bluuebunny/crossref_metadata_2025 huggingface dataset:
The Prevention of Gastric Inflation — A Neglected Benefit of Cricoid Pressure
Authors: Petito S. P. , Russell W. J.
Published: January 2019

The ability of cricoid pressure to prevent inflation of the stomach during mask ventilation of a patient was studied. Fifty patients were randomly allocated to either have or not have cricoid pressure applied during a three-minute period of standardised mask ventilation. Patients who had had cricoid pressure applied had less gas in the stomach after mask ventilation (P< 0.001). However, in a subgroup of patients considered difficult to ventilate, cricoid pressure seemed less successful in preventing gastric inflation. Cricoid pressure is a useful technique for reducing gastric inflation during mask ventilation, particularly in patients who are relatively easy to ventilate.
Total Intravenous Anaesthesia Using Propofol Infusion — 50 Consecutive Cases
Authors: Galletly D. C. , Short T. G.
Published: January 2019

Fifty consecutive patients in the authors’ practice were anaesthetised with a total intravenous technique using propofol infusion, fentanyl, vecuronium and oxygen in air. Patients were predominantly elderly and undergoing major upper gastrointestinal surgery for a mean duration of 133 minutes (range 20 minutes to 7 hours). Twenty-one patients had significant concomitant medical illness.

Propofol was found to give a rapid, smooth induction with wide variation in dose requirement (0.5 to 2.9 mg/kg). There was a mean systolic blood pressure fall of 27% from preoperative values, greatest in elderly patients. Depth of anaesthesia was readily adjusted by alteration in infusion rate according to standard clinical criteria. The dose of propofol required for maintenance was highly variable (range 2–15 mg/kg/hr in the first hour). Three patients reported dreaming and two of these had shown signs of light anaesthesia. Recovery was rapid, with few side-effects, and a mean time to open eyes on command of 8.5 minutes from the end of infusion. Propofol was considered to be a satisfactory intravenous agent for the induction and maintenance of anaesthesia in the majority of patients studied. The most significant problem was hypotension following the induction dose.
A Double-Blind Comparative Study of Three Formulations of Diazepam in Volunteers
Authors: Forrest P. , Galletly D. C.
Published: January 2019

The sedation and subsequent recovery following administration of three formulations of diazepam (propylene glycol, mixed micelle and lipid emulsion) were compared in a randomised, double-blind, crossover study of twelve male volunteers. Following intravenous injections of 10 mg of each formulation, sedation was assessed for ten minutes using a six-point ordinal sedation score and subsequent recovery was assessed using a psychomotor/sedation battery including simple reflex time, letter deletion test, a simple arithmetic exercise, digit recall and a linear analogue sedation scale.

Diazepam in propylene glycol was found to be more sedating that diazepam, either in a lipid formulation or as mixed micelles and appeared faster in its rise to peak effect than the lipid formulation. Subsequent recovery did not differ between the three groups. A significant increase in the level of sedation achieved by the preparations was found with each study day indicating that subject or testing factors were also important in determining the sedative response.

Our results suggest that the new solvent systems, and in particular the lipid emulsion, primarily alter initial drug efficacy.
Hypoxia in Children following General Anaesthesia
Authors: Tomkins D. P. , Gaukroger P. B. , Bentley M. W.
Published: January 2019

The oxygen saturations of 152 children were studied for the first 30 minutes following general anaesthesia with a pulse oximeter. Thirty-six patients (24%) recorded oxygen saturations of less than 90% while breathing room air and in all cases this occurred during the first ten minutes.

Intubation (P < 0.001), use of muscle relaxants (P < 0.01), intravenous induction (P < 0.01) and duration of anaesthesia of greater than one hour (P < 0.02) were all associated with an increased incidence of hypoxaemia. There was no significant correlation with age, weight, procedure, time to wakening, or use of opiates.

Clinical signs correlated poorly with hypoxaemia and it is recommended that all children should receive supplementary oxygen during transport to recovery wards and for at least the first ten minutes in recovery following general anaesthesia.
A Controlled Oximetric Evaluation of Inhalational, Opioid and Epidural Analgesia in Labour
Authors: Zelcer J. , Owers H. , Paull J. D.
Published: January 2019

The effects on patient oxygenation of nitrous oxide, narcotic and epidural analgesia in labour were evaluated using pulse oximetry. Five groups of ten patients received either no analgesia (Control, Group I), an epidural block alone (Group 2), nitrous oxide in oxygen alone (Group 3), intramuscular pethidine (Group 4), or nitrous oxide in oxygen combined with intramuscular pethidine (Group 5). Derived parameters included the maximum (MAX), minimum (MIN), average maximum (AV MAX), and average minimum (AV MIN) arterial haemoglobin oxygen saturation (Sao2), and differences between maxima and minima (MAX-MIN). There was a statistically significant difference between Group 1 and Group 5 for MIN, AV MIN and MAX-MIN SaO2 (P < 0.05). All other groups showed no significant difference in any parameter when compared with the control group. The results are discussed with reference to normal and disordered maternal physiological changes in pregnancy. It is suggested that nitrous oxide should not be used for analgesia in labour where there is concern about maternal, placental or foetal reserve.
Post-Cholecystectomy Pulmonary Function following Interpleural Bupivacaine and Intramuscular Pethidine
Authors: Oxorn D. C. , Whatley G. S.
Published: January 2019

Twenty-four patients who were to undergo cholecystectomy were randomised into two groups, one to receive postoperative analgesia with interpleural bupivacaine, 20 ml of a 0.5% solution with adrenaline 5 μg/ml, and the other to receive intramuscular pethidine, 1 mg/kg. Preoperative and postoperative pulmonary function, postoperative pain scores, and days from operation to hospital discharge were recorded and statistically compared.

There was no significant difference in pain scores, nor in days to discharge; however, postoperative pulmonary mechanics were significantly poorer in the interpleural group. A hypothesis to explain the differences is offered.
Isoflurane for Thymectomy in Myasthenia Gravis
Authors: Rowbottom S. J.
Published: January 2019

The clinical and electromyographic effects of isoflurane were studied in eight myasthenic patients undergoing trans-sternal thymectomy. After inhalational induction of anaesthesia, intubating and operating conditions were good. Recovery from anaesthesia was rapid with minimal postoperative residual muscle weakness or respiratory depression. All patients were extubated within the first postoperative hour. Integrated electromyographic monitoring of the train-of-four response of adductor pollicis demonstrated that myasthenics are more sensitive than non-myasthenics to the neuromuscular depressant effects of isoflurane. Recovery of the integrated electromyographic response was incomplete despite a satisfactory clinical recovery.
Postoperative Analgesia in Neonates: An Australia-Wide Survey
Authors: Campbell N. N. , Reynolds G. J. , Perkins G.
Published: January 2019

An Australia-wide survey of the use of postoperative analgesia in neonates has been conducted. A high overall use of analgesia has been recorded with 75% of respondents prescribing an opioid. The frequency of use of local or regional analgesia was disappointingly low at 8% overall. The general attitude is that analgesia is desirable but a fear of respiratory depression inhibits its use, particularly in non-ventilated neonates and after more minor surgery. It is suggested that a wider use of regional anaesthesia techniques may reduce this problem.
A Method for Implementing Programmed Infusion of Thiopentone and Methohexitone with a Simple Infusion Pump
Authors: Crankshaw D. P. , Karasawa F.
Published: January 2019

We have tabulated the series of steps in infusion rate required to maintain constant arterial levels of thiopentone and methohexitone. The tables are based on multiexponential equations for infusion rate, derived from plasma drug efflux studies. In each table an initial bolus is followed by nine steps in infusion rate over three hours. The tables provide rates suitable for delivery by a standard syringe pump to achieve and maintain an arterial concentration of 10 mg/l of thiopentone and 5 mg/l of methohexitone. Other desired drug concentrations can be derived from the table by simple multiplication.
Effect of Premedication on Arterial Blood Gases Prior to Cardiac Surgery
Authors: Jones R. D. M. , Kapoor S. C. , Warren S. J. , Moffatt C. , Merridew C. G. , Mackillop A. , Hui P. W.
Published: January 2019

The effect of premedication on arterial blood gas tensions was studied in thirty adult surgical patients with valvular disease. They were divided into three groups, each group having a different premedication regimen. Blood gas tensions were compared in these patients when awake on the night before surgery, asleep, after premedication and just prior to induction of anaesthesia. Samples were taken while the patient breathed air and each patient acted as his/her own control. The patients were randomised into one of three premedication regimens: 1. intramuscular lorazepam, 2. intramuscular morphine and hyoscine (scopolamine) and 3. oral lorazepam plus intramuscular morphine and hyoscine. There was a statistically significant though not clinically significant rise in PaCO2 and fall in pH following premedication with lorazepam, morphine and hyoscine. There was also a significant fall in PaO2 associated with morphine and hyoscine premedication which was greater than that which occurred with unsedated sleep. Patients who are to undergo cardiac valvular surgery should receive supplementary oxygen following premedication and during transfer to the operating room.
A Double-Blind Comparison of Epidural Bupivacaine and Bupivacaine-Fentanyl for Caesarean Section
Authors: Paech M. J. , Westmore M. D. , Speirs H. M.
Published: January 2019

The effect of adding fentanyl 100 mcg to bupivacaine 0.5% plain to establish epidural anaesthesia for elective caesarean section was investigated in a randomised, double-blind study of sixty healthy women. The quality of intraoperative analgesia as assessed by both patients and anaesthetists was significantly improved with fentanyl. The onset and duration of sensory anaesthesia, degree and duration of motor block, and other characteristics of epidural anaesthesia were unaltered. No adverse maternal side-effects (except mild pruritis) were noted and neonatal outcome was unaffected. The pharmacokinetics of epidural fentanyl administration were investigated by plasma fentanyl assays from maternal and cord blood taken at delivery.

Epidural bupivacaine-fentanyl combination is a valuable therapeutic approach to the conduct of epidural anaesthesia for caesarean section in healthy women and foetuses. Further neonatal evaluation of the premature or compromised foetus is suggested before the universal application of this technique.
Effect of Adrenaline, Fentanyl and Warming of Injectate on Shivering following Extradural Analgesia in Labour
Authors: Shehabi Y. , Gatt S. , Buckman T. , Isert P.
Published: January 2019

This prospective, controlled study was undertaken to determine whether addition of adrenaline or fentanyl to bupivacaine or warming of the injectate had any effect on the incidence of shivering following extradural analgesia in the labouring parturient. Eighty-four patients were sequentially allocated to four groups (control, warm injectate, extradural adrenaline and extradural fentanyl). The adrenaline group had the highest incidence of shivering, the warm injectate and fentanyl groups the lowest. Extradural fentanyl also seemed promising in reducing shivering in pre-block shiverers. This paper also explores the rapidity of temperature decay of solutions of bupivacaine in different clinical situations.
Pre-Bypass Myocardial Ischaemia in Patients Undergoing Coronary Artery Surgery
Authors: Davies M. J. , Kluger R. , Molnar R. , Domaingue C. M. , Silbert B.S. , Cronin K. D. , Koumoundouros E.
Published: January 2019

One hundred patients undergoing elective coronary artery surgery were studied to determine the incidence of pre-bypass myocardial ischaemia. Leads II, aVF and V5 of the electrocardiogram (ECG) were recorded at five-minute intervals from arrival in the anaesthetic room until onset of cardiopulmonary bypass. Thirteen patients developed sixteen episodes of significant ST depression on the ECG during the study period. Three patients were diagnosed as having postoperative myocardial infarction by ECG criteria and creatine phosphokinase-MB rise above 80 units. None of these patients had pre-bypass ST depression. Comparisons of these results with similar studies are presented.
Anaesthesia for Resection of Lesions of the Trachea and Main Bronchi using the Neodymium Yttrium Aluminium Garnet (Nd YAG) Laser. A Report of 75 Treatments in 52 Patients
Authors: Jackson K. A. , Morland M. H.
Published: January 2019

The management of anaesthesia and outcome of 75 treatments in 52 patients are discussed. Total intravenous anaesthetic techniques were used with venturi ventilation via a rigid bronchoscope. A number of complications occurred, but there was no death or major surgical complication. All complications except one were apparent intraoperatively or in the recovery room. As the considerable risk of intraoperative hypoxia was considered to outweigh the minimal risk of intratracheal fire or explosion, no attempt was made to limit inspired oxygen concentration (FIO2) during the application of the laser. The results of ventilation/perfusion studies and a recent diagnostic bronchoscopy were very helpful in patient selection.
Does the Radial Arterial Line Degrade the Performance of a Pulse Oximeter?
Authors: Morris R. W. , Nairn M. , Beaudoin M.
Published: January 2019

The presence of radial arterial lines may diminish distal digital perfusion. Using a pair of pulse oximeters on the index fingers of cannulated and noncannulated arms the saturation and oximeter pulse strength were assessed. Three hundred paired measurements in fifty consecutive Intensive Care patients were undertaken more than two hours after cannula insertion.

The pulse strength was 19.7 (SD 6.1) and 19.7 (SD 5.7) on the cannulated and noncannulated sides while the saturation was 97.3 (SD 2.3) and 97.1 (SD 2.4) respectively. These differences are not clinically important and the study demonstrates that reliable pulse oximetry measurements may be made distal to a radial artery cannula. It is recommended that in each individual the placement of the sensor be such as to ensure the best signal and the most stable saturation readings.
A Comparison of Lignocaine 2% with Adrenaline 1:200,000 and Lignocaine 2% with Adrenaline 1:200,000 plus Fentanyl as Agents for Caudal Anaesthesia in Children Undergoing Circumcision
Authors: Jones R. D. M. , Gunawardene W. M. S. , Yeung C. K.
Published: January 2019

This randomised double-blind study compares the onset, quality and duration of analgesia in two groups of children (n = 30), aged between two and twelve years undergoing circumcision. Under concurrent general anaesthesia, the children received caudal anaesthesia employing either lignocaine 2% with adrenaline 1:200,000 plus normal saline 0.01 ml/kg, or lignocaine 2% with adrenaline 1:200,000 plus fentanyl 1.0 microgram/kg. The results show no statistical or clinical difference in the onset, duration, quality of pain relief, or side-effects between the two solutions.
Flumazenil: A Twelve-Month Survey of Use in a New Zealand Public Hospital
Authors: Galletly D. C. , Ure R. , Turley A.
Published: January 2019

As part of a program of postmarketing surveillance, the use of flumazenil was monitored prospectively in a New Zealand public hospital for a period of twelve months. A questionnaire on usage, efficacy and side-effects was completed by clinicians for 118 patients receiving the drug.

Our conclusions are these:

1. Flumazenil was used most frequently after anaesthesia and in the initial management of intentional drug overdose.

2. In two-thirds of cases, flumazenil was used to antagonise benzodiazepines in the presence of non-benzodiazepine drugs and its efficacy was primarily determined by the presence of these latter drugs.

3. The complications of flumazenil are mild although important complications may arise from interaction with other drugs and unmasking of conditions such as postoperative pain.

4. Resedation was common (24%), although rarely a problem unless large doses of benzodiazepine agonist had been administered or if other hypnosedatives were given subsequently.
Epidural Medication after the Initial Dose: Reflections on Current Methods of Administration during Labour
Authors: Brownridge P.
Published: January 2019

Most women who receive epidural pain relief during labour require additional epidural analgesia following the initial dose. This review examines the relative merits associated with current methods of epidural drug delivery when further analgesia is required. Apart from considerations of patient safety and convenience the review compares the relative flexibility in pain management which can be provided by these different regimens. It is postulated that patient satisfaction is enhanced when the mother has some personal control over the density of neural blockade provided by epidural analgesia.
Epidurals, Spinals and Bleeding Disorders in Pregnancy: A Review
Authors: Sage D. J.
Published: January 2019

Paraplegia caused by spinal haemorrhage is a very rare but disastrous complication of spinal or epidural insertion. The risk in uncomplicated surgical and obstetric patients is outlined. Bleeding disorders in pregnant patients may prevent the use of major regional anaesthesia. Factors which influence the choice of anaesthetic technique for patients with pregnancy-induced hypertension, von Willebrand's disease, and anticoagulation therapy, are discussed.
Dose-response Characteristics of Pancuronium in Neonates, Infants and Children
Authors: Meretoja O. A. , Luosto T.
Published: January 2019

This paper presents pharmacodynamic data for pancuronium in neonates, infants, children and adolescents during N2O-O2 fentanyl anaesthesia. Neuromuscular block (NMB) was evaluated by the adductor pollicis electromyogram. Dose-response curves of pancuronium were parallel in all age-groups. ED95 was greatest in children and least in infants (93 vs. 66 μg/kg, P<0.05). The rate of spontaneous recovery following 95% NMB was comparable in all age-groups, as was the maintenance requirement of pancuronium when related to ED-values. The hourly requirement to maintain NMB > 85% was 60–68% of the individual ED95 dose. When administered on this basis, pancuronium is an equally long-acting neuromuscular blocking agent in patients of all ages.
Response to Nondepolarizing Muscle Relaxants in Children with Tumours
Authors: Brown T. C. K. , Gregory M. , Bell B. , Clare D.
Published: January 2019

The rate of onset of action of d-tubocurarine (64 patients) or alcuronium (36 patients) was studied electromyographically in 100 children who had abdominal, bone or cerebral tumours. It was found that there was a significantly delayed onset (over three times longer than controls) or additional doses were required in patients with malignant liver, renal and bone tumours who received d-tubocurarine. The onset of alcuronium blockade was also prolonged but to a lesser extent. When tumours with an abnormal prolongation of onset of relaxation were successfully treated by chemotherapy and/or surgery, the response reverted to normal. Children with benign tumours or masses had normal responses.

In contrast, neuroblastomas were associated with little prolongation of onset. Cerebral tumours showed a variable response, with the observed changes being unreliable indicators of degree of malignancy.
Responses to Small Doses of Suxamethonium in Four Children with Abnormal Cholinesterase — A Case Report
Authors: Brown T. C. K. , Meretoja O. A. , Bell B. , Clare D.
Published: January 2019

Four patients with genetic cholinesterase abnormalities were studied with electromyography after being given suxamethonium 0.1 mg/kg. An abnormal homozygous patient was paralysed for 17 minutes. The duration of response in heterozygous patients was 2–4 minutes, being shorter when cholinesterase activity levels were near normal.
Does Suxamethonium Influence the Subsequent Dose Requirements of Alcuronium and Its Reversibility in Children?
Authors: Brown T. C. K. , Meretoja O. A. , Clare D. , Bell B.
Published: January 2019

Suxamethonium is often used for intubation prior to the use of a nondepolarising muscle relaxant. This study was performed to determine whether suxamethonium altered the dose of alcuronium required to produce neuromuscular block. The findings were that suxamethonium 1.0 mg/kg did not alter the depth, duration or reversibility of block if given before alcuronium 0.3 mg/kg. Reversal with neostigmine was more rapid following 50 fig/kg than after 25 μg/kg. If recovery from neuromuscular block was greater than 25 per cent, the lower dose produced satisfactory reversal, whether or not suxamethonium had been given previously.
Tubeless Anaesthesia for Microlaryngeal Surgery
Authors: Aun C. S. T. , Houghton I. T. , Sot H. Y. , Van Hasselt C. A. , Oh T. E.
Published: January 2019

An anaesthetic technique for laryngeal microsurgery is described and evaluated using intravenous propofol infusion and topical lignocaine with the patient breathing spontaneously without an endotracheal tube. Eighty adult patients divided into two groups according to their ASA status (Group A; 58 ASA I and II; Group B; 22 ASA III and IV) were analysed. Operating conditions were good in all but one case. Good anaesthesia was achieved in about 70% of patients. The requirement for propofol was less in Group B. Blood pressures decreased signifcantly following induction (P < 0.001) but returned towards the preoperative values after ten minutes in Group A patients whereas the recovery was slower in Group B. Apnoea occurred on induction in about 40% of patients overall. Paco2 showed a similar small increase in both groups. Oxygenation was adequate. The results show that propofol as an infusion in this simple tubeless technique is satisfactory. As the technique was considered potentially hazardous in those patients with upper airway obstruction, such patients were not included in this study.’
Modified Jet Ventilation during Total Laryngectomy: A Prospective Study using Pulse Oximetry and a Pressure Regulator
Authors: Chan A. S. H. , Wei W. I. , Lau W. F. , Lam K. H.
Published: January 2019

A method of jet ventilation during total laryngectomy is described. During the construction of the terminal tracheostomy, a small metal tube is used, instead of the traditional tracheostomy tube, to provide intermittent jet ventilation down the distal trachea. A pressure regulator is also employed to choose a driving pressure best suited to the chest and lung compliance of each patient. Excellent surgical access for tracheo-cutaneous anastomosis is achieved. Satisfactory ventilation during the jet period is also confirmed by unaltered Paco2 and increased Pao2 levels. The use of pulse oximetry as a non-invasive and continuous monitor of arterial oxygenation is a simple alternative to arterial blood sampling.
Positioning Central Venous Catheters – A Prospective Survey
Authors: Peres P. W.
Published: January 2019

This paper reports the results of a prospective survey of 266 attempted central venous catheterisations by various routes, evaluating their success rate and incidence of immediate complications and attempts to demonstrate a relationship between patient height in centimetres (H) and ideal catheter length. The overall rate of intrathoracic placement was 230 from 239 catheterisations (96%) after 266 attempts (86%). Of these 230 catheters, 54 terminated in the right atrium (24%). To avoid right atrial placement with its well documented risk of cardiac tamponade, it is recommended that right infraclavicular subclavian catheters are inserted to H/10-2 cm, right internal or external jugular catheters to H/10 cm and left external jugular catheters to H/10 + 4 cm.
Contamination of Parenteral Nutrition Solutions Not a Hazard with Additions Made at Ward Level
Authors: Breheny F. , McGechie D. , Toohey M.
Published: January 2019

Pre-mixed amino acid and dextrose solutions used for parenteral nutrition had additions made to them at a ward level by medical officers. Samples of the solutions of the study group and a control group were taken at six hours and at the end of the infusion time and were analysed microbiologically for growth of microorganisms. No organism was isolated from either group. We conclude that making additions to pre-mixed amino acid/dextrose solutions at the ward level does not constitute a microbiological hazard for the patient.
Fluid Uptake in Laser Endometrial Ablation
Authors: Osborne G. A. , Rudkin G. E. , Moran P.
Published: January 2019

Fluid uptake was measured from accurate preoperative and postoperative patient weights for 25 consecutive patients undergoing Nd: YAG laser endometrial ablation under general anaesthesia. One patient had a uterine perforation with 5.1 litres of fluid deposited in the peritoneal cavity. In the remaining 24 cases, maximum fluid uptake was 5.1 litres, three patients absorbed more than four litres and eight absorbed more than two litres. In those same 24 patients, the mean fluid uptake was 1.5 litres (SD 1.6) and six patients without tubal ligation had a higher mean uptake (2.2 litres, SD 1.7) than the eighteen with surgically occluded Fallopian tubes (1.3 litres, SD 1.4) but the difference was not statistically significant. Fluid uptake has the potential to cause significant morbidity in this procedure. Both procedure duration and volume of uterine irrigation fluid were poor predictors of fluid gain. Observation of the ongoing volume deficit between infused and collected fluid provided intraoperative monitoring of fluid gain that prevented complications from fluid overload in healthy patients. However, this method of monitoring fluid uptake may be insufficient to prevent either complications from glycine absorption, if glycine is used for irrigation, or fluid overload in patients with cardiac disease.
Disturbance in Respiratory Mechanics with Extreme Truncal Flexion during Anaesthesia in Children
Authors: Sly P. D. , Lanteri C. J. , Kelly J. H. , Meretoja O.
Published: January 2019

Respiratory mechanics were studied in five anaesthetised children, aged 3 to 33 months undergoing urological surgery, in both the supine position and with extreme truncal flexion. Extreme truncal flexion was associated with a reduced respiratory system compliance. Dynamic compliance decreased significantly, by 30% (range 12–55%) and static compliance decreased significantly, by 40% (range 18–65%). There were no changes in respiratory system resistance. Tidal volume was also significantly reduced (mean 20%) despite a significant increase (mean 22%) in peak ventilator pressure. These changes in mechanics must be recognised to avoid alveolar hypoventilation, with a consequent decrease in gas exchange during surgery.
A New Continuous Positive Airway Pressure (CPAP) Device
Authors: Hillman K. , Huggins C.
Published: January 2019

While continuous positive airway pressure (CPAP) is being increasingly employed for many forms of acute respiratory failure and postoperative hypoxaemia, most CPAP systems are either ‘home made’ or incorporated in sophisticated ventilators used in intensive care units. This paper describes the development of a continuous low flow CPAP system using a large latex reservoir bag and venturi generated positive end expiratory pressure (PEEP). The system has been successfully used for over twelve months in the general wards, the intensive care unit, accident and emergency department, the recovery ward and the coronary care unit.
An Adjustable Multiple Angle Laryngoscope Adaptor
Authors: Dhara S. S. , Cheong T. W.
Published: January 2019

An adaptor has been devised which, when fitted between the handle and the blade of a standard Macintosh design laryngoscope, allows the angle to be adjusted to several clinically useful positions. An appropriate angle can be easily found either for introduction of the blade, laryngoscopy or exploration of the pharynx through a simple mechanism operated by the hand holding the laryngoscope.
Assessment of a New Infusion Pump for Epidural PCA
Authors: Baldwin A. M. , Ilsley A. H. , Kluger M. T. , Owen H.
Published: January 2019

The use of epidural fentanyl by patient-controlled analgesia (PCA) may be a useful method of providing high-quality postoperative analgesia on the general surgical ward. The successful use of this technique requires an infusion pump with specific characteristics. Three Provider 5500, newly-developed, battery-powered PCA pumps, were tested to determine their accuracy, threshold of occlusion alarm limits and stored volume characteristics. These measurements were repeated following the in-line addition of an 18 gauge epidural catheter and two 0.2 micron filters. Pumps delivered on average within 3% of stated infusion rates and within 3% of bolus dose size. Occlusion pressures generated were between 1200 and 1360 mmHg, while the mean stored volume was 0.12 ml. Accuracy of delivery was maintained at lower voltage inputs. Addition of the catheter failed to alter the accuracy of the pumps tested. Siphoning of fluid was possible on disconnection of cartridge from pump. This problem did not occur with the addition of an epidural catheter and filter. This device has features which make it suitable for the safe delivery of epidural PCA. Care, however, needs to be taken on changing cartridges to prevent accidental administration of a drug bolus to the patient.
Intraoperative Assessment of the Lawrence 3000 Doppler Cardiac Output Monitor
Authors: Stein M. S. , Barratt S. McG. , Purcell G. J.
Published: January 2019

Transoesophageal Doppler cardiac output measurement was evaluated against the thermodilution method in eleven patients undergoing elective cardiac surgery. A total of 106 pairs of Doppler and thermodilution values were obtained. Cardiac output was measured over a range of 2.3 l.min−1 to 11.5 l.min−1, The mean difference between the Doppler and thermodilution measures was −1.0 l.min−1 (thermodilution minus Doppler). Standard deviation was 1.8 l.min−1. This is a significant difference. It is concluded that these techniques do not agree when measuring cardiac outputs.
Persistence of Allergy to Anaesthetic Drugs
Authors: Fisher M. M. , Baldo B. A.
Published: January 2019

Intradermal testing and RIA testing for specific IgE antibodies to neuromuscular blocking drugs (NMBDs) were performed in patients referred to an Anaesthetic Allergy Clinic. Six patients were initially investigated four to 29 years after clinical anaphylaxis during anaesthesia and two of these patients and sixteen others were investigated by intradermal testing on two occasions at least four years apart. Seven patients had RIA tests for NMBD-specific IgE antibodies on two occasions at the time of skin testing. In all but two patients the evidence for drug-specific antibodies persisted 4–29 years after the reactions. In one patient all tests became negative and in another the skin test became negative but the positive RIA persisted.

Evidence of antibodies to NMBDs persisted in 21 of 22 patients who had had anaphylactic reactions to these drugs during anaesthesia. In the absence of evidence of allergy diminishing with time in the majority of patients it would seem wise to avoid drugs responsible for reactions for the rest of the patient's life.
The Relationship between a Person's Height and Appropriate Endotracheal Tube Length
Authors: Eagle C. C. P.
Published: January 2019

The relationship between a person's height and the dimensions of that person's upper airways has been studied in adult subjects. Using this relationship, formulae have been derived which predict appropriate lengths for endotracheal tubes.

The formulae are as follows: 1. Orotracheal tube (teeth to mid-point of trachea) [Formula: see text] 2. Orotracheal tube (teeth to mid-point of trachea + 3 cm) [Formula: see text] 3. Nasotracheal tube (external naris to mid-point of trachea) [Formula: see text]

These formulae are not foolproof but provide a useful working guide. All usual comfirmatory tests of correct placement should be employed.
Flumazenil Reversal of Conscious Sedation for Minor Oral Surgery
Authors: Rodrigo M. R. C. , Chan L. , Hui E.
Published: January 2019

In order to find out whether resedation occurred following antagonism with flumazenil of sedation for minor oral surgery, in a double-blind randomised cross-over study thirty healthy Hong Kong Chinese patients undergoing bilateral third molar surgery at two visits were sedated with midazolam. Following surgery they received either flumazenil or placebo at one visit and the alternative at the other visit. Recovery was monitored by observation and objective tests. Following recovery they were monitored for resedation for a total period of two hours from the injection of the reversal agent. Resedation, sufficient to prevent a patient from being discharged to be accompanied home with an escort, did not occur provided the patient responded to verbal command following sedation.
Red Cell, Plasma and Albumin Transfusion Decision Triggers
Authors: Nicholls M. D. , Whyte G.
Published: January 2019

Hypothetical clinical cases were used to investigate transfusion-related decision-making. Three red cell, three fresh frozen plasma (FFP) and three albumin transfusion decision cases were administered by questionnaire to 228 medical staff. The transfusion decision triggers were identified and comparisons made between resident and specialist groups and between Melbourne and Sydney participants.

Factors important in red cell transfusion decisions included haemoglobin, symptoms of anaemia, presence of co-morbidities or surgery, gender, period of hospitalisation and the degree of documented blood loss. FFP administration was influenced by an abnormal coagulation test, the presence of co-morbidities and by the number of red cell units transfused. The administration of albumin, concentrated or 5% SPPS, was influenced by the period of hospitalisation and clinical circumstances such as a falling urine output postoperatively, and by the presence of hypotensive complications.

Different transfusion responses were noted: resident staff transfused red cells and FFP earlier than specialists; Sydney specialists were more conservative of red cell transfusion; Melbourne specialists more conservative of FFP administration and surgeons were four times more likely to transfuse patients than physicians or anesthetists at certain haemoglobin values.
High-Dose Adrenaline in Adult In-Hospital Asystolic Cardiopulmonary Resuscitation: A Double-Blind Randomised Trial
Authors: Lipman J. , Wilson W. , Kobilski S. , Scribante J. , Lee C. , Kraus P. , Cooper J. , Barr J. , Moyes D.
Published: January 2019

Forty intensive care unit patients requiring cardiopulmonary resuscitation were randomised to receive either the standard dose of adrenaline (1 mg every five minutes) or high-dose adrenaline (10 mg every five minutes). In the majority of patients, overwhelming sepsis was the major contributing factor leading to cardiac arrest. In this group of patients no difference could be detected in response to high-dose adrenaline compared with the standard dose. Although no side-effects were noted with this high dose of adrenaline, more investigation is required prior to its routine use in cardiopulmonary resuscitation.
An Alarm for Monitoring CPAP
Authors: Carter B. , Clare D. , Hochmann M. , Osborne A. , Fraser T.
Published: January 2019

We have built a device for use within the hospital and at home that is designed to warn of circuit disconnection when used in conjunction with continuous positive airway pressure (CPAP) therapy delivered via ventilators or CPAP generating systems. The Royal Children's Hospital CPAP alarm is a compact, battery operated alarm and monitor of circuit pressure. The device includes intrinsic safety features including a safety blow-off valve, a high pressure alarm and design features that make the device practical, safe and easy to use by both trained hospital personnel and home care attendants with limited training.
A Comparison of the Effect of Propofol or Thiopentone on the Incidence and Severity of Suxamethonium-Induced Myalgia
Authors: Mcclymont C.
Published: January 2019

We conducted a prospective, randomised single-blind study in 48 adult women undergoing laparoscopic gynaecological surgery to assess the incidence of suxamethonium-induced myalgia. Anaesthesia was induced with either thiopentone or propofol. All other aspects of clinical care were standardised between the groups. The propofol group had a significantly lower incidence of suxamethonium myalgia (19%) compared with the thiopentone group (63%) (P <0.05). The mechanism of this effect is not understood.
Robertshaw Double Lumen Tubes: A Reappraisal Thirty Years On
Authors: Conacher I. D. , Herrema I. H. , Batchelor A. M.
Published: January 2019

A propsective analysis of 100 successive intubations with Robertshaw tubes in patients submitted for routine thoracic surgery is presented. Clinical guidelines for intubation were used as the protocol. Tube position was judged on clinical assessment only and not confirmed with fibreoptic bronchoscopy. In approximately 60% of cases the tubes were judged to be correctly placed on initial introduction. In 20-30% of cases, minor and simple adjustments were required to achieve suitable conditions for one lung anaesthesia. In no case did it prove impossible to achieve conditions adequate for surgery. Common problems related to the endobronchial portion of tubes entering the wrong bronchus, being inserted too far, or not far enough. Two of six episodes of hypoxaemia related to minor problems with tubes and were easily corrected. The experience is compared with that of other workers. The pertinence and implications of the experience and the data to the training of personnel in the techniques of one-lung ventilation and the future of Robertshaw tubes are discussed. It is concluded that the good practical results achieved are specifically related to the Robertshaw design and the material of manufacture.
Thrombelastographic Patterns following Abdominal Aortic Surgery
Authors: Gibbs N. M. , Crawford G. P. M. , Michalopoulos N.
Published: January 2019

Postoperative changes in thrombelastographic patterns were studied in thirty patients undergoing elective abdominal aortic bypass surgery. Native whole blood thrombelastography was performed preoperatively and on days 1, 2, and 3 postoperatively. The thrombelastographic changes included a decrease in r on day one (P < 0.0001), with concurrent increases in α (P < 0.0001) and MA (P < 0.001). On days 2 and 3 there were further increases in MA (P < 0.0001). These changes indicate enhanced procoagulant activity and progressive increases in maximum clot strength. The results confirm that hypercoagulability occurs in whole blood following abdominal aortic bypass surgery. Further studies are warranted to determine whether modification of postoperative hypercoagulability reduces the incidence of thrombotic complications in this group of patients.
Premedication with Oral Midazolam in Children—an Assessment of Psychomotor Function, Anxiolysis, Sedation and Pharmacokinetics
Authors: Jones R. D. M. , Visram A. R. , Kornberg J. P. , Irwin M. G. , Gunawardene W. M. S.
Published: January 2019

We studied 30 children, aged 4 to 12 years, undergoing elective circumcision, premedicated with midazolam 0.5 mg.kg−1 and atropine 0.02 mg.kg−1 by mouth. A modified postbox test and the coding component of the Wechsler intelligence scale (WISC-R) was used to assess the preoperative effect of premedication on psychomotor function. Mood and sedation were also scored and related to serum midazolam concentrations. The children showed a significant decline in psychomotor performance 30 and 60 minutes after premedication when compared with their best unmedicated performance recorded the previous evening. This decline in psychomotor performance was only weakly associated with serum midazolam concentrations (r = 0.1). The postbox toy ratio is a suitable measurement of psychomotor performance in children because of its simplicity and ease of use in the clinical environment, although it may suffer the “test-retest” limitations of similar types of assessment. The sedative and anxiolytic effects of midazolam provide a quiet environment for a smooth induction of anaesthesia.
Propofol Injection Pain: Comparing the Addition of Lignocaine or Metoclopramide
Authors: Mecklem D. W. J.
Published: January 2019

Lignocaine has been shown to reduce the incidence of pain on injection of propofol. Metoclopramide, a weak local anaesthetic and commonly used antiemetic, was combined with propofol and the mixture compared, in a prospective, randomized trial, with a lignocaine-propofol combination. The incidence of injection pain was similar in both groups, as were recovery times and incidence of vomiting. The metoclopramide-propofol group experienced a lower incidence of nausea. One patient in the metoclopramide-propofol group had a minor extrapyramidal reaction. No adverse local or haemodynamic effects were seen.
Ondansetron for Prevention of Postoperative Nausea and Vomiting following Minor Oral Surgery: A Double-blind Randomized Study
Authors: Rodrigo M. R. C. , Campbell R. C. H. , Chow J. , Tong C. K. A. , Hui E. , Lueveswanij S.
Published: January 2019

The efficacy and safety of ondansetron in preventing postoperative nausea and vomiting following minor oral surgery was evaluated in a prospective randomized double-blind study. Of a total of seventy-seven patients, randomly 38 had 4 mg of ondansetron and 39 had normal saline as placebo intravenously immediately prior to induction of anaesthesia. A standard general anaesthetic with thiopentone, suxamethonium, fentanyl, nitrous oxide and isoflurane was employed. Postoperatively nausea was assessed verbally and on a visual analog scale at 1, 4 and 24 hours from the time of awakening. Episodes of vomiting were recorded. Eight patients (21.1%) in the ondansetron group compared to 19 (48.7%) in the placebo group had nausea (P < 0.05) and 1 (2.6%) in the ondansetron group compared with 9 (23.1%) in the placebo group vomited (P < 0.05). Patients who vomited twice or more and the number who required a rescue antiemetic were significantly fewer in the ondansetron group (P < 0.05). Cardiovascular parameters were stable and showed no significant difference in the two groups. There were no significant adverse effects that could be directly attributable to ondansetron.
Alterations in Endotracheal Tube Position during General Anaesthesia
Authors: Yap S. J. , Morris R. W. , Pybus D. A.
Published: January 2019

The effect of head and neck movement and Trendelenburg tilt on endotracheal tube position, relative to the carina, was studied in fifty adult patients requiring intubation for elective surgery.

On average, inward movement, that is shortening of the distance between the endotracheal tube tip and the carina, resulted from neck flexion (mean = −5.5 mm), whereas outward movement occurred with neck extension (mean = 6.3 mm).

Neck rotation, to right and left, and Trendelenburg tilt did not show any trend towards inward nor outward movement (mean = 0.3 mm/1.7 mm/—0.6 mm, respectively).

Whilst these mean positional changes for flexion and extension confirm the findings of earlier investigations, our range of maximum inward and outward displacement for flexion (23 mm in/19 mm out), extension (21 mm in/33 mm out), rotation to right (19 mm in/17 mm out), to left (22 mm in/19 mm out) and Trendelenburg tilt (22 mm in/16 mm out) indicate that for any given postural change in any one patient, the direction and magnitude of endotracheal tube displacement is not readily predictable.
The Effect of Oral Cisapride Premedication on Fasting Gastric Volumes
Authors: Kluger M. T. , Owen H. , Plummer J. L. , Mclean C.
Published: January 2019

The aim of this study was to determine whether fasting gastric volumes could be reduced by preoperative administration of cisapride. One hundred and twenty-one patients undergoing elective general anaesthesia were randomly allocated to receive either cisapride 20 mg plus diazepam 10 mg or placebo tablets plus diazepam 10 mg, two hours prior to induction. Immediately following induction blind gastric aspiration was performed using a 16Fr multiorificed orogastric tube. Gastric volume, pH, and cisapride blood concentration were measured at this time. Gastric volumes were significantly smaller in the cisapride group, 20.5 (SD 22.2) ml compared to placebo 28.2 (SD 26.0) ml but there was no significant difference with respect to pH.

Some patients in both groups had large gastric volumes despite fasting. No significant adverse effects were noted with cisapride.
The Impact of Heat and Moisture Exchanging Humidifiers on Work of Breathing
Authors: Johnson P. A. , Raper R. F. , Fisher M. Mcd.
Published: January 2019

In this study the resistive work or breathing (WOB) associated with eleven commercially available heal and moisture exchangers (HMEs) was evaluated for gas flow rates of 20 to 60 l.min-1. The Gibeck Humid-Vent 2S Flex was also assessed after 24 hours patient usage (n=50). The WOB associated with these devices was compared with that of standard endotracheal tubes and standard humidifying circuits with flex-tube connectors.

The range of work imposed by the eleven HMEs approximated the range shown by water bath circuitry when used with two different commonly used flex-tube connectors. The excess WOB attributed to the HMEs was significantly less than that imposed by standard endotracheal tubes. After 24 hours of patient use, 96% of the Gibeck HMEs tested demonstrated a resistive WOB within the range of the two flex-tube connectors.

To assess the clinical significance of this circuit-related WOB, we compared respiratory variables in 40 patients breathing on either CPAP or pressure support ventilation, using a variation in flex-tube resistance which imposed a range of WOB comparable to that shown by the HMEs. A small but statistically significant reduction was found for both the peak flow (48±1.4 vs 45±1.1 l.min-1, P<0.0005) and the minute volume (8.6±0.35 vs 7.9±0.31 l, P < 0.0005).

These data suggest that the range of resistive work imposed by commercially available HMEs has a small but potentially significant effect on clinical respiratory parameters.
A Comparison of Postoperative Thrombotic Potential following Abdominal Aortic Surgery, Carotid Endarterectomy, and Femoro-Popliteal Bypass
Authors: Gibbs N M , Crawford G P M , Michalopoulos N
Published: January 2019

Postoperative changes in procoagulant, anticoagulant, and antifibrinolytic factors were compared in patients undergoing abdominal aortic surgery, carotid endarterectomy, and femoro-popliteal bypass. There were increases in plasma fibrinogen (P<0.01) and factor VIII coagulant (P<0.01) levels following all three procedures. There were decreases in antithromhin III (P<0.01) and protein C (P<0.01), and increases in thrombin-antithrombin complex levels (P<0.01) in the abdominal aortic group only. There were no significant changes in type 1 plasminogen activator inhibitor levels following any of the procedures. The results indicate that all three procedures are associated with an increased potential for thrombosis due to increases in procoagulant factors. However, patients undergoing abdominal aortic surgery are particularly at risk due to concurrent decreases in natural anticoagulant factors. Specific antithrombotic therapy should be considered for all patients undergoing vascular surgery, but particularly for those undergoing major procedures such as abdominal aortic surgery.