Anaesthesia
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Editorial Comment
Carbon dioxide clearance during apnoea with high-flow nasal oxygen: epiphenomenon or a failure to THRIVE?
Toner notes the rapid adoption of high-flow nasal oxygen for apnoeic oxygenation, particularly in the context of competing alternatives that have not enjoyed the same popularity.
Specifically, it is highlighted that there is a lack of high-quality RCTs confirming the ability of Transnasal humidified rapid-insufflation ventilatory exchange (THRIVE) to acceptably clear CO2 with prolonged periods of apnoea. RCT results are awaited.
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Randomized Controlled Trial
Reversal of neuromuscular blockade with sugammadex during continuous administration of anaesthetic agents: a double-blind randomised crossover study using the bispectral index.
Sugammadex, a specific reversal agent for steroidal neuromuscular blocking drugs, has on occasion been reported to be associated with clinical signs of awakening. We performed a study to systematically search for an increase in bispectral index values and signs of awakening in patients maintained under general anaesthesia following sugammadex administration. Patients, scheduled to receive general anaesthesia with neuromuscular blockade, were included in this double-blind randomised crossover study. ⋯ Saline had no effect on bispectral index values, clinical signs of awakening or degree of neuromuscular blockade. This study confirms that reversal of neuromuscular blockade with sugammadex may be associated with clinical signs of awakening despite maintenance of anaesthesia. Intravenous anaesthesia should be maintained until complete recovery of muscle function is achieved, especially when sugammadex is administered.
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Review
Choice of local anaesthetic for epidural caesarean section: a Bayesian network meta-analysis.
Rapid-onset epidural local anaesthesia can avoid general anaesthesia for caesarean delivery. We performed a Bayesian network meta-analysis of direct and indirect comparisons to rank speed of onset of the six local anaesthetics most often used epidurally for surgical anaesthesia for caesarean delivery. We searched Google Scholar, PubMed, EMBASE, Ovid, CINAHL and CENTRAL to June 2019. ⋯ Speed of onset was similar to bupivacaine 0.5% after ropivacaine 0.75% and l-bupivacaine 0.5%: 1.6 (-1.4 to 4.8) min faster and 0.4 (-2.2 to 3.0) min faster, respectively. The rate (95%CrI) of intra-operative hypotension was least after l-bupivacaine 0.5%, 315 (236-407) per 1000, and highest after 2-chloroprocaine 3%, 516 (438-594) per 1000. The rate (CrI) of intra-operative supplementation of analgesia was least after ropivacaine 0.75% 48 (19-118) per 1000 and highest after 2-chloroprocaine 3%, 250 (112-569) per 1000.
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Randomized Controlled Trial
The impact of fluid optimisation before induction of anaesthesia on hypotension after induction.
Intra-operative hypotension is a known predictor of adverse events and poor outcomes following major surgery. Hypotension often occurs on induction of anaesthesia, typically attributed to hypovolaemia and the haemodynamic effects of anaesthetic agents. We assessed the efficacy of fluid optimisation for reducing the incidence of hypotension on induction of anaesthesia. ⋯ Forty-two (30%) goal-directed fluid therapy patients underwent fluid optimisation after finding an intravascular fluid deficit via passive leg raise testing; 106 (75%) goal-directed fluid therapy and 112 (79%) standard fluid therapy patients met criteria for haemodynamic instability. There was no significant difference in the incidence of haemodynamic instability between the goal-directed fluid therapy and standard fluid therapy groups using absolute mean arterial pressure drop below 55 mmHg (p = 0.58) or using pre-surgical testing or pre-surgical mean arterial pressure values as baseline (p = 0.21, p = 0.89, respectively); however, the difference in the incidence of haemodynamic instability was significant using the operating theatre baseline mean arterial pressure (p = 0.004). We conclude that fluid optimisation before induction of general anaesthesia did not significantly impact haemodynamic instability.