Clinical Trial – Hypobaria and Traumatic Pneumothorax

The purpose of this research is to see if people who have had a collapsed lung that has been
re-expanded can be safely taken to an elevation that a person might experience while in a
commercial airplane without having their lung partially collapse again, or have any symptoms
such as feeling short of breath or having oxygen levels in the blood decrease while at the
simulated altitude.

The investigators hypothesize that subjects who have had a collapsed lung that has been
re-expanded will not have any adverse symptoms or signs while subjected to a simulated
altitude of 8400 feet (565mm Hg) or 12650 ft (471mm Hg).

Clinical Trial – ET 50 for Post Caesarean Section Spinal Hypotension

Hypotension is extremely common after induction of spinal anesthesia for cesarean delivery.
Anesthetic blockade of the sympathetic outflow of the spinal cord causes vasodilation, and is
one cause of this hypotension. The higher the spread of the blockade will result in a higher
incidence of hypotension. Injected hyperbaric medication has about 15 minutes to spread
within the intrathecal space before it will be taken up by the nerve roots. The time that a
patient remains in one position after medication injection will affect the spread of the
resultant anesthetic block. A patient who is left sitting for a longer period of time after
injection of hyperbaric medication will have a lower level of block than someone who is
placed supine immediately. In this study, the investigators wish to use up down sequential
analysis to determine the time period a patient should remain seated after intrathecal
injection of hyperbaric bupivacaine that will result in a 50% rate of hypotension.