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pearl
1
Phenylephrine is currently recommended as the consensus choice for managing hypotension during spinal anaesthesia for Caesarean section. Ephedrine should only be used when mild hypotension is associated with bradycardia.
Kinsella SM, Carvalho B, Dyer RA et al. International consensus statement on the management of hypotension with vasopressors during caesarean section under spinal anaesthesia. Anaesthesia. 2018 Jan 1; 73 (1): 71-92.
  Daniel Jolley
pearl
2
Metaraminol infusion for hypotension prevention during spinal anaesthesia for Caesarean section is non-inferior to phenylephrine infusion.
McDonnell NJ, Paech MJ, Muchatuta NA et al. A randomised double-blind trial of phenylephrine and metaraminol infusions for prevention of hypotension during spinal and combined spinal-epidural anaesthesia for elective caesarean section. Anaesthesia. 2017 May 1; 72 (5): 609-617.
  Daniel Jolley
summary
1
McCombe and Bogod report on their analysis of 55 medicolegal claims relating to obstetric neuraxial anaesthesia and analgesia.
Why is this important?
Not only is neurological injury the second most common reason for obstetric anaesthetic claims (behind inadequate regional anaesthesia resulting in pain during Caesarean section), the average claim cost is greater.
McCombe and Bogod provide a factful exploration of many of the causes of neurological complications.
Which themes emerged from their analysis?
1. Consent, particularly around providing inadequate pre-procedure information of the risk of neurological injury¹ and the challenges, medical and legal, to achieving informed consent.
2. Nerve injury and it's mechanisms: non-anaesthetic causes², direct trauma, chemical, and compression (abscess, haematoma).
3. Complication recognition & management means timely follow-up and assessment, and maintaining a high index of suspicion for abnormalities. Remember the 4 hour rule: blocks should be regressing 4 hours after the last dose.
Important reminders
The level of spinal cord termination varies a lot among individuals, as does the level of Tuffier's line³. Considering the inaccuracy of spinal level identification by anaesthetists, there is a lot of potential to place a needle higher than expected.
Bottom-line: the intrathecal space should be accessed at the lowest possible level, and "the L2/3 interspace should not be an option."
And never allow chlorhexidine to contaminate gloves, the sterile workspace or neuraxial equipment.
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1. Noting from NAP3 the risk of nerve injury ranges from, temporary injury 1:1,000, prolonged (>6 months) 1:13,000, to severe (including paralysis) 1:250,000. ↩

2. 'Obstetric palsy' (pelvic nerve compression) estimated by Bromage as occurring in 1:3000 deliveries; arterial obstruction & ischaemia 1:15,000; AV malformations 1:20,000. A prospective French study found postpartum neuropathy in 0.3%, 84% were femoral, and 69% resolved at 6 weeks. ↩

3. Although generally accepted as being at the L4/5 interspace, in up to 50% of people the intercristal line might be at or above L2/3! ↩
McCombe K Bogod DG. Learning from the law. A review of 21 years of litigation for nerve injury following central neuraxial blockade in obstetrics. Anaesthesia. 2020 Apr 1; 75 (4): 541-548.
  Daniel Jolley
pearl
1
Spinal anaesthesia should not be performed above the L3/4 interspace if relying on surface anatomy to determine spinal level.
Reynolds F. Logic in the safe practice of spinal anaesthesia. Anaesthesia. 2000 Nov 1; 55 (11): 1045-6.
  Daniel Jolley
summary
0
"Anaesthetists may feel justified in using a high lumbar interspace for spinal anaesthesia when it is condoned by so many texts, but more caution must be exercised. The L2/3 interspace should not be an option, and several textbooks need to be re-written to allow for human variability."
Reynolds F. Logic in the safe practice of spinal anaesthesia. Anaesthesia. 2000 Nov 1; 55 (11): 1045-6.
  Daniel Jolley
pearl
1
Anaesthetists are inaccurate when identifying lumbar spinal interspace level using bony landmarks.
Broadbent CR, Maxwell WB, Ferrie R et al. Ability of anaesthetists to identify a marked lumbar interspace. Anaesthesia. 2000 Nov 1;55(11):1122-6.
  Daniel Jolley
summary
1
When anaesthetists were assessed on their ability to correctly identify a lumbar interspace level in 100 patients undergoing spinal MRI:
• Only 29% identified the space correctly.
• 68% indicated the space was lower than actual.
• 51% were one space out in their estimate.
• 15.5% two spaces.
• 1% three spaces.
• 0.5% four spaces.
Broadbent CR, Maxwell WB, Ferrie R et al. Ability of anaesthetists to identify a marked lumbar interspace. Anaesthesia. 2000 Nov 1;55(11):1122-6.
  Daniel Jolley
pearl
1
Among a prospective French obstetric cohort, 1 in 300 women demonstrated postpartum neuropathy, most commonly primiparous, sensory and in femoral nerve territory.
Tournier A, Doremieux AC, Drumez E et al. Lower-limb neurologic deficit after vaginal delivery: a prospective observational study. Int J Obstet Anesth. 2020 Feb 1; 41: 35-38.
  Daniel Jolley
pearl
1
Duration of pre-operative fasting in children is associated with increased risk of post-induction hypotension.
Simpao AF, Wu L, Nelson O et al. Preoperative Fluid Fasting Times and Postinduction Low Blood Pressure in Children: A Retrospective Analysis. Anesthesiology. 2020 Sep 1; 133 (3): 523-533.
  Daniel Jolley
pearl
1
A restrictive transfusion strategy in adult cardiac surgery does not alter mortality or complications.
Kashani HH, Lodewyks C, Kavosh MS et al. The effect of restrictive versus liberal transfusion strategies on longer-term outcomes after cardiac surgery: a systematic review and meta-analysis with trial sequential analysis. Can J Anaesth. 2020 May 1; 67 (5): 577-587.
  Daniel Jolley