RESEARCH ON DEEP SUBMERGENCE DIVING PHYSIOLOGY AND DECOMPRESSION TECHNOLOGY UTILIZING SWINE: EVALUATION OF SWINE AS A HYPERBARIC ANALOG TO MAN AND DETECTION OF EMBOLI BY USE OF THE ULTRASONIC DOPPLER FLOWMETER
Abstract
Sixteen miniature swine of similar size performed 83 dry chamber air dives, using no-stage profiles with linear ascent and descent rates of 60 ft/ min, depths of 60 to 180 ft, and bottom times up to 120 min. Surface intervals always exceed 48 hr. Signs considered diagnostic of bends were lameness, persisting for 15 minutes or more and relieved by recompression, and/or acute, progressive respiratory distress, and/or central neurologic signs, e.g. paralysis. Bends was not observed at 60 ft with bottom times up to 120 min; a 60% incidence was recorded for 140 ft/60 min and a 16% incidence for 180 ft/20 min. Doppler flowmeter studies have shown that individual glass microballoons of 80-150 micra diameter are easily detectable in the thoracic caudal vena cava, and that 40 micra balloons, while difficult to detect individually, are easily detected when injected in large quantities. Severe caval air embolism has been recorded following 180 ft/15 min excursions without bends signs, confirming that significant gas embolism can exist in the absence of such signs and showing the value of the Doppler flow meter for embolism detection.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 06, 1970
- Accession Number
- AD0708748
Entities
People
- Murlin F. Gillis
Organizations
- Battelle Memorial Institute