Search PubMed⌕ Search

Biomedical subjects

D R Gerstmann

Publications and source records attributed to D R Gerstmann.

42 records · Page 3Linked to original sources
PubMed1987

Acute hemorrhagic hypotension and its effect on the pulmonary clearance of helium instilled into the rabbit colon.

The study investigates the effect of acute and incremental posthemorrhagic hypotension on pulmonary clearance of helium (CHe) introduced into the colon. Eighteen New Zealand White rabbits were cannulated and connected to a respirator at constant minute ventilation. A helium mass spectrometer was used to monitor airway gas. After 30 min stabilization, 10 ml/kg of helium were injected rectally while CHe and mean aortic blood pressure (BPm) were continuously monitored. Control animals (group 1, n = 5) achieved constant CHe (0.8-3.0 microliter/kg/min) by 20 min, with CHe and BPm continuing unchanged over a 90-min period. Group 2 animals (n = 5) underwent acute blood loss of 12 ml/kg with reinfusion after 30 min. Group 3 animals (n = 8) underwent incremental blood loss of 4 ml/kg up to a maximum of 28 ml/kg without reinfusion. Two animals in group 3 had electromagnetic flow probes placed around their distal abdominal aortae. At 12 ml/kg blood loss, group 2 and 3 animals experienced falls in BPm of 46 and 58% along with simultaneous falls in CHe of 33 and 53%, respectively. These changes were statistically significant (p less than 0.05). Reinfusion (group 2) caused initial parallel increases in CHe and BPm. However, CHe remained elevated as BPm returned to baseline, a finding consistent with colonic reperfusion hyperemia. At blood loss of more then 12 ml/kg (group 3), BPm and electromagnetic flow stabilized while CHe continued to decrease. Under these conditions CHe appeared to reflect shunting of intestinal blood flow away from the mesenteric bed.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Pulmonary interstitial emphysema treated by high-frequency oscillatory ventilation.

Twenty-seven low birth weight infants who developed pulmonary interstitial emphysema (PIE) and respiratory failure while on conventional ventilation were treated with high-frequency oscillatory ventilation (HFOV). The mean birth weight was 1.2 kg (range 0.55 to 2) with gestational age of 28 wk (range 25 to 34). Ten patients died, six of whom had documented sepsis with shock and were therefore excluded from analysis. All patients showed initial improvement on HFOV. Surviving patients showed continued improvement in oxygenation and ventilation at increasingly lower fraction of inspired oxygen and proximal airway pressure with resolution of PIE, while nonsurvivors progressively developed chronic respiratory insufficiency with continued PIE from which recovery was not possible. Overall survival in nonseptic patients was 80% (16 of 20). We found HFOV to be effective in the treatment of PIE and hypothesize that interstitial airleak is decreased during HFOV because adequate ventilation is provided at lower peak distal airway pressures.

Critical Care↗
PubMed1985

A noninvasive method for monitoring intestinal ischemia: changes in the pulmonary clearance of helium instilled into the colon as an index of colonic blood flow.

To evaluate the concept that changes in colonic blood flow will predictably alter the absorption of colonic gas, we measured the pulmonary clearance rate of helium (CHe) which was instilled rectally into the colon of rabbits at a dose of 2 ml/kg. CHE reached a plateau after 20 min at 109 nmol/min/kg. Using hypoxemia as a cause for bowel ischemia, at PAO2 = 38 torr, we noted a marked decreased in CHe from 110 nmol/min/kg to 75 nmol/min/kg (p less than 0.025). Because helium absorption from the colon is diffusion limited, a model can be developed relating "subvillus" colonic blood flow to pulmonary helium clearance. From this model we would predict the hypoxemia induced change in CHe to be secondary to colonic hypoperfusion. This type of indirect monitoring could be useful in detecting patients with bowel ischemia.

Animals↗
PubMedDate not supplied

Extracorporeal membrane oxygenation as a means of stabilizing and transporting high risk neonates.

Term or near term newborns whose severity of cardiac or respiratory failure makes them candidates for extracorporeal membrane oxygenation (ECMO) are often too unstable to be safely transported to an ECMO-competent center. Faced with a large military and civilian referral population that is distributed across the entire continental United States, the authors have addressed this dilemma by developing a transportable ECMO system that can be taken to the referring hospital in a small transport aircraft. This system was on hand, but was not required, to stabilize and transport the infant in question in four cases. All had uneventful transports. Thirteen infants were placed on ECMO at their referring hospitals, one of whom died shortly after the institution of bypass. The remaining 12 infants were stabilized and transported successfully on ECMO over distances ranging from 17 to 1,437 miles, with 11 of these being long distance air transports. Four patients are long-term survivors. The authors conclude that a properly configured and managed ECMO system can effectively stabilize and transport even extremely ill neonates if the pertinent physiologic and aeromedical considerations are addressed.

Aerospace Medicine↗
PubMedDate not supplied

High frequency ventilation--the relationship between ventilator design and clinical strategy in the treatment of hyaline membrane disease and its complications: a brief review.

Progress in the application of techniques of HFV to clinical settings has been hampered by a lack of comparative data. Ventilator design and/or strategy place clear limitations on the effective and safe use of these devices. There is a definite need to develop clear therapeutic goals for HFV, to define the operating characteristics and limitations of each device, and to develop effective and safe strategies for their use in various clinical settings. Only then can adequate controlled clinical trials be performed and the role of these techniques be firmly established.

Cardiac Output↗