Research Articles (Anaesthesiology and Critical Care)

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Browsing Research Articles (Anaesthesiology and Critical Care) by Subject "Anaesthesia"

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    A comparison of induction of anaesthesia using two different propofol preparations
    (Southern African Journal of Anaesthesia and Analgesia, 2008) Terblanche, Nico; Coetzee, Johan F.
    Background: Investigators have reported inter-patient variability with regard to propofol dosage for induction of anesthesia, since early dose finding studies. With the arrival of generic formulations of propofol, questions have arisen regarding further variability in dose requirements. Various studies have confirmed that generic propofol preparations are pharmacokinetically and pharmacodynamically equivalent to Diprivan®. Nevertheless a number of practitioners are under the impression that certain generic propofol preparations require greater doses for induction of anaesthesia than does Diprivan®. Methods: 20 female patients of ASA status I-II, between the ages of 18-55 years, scheduled for routine surgery were randomly allocated to two groups to undergo induction of anaesthesia using two different propofol formulations; Diprivan® and Propofol 1% Fresenius®. Either preparation was administered using a target-controlled infusion of propofol (STEL-TCI) targeting the plasma (central) compartment at a concentration of 6 μg.ml-1, employing the pharmacokinetic parameters of Marsh et al. A processed EEG (bispectral index) was continuously recorded. Loss of consciousness (LOC) was regarded as the moment at which the patient could not keep her eyes open and was confirmed by the absence of an eyelash reflex. At this point propofol administration was discontinued and data were recorded for a further two minutes, before administering an appropriate opioid and/or nitrous oxide/volatile agent and/or muscle relaxant to maintain anaesthesia. Time to LOC after start of propofol administration, and the dose of propofol administered during induction were annotated. Results: There were no demographic differences between the groups. There were no differences between the groups with regard to the mean dose for LOC, time to LOC and to the mean BIS values obtained at the following stages: awake, at LOC, at 1 and 2 minutes after LOC as well as the lowest recorded value. Conclusions: Our results confirm that the two propofol formulations that we studied, are pharmacologically equivalent with regard to induction of anaesthesia. Other mechanisms can explain the variability in clinical response to bolus administration of propofol. The most important is the recirculatory or “front-end” kinetics of propofol in which cardiac output plays a major role, as well as the rate of drug administration. Emulsion degradation can also influence dose-response and in this regard it should be noted that the addition of foreign substances such as lignocaine, can result in rapid deterioration of the soyabean emulsion.
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    Narkose vir timektonie in myasthenia gravis
    (Health & Medical Publishing Group, 1981-10-17) Roelofse, J. A.
    ENGLISH ABSTRACT: This report emphasizes the medical, surgical and anaesthetic aspects of the treatment in cases of myasthenia gravis. Since many of the drugs used in anaesthesia affect the activity of the neuromuscular conduction mechanism, the anaesthetist should be aware of the pathophysiology of the disease and of the effect which these drugs have on it.
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    Obstructive sleep apnoea in pregnancy and its association with pre-eclampsia
    (Informa UK Limited, trading as Taylor & Francis Group, 2017) Lintott, N. C.; Van Zyl, D. G.; Burke, J. L.
    Background: Obstructive sleep apnoea (OSA) in pregnancy is associated with an increased morbidity and mortality to both mother and foetus. In the South African setting the proportion of pregnant females suffering from OSA has not been well studied; nor has the association with pre-eclampsia. This study aimed to determine the prevalence of OSA in females before 35 weeks gestation using the STOP-BANG questionnaire and to determine the association with pre-eclampsia in a local South African setting. Methods: A cross-sectional analytical study including 234 patients was conveniently sampled from Kalafong Hospital’s antenatal ward, clinic and labour ward. Participants were of more than 20 weeks and less than 35 weeks gestation. All participants were interviewed with a modified STOP-BANG questionnaire. Patients were consecutively enrolled without prior knowledge of the presence of pre-eclampsia. At Kalafong hospital all pregnant patients are routinely screened and investigated for pre-eclampsia according to standard criteria. Results: The median gestational age in this sample was 28 weeks; 80.3% (CI 74.62–85.2%) of pregnant females had a low risk for OSA, 15.4% (CI 11.01–20.65%) had an intermediate risk and 3% (CI 6.47–14.58%) had a high risk for OSA. A modified STOP-BANG questionnaire had a sensitivity of 62.5% and a specificity of 82.1% for pre-eclampsia when a score of 3 and more was scored. Females at high risk of OSA had an OR of 8.4 (CI 2.88–24.6) for having pre-eclampsia. Conclusions: The authors report 15.4% of the study’s pregnant population to be at intermediate risk and 3% at high risk of OSA. The association between the hypertensive disorders and OSA must be considered and screening implementation considered.
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    Skin disinfection practice before skin anaesthesia, prior to neuraxial blockade : a survey of government hospital practices in South Africa
    (Medpharm Publications, 2019) Coetzee, D. F.; Senekal, A.; Scheepers, P. A.
    ENGLISH ABSTRACT: Infectious complications following neuraxial block, although being of low incidence, may lead to morbidity and mortality. Two common methods utilised for skin disinfection before skin anaesthesia prior to a neuraxial block are the isopropanol only method (isopropanol method) and the full aseptic technique (classic method). The objective of this study was to survey government-employed South African anaesthesiologists’ preference regarding the disinfection practices before the administration of local anaesthetic agents to the skin prior to the performance of a neuraxial block. Methods: Ethics approval was obtained prior to commencing the study. An electronic, web-based questionnaire in the form of a survey was distributed to various anaesthetic departments in various government teaching hospitals in South Africa. Descriptive statistics were used on the raw data using the Fisher exact test to measure associations between the different categorical variables. Results: A significant response rate of 60.3% was achieved. Regarding subarachnoid blocks, more than half of the participants (52.0%) that participated in the survey utilise the isopropanol method whereas less than half of the participants utilise the isopropanol method when performing an epidural block. Close to 75% of participants with zero to five years anaesthetic experience prefer the isopropanol method whilst only 20.9% of anaesthetists with more than ten years’ experience prefer the isopropanol method when performing a subarachnoid block (p < 0.01). Conclusion: Both methods described in this study (classic and isopropanol methods) are practised commonly by the participants in the survey and neither the classic nor the isopropanol method dominates. Local guidelines need to address the technique used to disinfect the skin before the administration of the local anaesthetic agent to the skin prior to performing a neuraxial block.