Weight gain during pregnancy does not influence the spread of spinal analgesia in the term parturient

It is still controversial whether the spread of spinal anaesthesia in pregnancy is influenced by particular physique. Investigation was based on a clinical observation that parturients with a pronounced "pregnant" physique, e.g. generalised oedema and heavy abdomen, tended to develop more cephalad sensory blockades than parturients without these physical signs. Using weight gain during pregnancy as a measure for the physique at term, we aimed to determine whether this parameter influences the distribution of analgesia after subarachnoidal injection of plain bupivacaine.

Thirty women presenting for elective Caesarean section were studied. All the women received 13.5 mg plain bupivacaine via subarachnoid injection at the L2-3 interspace. Thirty minutes after the injection, while the women were in the supine position with a left lateral tilt on a horizontal operating table, the maximum cephalad extent of sensory analgesia (loss of sensation to sharpness of pinprick) was determined.

Neither weight gain during pregnancy (6-22 kg, range), height (152-185 cm), weight (56-98 kg) nor body-mass index (20.2-31.8 kg/m2) correlated with the cephalad spread of sensory blockade.

In parturients, weight gain during pregnancy, height, weight and body-mass index did not influence the extent of sensory analgesia after subarachnoidal administration of plain bupivacaine.