bluuebunny/crossref_metadata_2025_split huggingface dataset:
Liver Dysfunction in Critical Illness
Authors: Hawker F. 
Published: January 2019

Abnormal liver function commonly accompanies critical illness. Ischaemic hepatitis occurs with shock and is characterised by elevated plasma aminotransferase concentrations. ‘ICU jaundice’ occurs later in critical illness, especially after trauma and sepsis. The major biochemical abnormality is conjugated hyperbilirubinaemia. The clinical setting suggests that hepatic ischaemia and hepatotoxic actions of inflammatory mediators are the major aetiological factors. Massive blood transfusion, effects of nutritional support and drug toxicity may contribute. Both the presence and degree of jaundice are associated with increased mortality in several nonhepatic diseases. It is proposed that Kupffer cell phagocytic depression associated with liver dysfunction permits systemic spread of endotoxin and inflammatory mediators and thus predisposes to multiple organ failure. Immunosuppression, metabolic abnormalities, impaired drug oxidation and myocardial depression may contribute to the poor prognosis. There is no specific treatment, but prompt resuscitation, definitive treatment of sepsis and meticulous supportive care will likely reduce the incidence and severity.
Prediction of Difficult Laryngoscopy: An Assessment of the Thyromental Distance and Mallampati Predictive Tests
Authors: Butler P. J. , Dhara S. S. 
Published: January 2019

Two hundred and fifty patients were assessed preoperatively using the Mallampati classification and by measuring their thyromental distances. The ease or difficulty of direct laryngoscopy was assessed at the time of induction of anaesthesia. Retrognathia was seen in 15.6% of patients and the incidence of difficult laryngoscopy without external laryngeal pressure was 8.2%. It was found that both assessments predicted less than two in three difficult laryngoscopies and had high false positive rates. It was found that external laryngeal pressure often improved the view of the glottis in difficult laryngoscopies.
A Survey of Fellows of the Faculty of Anaesthetists of the Royal Australasian College of Surgeons Endorsed in Intensive Care by Examination in the First 10 Years of Final Examinations in Intensive Care
Authors: Harrison G. A. , Byth P. L. 
Published: January 2019

Fifty-nine of the 70 Fellows of the Faculty of Anaesthetists who had passed the Final Examination in Intensive Care including that of October 1989, responded to a questionnaire on the pattern of their intensive care and anaesthetic practice and their perception of the training and examination. Responses came predominantly from Fellows who had passed the examination more than two years previously. Forty-eight (81%) were practising intensive care at least 50% of the time and 51% had become Director or Deputy Director of an Intensive Care Unit. However, 51% maintained some anaesthetic practice. Although individuals had changed the intensive care/anaesthetic distribution of their practice, the group overall had not. With one exception all Fellows were practising in public hospitals but 26% in private hospitals also. Only eight had sought intensive care as their first vocational qualification. Training and examination were generally regarded favourably except for training in research methods and experience in internal medicine. The results suggest that the intensive care specialist is not likely to leave such practice in the long term, but there has been a reluctance to abandon altogether training and some subsequent practice in anaesthetics.
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.
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.
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.
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.
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.
Challenging the Current Concept of Critical Glenoid Bone Loss in Shoulder Instability: Does the Size Measurement Really Tell It All?
Authors: Moroder Philipp , Damm Philipp , Wierer Guido , Böhm Elisabeth , Minkus Marvin , Plachel Fabian , Märdian Sven , Scheibel Markus , Khatamirad Mohammad 
Published: January 2019

Background: Bone loss at the anterior glenoid rim is a main reason for failure of soft-tissue based surgical stabilization procedures in patients with anterior shoulder instability. Purpose: To evaluate the capability of conventional glenoid bone loss measurement techniques to provide an adequate estimation of the actual biomechanical effect of glenoid defects. Study Design: Descriptive laboratory study. Methods: Thirty consecutive patients with unilateral anterior shoulder instability and varying degrees of glenoid defect were included. Patient-specific computer tomography–based 3-dimensional shoulder models of the affected and unaffected sides were created. The bony shoulder stability ratio (SR) was determined in various potential dislocation directions with finite element analysis. Values obtained from conventional glenoid defect size measurement techniques (Pico and Sugaya) were correlated with the finite element analysis results. Additionally, a mathematical model was developed to theoretically analyze the correlation between glenoid defect size measurements and the SR. Results: The authors found substantial interindividual differences of the SR of the unaffected shoulders in all directions of measurement. Bone loss at the anterior glenoid rim significantly reduced the SR in the 2-o’clock ( P = .011), 3-o’clock ( P < .001), and 4-o’clock ( P < .001) directions referring to a right shoulder. The correlation between the defect size measurements and the SR for the 2-o’clock (rho = −0.522 and −0.580), 3-o’clock (rho = −0.597 and −0.580), and 4-o’clock (rho = −0.527 and −0.522) directions was statistically significant. However, it showed only moderate strength and was nonlinear as well as dependent on the inherent shape of the concavity. As shown by the mathematical model, bone loss has the most considerable effect at the edge of the glenoid rim, and an increasingly concave-shaped glenoid leads to an increase in loss of SR provoked by the same extent of bone loss. Conclusion: Current glenoid bone loss measurements are unable to provide an adequate estimation on the actual biomechanical effect of glenoid defects because (1) the relation between the glenoid defect size and its biomechanical effect is nonlinear and (2) patients with shoulder instability have constitutional biomechanically relevant glenoid concavity shape differences. Clinical Relevance: These findings challenge the current concept of setting a general threshold for critical glenoid bone loss, which requires bony reconstruction surgery.