The Effect of Lithotomy Position on Arterial Blood Pressure After Spinal Anesthesia

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Comment This simple yet clinically relevant study demonstrated the effectiveness of proper placement in the lithotomy position for attenuating systolic hypotension without elevating the sensory level of subarachnoid block (SAB). The thighs of the women were meticulously placed at 90® at the hips to the torso. Placing the thighs at a decreased angle to the torso (more flexion at the hip) may decrease venous return by lowering the level of the thigh, compressing the abdominal cavity, and obstructing venous return favoring the development of phlebitis. In the gravid or obese patient, such improper lithotomy position might actually accentuate hypotension by forcing the uterus or abdominal viscera on both the vena cava and aorta, causing or further increasing aortocaval compression. The authors referred to an earlier study of theirs, which showed that placing the patient head down in the Trendelenburg position was not only less effective than lithotomy in attenuating the decreased systolic blood pressure (SBP) after SAB but also was associated with a higher level of block. They attributed the better results of lithotomy in combating systolic hypotension to the greater head of pressure that would occur in the thighs placed at 90® to the torso. Unfortunately, under most surgical conditions, the lithotomy position is contraindicated by the surgery itself. Simply elevating the entire lower