2004 Annual Report - Department of Anesthesiology - Duke University

21 • CLINICAL SERVICES, Center for Hyperbaric Medicine and Environmental Physiology
lation of nitroxidergic nerves in the brain and brainstem
that generate adverse effects on pulmonary airway and vascular
function in vivo.
Effects of Exercise, Gas Density, and Static Lung
Loads on End Tidal-Arterial PCO2 Differences
Breathing N2-O2 Mixtures during Immersed Prone
Exercise (Drs. Moon, Pollock, Freiberger, Stolp)
During heavy exercise underwater hypercapnia can
occur due to the combined effects of high breathing resistance,
nitrogen narcosis, static lung load and high inspired
PO2 . Ideally, PCO2 is measured in arterial blood (PaCO2 ).
However, in practice end tidal CO2 (PETCO2 ) is generally
used as an estimate of PaCO2 . During diving, PETCO2 may over or underestimate the PaCO2 depending on the
depth, inspired PO2 , static lung load, and exercise level.
This study will measure PaCO2 and PETCO2 simultaneously
during exercise at 1 ATA dry and immersed at 120
fsw. The effect of static lung loads (-10, 0, +10 cmH2O), inspired PO2 (0.7-1.3 ATA) high flow resistances and
heavy exercise will be conducted in volunteers instrumented
with arterial and pulmonary artery catheters. A method
of determining PaCO2 from PETCO2 , taking into account
the various breathing environment parameters will be
devised.
Utilization of a Deep Stop to Prevent Neurological
Decompression Sickness in Scuba Divers
(Drs. Bennett and Marroni)
In spite of many modifications to decompression schedules,
the incidence of neurological (Type II) decompression
sickness has remained the same. Our hypothesis was
that by combining a deep stop at half the depth of dive with
the standard safety stop at 15-20 ft, such decompression
sickness can be avoided. Using 22 volunteer Italian scuba
divers, this was tested with a matrix of dives with no stop,
shallow stop and deep and shallow stop. Doppler measurements
and computer calculated tissue gas tensions showed
a significant reduction of Doppler bubbles together with
the fast 5- and 10-min tissues compatible with the spinal
cord tissue half time of 12.5 min. We are presently testing
deep-to-shallow dives with the introduction of a deep stop.
CLINICAL RESEARCH
The Effect of Hyperbaric Hyperoxia on Glycemic Control
and Vascular Reactivity in Type 2 Diabetes
DIVISION PUBLICATIONS
Allen BA, Piantadosi CA: How do red blood cells dilate
blood vessels? [Letter to the editor] Circ Res 2004;
94:e105
Bennett PB: Inert gas narcosis and high pressure nervous
syndrome, Diving Medicine. Edited by Bove AA,
Philadelphia, WB Saunders, 2004, pp 225-239.
Conkin J, Gernhardt ML, Powell MR, Pollock NW: A probability
model of decompression sickness at 4.3 psia after
exercise prebreathe, National Aeronautics and
Atmospheric Administration Technical Publication,
NASA/TP-2004-213158, 2004.
Cronje FJ, Carraway MS, Freiberger JJ, Suliman HB,
Piantadosi CA: Carbon monoxide actuates O 2 -limited
heme degradation in the rat brain. Free Radical Biol & Med
2004; 37:1802-12
Dear G de L, Pollock NW, Uguccioni DM, Dovenbarger J,
Feinglos MN, Moon RE: Plasma glucose responses in recreational
divers with insulin-requiring diabetes. Undersea
Hyperb Med 2004; 31:291-301
Freiberger J, Coulombe KA, Suliman HB, Carraway MS,
Piantadosi CA: Superoxide dismutase responds to hyperoxia
in rat hippocampus. Undersea Hyperb Med 2004;
31:227-232
Freiberger J, Lyman S, Denoble PJ, Pieper CF, Vann RD:
Consensus factors used by experts in the diagnosis of
decompression illness. Aviat Space Environ Med
2004;75:1023-1028
Kotani M, Kotani T, Li Z, Silbajoris R, Piantadosi CA,
Huang Y-C: Reduced inspiratory flow attenuates IL-8
release and MAPK activation of lung over-stretch. Eur
Respir J 2004; 24:238-246
Mamo LB, Suliman HB, Giles BL, Auten RL, Piantadosi
CA, Nozik-Grayck E: Discordant extracellular superoxide
dismutase expression and activity in neonatal hyperoxic
lung. Am J Respir Crit Care Med 2004; 170:313-318
Marroni A, Bennett PB, Cronje, FJ, Cali Corleo R,
Germonpre P, Pieri M, Bonuccelli C, Balestra C: A deep
stop during decompression from 82 fsw (25 m) significantly
reduces bubbles and fast tissue gas tensions. Undersea
Hyperb Med 2004; 31:233-243
Moon RE: Treatment of decompression sickness and arterial
gas embolism, Diving Medicine. Edited by Bove AA,
Philadelphia, WB Saunders, 2004, pp 195-223.
Moon RE, Bove AA: Transcatheter occlusion of patent foramen
ovale: A prevention for decompression illness?
[Editorial]. Undersea Hyperb Med 2004; 31:271-274
Moon RE, Camporesi EM: Clinical care in altered environments:
At high and low pressure and in space, Anesthesia,
6th edition. Edited by Miller R, Philadelphia, Churchill
Livingstone, 2004, pp 2665-2701
DEPARTMENT OF ANESTHESIOLOGY • 2004 ANNUAL REPORT • DUKE UNIVERSITY MEDICAL CENTER