Regional Blocks Prove Superior to General Anesthesia in Cesarean Sections

General anesthesia (GA) is associated with an increased risk of infant intubation and low Apgar scores relative to regional anesthesia, according to new study.

Researchers from the Kolling Institute of Medical Research (Sydney, Australia) and the Royal North Shore Hospital (RNSH; Sydney, Australia) studied births in the state of New South Wales (NSW, Australia) between 1998 and 2004, and analyzed 50,806 cesarean deliveries. Deliveries performed under GA were compared with those performed under spinal or epidural anesthesia, for the outcomes of neonatal intubation and 5-minute Apgar (Apgar 5) of less than 7 (< 7).


The researchers found that the risk of adverse outcomes was increased for caesarean sections under GA 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 per 100, and Apgar 5 < 7 relative risk was 13 per 100 deliveries. The largest absolute increase in risk was for unplanned caesareans due to fetal distress: there were five extra intubations per 100 deliveries and six extra Apgar 5 < 7 per 100 deliveries. The researchers also found that although current guidelines recommend regional blocks, GA was still used for 12.6% of cesareans across NSW in 2006. The study was published on April 29, 2009, in the open access journal BMC Medicine, a publication of BioMed Central.

"The increased rates of neonatal intubation after GA shown in this study represent harm in and of itself, and the persistence of low five-minute Apgar scores suggests that deleterious effects may last longer than the immediate aftermath of delivery," said lead author Charles Algert, M.D., of the perinatal research unit at the Kolling Institute. "Clinicians considering the use of GA for a cesarean delivery should be aware of these possible consequences for the infant, for both planned and emergency sections."

The Apgar score is now used worldwide to quickly assess the health of an infant one minute and five minutes after birth. The one-minute Apgar score measures how well the newborn tolerated the birthing process; the five-minute Apgar score assesses how well the newborn is adapting to the environment. The Apgar score uses measures of 0, 1, or 2 for five categories, with the best possible total score equaling 10. The categories measured are heart rate, respiration, muscle tone, response to stimulation, and color. It is generally presumed that any harm caused by GA is short lasting, with most studies focusing on resuscitation and the Apgar score at one minute

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Kolling Institute of Medical Research