What height of block is needed for manual removal of placenta under spinal anaesthesia?

The technique of spinal anaesthesia for manual removal of placenta was examined prospectively in 101 women. Factors associated with maternal discomfort during surgery were the height of the block (P = 0.007) and the force applied by the surgeon in removing the placenta (P = 0.04). A sensory block to cold to T9 or T10 resulted in discomfort for six out of 27 women (22%). Only two women out of 38 experienced discomfort with a block to T6 or above. A block to cold to T6 or above is therefore recommended for manual removal of placenta under subarachnoid block. Factors not affecting maternal comfort were grade of the obstetrician, (P = 0.61), grade of the anaesthetist (P = 0.88), position of the mother during spinal injection (P = 0.32), volume of hyperbaric bupivacaine injected (P = 0.75), time from spinal injection to the start of surgery (P = 1.0), and duration of surgery (P = 0.77). Intraoperative hypotension was more common in those women with greater blood loss, (P = 0.002), but not with higher sensory levels (P = 0.31).