The edition · Anaesthesiology
The capnograph is telling you something the arterial line is not
In 185,455 anaesthetics, low end-tidal carbon dioxide predicted in-hospital death independently of both hypotension and minute ventilation; underweight children desaturate and fail first-pass intubation; and a bolus phenylephrine regimen needed half the interventions of an infusion.
The edition in brief
Today's anaesthesiology edition opens with a retrospective cohort of 185,455 adults having non-cardiac surgery under general anaesthesia at a single tertiary centre over eleven years. Lower mean intraoperative end-tidal carbon dioxide was associated with in-hospital mortality in a non-linear fashion, with an adjusted odds ratio of 1.63 per 5 mmHg fall below the median, and the association held after adjustment for both minute ventilation and intraoperative hypotension, with no interaction between the two. A registry analysis of 18,835 paediatric induction encounters across 12 Japanese hospitals found no association between weight category and composite airway adverse events, but both obese and underweight children desaturated more often — adjusted odds ratios 2.12 and 1.31 — and underweight children had notably lower first-attempt intubation success, 80.5% against 89.2%, with an adjusted odds ratio of 0.69. A randomised trial in 217 knee arthroplasties found an eight-nerve block combination no better than local infiltration analgesia on pain at any of seven time points, with exploratory reductions in 48-hour opioid use and length of stay. A 50-patient non-inferiority trial of bicarbonate-buffered crystalloid against compound sodium lactate in major abdominal surgery was inconclusive — the confidence interval crossed the margin in both analyses — and establishes nothing about interchangeability. The practice-changer is a double-blind non-inferiority trial showing that a modified prophylactic phenylephrine bolus regimen at elective caesarean needed a median of three interventions against six for a variable-rate infusion, at less than half the total drug.
Low end-tidal carbon dioxide predicts death, and not through the blood pressure
Treat a persistently low end-tidal carbon dioxide that ventilation and blood pressure do not explain as an independent risk signal — investigate the cause and let it inform the postoperative destination.
The thin child is the harder airway
In an underweight child, expect a lower first-pass intubation success and a faster desaturation — send the most experienced operator first and have apnoeic oxygenation running before induction.
Eight blocks did not beat one infiltration on pain
An eight-nerve block gave no better analgesia than local infiltration after knee replacement — adopt it only to reduce opioid exposure, and audit whether it does so in your unit.
A fluid trial that answered nothing, and says so
Keep using compound sodium lactate, and remember that a lactate-free crystalloid lowers the measured lactate without telling you anything about the patient.
Say the baseline pressure out loud before the spinal
Establish the baseline systolic pressure from three settled pre-block readings, then say the number and the treatment threshold aloud and write both down.
Boluses needed half the interventions of the infusion
For elective caesarean under spinal anaesthesia in a healthy woman, a 100 µg phenylephrine bolus at induction repeated below 90% of baseline is a workable default — no syringe pump needed, and fewer interventions than an infusion.
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