Anaesthesia
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Recommendations from the guidelines:
- Hypotension following spinal or combined spinal-epidural anaesthesia at caesarean section causes both maternal and fetal/neonatal adverse effects.
- Hypotension is frequent – vasopressors should be used routinely and preferably prophylactically.
- α‐agonist drugs are the most appropriate agents to treat or prevent hypotension following spinal anaesthesia. Although those with a small amount of β‐agonist activity may have the best profile (noradrenaline (norepinephrine), metaraminol), phenylephrine is currently recommended due to the amount of supporting data. Single‐dilution techniques, and/or prefilled syringes should be considered.
- Left lateral uterine displacement and intravenous (i.v.) colloid pre‐loading or crystalloid coloading, should be used in addition to vasopressors.
- The aim should be to maintain systolic arterial pressure (SAP) at ≥ 90% of an accurate baseline obtained before spinal anaesthesia, and avoid a decrease to < 80% baseline. We recommend a variable rate prophylactic infusion of phenylephrine using a syringe pump. This should be started at 25–50 μg.min−1 immediately after the intrathecal local anaesthetic injection, and titrated to blood pressure and pulse rate. Top‐up boluses may be required.
- Maternal heart rate can be used as a surrogate for cardiac output if the latter is not being monitored; both tachycardia and bradycardia should be avoided.
- When using an α‐agonist as the first‐line vasopressor, small doses of ephedrine are suitable to manage SAP < 90% of baseline combined with a low heart rate. For bradycardia with hypotension, an anticholinergic drug (glycopyrronium (glycopyrrolate) or atropine) may be required. Adrenaline (epinephrine) should be used for circulatory collapse.
- The use of smart pumps and double (two drug) vasopressor infusions can lead to greater cardiovascular stability than that achieved with physician‐controlled infusions.
- Women with pre‐eclampsia develop less hypotension after spinal anaesthesia than healthy women. Abrupt decreases in blood pressure are undesirable because of the potential for decreased uteroplacental blood flow. A prophylactic vasopressor infusion may not be required but, if used, should be started at a lower rate than for healthy women.
- Women with cardiac disease should be assessed on an individual basis; some conditions are best managed with phenylephrine (an arterial constrictor without positive inotropic effect), whereas others respond best to ephedrine (producing positive inotropic and chronotropic effect).
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Randomized Controlled Trial
Human cadavers preserved using Thiel's method for the teaching of fibreoptically-guided intubation of the trachea: a laboratory investigation.
We assessed the suitability of human cadavers preserved using Thiel's method for teaching flexible fibreoptic tracheal intubation. Thirty-one anaesthetists unacquainted with this technique received didactic teaching followed by handling of the fibrescope on the Oxford teaching box. They then carried out fibreoptic intubations in two cadavers to establish a baseline sample of their intubation skills. ⋯ The training effect of the cadaveric method was greater than with the manikin method (p = 0.0016). Thirty-four failed intubations occurred at baseline vs. eight at the end of study (RR 0.24, 95%CI 0.11-0.51, p = 0.0002, NNT 9.6); six in the cadaver group and two in the manikin group (p = 0.22). We conclude that human cadavers preserved using Thiel's method are potentially better for teaching flexible fibreoptic tracheal intubation compared with manikins.
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'Obstetric anaesthesia is a litigious area of medical practice - patient expectations are high, and many of the interventions undertaken by anaesthetists are performed urgently or emergently, frequently out of hours. The complications that occur during obstetric practice are not unique to this area of anaesthesia, but some of the physiological and anatomical changes that take place during pregnancy can affect the frequency with which these happen. In this narrative review, we hope to cover a few of the more common complications in obstetric anaesthesia, as well as some of the more severe, yet less frequently occurring problems.
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Intra-operative acute hypersensitivity reactions require a decision to be made regarding whether to proceed with or abandon the planned surgical procedure once the patient has stabilised. Using retrospective case controls, we examined all cases (223) of proven acute hypersensitivity reactions from 2005 to 2014 in Western Australia, in which the syndrome was recognised by the treating clinician before or during surgery, to determine whether recovery outcomes were adversely affected by proceeding with the planned procedure. Surgery proceeded in 104 patients (47%) and was abandoned in 119 (53%). ⋯ Our results suggest that, once initial resuscitation has been achieved and if resuscitative efforts can be re-instituted if required, continuing with planned surgery in grade 1, 2 and 3 immediate hypersensitivity was not associated with poorer outcomes. After grade 3 reactions, there was a significant incidence of complications attributable to acute hypersensitivity regardless of whether surgery proceeded or was abandoned. Surgery was frequently abandoned in grade 4 immediate hypersensitivity and was associated with a high rate of complications.