Rommelsheim K, Schäfer R, Biersack H J, Bastian L H, Thelen M, Venzke H
Prakt Anaesth. 1978 Aug;13(4):283-92.
The changes in blood flow in the pulmonary circulation arising from the lateral position during surgery were tested by means of 99mTc microspheres and a scanning camera computer system in 30 patients who had urological operations. Blood flow in the undermost lung increased by an average of 17% of the total pulmonary blood flow (SD = 8.0) in a group of 18 persons whose average age was 39.9 years. This redistribution occurred immediately after the patient was placed on his side and was more marked in younger persons than it was in older ones. Accompanying changes in O2 pressure showed no quantitative correlation with the changes in perfusion. The lateral position also affected ventilation by reducing ventilation of the undermost lung. This ventilatory disturbance which was demonstrable in more than 50% of the cases persisted for a short time after the operation whereas the pulmonary circulation returned to normal immediately after the patient resumed a normal position.
