Anaesthesia
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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?
- Consent, particularly around providing inadequate pre-procedure information of the risk of neurological injury1 and the challenges, medical and legal, to achieving informed consent.
- Nerve injury and it's mechanisms: non-anaesthetic causes2, direct trauma, chemical, and compression (abscess, haematoma).
- 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.
summary
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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. ↩
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'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. ↩
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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! ↩
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Spinal hypotension is a common and clinically important problem during caesarean section. Current consensus recommendations for resource-rich settings suggest the use of a titrated phenylephrine infusion, in combination with fluid coloading, for prevention of maternal hypotension. In resource-limited settings, where syringe drivers are unavailable, these recommendations advise the addition of 500 μg phenylephrine to the first 1 l of intravenous fluid given after initiation of spinal anaesthesia, with additional vasopressor boluses as required. ⋯ The six highest systolic arterial pressure readings occurred in the phenylephrine infusion group (range 166-188 mmHg), and there were four instances of bradycardia (heart rate < 50 beats.min-1 ) with preserved systolic arterial pressure in each group. There were no adverse clinical sequelae, and no differences in neonatal Apgar scores in either group. The consensus recommendation for phenylephrine and fluid co-administration in resource-limited settings appears effective in preventing maternal hypotension, but at the cost of sporadic systolic hypertension.
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Observational Study
Red blood cell transfusion in surgery: an observational study of the trends in the USA from 2011 to 2016.
Guidelines recommend restrictive red blood cell transfusion strategies. We conducted an observational study to examine whether the rate of peri-operative red blood cell transfusion in the USA had declined during the period from 01 January 2011 to 31 December 2016. We included 4,273,168 patients from all surgical subspecialties. ⋯ Compared with 2011, the adjusted hazard ratios (95%CI) in 2012 and 2016 were 0.96 (0.90-1.02) and 1.05 (0.99-1.11) for myocardial infarction, 0.91 (0.83-0.99) and 0.99 (0.92-1.07) for stroke and 0.98 (0.94-1.02) and 0.99 (0.96-1.03) for all-cause mortality. Use of peri-operative red blood cell transfusion declined from 2011 to 2016. This was not associated with an increase in adverse clinical outcomes.
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There is conflicting evidence whether allogeneic blood transfusion influences survival or cancer recurrence after resection of hepatocellular cancer. We followed up 1469 patients who had undergone hepatocellular resection for a median (IQR [range]) of 45 (21-78 [0-162]) months, of whom 626 (43%) had had blood transfusion within 7 days of surgery. Both disease-free survival and patient survival were measured using a proportional hazards regression model and inverse probability of treatment weighting. ⋯ Adjusted hazard ratios (95%CI) for the association of blood transfusion with cancer recurrence and all-cause mortality were 1.3 (1.1-1.4) and 1.9 (1.6-2.3), p < 0.001 for both. With more units transfused cancer recurrence was more likely and survival was shorter. The association of the number of transfused units was non-linear for cancer recurrence and linear response for all-cause mortality.