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Biomedical subjects

R E Dutton

Publications and source records attributed to R E Dutton.

At least 55 records · Page 3Linked to original sources

Cardiopulmonary adjustments following single high dosage administration of methylprednisolone in traumatized man.

Pharmacologic doses of methylprednisolone sodium succinate were administered to 10 critically ill patients when the steroid was the only variable. Measurements of respiratory and circulatory physiologic parameters were obtained in all patients prior to injection and at 30 and 90 minutes following injection of methylprednisolone sodium succinate. A significant increase in Cardiac Index was seen (P less than .01) which appeared to be in association with a decrease in pulmonary vascular resistance (P less than .01) at a time when physiologic shunting of blood through the lungs increased (P less than .01). These changes imply improved perfusion of non- or poorly ventilated portions of the lungs. Four of ten patients demonstrated removal of lactate by the lung during the control period. Following methylprednisolone sodium succinate injection, 9 of 10 patients demonstrated production or a washout of lactate from the lungs.

Accidents, Traffic↗

Gas-blood PCO2 gradients during avian gas exchange.

The avian respiratory system is a crosscurrent gas exchange system. One of the aspects of this type of gas exchange system is that end-expired PCO2 is greater than arterial PCO2, the highest possible value being equal to mixed venous PCO2. We made steady-state measurements of arterial, mixed venous, and end-expired PCO2 in anesthetized, spontaneously breathing chickens during inhalation of room air or 4-8% CO2. We found end-expired PCO2 to be higher than both arterial and mixed venous PCO2, the sign of the differences being such as to oppose passive diffusion. The observation that end-expired PCO2 was higher than arterial PCO2 can be explained on the basis of crosscurrent gas exchange. However, the observation that end-expired PCO2 exceeded mixed venous PCO2 must be accounted for by some other mechanism. The positive end-expired to mixed venous PCO2 gradients can be explained if it is postulated that the charged membrane mechanism suggested by Gurtner et al. (Respiration Physiol. 7: 173-187, 1969) is present in the avian lung.

Acetazolamide↗