Regional block versus general anaesthesia for caesarean section and neonatal outcomes: a population-based study.
BACKGROUND
Anaesthesia guidelines recommend regional anaesthesia for most caesarean sections due to the risk of failed intubation and aspiration with general anaesthesia. However, general anaesthesia is considered to be safe for the foetus, based on limited evidence, and is still used for caesarean sections.


METHODS
Cohorts of caesarean sections by indication (that is, planned repeat caesarean section, failure to progress, foetal distress) were selected from the period 1998 to 2004 (N = 50,806). Deliveries performed under general anaesthesia were compared with those performed under spinal or epidural, for the outcomes of neonatal intubation and 5-minute Apgar (Apgar5) <7.


RESULTS
The risk of adverse outcomes was increased for caesarean sections under general anaesthesia for all three indications and across all levels of hospital. The relative risks were largest for low-risk planned repeat caesarean deliveries: resuscitation with intubation relative risk was 12.8 (95% confidence interval 7.6, 21.7), and Apgar5 <7 relative risk was 13.4 (95% confidence interval 9.2, 19.4). The largest absolute increase in risk was for unplanned caesareans due to foetal distress: there were five extra intubations per 100 deliveries and six extra Apgar5 <7 per 100 deliveries.


CONCLUSIONS
The infants most affected by general anaesthesia were those already compromised in utero, as evidenced by foetal distress. The increased rate of adverse neonatal outcomes should be weighed up when general anaesthesia is under consideration.
Algert
Charles S
CS
Kolling Institute of Medical Research, Clinical and Perinatal Population Health Research, University of Sydney, Australia. calgert@med.usyd.edu.au
Bowen
Jennifer R
JR
Giles
Warwick B
WB
Knoblanche
Greg E
GE
Lain
Samantha J
SJ
Roberts
Christine L
CL
D000328:Adult; D000765:Anesthesia, Conduction / Q000009:adverse effects* / Q000379:methods*; D000768:Anesthesia, General / Q000009:adverse effects* / Q000379:methods*; D001034:Apgar Score; D002585:Cesarean Section / Q000379:methods*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007440:Intubation / Q000706:statistics & numerical data; D011247:Pregnancy; D016896:Treatment Outcome; D055815:Young Adult