Browsing by Subject "Anaesthesia"

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    A retrospective descriptive analysis of prehospital advanced airway management in a South African private emergency medical service
    (2021) Araie, Farzana; Joubert, Ivan; Stassen, Willem
    Introduction: Emergency medical systems have evolved from mostly providing patient transport to healthcare facilities to the provision of emergency care interventions on scene or en route to a healthcare facility. Endotracheal intubation is one of these interventions but despite being performed in the prehospital setting for nearly two decades, the practice of prehospital ETI has not yet been examined on a national level. Methods: This is a retrospective chart review of prehospital ETI performed by non-physician prehospital providers of a ground-based emergency medical service that operates on a national level over a 12 month period. Results: Of the 806 cases recorded in the study period, 683 met the criteria for analysis. Male patients accounted for 67% of the cases. The majority of patients (56%) intubated were trauma patients while the remaining 44% were intubated for medical reasons. The first pass success rate was 74% and the overall success rate was 98%. Rapid sequence intubation was the method used to intubate 34% of patients. Approximately 29% received drug facilitated intubation and 27% of patients were intubated whilst being treated for cardiac arrest. Approximately 65% of patients had documented risk factors for difficult intubation. Clinical adverse events were recorded in 14% of cases. Discussion: The first pass success and overall success rates compare favourably with those reported in similar contexts. Adverse events were thought to be under-reported.
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    Anaemia in a South African colorectal ERAS programme – identifying the prevalence and predictors of preoperative anaemia and the effect on post-operative complications and length of stay
    (2023) Nieuwenhuis, Kathryn; Gibbs, Matthew; Louw, Vernon; Alphonsus; Warden, C; Boutall, A; Bannister, S
    Background: Anaemia is a widespread public health problem associated with increased mortality and morbidity. In a surgical population, the prevalence of preoperative anaemia often exceeds that of the general population. Elective colorectal patients often have multiple risk factors for preoperative anaemia. The fourth updated ERAS Society guidelines for optimal perioperative care in colorectal surgery include specific recommendations for screening and treatment of preoperative anaemia as well as utilising restrictive blood transfusion practice. Assessing the prevalence and predictors of anaemia and outcomes in this population may allow for improved preoperative assessment and treatment of colorectal patients in a resource limited setting. Objectives: The primary objective of this retrospective study was to determine the prevalence of anaemia in the colorectal surgical population who were part of the enhanced recovery after surgery (ERAS) programme at a tertiary level hospital in the Western Cape, South Africa. Secondary objectives were to determine independent risk factors of preoperative anaemia, and the effect of anaemia on post-operative complications and length of stay after elective colorectal surgery. Methods: We performed a secondary analysis of data collected for the colorectal surgical ERAS programme. Data of 260 patients was reviewed from the initiation of the database 01 September 2016 to 30 September 2019. Three regression analyses were performed as part of the secondary objective to determine the risk factors for preoperative anaemia and predictors for postoperative complications and length of hospital stay. Patients were defined as anaemic if their haemoglobin was less than 13.0 g/dL. Results: The prevalence of preoperative anaemia was 157/260 (60.3%). Female sex (odds ratio (OR) 2.44, 95% confidence interval (CI) 1.43 – 4.18; p=0.001) and the presence of malignancy (OR 2.42, CI 1.26- 4.67; p=0.008) showed a significant association with anaemia. Anaemia was not associated with increased risk of post-operative complications or length of hospital stay. Conclusion: South African colorectal surgical patients in an enhanced recovery after surgery programme have a higher prevalence of preoperative anaemia compared to the general surgical population. Predictors of preoperative anaemia in this population included female sex and the presence of malignancy. Long waiting lists for patients awaiting elective colorectal surgery allow time for evaluation and optimisation of patients at risk for anaemia preoperatively
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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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    Coagulopathy in severe, isolated traumatic brain injury: A prevalence study
    (2018) Lawrie, Ruchi; Reed, Anthony
    Introduction: Traumatic brain injury (TBI) is an important cause of morbidity and mortality in the developing world, and remains the leading cause of death and long-term disability in young adults. Hypocoagulopathy is a well described sequela of severe TBI and is associated with prolonged intensive care unit stays and poor outcomes. This study was conducted to determine the prevalence of coagulopathies in patients with severe, isolated TBI. The secondary outcome was to note any difference in the prevalence of detected coagulopathy between blunt and penetrating TBI. Methods: This is a prospective observational study of fifty patients with severe, isolated TBI (AIS head >3, AIS body <3), presenting to, or were referred to Groote Schuur Hospital. We drew blood for International Normalised Ratio (INR), activated partial thromboplastin time (aPTT), platelets count, sodium, potassium, urea and thromboelastography (TEG) on all patients at 12 hours (±3 hours), 36 hours (±3 hours) and eligible patients at 60 hours (±3 hours) post injury. Coagulopathy was defined as any one of the following: platelet count<120 x 109/L, INR>1.2, PTT>37 seconds, R time<4 minutes or >8 minutes, K time>4 minutes, α angle<47˚ or >74˚, maximum amplitude<54 mm or >72mm, EPL>15%, LY30>8 %, coagulation index<-3 or >3. Results: The patients were mostly male (n=47), with a mean age of 31 years. Median AIS head and body were 5 and 1, respectively. Thirty-six patients sustained blunt, and the remaining 14 penetrating trauma. Sixteen of the fifty patients demised during the course of the study. The cumulative prevalence of coagulopathy, as diagnosed by TEG, was 84% as diagnosed by TEG. Of the total 109 TEGs, 59 samples were hypercoagulable, 10 were hypocoagulable and the remaining 40 normal. There was poor correlation between laboratory-based coagulation assessments and TEG. Conclusions: Contrary to what is reported in the literature, we found little evidence of a hypocoagulable state as defined by TEG (10 of the 109 samples). Many patients were significantly hypercoagulable (59 of the 109 samples) according to criteria specified by the TEG manufacturer. When considering the CBT results, we had a much higher number of hypocoagulable samples (72 of the 109 samples), with none showing a hypercoagulable state. Moreover, there was poor correlation between coagulation status as measured by TEG described and that found on conventional blood testing. No significant differences in the prevalences of coagulopathy amongst blunt and penetrating mechanisms of injury were noted. Some differences in fluid balance and presenting vitals in the hypocoagulable group when compared to the normal and hypercoagulable groups were noticed, but this does not attain any statistical significance due to the small numbers of hypocoagulable patients in our study.
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    Comparison of a novel low-cost hyperangulated video intubation stylet with the Bonfils fiberscope: a simulated difficult airway manikin study.
    (2023) Jacobs, Jan; Roodt, Francois
    Introduction Optic stylets are safe, efficient airway tools, with improved intubation success rates compared to direct laryngoscopy. Economic constraints often limit access to costly difficult airway equipment. The Hyperangulated Video Intubation Stylet (HiVIS) is a novel, low-cost, stainless-steel stylet with a Wi-Fi camera connecting to a smartphone. We aim to demonstrate that performance of the HiVIS, as an alternative low-cost device, is non-inferior to the Bonfils. Methods We performed a randomised, cross-over non-inferiority study following institutional and ethics approval (UCT HREC 816/2020). Randomised participants received training (instructional video and practice intubations on a Laerdel airway manikin™) and subsequently intubated a Trucorp Airsim manikin™ simulating a difficult airway with the Bonfils and HiVIS alternately. Our primary outcome was time-to-intubation with a pre-specified non-inferiority margin of 5 seconds. Secondary outcomes were best laryngeal view, airway trauma, and number of attempts. Participants completed a questionnaire regarding device preference and overall satisfaction. Results Thirty doctors participated: 33% interns and 54% medical officers from various specialties. 63% performed ≤1 intubation per week, and 10% had optical stylet experience. Both devices had 100% first-pass intubation success: 10.4 seconds Bonfils versus 11.2 seconds HiVIS (p<0.0001). The mean difference in time-to-intubation was 0.8 seconds (90% CI -0.4; 2.1). All Bonfils intubations had a grade 1 laryngeal view compared to 83% of HiVIS intubations (27% grade 2). The Bonfils had the only incident of airway trauma. Two-thirds of participants preferred HiVIS, with similar user satisfaction scores for both devices. Conclusion The HiVIS is non-inferior to Bonfils in a single attempt difficult airway manikin simulation with predominantly novice, non-anaesthesia users. The HiVIS could be a cost-effective tool for difficult airway management in resource-constrained settings.
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    The Department of Anaesthesia, UCT 1920-2000 : a history
    (2002) Parbhoo, Nagin
    Bibliography: leaves 307-312.
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    The development of an in vivo nerve-muscle model in the rat : and an experiment "The interaction between rocuronium and thiopentone" to test the validity of the model
    (2005) Rous, Stephen Alexander; James, Michael Frank Mansel
    Experimentation involving small animals has, over the years, been of major importance in the development of our current understanding of nerve - muscle physiology. This dissertation describes the development of an in vivo model of the rat nerve interface at the Faculty of Health Sciences at the University of Cape Town. Such a model was not previously available to the faculty. The development was the result of collaboration between the Departments of Anaesthesia and Human Biology.
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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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    The effect of in vitro haemodilution on coagulation
    (1996) Ruttmann, Thomas Gotthard; Viljoen, J F
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    Efficacy of transversus abdominis plane blocks as part of a multimodal analgesia regime for total abdominal hysterectomies
    (2014) Marais, Adri
    Patients who undergo a total abdominal hysterectomy (TAH) experience a significant amount of pain postoperatively. Several multimodal pain regimes have been used in the past to manage these women’s pain. Neuraxial anaesthesia is usually not a feasible option in these cases, because of the risks involved. Limited resources with the lack of high care unit beds available when intrathecal opioids are given are also a problem. Effective analgesia includes both improved comfort and decreased opiate side-effects, if morphine requirements can be decreased. After approval from the University of Cape Town Human Research Ethics Committee, the trial was registered with the South African National Clinical Trial Register (DOH-27-0212-3945) and the South African National Human Research Ethics Council. All patients between the ages of 20-65 with an ASA score I-III were included in a prospective double-blind randomised controlled trial after obtaining written informed consent from them the day before their operation. Patients were excluded if they were allergic to any of the trial medication (morphine, bupivacaine), had a history of opioid addiction, coagulation disorders, infection at needle insertion site or were unable to give informed consent. If surgery did not for some reason proceed to a TAH, the patient was also excluded. The patients were visited in the ward the day before their operation to obtain informed consent. All the patients received a patient-controlled analgesia (PCA) pump and this as well as the visual analogue pain scale (VAS) were demonstrated and explained to them. This was done by the same person (principle investigator) for all the patients. Our aim with this double-blind randomised controlled trial was to study the efficacy of ultrasound-guided transversus abdominis plane blocks in patients undergoing total abdominal hysterectomy. We randomly allocated thirty patients to two groups, a transversus abdominis plane block group (n=15) and a placebo group (n=15). The transversus abdominis plane blocks were done with 0.25% bupivacaine. The placebo group received a sham block with normal saline post induction of anaesthesia. All patients received postoperative morphine patient-controlled analgesia. Pain scores and morphine consumption were assessed at 0, 6 and 24 hours postoperatively. Our trial showed a significant between-group difference in morphine requirements (5.2±3.9 vs. 9.7±4.3 mg [p=0.007], and 12.9±8.9 mg vs. 25±12.1 [p=0.006]) for the transversus abdominis plane- compared with placebo group at 6 and 24 hours respectively. There were no significant between-group differences in pain scores. There were no complications associated with any block. Ultrasound-guided transversus abdominis plane block is an effective addition to a multimodal postoperative analgesia regimen for abdominal hysterectomy.
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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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    Feedback control of sedation and general anaesthesia
    (2004) Absalom, Anthony Ray
    The man aim of my studies was to investigate the safety and efficacy of two modes of feedback control of sedation and anaesthesia. A secondary aim was to add to the body of knowledge on the Bispectral Index (BIS). I also wrote a computer program (BISCLAN) that was used in all the studies as a BIS data management tool, and in some studies for manual or automatic control of a propofol infusion. Two studies did not involve feedback control, but were performed to further our understanding of the BIS. For one, I recorded BIS values and the times at which clinical events occurred during 200 general anaesthetics. and studied memory of perioperative events. Broad variation in BIS values at similar levels of anaesthetic depth was found, although there was good separation between the majority of BIS values found during periods of consciousness and unconsciousness. BIS values on awakening were not predictive of memory for subsequent events. For the second study I investigated the effects of the stimuli used lo generate auditory evoked potentials on consciousness levels and the BIS, during sedation and anaesthesia. No effect was found. Three studies of BIS-guided computer control of anaesthesia and sedation were performed. Control performance was assessed in terms of clinical adequacy of anaesthesia and with recognised mathematical criteria. BISCLAN was able to control anaesthesia successfully. Cardiovascular parameters were stable in all patients. With two exceptions, operating conditions were also adequate. Control parameters during sedation and anaesthesia were acceptable and compare favourably with those found in other studies. Two studies of a second mode of feedback control of sedation (patient-maintained sedation) were performed. In both the goal was to determine if system safety was sufficient to prevent volunteers from purposefully inducing loss of consciousness. Sedation scores, propofol concentrations and physiological data were recorded. Secondary data included BIS values, and tests of memory for words. In one study a revised version of a previously developed blood concentration targeted infusion system was used, and in the other an effect-site targeted system. One subject in the second study became over-sedated, but no subjects lost consciousness. There was correlation among BIS values and propofol concentrations, and among BIS and propofol concentrations and the likelihood of memory for words. Several subjects remained conscious during periods when the BIS was < 60.
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    Global Airway Management of the Unstable Cervical Spine Survey
    (2021) Stegmann, George Frederik; Hofmeyr, Ross; Llewellyn, Richard
    Background Rapid growth in optical and video devices for indirect visualisation of the airway has expanded the options for emergency and elective endotracheal intubation in patients with unstable fractures of the cervical spine. Aiming to ascertain whether video laryngoscopy (VL) has replaced awake flexible intubation (AFI) as the preferred technique for airway management, we conducted a global survey to evaluate current clinical practice. Methods After ethics approval, we created a questionnaire featuring one emergency and one urgent elective hypothetical patient with unstable injuries of the cervical spine. Target sample sizes per country were estimated using data from the World Federation of Societies of Anaesthesiologists' (WFSA) Global Anaesthesia Workforce Survey. Respondents were asked about their training, experience, airway skills, current clinical setting, and availability of airway equipment, as well as their preferred airway strategy in each case. The questionnaire was actively distributed for one year through the WFSA member societies and via social networks to physician anaesthesia providers (PAPs). Global and regional trends were assessed using descriptive statistics. Results Of a total of 1904 responses, 1153 (101 countries) were included in the final analysis. In the emergency case, 46.9% (95% confidence interval [CI]: 44.0–49.8%) of participants preferred VL and 39.8% (95% CI: 38.0-42.6%) chose AFI. In the urgent elective case, 51.3% (95% CI: 48.3-54.3%) selected VL as their preferred method, while 37.3% (95% CI: 34.4-40.2%) indicated AFI. Significant regional variations in preference were found. Conclusion The results suggest that practice in airway management of unstable cervical spine fractures is changing, and currently tends to favour VL over AFI. There is a statistically significant preference for VL in elective cases, traditionally considered to be a stronghold of AFI.
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    Haemodilution and coagulation
    (2003) Ruttmann, Thomas Gotthard; James, Michael Frank Mansel
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    Haemodynamic consequences of Spinal Anaesthesia for non-emergency Caesarean section
    (2009) Dyer, Robert A; James, Michael Frank Mansel
    Single shot spinal anaesthesia for caesarean section is currently accepted as the favoured method in the absence of contraindications, for reasons of safety and comfort. Firstly, there is an increased risk of failed intubation associated with general anaesthesia. Secondly, spinal anaesthesia, if practiced correctly, allows for a superior experience of the delivery and improved bonding with the infant. Maternal haemodynamic stability is desirable both for maternal and neonatal safety, and to diminish maternal side-effects such as nausea and vomiting. Therefore, after an extensive literature review, clinically relevant aspects of spinal anaesthesia were studied, with a view to contributing to knowledge which could improve safety and outcome. The central themes explored in this thesis were fluid management during spinal anaesthesia for caesarean section in healthy parturients, the haemodynamic effects of the vasoactive agents ephedrine, phenylephrine and oxytocin during spinal anaesthesia for caesarean section in healthy patients and in patients with preeclampsia, and short term neonatal outcome after spinal anaesthesia in patients with severe preeclampsia. Research methodology included non-invasive measures as well as the use of a pulse wave form analysis monitor to measure maternal cardiac output. A validation study was performed comparing this method with thermodilution in patients with postpartum complications of preeclampsia. Abstract viii The results of these studies showed that: The pulse wave form monitor employed showed acceptable limits of agreement with the thermodilution method. Crystalloid coload was associated with lower vasopressor requirements than conventional preload. Spinal anaesthesia was associated with afterload reduction, which was more pronounced in healthy patients than in preeclamptics. Ephedrine maintained or increased, and phenylephrine reduced maternal cardiac output in healthy patients. Oxytocin was associated with transient haemodynamic instability in healthy and preeclamptic patients, which was obtunded by phenylephrine in the healthy population. Spinal anaesthesia for caesarean section was associated with a greater umbilical arterial base deficit than general anaesthesia in patients with preeclampsia. Overall, these studies should contribute to improved knowledge of haemodynamic responses during spinal anaesthesia for caesarean section, and ultimately to improved maternal morbidity and mortality.
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    The influence of delayed sample processing time on the PO₂ values in critically ill patients with sepsis-induced leukocytosis
    (2017) Pretorius, Petrus Rohan; Myburgh, Adriaan
    Background: The ability to correctly measure the partial pressure of Oxygen is one of the fundamental test that influence clinical decision making in a septic ICU patient. The study examined the extent of error over time, from collection to processing, when measuring blood gas samples for PO₂, PCO₂, pH, in critically-ill patients with sepsis and metabolically active leucocytosis > 12 000/mm³ and compares it with a control, where immersing it in ice has stopped metabolism. Methods: Thirty septic ICU patients with confirmed leucocytosis > 12 000/mm³, who had routine arterial blood analysed was included in the study. Blood form the standard PICO50 radiometer arterial blood sampler (2ml) syringe was decanted into two 1ml Glass syringes that was pre-heparinised with 1ml Heparin 1000U - all excess Heparin removed. One syringe was cooled with ice slurry and tested as a control at 60 minutes The other syringe was used to repeatedly analyse the sample at 0,10, 30 and 60 minutes. The syringes were sealed with plastecine and a glass capillary tube was use to decant the sample just prior to analysis to fit the analyser. Samples were processed using an ABL 800 blood gas analyser. Results: The mean absolute difference in PO₂ at 10 minutes was -0.94 kPa (95% CI: -1.48 to -0.4 kPa), at 30 minutes -2.42 kPa (95% CI: -3.10 to -1.75 kPa) and at 60 minutes -4.44 kPa (95% CI: -5.54 to -3.34 kPa). The relative difference in pO₂ at 10 minutes was -4.98% (95% CI: -8.12 to -1.84%), at 30 minutes -13.79% (95% CI: -17.40 to -10.17%) and 60 minutes -25.46% (95% CI: -30.97 to -19.95%). The absolute difference in PO₂ at 60 minutes on Ice was - 0.31 kPa. Conclusion: Delayed blood gas analysis in Septic ICU patients with a raised WCC > 12 000/mm³, results in statistical and possible clinical significant abnormality in the pO₂, that progressively worsens with time. After 10 minutes there was a 5% change, at 30 minutes a 14% change and there was a 25% change from baseline PO₂ at 60 minutes. The magnitude of change with statistical mixed linear models shows the rate of decline to be of the magnitude of 1% per minute. So at 60 minutes, the ratio change is 0.7313859 (0.9948 to the power of 60).This deviation may alter clinical decision making.
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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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    Maternal and cardiac output response to vasopressor therapy during spinal anaesthesia for Caesarean Section in severe preeclampsia
    (2017) Daniels, Abigail Hanlise; Dyer, Robert A
    Background: The maternal haemodynamic responses to vasopressors during spinal anaesthesia for caesarean delivery in patients with severe preeclampsia, have not been accurately described. This study compared the haemodynamic effects of the vasopressors ephedrine and phenylephrine during spinal anaesthesia. Methods: Thirty nine women with treated severe preeclampsia presenting for spinal anaesthesia for caesarean section for a maternal indication, were studied. Baseline maternal haemodynamics were measured in the left lateral position, using minimal invasive cardiac output monitoring (LiDCOrapid). A 300 mL colloid preload was then administered. After standard spinal anaesthesia, 20 patients whose mean arterial pressure decreased to a predetermined target value were randomised to 2 groups of 10, to receive an initial bolus of either 7.5 mg ephedrine or 50 μg phenylephrine, and the haemodynamic responses recorded. The primary outcome was the percentage change in cardiac index. Results: Spinal hypotension in 20 patients was associated with an increase in mean cardiac output from baseline (mean difference 0.7 L/min, p<0.0001). In response to vasopressor, the mean [SD] percentage change in cardiac index was greater, and negative, in patients receiving phenylephrine versus ephedrine (-12 [7.3] vs 2.6 [6] L/min respectively, p=0.0001).] L/min respectively, p=0.0001). Post-vasopressor mean percentage change [SD] in heart rate and systemic vascular resistance (SVR) were higher in patients receiving phenylephrine (-9.1 [3.4] vs 5.3 [12.6], p=0.0027, and 22.3 [7.5] vs -1.9 [10.5] %, p<0.0001 respectively). Conclusions: Phenylephrine effectively reverses spinal anaesthesia-induced haemodynamic changes in severe preeclampsia, if left ventricular function is preserved.