperative mortality rate associated with minor gynaecologic laparoscopic procedures, laparoscopic general surgical procedures are performed on older patients and patients with acute surgical conditions and are likely to be associated with a higher incidence of perioperative complications. The major problems during laparoscopic surgery are related to the cardiopulmonary effects of pneumoperitoneum, systemic carbon dioxide absorption, extraperitoneal gas insufflation, venous gas embolism and unintentional injuries to intra-abdominal structures. An appraisal of the potential problems is essential for optimal anaesthetic care of patients undergoing laparoscopic surgery. Appropriate anaesthetic techniques and monitoring facilitate surgery and allow early detection and reduction of complications. The need for rapid recovery and short hospital stay impose additional demands on the anaesthetist for skillful practice.
Cognitive Function during Moderate Hypoxaemia
Authors: Noble J. , Jones J. G. , Davis E. J.
Published: January 2019

The effect of hypoxaemia (mean SpO2 78%) on cognitive function was measured in two groups of twelve normal subjects. A series of psychometric tests was administered to each subject in the same sequence and consisted of the Reitan trail-making test, a digit symbol substitution test, a visuospatial orientation test and the simple unprepared reaction-time test. Psychomotor performance was assessed in a double-blind manner while the subjects were breathing first air and then either air or a hypoxic mixture.

While there was improvement in time for the trail-making test during a repeat study breathing air, there was significant deterioration of time to completion of the test in conditions of hypoxia. A significant learning effect in the orientation test was seen in the control group but this did not occur in hypoxic subjects. Hypoxaemia was shown to cause a significant impairment of simple unprepared reaction time compared with controls. All the changes in cognitive function were small and there were no subjective differences in the air or hypoxic groups. The usefulness of the Reitan trail-making and the simple unprepared reaction-time test in the assessment of psychomotor performance deficit under conditions of hypoxaemia has been demonstrated by this study in normal subjects. It was concluded that a mean oxygen saturation of 78% caused only minor changes in cognitive function in normal subjects.
Phenytoin-Induced Resistance to Vecuronium
Authors: Platt P. R. , Thackray N. M.
Published: January 2019

Chronic phenytoin therapy causes resistance to some nondepolarising muscle relaxants. We have confirmed that this resistance is seen with vecuronium and suggest that at least a week of phenytoin therapy is required for a significant effect to develop. The mechanism of this resistance is not known. We have shown that an exaggerated rise in serum potassium after succinylcholine does not occur in patients with demonstrated resistance to vecuronium from chronic phenytoin therapy. This would suggest that significant extrajunctional acetylcholine receptor proliferation is an unlikely mechanism.
Analgesia following Arthroscopic Knee Surgery. A Controlled Study of Intra-articular Morphine, Bupivacaine or Both Combined
Authors: McSwiney M. M. , Joshi G. P. , Kenny P. , McCarroll S. M.
Published: January 2019

In a double-blind, randomised controlled trial, we studied 40 patients who received one of four intra-articular injections at the end of arthroscopic surgery. Each group contained ten patients. The patients in Group 1 received normal saline 25 ml; those in Group 2 received bupivacaine 0.25% 25 ml; those in Group 3 received morphine 5 mg in normal saline 25 ml; and those in Group 4 received a combination of bupivacaine 0.5% 12.5 ml and 5 mg of morphine made up to 25 ml with normal saline to produce the same bupivacaine concentration as Group 2. At the time the patient awoke, and 30min, Ihr, Ihr 30min, 2hr, 4hr, 8hr, 12hr, and 24hr postoperatively, pain was assessed using a visual analogue scale. The need for supplementary analgesic agents in the first 24 hours was recorded.

All pain scores were significantly lower (P< 0.05) in Groups 2, 3 and 4 compared with the control group with the exception of Group 2 at 24 hours. Pain scores were significantly lower (P<0.05) for Group 2 compared with Group 3 for the first 90 minutes postoperatively. At 4, 8, 12 and 24 hours postoperatively the pain scores were significantly lower (P<0.05%) for Group 3 compared with Group 2. Group 4 had the lowest pain scores over the recorded period compared with the other groups. The need for supplemental analgesia was significantly lower (P<0.05) in the treatment Groups 2, 3 and 4 compared to the control Group 1. There was no significant difference in supplemental analgesic requirements between Groups 2, 3 and 4.

A combination of bupivacaine and morphine injected intra-articularly following arthroscopy provided superior analgesia compared with that achieved by either drug alone.
Informed Consent—Recall of Risk Information following Epidural Analgesia in Labour
Authors: Swan H. D. , Borshoff D. C.
Published: January 2019

Recall of information pertaining to informed consent for epidural insertion in 40 primiparous labouring women was assessed. The recall of informed consent was compared between those patients who had attended antenatal epidural education classes, and those who had not. Overall recall of information was poor. Recall of information was significantly better in patients who had attended antenatal epidural education classes. We recommend that informed consent for epidural analgesia in labour be obtained antenatally whenever possible, and that details of the consent be recorded in the patient's notes.
Preoperative and Postoperative Oxygen Saturation in the Elderly following Spinal or General Anaesthesia—An Audit of Current Practice
Authors: Brown A. G. , Visram A. R. , Jones R. D. M. , Irwin M. G. , Bacon-Shone J.
Published: January 2019

We have compared the incidence of preoperative and postoperative oxygen desaturation in 20 elderly patients undergoing dynamic hip screw insertion for fractured neck of femur, allocated randomly to two groups to receive subarachnoid anaesthesia (SA, n = 10) or a general anaesthetic (GA, n = 10). Oximetry data were recorded during the preoperative night and the first 48 hours after surgery using Satmaster.™ Data associated with zero amplitude signal were automatically invalidated by the software and decreases in SpO2 which were preceded by contemporaneous changes in signal amplitude which conformed to a previously described template were assumed to be artefactual and were discarded from final data analysis. Data demonstrated a wide interpatient variability. However, those patients who desaturated preoperatively continued to do so in the postoperative period. The differences between the preoperative and postoperative oximetry profiles were examined for each patient and demonstrated a significantly longer time spent with SpO2 <90% in the GA group compared with the SA group, in all the recorded time periods, except on the day of surgery. The SA group showed an improvement in oxygen saturation postoperatively when compared to the preoperative night, spending less time with an SpO2 <85%. We conclude that the subarachnoid anaesthetic technique was associated with a lower incidence of postoperative oximetry desaturation when compared with general anaesthetic for these elderly patients undergoing repair of fractured neck of femur.
Sodium Nitropusside Induced Hypotension: Haemodynamic Response and dose Requirements during Propofol or Halothane Anaesthesia
Authors: Abdulatif M.
Published: January 2019

This study was designed to investigate the influence of anaesthesia induced and maintained with propofol on the haemodynamic effects and the dose requirements of SNP during the course of induced hypotension.

Twenty-four adult ASA physical status I patients undergoing middle ear surgery were randomly assigned to receive anaesthesia with either morphine, thiopentone, d-tubocurarine, halothane 0.6% end-tidal and N2O 70% in oxygen (group I n=12), or morphine, propofol, d-tubocurarine, propofol infusion 108 μg. kg−1. min−1 and N2O in oxygen (group 2 n = 12). Mean arterial blood pressure (MAP) was reduced to 60-65 mmHg in all patients using a continuous infusion of sodium nitroprusside (SNP) 0.01%. Propofol produced a significant (17%) reduction in the MAP before institution of SNP infusion. This was related to a 24% reduction in the systemic vascular resistance index (SVRI). In the halothane group SVRI was significantly reduced during SNP infusion. Halothane anaesthesia was associated with significant reflex tachycardia in response to SNP induced hypotension. Eight patients in the halothane group (66%) required propranolol 0.5-3 mg to control tachycardia. Propofol anaesthesia attenuated significantly the reflex tachycardia in response to SNP induced hypotension. Two patients in the propofol group (16%) required 0.5 mg propranolol to control reflex tachycardia. The mean SNP dose requirements were 7.25 ± 1.6 and 2.1 ± 1.4 μg. kg−1.min−1 in the halothane and propofol groups, respectively (P < 0.0001). None of the patients in the two groups developed rebound hypertension following SNP withdrawal. It is concluded that propofol anaesthesia reduces significantly the dose requirements for SNP through attenuation of the homeostatic reflex increase in the heart rate and systemic vascular resistance.
Assessment of Upper Airway Anatomy in Awake, Sedated and Anaesthetised Patients Using Magnetic Resonance Imaging
Authors: Shorten G. D. , Opie N. J. , Graziotti P. , Morris I. , Khangure M.
Published: January 2019

Magnetic Resonance Imaging was used to quantify the effects of 1. sedation and 2. general anaesthesia with a laryngeal mask airway (LMA) in place on the minimum antero-posterior (A-P) diameters of the naso-, oro- and hypopharynx and on the angle of the epiglottis relative to the adjacent posterior pharyngeal wall. Median saggital T1-weighted images of the pharynx were obtained in 46 patients (16 awake, 14 sedated, 16 under general anaesthesia). In sedated patients, the A-P diameters of the pharynx were less than in awake patients, in particular at the levels of the epiglottis and soft palate. General anaesthesia and placement of a LMA was also associated with a reduced A-P diameter at the level of the soft palate, but with increased diameters at the levels of the tongue and epiglottis. Placement of a LMA caused abnormal downfolding of the epiglottis in most cases but this did not cause clinically significant airway obstruction.
In Vitro Buffering Capacities of Proprietary Non-Particulate Antacids Available in New Zealand
Authors: Watts D. W.
Published: January 2019

Four commercially available non-particulate antacid preparations were titrated against 1M hydrochloric acid to assess buffering capacity as compared to 30 ml 0.3M sodium citrate solution. All antacids were used in the manufacturers “unit dose”. All antacids tested demonstrated some in vitro buffering capacity, and “Eno” (Reckitt and Colman) had a buffering capacity similar to that of sodium citrate. The retail cost per unit dose was established for each proprietary antacid and for sodium citrate. It was concluded that while proprietary antacids are cheaper per dose than sodium citrate, preparations differ in their acid-neutralising capacity.
Spinal Anaesthesia for Caesarean Section in the Solomon Islands
Authors: Sparks C. J. , Perndt H. , Agiomea K. , Fa'Arondo J.
Published: January 2019

Results were kept on 43 spinal anaesthetics performed for caesarean section in the Solomon Islands, a developing tropical country in the Pacific Ocean. A 25-gauge Quincke needle was used and either 2.5 ml of heavy bupivacaine 0.5% or 2.0-2.5 ml of plain bupivacaine 0.5% were injected. Hypotension down to 85 mmHg occurred in four patients and there were no spinal headaches. Five patients had to be given a general anaesthetic. We recommend this technique to other doctors working in the Pacific Islands.
Depth of Central Venous Catheterization: An Audit of Practice in a Cardiac Surgical Unit
Authors: Rutherford J. S. , Merry A. F. , Occleshaw C. J.
Published: January 2019

Central venous catheter (CVC) depth relative to the cephalic limit of the pericardial reflection (CLPR) was assessed retrospectively in 100 adult patients from chest radiographs taken after admission to the intensive care unit. A well known landmark proved to be considerably influenced by parallax; therefore we located the CLPR by a new landmark, the junction of the azygos vein and the superior vena cava, identified by the angle of the right main bronchus and the trachea. The majority (58) of CVC tips lay below the pericardial reflection on the first chest radiograph (CXR). Of these only two had been corrected by the time of the next routine CXR. No case of cardiac tamponade secondary to erosion by a CVC could be remembered, or identified from records of routine departmental audit meetings, for the last ten years. Nevertheless, reported incidents of this complication have often been fatal and vigilance is necessary in any patient with a CVC.
Rectal Indomethacin for Analgesia after Appendicectomy in Children
Authors: Sims C. , Johnson C. M. , Bergesio R. , Delfos S. J. , Avraamides E. A.
Published: January 2019

A prospective randomised controlled trial comparing rectal indomethacin with placebo was performed in children. Thirty children aged seven years and over undergoing open appendicectomy were given suppositories of either indomethacin 2 mg/kg or placebo. Suppositories were given at the conclusion of surgery and again 12 and 24 hours later. All children were given morphine by a patient-controlled analgesia pump. After 36 hours, children given indomethacin had used 0.51 (SD 0.34) mg/kg, and children given placebo 0.91 (SD 0.46) mg/kg (P <0.02). Pain scores measured with a visual analogue scale, sedation scores and the incidence of vomiting were similar in both groups. Children given indomethacin suppositories used 44% less morphine than children given placebo, and at the same time obtained similar postoperative analgesia.
A Novel Equipment Bridge for Helicopter Transport of Critically Ill Patients
Authors: Evans J. S. M. , Hotter A.
Published: January 2019

A three-piece equipment bridge designed to simplify transfer of critically ill patients by helicopter or land ambulance is described. A lightweight, support frame is first secured onto a standard stretcher while still allowing access to the patient. An equipment module can then be attached to the frame. Emergency access to the patient is quickly achieved by detaching the equipment module, while ventilation and monitoring continue uninterrupted. The unit is fully self-contained and has a low centre of gravity to assist stability.
Referral of Surgical Patients to an Anaesthetic Clinic: A Decision-making Analysis
Authors: Lee A. , Lum M. E. , Hillman K. M. , Bauman A.
Published: January 2019

Effective utilization of an anaesthetic clinic depends on appropriate referral of high-risk surgical patients. The decision-making behaviour of anaesthetists and nurses was examined to identify factors that influence the referral of patients to an outpatient anaesthetic clinic. Eleven consultant anaesthetists, seven anaesthetic trainees and sixteen nurses working in anaesthetic areas estimated the likelihood that they would refer patients for each of the 30 scenarios presented. The relative importance of each factor influencing the decision to refer as determined by the 34 participants were: type of procedure (22%), co-morbidities (18%), fitness (13%), history of anaesthetic problems (12%), medications (11%), age (10%), obesity (8%) and anxiety (6%). Indicative risk factors identified were aged 65 years or over, unable to climb more than two flights of stairs, presence of significant medical problems, gross obesity, history of anaesthetic problems, taking regular medications, scheduled for major surgery and expressed anxiety about the anaesthetic. There were large variations in the decision-making behaviour among health professional groups.
Patient-Controlled Analgesia: A Comparison with Nurse-controlled Intravenous Opioid Infusions
Authors: Murphy D. F. , Graziotti P. , Chalkiadis G. , Mckenna M.
Published: January 2019

Patient-controlled analgesia (PCA) with intravenous pethidine was compared with nurse-controlled pethidine infusions for pain relief in 200 patients after major abdominal or thoracic surgery. Pain, level of sedation, nausea and presence of other adverse effects, in addition to cumulative pethidine requirement, were measured for the first 24 hours after surgery. Both groups were similar for age, weight and type of surgery. There was no significant difference between the quality of analgesia achieved in both groups. The frequency and severity of adverse effects was also similar. The cumulative pethidine dose administered to both groups was identical. It is concluded that nurse-controlled opioid infusions are as effective as PCA and may be used as an alternative to PCA where this is either unavailable or unsuitable.
Anaesthesia for Three-Stage Thoracoscopic Oesophagectomy: An Initial Experience
Authors: Chui P. T. , Mainland P. , Chung S. C. S. , Chung D. C.
Published: January 2019

We report our experience in the anaesthetic management of five patients undergoing three-stage thoracoscopic oesophagectomy. One patient required conversion to open thoracotomy because of extensive pleural adhesions. The other four patients, aged between 68 and 78, were all chronic smokers with mid-oesophageal squamous cell carcinoma. The duration of thoracoscopic surgery (and obligatory one-lung ventilation) ranged from 2.5 to 4 hours with total surgical time ranging from 7.5 to 9.5 hours. Anaesthetic considerations included the use of one-lung ventilation to provide surgical access, the cardiorespiratory effects of capnothorax, difficulties in assessing surgical blood loss during thoracoscopic dissection, crowding in the operating room with limitation of access to the patient and the risk of intraoperative dislodgement of the endobronchial tube. Postoperative pulmonary complications were not decreased in our patients despite the avoidance of thoracotomy. The thoracoscopic technique might contribute to pulmonary complications because of prolonged thoracoscopic dissection and unintentional pulmonary injuries. The concept of minimally invasive surgery needs further evaluation when the technique is applied in extensive procedures such as oesophagectomy.
A Study of the Combined Haemodynamic Effects of Dobutamine and Enoximone in Patients Taking β Adrenoceptor Antagonists
Authors: Harvey W. R. , Monk C. R.
Published: January 2019

We conducted a randomized, double-blind investigation to determine whether enoximone affects the actions of dobutamine in patients taking β adrenoceptor antagonists. We studied sixteen patients with good ventricular function after coronary artery bypass operations. All patients were taking α β adrenoceptor antagonist. The patients received a standardized intravenous anaesthetic, which was maintained throughout the investigation. They received a masked infusion, containing either normal saline or enoximone. Haemodynamic data were recorded before, during, and after an infusion of dobutamine, which was given at three different rates.

Patients receiving enoximone had a greater cardiac output, a higher heart rate and a lower systemic vascular resistance than patients receiving saline. They also required an average of 1500 ml more intravenous colloid in the immediate postoperative period to achieve haemodynamic stability. Dobutamine produced a consistent, significant peripheral vasoconstriction, but no inotropic or chronotropic effect. There was no significant difference in this effect between the two groups, and it was not influenced by concurrent therapy with enoximone. The α adrenergic action of dobutamine prevented us from using high enough rates of infusion to explore any interaction between the inotropic actions of dobutamine and enoximone.
Changes in Vancomycin Pharmacokinetics in Critically Ill Infants
Authors: Gous A. G. S. , Dance M. D. , Lipman J. , Luyt D. K. , Mathivha R. , Scribante J.
Published: January 2019

We aimed to assess the pharmacokinetics of vancomycin in critically ill infants, and to evaluate the standard recommended dose of 10 mg/kg 6 hourly.

All infants admitted to the Baragwanath Hospital ICU who had arterial lines in situ, and for whom vancomycin 10 mg/kg 6 hourly was prescribed for an infective insult and who had parental consent, were included in the study.

Vancomycin was infused over 60 minutes. Serum samples were taken immediately before the dose and at 30, 60, 120 and 300 minutes after the end of the vancomycin infusion, on days 2 and 8 of therapy. Extrapolated peak concentration (Cmax), trough concentration (Cmin), apparent volume of distribution (Vd), elimination half-life (t½el) and clearance (CL) were determined for each patient. Day 2 values were compared with those of day 8.

Day 2 serum concentrations were assayed on 20 patients and day 8 concentrations in 15. The mean vancomycin Vd on day 2 (0.81 l/kg) was significantly (P=0.007) larger than that on day 8 (0.44 l/kg). The change in Vd resulted in a significant change in mean Cmax (29.1 vs 35.5 μg/ml) (P=0.02) and mean t½el (5.3 vs 3.4h) (P=0.01) over the treatment period.

Critically ill infants displayed a large initial volume of distribution which probably resulted from aggressive fluid resuscitation. This also results in a large variation in other pharmacokinetic parameters, namely Cmax and t½el. Although the routine monitoring of vancomycin serum concentrations remain controversial, we feel that in view of these large pharmacokinetic variations, the critically ill infant is a specific group where monitoring of vancomycin serum levels is indicated.
What is the Role of Absorption Atelectasis in the Genesis of Perioperative Pulmonary Collapse?
Authors: Joyce C. J. , Baker A. B.
Published: January 2019

During anaesthesia the combination of breathing at low lung volume, the administration of nitrous oxide and high inspired oxygen concentrations produces conditions that favour absorption atelectasis. Measures such as adding nitrogen to the inspired mixture and avoiding high inspired oxygen concentrations would reduce the amount of perioperative atelectasis if gas absorption was important in the genesis of perioperative pulmonary collapse. Experimental results demonstrate that these measures do not protect against atelectasis. This indicates that absorption atelectasis does not play a significant role in the genesis of perioperative pulmonary collapse. Compression atelectasis may be the underlying mechanism.
Australian Intensive Care Educational Links with Asian Countries
Authors: Mclean A. S. , Egan E. J.
Published: January 2019

A survey examining the level of Australian Intensive Care Unit involvement in the education of Asian critical care doctors and nurses was performed. Of the 49 hospitals surveyed, 34% have ongoing links. An analysis of countries involved, proportion of medical and nursing numbers, and whether the teaching was performed in Australia or the Asian country was undertaken. The survey revealed that a high proportion of Australian Intensive Care Units are actively involved, or would consider future participation, in educational links with Asian units.
Cerebral Effects of Propofol following Bolus Administration in Sheep
Authors: Ludbrook G. L. , Upton R. N. , Grant C. , Gray E. C.
Published: January 2019

The effects of bolus administration of propofol (50 mg, 100 mg and 200 mg) on cerebral blood flow and cerebral metabolic rate for oxygen were examined in a chronically catheterized sheep preparation. Depth of anaesthesia was simultaneously measured using a withdrawal response to a noxious electrical stimulus and it was demonstrated that the 100 mg dose induced moderate sedation while the 200 mg dose induced relatively deep anaesthesia. Propofol caused transient dose-dependent decreases in cerebral blood flow, despite minimal changes in blood pressure. These were accompanied by parallel decreases in cerebral metabolic rate but no change in cerebral oxygen extraction. As cerebrovascular responses in the sheep appear similar to those in man, the parallel changes in cerebral blood flow and metabolic rate demonstrated in this study supports the suitability of propofol as a neuroanaesthetic agent.
Analgesia for Acute Musculoskeletal Trauma: Low-Dose Subcutaneous Infusion of Ketamine
Authors: Gurnani A. , Sharma P. K. , Rautela R. S. , Bhattacharya A.
Published: January 2019

Low-dose ketamine by subcutaneous infusion (0.1 mg/kg/h) was compared in double-blind fashion with intermittent morphine (0.1 mg/kg intravenously, four-hourly) as analgesic regimen in 40 ASA-I adults after acute musculoskeletal trauma. Pain was assessed using visual analogue scales and sedation was graded on a four point rank drowsiness score. Objective cardiovascular and respiratory parameters and patient acceptability in terms of supplementary analgesia and early mobilization were also recorded. Pain relief was better with the ketamine infusion than with intermittent morphine (P< 0.001). Patients were more awake and alert with ketamine infusion as evidenced by the drowsiness score (P<0.001). Peak expiratory flow rate improved significantly with the ketamine infusion (P<0.05). None of the patients in ketamine group required supplementary analgesia (P<0.001) and the patients could be easily mobilized for traction/splintage as compared with patients in the control group (P<0.001). The incidence of nausea and vomiting in the morphine group was high (P<0.01). The study shows that subcutaneous infusion of ketamine provides safe and effective analgesia in acute musculoskeletal trauma.
Intraoperative Ventilation with Air and Oxygen during Laparoscopic Cholecystectomy Decreases the Degree of Postoperative Hypoxaemia
Authors: Fujii Y. , Tanaka H. , Toyooka H.
Published: January 2019

We studied the effects of intraoperative use of air in oxygen (O2) (FiO2 = 0.33) versus nitrous oxide (N2O) in O2 (FiO2 = 0.33) on the degree of postoperative hypoxaemia in 30 patients undergoing laparoscopic cholecystectomy. Patients were randomly allocated to receive either general anaesthesia with air (Group A, n=15) or with N2O (Group N, n=15). Arterial gas tensions were measured before, 24h and 48h after surgery while breathing room air. The mean PaO2 24h and 48h postoperatively decreased significantly in both groups compared with the preoperative values. The mean PaO2 24h postoperatively in Group N (74.6±6.4 mmHg) tended to be lower than that in Group A (78.1±8.3 mmHg). The mean PaO2 48h postoperatively in Group N (75.0± 7.8 mmHg) was significantly lower than that in Group A (83.5±7.9 mmHg) (P<0.05). On the contrary, the mean PaCO2 did not show any significant change during 48h postoperatively in either group. Our results suggest that ventilation with N2O and O2 during laparoscopic cholecystectomy is associated with a lower degree of postoperative hypoxaemia.
Percutaneous Dilational Tracheostomy - A Clinical Study Evaluating Two Systems
Authors: Van Heerden P. V. , Webb S. A. R. , Power B. M. , Thompson W. R.
Published: January 2019

Percutaneous dilational tracheostomy (PDT), first described in the 1950s, has become a common bedside technique in the Intensive Care Unit (ICU). This study compares the early complications associated with the use of the Ciaglia PDT (Cook Critical Care, Bloomington, USA) technique, with the newly available Portex PDT technique (Portex Ltd., UK). The Ciaglia technique was adopted in this ICU in July 1994 and twenty-nine patients had a tracheostomy using this set until January 1995. Complications during the procedure were collected prospectively. When the Portex PDT set became available in January 1995, it was decided to assess the complication rate of this technique and compare them to the previously-collected data using the Ciaglia PDT set. Twenty-five patients have had a tracheostomy using the Portex PDT set. There has been no mortality associated with either PDT set. Bleeding requiring intervention occurred in two patients in the Ciaglia group and three patients in the Portex Group. All these patients had a bleeding diathesis. Loss of airway control occurred on one occasion in the Ciaglia group due to premature removal of the endotracheal tube. The first routine tracheostomy tube change at day 7 was complicated in four cases in the Ciaglia group. One infected stoma was noted in the Ciaglia group at day 7. Both techniques result in rapid, safe placement of a tracheostomy tube in critically ill patients in the ICU, obviating the need for surgical referral and transport to the operating room.
Echocardiography Assessment of Left Ventricular Function in the Critically Ill
Authors: Mclean A. S.
Published: January 2019

Echocardiography is fast becoming the technique of choice for noninvasive evaluation of left ventricular function in the critically ill patient. Current technology allows for assessment of overall left ventricular performance and for diastolic and systolic function. Doppler technology has greatly enhanced the diagnostic capability of two-dimensional echocardiography. The critical care physician should be aware not only of currently available techniques, but also those which will be used in the routine care of the critically ill subject in the foreseeable future.
Deaths Attributed to Anaesthesia in New South Wales, 1984–1990
Authors: Warden J. C. , Horan B. F.
Published: January 2019

The New South Wales Special Committee Investigating Deaths Under Anaesthesia classified 1503 deaths before full recovery from anaesthesia occurring between 1984 and 1990. 172 deaths were attributed to anaesthesia, including 11 in which the anaesthetic choice or management could not be criticized. In the remaining 161 an average of 1.8 errors per case were identified, the most frequent being inadequate preparation of the patient (in 72 cases), inadequate postoperative care (52 cases), the technique of anaesthesia chosen (44 cases) and overdose (43 cases). Death was most commonly attributed to anaesthesia in elderly patients (modal age group 70–79), in males (1.9:1) and was most commonly associated with abdominal and orthopaedic operations. Urgent non-emergency cases, 10% of the 1503 cases classified, constituted 26% of those deaths attributed to anaesthesia. One death attributable to anaesthesia occurred per 20,000 operations and the rate of such deaths was 0.44 per 100,000 population per annum.
Monitoring Nitric Oxide: A Comparison of Three Monitors in a Paediatric Ventilator Circuit
Authors: Frawley G. P. , Tibballs J.
Published: January 2019

Simultaneous measurements of nitric oxide (NO) (0-80 ppm) using a chemiluminescence monitor and two electrochemical monitors were performed during simulated paediatric mechanical ventilation. The mean difference (bias) between the chemiluminescence (Model 42H Thermo Environmental Instruments Inc) and an electrochemical monitor (Pulmonox Research and Development Corp) was 0.52±6.52 ppm (SD). The 95% confidence limits of the mean difference were 3.00 to −1.96 ppm and the limits of agreement between the two techniques were 13.56 to −12.52 ppm. The mean difference between the chemiluminescence monitor and another electrochemical monitor (NOxBox, Bedfont Scientific Inc) was −7.27±4.29 ppm. The 95% confidence limits of the mean difference were −9.02 to −5.56 ppm and limits of agreement of the two techniques were −16.13 to 1.55 ppm. These results suggest that electrochemical monitors may be used to guard against potentially toxic concentrations of NO (greater than 20 ppm). However they do not suggest that either of the electrochemical monitors may be used with confidence in lieu of the chemiluminescence monitor to regulate NO at low clinical NO levels (1-5 ppm).
Effect of Low Concentrations of Prostacyclin on Platelet Function in Vitro
Authors: Van Heerden P. V. , Gibbs N. M. , Michalopoulos N.
Published: January 2019

The study was performed to determine the possible direct effects of low concentrations of prostacyclin that might spill over into the systemic circulation during the administration of inhaled aerosolized prostacyclin.

Platelet aggregation in response to adenosine diphosphate and collagen, as well as measurement of the maximum amplitude of the thrombelastograph (TEG), was undertaken in vitro using venous blood exposed to low concentrations of prostacyclin (0, 10, 100 and 500 pg/ml) from eight healthy volunteers.

There were statistically significant reductions in parameters of platelet aggregation in response to the agonists adenosine diphosphate (1 μmol/l and 8 μmol/l) and collagen (10 μmol/l) following exposure to as little as 10 pg/ml of prostacyclin. The maximum amplitude of the TEG was unchanged over the entire range of prostacyclin concentrations studied.

The results indicate that low concentrations of prostacyclin or prostacyclin metabolite such as may be observed during inhaled aerosolized prostacyclin therapy are likely to be associated with a marked platelet aggregation defect. This defect was not detected by the TEG.
The Effect of Supplemental Oxygen on the Incidence of Hypoxaemia after Premedication in Patients Undergoing Cardiac Surgery
Authors: Royse C. F. , Tiernan R. J. B. , Portelli S. M. , Davies S. , Arblaster R. , Bjorksten A. R. , Tatoulis J.
Published: January 2019

Opiate premedication may cause significant respiratory depression, particularly when other sedative agents such as scopolamine or benzodiazepines are added. This can cause hypoxaemia with potential for worsening myocardial ischaemia in cardiac surgery patients. The aim of this study was to investigate the incidence of hypoxaemia (SpO2 <90%) in elective patients undergoing cardiac surgery and to assess the efficacy of supplemental oxygen in preventing it.

One hundred elective patients without significant respiratory disease or cardiac failure, who received both an opiate and a sedative premedication, were prospectively randomized to receive either oxygen via a facemask at 4 l/min or no oxygen. Continuous arterial oxygen saturation was recorded using a pulse oximeter from the time of premedication until the patient arrived in theatre. An SpO2 <90% was recorded as a significant event and oxygen was administered to the patients.

Six patients were excluded because of equipment failure or protocol violations. The patient groups were comparable with respect to patient demographics, premedication type and dose or the duration of monitoring. In patients receiving oxygen (n=48) there were no episodes of hypoxaemia (0%). In patients not receiving oxygen (n=46) there were 14 episodes of hypoxaemia (30%, P<0.0001).

We conclude that there is a significantly high incidence of hypoxaemia in cardiac surgery patients following combined opiate and sedative premedication and that it can be reduced by the routine administration of supplemental oxygen.
Bacteraemia following Percutaneous Dilational Tracheostomy
Authors: Teoh N. , Parr M. J. A. , Finfer S. R.
Published: January 2019

This study reports the incidence of bacteraemia following 106 consecutive bedside percutaneous tracheostomies.

Post-tracheostomy blood culture results were compared with other blood cultures from the same population.

The incidence of positive post-tracheostomy blood cultures was 10.4% (11/106), compared with 6.6% (7/106) for other blood cultures (odds ratio 1.64, 95% confidence interval 0.61-4.40, P=0.46). Staphylococcus epidermidis was the most common organism cultured, 7/106 (6.6%) of post-tracheostomy cultures, compared with 3/106 (2.8%) for other cultures (odds ratio 2.43, 95% confidence interval 0.61-9.65, P=0.33). The other four post-tracheostomy cultures grew an organism cultured from that patient's tracheal secretions. Seventy-four patients were receiving antibiotics at the time of tracheostomy, of these 7 (9.5%) had positive blood cultures, a similar incidence (4 of 32, 12.5%) to those not receiving antibiotics (odds ratio 0.73, 95% confidence interval 0.20-2.70, P=0.90).

We conclude bacteraemia is a common complication of percutaneous tracheostomy; the causative organisms come from the patients’ trachea or skin.
Management of Malignant Hyperthermia Susceptible Parturients
Authors: Pollock N. A. , Langton E. E.
Published: January 2019

The management of eleven women susceptible to malignant hyperthermia during twenty deliveries is presented. These women were managed over a six-year period following guidelines that were established in 1990.

Initial problems identified were the management of labour and caesarean section, the use of sympathomimetics and potential problems for the newborn, viz. placental transfer of drugs and the possibility of a stress-induced malignant hyperthermia reaction in the newborn.

There was little evidence that the stress of labour produced hypermetabolic responses in either mother or neonates and the use of sympathomimetics increased throughout the six-year period with no evidence of adverse effects. A caesarean section using general anaesthesia was not required but the management of this situation is described in both the protocol and discussion sections of this paper.
Inspired Oxygen Concentrations with or without an Oxygen Economizer during Ether Draw-Over Anaesthesia
Authors: Khaing T. T. , Yu S. , Brock-Utne J. G.
Published: January 2019

An oxygen economizer tube is attached to draw-over vaporizers and acts as a reservoir of supplemental oxygen. The clinical importance of the presence or absence of the economizer tube (volume 130 ml) has not been adequately studied in manually ventilated patients using ether from an Ohmeda Cyprane Portable Anesthesia Complete (PAC) draw-over vaporizer.

A total of sixteen patients ASA 1-2, undergoing elective surgery for peripheral orthopaedic procedures were studied with and without an economizer tube. Each patient acted as his or her own control. Standard procedures were used for anaesthetic induction with muscle relaxant, endotracheal intubation and anaesthetic maintenance. Supplemental oxygen was supplied by an oxygen concentrator. Using the draw-over vaporizer without an oxygen economizer tube, there was a slight increase in FiO2 of 20%, 23%, 27%, 30%, 33% and 33%, with increasing oxygen supplementation of 0 to 5 l/min, respectively.

With an economizer tube, the FiO2 values increased to 20%, 26%, 35%, 46%, 54% and 66% at 0 to 5 l/min of oxygen respectively. The FiO2 values were significantly different at 3, 4, and 5 l/min (P<0.05), showing the potential advantages of an oxygen economizer tube attached to a draw-over vaporizer in this setting.

No significant differences were seen in the oxygen saturations of these healthy patients with or without an oxygen economizer.
Incidence of Phrenic Nerve Block and Hypercapnia in Patients Undergoing Carotid Endarterectomy under Cervical Plexus Block
Authors: Emery G. , Handley G. , Davies M. J. , Mooney P. H.
Published: January 2019

Deep cervical plexus blockade blocks the second, third and fourth cervical nerve roots. The phrenic nerve arises from C3,C4,C5 and should therefore be commonly blocked with cervical plexus blockade. The aim of this study was to report the incidence of phrenic nerve block and to assess the effect of this on arterial carbon dioxide tension (PaCO2) in premedicated and sedated patients.

Forty patients were studied, blood gases being taken on the day before surgery, immediately before performing the block and then every 20 minutes until the operation was completed. Fluoroscopy was used to determine ipsilateral hemidiaphragmatic dysfunction due to phrenic nerve block. The patients were then divided into two groups of analysis. Group A patients had evidence of phrenic nerve block, Group B patients had no evidence of phrenic nerve block.

Fluoroscopy showed that 22 patients (55%) had evidence of phrenic nerve block (Group A), 18 patients showed no change (Group B). PaCO2 levels increased in both groups following premedication, from 41 ±5 mmHg (mean± SD) to 46±5 mmHg in Group A, and 41 ±4 mmHg to 45 ±4 mmHg in Group B; twenty minutes after cervical plexus block the PaCO2 rose to 49±6 mmHg in Group A, and 48±6 mmHg in Group B. These changes were not statistically significantly different when the two groups were compared.
Tracheal Intubation through the Intubating Laryngeal Mask Airway (LMA-Fastrach™) in Patients with Difficult Airways
Authors: Fukutome T. , Amaha K. , Nakazawa K. , Kawamura T. , Noguchi H.
Published: January 2019

The intubating laryngeal mask airway was used in 31 adult patients in whom tracheal intubation was known or suspected to be difficult. The intubating laryngeal mask airway was successfully inserted in 30 patients and provided a clinically patent airway. In the remaining one patient it was impossible to insert the device correctly. Tracheal intubation through the device was successful in 28 of 30 patients (93%). These results suggest that the intubating laryngeal mask airway has a potential role for tracheal intubation in adult patients with difficult airways.
Paraspinal Abscess Associated with Epidural in Labour
Authors: Raj V. , Foy J.
Published: January 2019

A 24-year-old presented in labour requesting an epidural. She had been diagnosed as having “pelvic arthropathy” at 37 weeks. After an uneventful epidural and instrumental delivery, she discharged herself home. She re-presented 19 days later with left hip pain and abnormal neurological signs in the lower limbs. On MRI, there was a large paraspinal abscess with an epidural granulation mass compressing her spinal cord. She had an urgent surgical decompression. In hindsight, it is likely that the paraspinal mass was present at the time of epidural insertion. The discussion highlights that complications are sometimes not what they seem.
Middle Cerebral Artery Flow Velocity and Cerebral Oxygenation during Abdominal Aortic Surgery
Authors: Liu G. , Burcev I. , Pott F. , Ide K. , Horn A. , Secher N. H.
Published: January 2019

Cerebral perfusion was evaluated in twelve patients undergoing elective infra-renal abdominal aortic aneurysmec-tomy by transcranial Doppler ultrasonography-determined middle cerebral artery mean flow velocity, near-infrared spectroscopy-assessed cerebral oxygen saturation and systemic haemodynamic variables. The middle cerebral artery mean flow velocity and cerebral oxygen saturation decreased during cross-clamping of the aorta, and both increased upon declamping of the aorta with the oxygen saturation change lagging behind the change in the flow velocity. The changes in cerebral flow velocity and oxygen saturation paralleled the deviations in cardiac output and end-tidal carbon dioxide tension.
Recurrent Laryngeal Nerve Injury Caused by a Laryngeal Mask Airway
Authors: Lowinger D. , Benjamin B. , Gadd L.
Published: January 2019

Although there have been few reports of serious complications with the laryngeal mask airway, we record a case of permanent unilateral vocal cord paralysis following the use of a laryngeal mask airway and review the literature describing injuries, not only to the recurrent laryngeal nerves but also to the hypoglossal and lingual nerves.
Anaesthesia for LSCS in a Morbidly Obese Patient
Authors: Patel J.
Published: January 2019

The management of a morbidly obese parturient with a body mass index of 88 is reported. She developed asthma during the pregnancy. Lumbar epidural anaesthesia was successfully used for an elective caesarean section and tubal ligation.
Intraoperative Transoesophageal Echocardiography for Paediatric Cardiac Surgery—An Audit of 200 Cases
Authors: Sheil M. L. K. , Baines D. B.
Published: January 2019

We report out initial experience with intraoperative transoesophageal echocardiography (TOE) in 200 patients undergoing repair of congenital heart disease. Complications associated with probe insertion precluded a full study in 11 patients (5.5%) and included airway obstruction (n=6), inability to pass the probe (n=4) and vascular compression (n=1). The preoperative diagnosis was confirmed by TOE in 176 of 189 cases (93%) with minor variances in 12 (6.3%) and one major variance (additional large muscular ventricular septal defect (VSD)). Unexpected abnormalities not diagnosed preoperatively were found at surgery in four cases (2%) and were all of trivial operative significance. Postoperative studies showed no residual defect in 96 (51%) and trivial or mild residual defects in 72 patients (38%). There were moderate or severe residual defects in 21 cases (11%). Ten cases (5.3%) returned to bypass for further surgery, with eight achieving complete or adequate amelioration. In six of the 10 cases, return to bypass was prompted by the TOE examination alone. There was one re-operation in the postoperative period for a VSD patch dehiscence. Routine TOE offers significant advantages in the management of patients undergoing repair of congenital heart disease, particularly in postoperative assessment. Careful monitoring of perfusion and ventilation is required, particularly during probe insertion in children weighing 5 kg or less.