Browsing by Author "James, Michael F M"

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    An assessment of the impact of large goitres on perioperative and postoperative airway management: a retropsective review
    (2017) Golding, Tarryn; Haylett, Revyl; James, Michael F M
    It is widely assumed in the literature that large thyroid goitres pose a significant risk to the airway perioperatively. They are of concern to anaesthetists because of anticipated difficulty relating to intubation, ventilation and post-thyroidectomy tracheomalacia. They are of concern to surgeons because of the anticipated risk of difficult dissection and increased risk of surgical complications including haemorrhage, laryngeal nerve injury and tracheomalacia. Objectives: To analyse the folders of patients who have undergone anaesthesia and surgery for large, nonmalignant goitre, to assess the impact of large goiters on perioperative and postoperative management. An attempt will also be made to identify possible predictive markers/ patient characteristics associated with difficult intubation. Design: A retrospective folder review Setting: Groote Schuur Hospital Participants: All patients who had thyroidectomies performed at Groote Schuur Hospital between Jan 2010 and June 2016 for large, non-malignant goitres. Measurements and main results: Of the patients who underwent a thyroidectomy procedure at Groote Schuur Hospital between Jan 2010 and June 2016, 196 were identified as having non-malignant goitre and size in one dimension of greater than fifty millimeters. There were seven documented difficult intubations and only one case of failed intubation. This case was subsequently put onto cardiopulmonary bypass and intubated successfully using a rigid fibreoptic bronchoscope. Of the one hundred and nighty-six cases, four were intubated using a fibreoptic bronchoscope, eight with a videolaryngoscope, and six cases, a bougie. All other patients underwent uneventful tracheal intubation via direct laryngoscopy. All glands were removed via a collar incision with no requirement to proceed to sternotomy. There was only one patient requiring blood intraoperatively and only four reported cases of postoperative haematomas. There were no instances of tracheomalacia. Two patients suffered long term recurrent laryngeal nerve injury with voice changes. Conclusion: The data shows that, in patients with large, benign goitre undergoing thyroidectomy, airway difficulties at intubation and surgical and anaesthetic complications postextubation are rare. Intravenous induction and direct laryngoscopy is a safe technique in appropriately experienced hands.
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    A dissertation and review of current knowledge on aspects relating to the use of Remifentanil to cover the tunnelling phase of Ventriculoperitoneal Shunt Insertion in paediatrics
    (2000) Chambers, Neil; James, Michael F M
    In this study, the administration of remifentanil to cover the tunnelling phase of shunt insertion in children caused good attenuation of haemodynamic and endocrine markers of stress, no delay in recovery and no additional post operative respiratory depression in all age groups, including xpremies and neonates.
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    Epidural analgesia for coronary artery bypass graft surgery
    (1999) Riedel, Bernard J C J; James, Michael F M
    On reviewing the medical literature, there is a clear resurgence of interest in the use of TEA (thoracic epidural analgesic) in cardiac anaesthesia. This resurgence was brought about by laboratory-based evidence that TEA-induced sympatholysis may be cardioprotective through the promotion of myocardial blood flow to areas at-risk and subsequent early, small clinical studies suggesting that TEA was feasible, and possibly also beneficial in CABG surgery [Joachimsson et. al, 1989; Liem (1-3) et. al, 1992; Stenseth et. al, 1994]. Despite the positive results of these early studies and suggestions that TEA may be the preferred anaesthetic/analgesic technique in select groups of patients (promoting early extubation and fast-tracking) undergoing cardiac surgery, many anaesthetists are still reluctant, however, to use this technique because of the theoretical increased risk of the patient suffering a spinal haematoma and subsequent paraplegia. In order to outweigh this theoretical risk it is important that we show that added benefit, in addition to the provision of analgesia and expedited postoperative convalescence, can be obtained by using TEA. It is therefore our duty as anaesthetists and perioperative physicians to determine whether TEA may also affect the pathophysiology of the disease process, especially in the perioperative period - and thereby influencing the subsequent long term outcome and quality of life of the patient. An example of this latter point would be the potential role of TEA in; • reducing the incidence of perioperative myocardial infarction (P-MI), through the suggested cardioprotective effects of TEA, • reducing the incidence of early postoperative graft failure, through either; * reduction of native coronary artery and/or graft (conduit) spasm, or * reduction of postoperative hypercoagulability.
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    Magnesium sulphate reversal of established bupivacaine electrophysiological cardiotoxicity
    (1998) Reed, Anthony Raddon; James, Michael F M
    The results of this study show that in intact rats magnesium produces a more rapid resolution of bupivacaine induced electrophysiological changes than placebo. The improvements are in rhythm and electrical conduction, although this is often at the expense of potentiating the bradycardic effects of bupivacaine toxicity. Whilst the bradycardia remains a problem it is potentially more amenable to therapy than the changes in rhythm and conduction which magnesium sulphate reversed. The opportunity therefore exists to explore the possibility of combining magnesium with a positive chronotrophic agent such as dobutamine.
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    Polypropylene and Polycarbonate containers have a varied effect on coagulation after haemodilution, as judged by TEG® in vitro
    (2001) Roche, Anthony Michael; James, Michael F M
    The reasons for this study were multi-factorial, but mostly due to some interesting data obtained from a pilot study conducted at University College London (UCL). In that study, the coagulation effects in vitro of two hetastarch solutions were compared with two crystalloids by means of thrombelastography (TEG®). The fluids compared were: 1. Hespan® (HES), a high molecular weight hetastarch (450kDa/O.7 substitution ratio) in a 0.9% saline solution - Laevosan, Austria. 2. Hextend® (HEX), also a high molecular weight hetastarch (670/0.75 substitution ratio) in a balanced electrolyte, lactate and glucose solution - BioTime Inc, Berkeley, California, USA. 3. Saline 0.9% 4. Hartmann's Solution (Ringer's Lactate) The crystalloids revealed no surprising differences known from previous published data, but data obtained from the hetastarch solutions revealed contradictory results to known in vivo results found in a phase III trial. This previous Phase III in vivo trial showed that HEX haemodilution produced a superior coagulation profile to HES, along with a significantly shorter r-time than HES. There was also a significantly smaller transfused volume of blood than HES in the HEX-treated patients. This Phase III study prompted the initial UCL in vitro haemodilution study mentioned above. In the UCL study, there were significantly impaired TEG® results, indicating severe hypocoagulability with HEX, when compared with HES. This included prolonged r-and k-times, as well as reduced a-angles and maximum amplitudes in the HEX group, compared with HES and crystalloid groups. Many theories were discussed for these controversial UCL results, but the thought was that a container-effect could have been responsible, as the in vitro UCL study methodology included the use of a polycarbonate container for initial storage, as well as for haemodilution of the blood in vitro. In view of the known wettable surface, as well as a strong negative surface charge of polycarbonate, it was suggested that the container surface itself could have affected coagulation. When different ionic compositions of the various fluids and starches were taken into account, it seemed possible that some interaction between the fluids and the material of the containers could have induced or inhibited coagulation at the container surface. The suspicion was that the observed change in TEG® variables was likely due to a methodologic idiosyncrasy. Previous track record of haemodilution and TEG research at the University of Cape Town made it an obvious setting for exploration of this problem. Preparations were thus made to test container effects with haemodilution in vitro at Prof MFM James' anaesthesia laboratory at the University of Cape Town. The hypothesis was that the use of polypropylene and polycarbonate containers, with their different chemical and surface properties, would lead to a variability in TEG® results obtained from fresh whole blood, as well as blood diluted with various fluid solutions. Choosing TEG® as a monitor of coagulation was essential, as it has a well-established track record in monitoring coagulation effects in trials of haemodilution (in vitro and in vivo). TEG® produces reliable and quick results, giving a reflection of global coagulation function. It, along with the Sonoclot®, are the only two devices which can reliably diagnose a hypercoagulable state. More will be mentioned on the TEG® later.
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    Survival after local anaesthetic overdose : a comparison of the success of resuscitation after established cardiotoxicity caused by ropivacaine or bupivacaine
    (1999) Whitehead, Paul Neville; James, Michael F M
    The purpose of this thesis is to review the pharmacology and toxicity of local anaesthetics, particularly highlighting the differences between bupivacaine and ropivacaine and to present an experiment attempting to establish whether ropivacaine is a safer drug, once cardiotoxicity has occurred.