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Biomedical subjects

J H Dougherty

Publications and source records attributed to J H Dougherty.

26 records · Page 2Linked to original sources
PubMed1968

Pulmonary and circulatory adjustments determining the limits of depths in breathhold diving.

Data on pulmonary gas exchange were collected in breathhold dives to 90 feet in a tank and in open-sea breathhold dives to depths of 217.5 and 225 feet. Thoracic blood volume displacements were measured at depths of 25, 50, 90, and 130 feet, by use of the impedance plethysmograph. The open-sea dives were carried out with an average speed of descent of 3.95 feet per second and an average rate of ascent of 3.50 feet per second. End-dive alveolar oxygen tensions did not fall below 36 millimeters of mercury, while alveolar carbon dioxide tension did not rise above 40 millimeters of mercury except in one case. These findings indicate that for diver Croft, who has unusual lung capacity, neither hypoxia nor hypercapnia determined the depth limits under those conditions. At depths of 90 and 130 feet blood was forced into the thorax, amounting to 1047 and 850 milliliters respectively.

Adaptation, Physiological↗
PubMedDate not supplied

Complications of lumbar puncture followed by anticoagulation.

The complications associated with lumbar puncture (LP) were compared in 2 groups of 342 patients. The first group of patients was anticoagulated after the LP, and the second was not. The incidence of minor headache or back pain was similar in the 2 groups (Group 1--62%, Group 2--64%). The anticoagulated patients had a higher incidence of paraparesis (Group 1, 5 patients, Group 2, No patients; p less than .05) and severe back or lumbosacral radicular pain lasting more than 48 hours (Group 1, 18 patients, Group 2, 6 patients; p less than .025). Seven of the anticoagulated patients developed spinal hematomas (5 with paraparesis, 2 with severe back pain). Among the anticoagulated patients the risk of a major complication was increased by a traumatic LP (p less than .001), starting anticoagulation within one hour of the LP (p less than .001), or aspirin treatment at the time of the LP (p less than .001). This study suggests that if LP is done, delaying anticoagulation for at least one hour and avoiding concurrent aspirin therapy may decrease the risk of developing an extraparenchymal spinal hematoma.

Anticoagulants↗