Nitroprusside abolishes the deleterious effects of surface cooling-induced hypothermia on immature pigs with ventricular septal defects

J. P. Gott, S. Cox, Constantine Mavroudis

Research output: Contribution to journalArticle

Abstract

The efficacy of systemic hypothermia in combination with cardiopulmonary bypass for the repair of congenital cardiac malformations is established. Surface cooling in infants with ventricular septal defects as a prebypass adjunct has been associated with visceral ischemic complications. Surface cooling in infant pigs with ventricular septal defects results in increased systemic vascular resistance and unchanged pulmonary vascular resistance with increased left-to-right shunting and a maldistribution of blood flow away from the viscera and kidneys. This study was to determine whether nitroprusside ameliorates the deleterious effects of increased systemic vascular resistance during hypothermia in infant pigs with ventricular septal defects. Nine neonatal pigs (4 weeks, 4 kg) had experimental ventricular septal defects resulting in a 2.3 ± 0.3 : 1 shunt. Systemic and pulmonary vascular resistances were determined by the flow probe and microsphere techniques. Systemic and pulmonary blood flow distributions were measured by the microsphere technique. Left-to-right shunt ratios were determined by oximetry, flow probe, and microsphere. The pigs were cooled to 28°C and measurements were made at 37°, 32°, and 28° C. We found that nitroprusside abolishes the deleterious effects of surface cooling by blocking the rise of systemic vascular resistance without significant changes in aortic pressure. As a result, the animals maintained control pulmonary-to-systemic flow levels and maintained control levels of oxygen delivery while showing a decline in oxygen consumption. Additionally, the vasodilatory effect allowed the animals to cool twice as fast as animals without nitroprusside. Regional blood flow distribution as percent cardiac output and absolute tissue flow were protected during surface cooling. This technique may have a role in cardiac operations on infants with left-to-right shunts.

Original languageEnglish (US)
Pages (from-to)647-657
Number of pages11
JournalJournal of Thoracic and Cardiovascular Surgery
Volume93
Issue number5
StatePublished - Jan 1 1987
Externally publishedYes

Fingerprint

Induced Hypothermia
Ventricular Heart Septal Defects
Nitroprusside
Vascular Resistance
Swine
Microspheres
Hypothermia
Lung
Oximetry
Viscera
Regional Blood Flow
Cardiopulmonary Bypass
Oxygen Consumption
Cardiac Output
Arterial Pressure
Oxygen
Kidney

ASJC Scopus subject areas

  • Surgery
  • Pulmonary and Respiratory Medicine
  • Cardiology and Cardiovascular Medicine

Cite this

@article{b91d29ba632b45e4b5ad646a4873bca4,
title = "Nitroprusside abolishes the deleterious effects of surface cooling-induced hypothermia on immature pigs with ventricular septal defects",
abstract = "The efficacy of systemic hypothermia in combination with cardiopulmonary bypass for the repair of congenital cardiac malformations is established. Surface cooling in infants with ventricular septal defects as a prebypass adjunct has been associated with visceral ischemic complications. Surface cooling in infant pigs with ventricular septal defects results in increased systemic vascular resistance and unchanged pulmonary vascular resistance with increased left-to-right shunting and a maldistribution of blood flow away from the viscera and kidneys. This study was to determine whether nitroprusside ameliorates the deleterious effects of increased systemic vascular resistance during hypothermia in infant pigs with ventricular septal defects. Nine neonatal pigs (4 weeks, 4 kg) had experimental ventricular septal defects resulting in a 2.3 ± 0.3 : 1 shunt. Systemic and pulmonary vascular resistances were determined by the flow probe and microsphere techniques. Systemic and pulmonary blood flow distributions were measured by the microsphere technique. Left-to-right shunt ratios were determined by oximetry, flow probe, and microsphere. The pigs were cooled to 28°C and measurements were made at 37°, 32°, and 28° C. We found that nitroprusside abolishes the deleterious effects of surface cooling by blocking the rise of systemic vascular resistance without significant changes in aortic pressure. As a result, the animals maintained control pulmonary-to-systemic flow levels and maintained control levels of oxygen delivery while showing a decline in oxygen consumption. Additionally, the vasodilatory effect allowed the animals to cool twice as fast as animals without nitroprusside. Regional blood flow distribution as percent cardiac output and absolute tissue flow were protected during surface cooling. This technique may have a role in cardiac operations on infants with left-to-right shunts.",
author = "Gott, {J. P.} and S. Cox and Constantine Mavroudis",
year = "1987",
month = "1",
day = "1",
language = "English (US)",
volume = "93",
pages = "647--657",
journal = "Journal of Thoracic and Cardiovascular Surgery",
issn = "0022-5223",
publisher = "Mosby Inc.",
number = "5",

}

TY - JOUR

T1 - Nitroprusside abolishes the deleterious effects of surface cooling-induced hypothermia on immature pigs with ventricular septal defects

AU - Gott, J. P.

AU - Cox, S.

AU - Mavroudis, Constantine

PY - 1987/1/1

Y1 - 1987/1/1

N2 - The efficacy of systemic hypothermia in combination with cardiopulmonary bypass for the repair of congenital cardiac malformations is established. Surface cooling in infants with ventricular septal defects as a prebypass adjunct has been associated with visceral ischemic complications. Surface cooling in infant pigs with ventricular septal defects results in increased systemic vascular resistance and unchanged pulmonary vascular resistance with increased left-to-right shunting and a maldistribution of blood flow away from the viscera and kidneys. This study was to determine whether nitroprusside ameliorates the deleterious effects of increased systemic vascular resistance during hypothermia in infant pigs with ventricular septal defects. Nine neonatal pigs (4 weeks, 4 kg) had experimental ventricular septal defects resulting in a 2.3 ± 0.3 : 1 shunt. Systemic and pulmonary vascular resistances were determined by the flow probe and microsphere techniques. Systemic and pulmonary blood flow distributions were measured by the microsphere technique. Left-to-right shunt ratios were determined by oximetry, flow probe, and microsphere. The pigs were cooled to 28°C and measurements were made at 37°, 32°, and 28° C. We found that nitroprusside abolishes the deleterious effects of surface cooling by blocking the rise of systemic vascular resistance without significant changes in aortic pressure. As a result, the animals maintained control pulmonary-to-systemic flow levels and maintained control levels of oxygen delivery while showing a decline in oxygen consumption. Additionally, the vasodilatory effect allowed the animals to cool twice as fast as animals without nitroprusside. Regional blood flow distribution as percent cardiac output and absolute tissue flow were protected during surface cooling. This technique may have a role in cardiac operations on infants with left-to-right shunts.

AB - The efficacy of systemic hypothermia in combination with cardiopulmonary bypass for the repair of congenital cardiac malformations is established. Surface cooling in infants with ventricular septal defects as a prebypass adjunct has been associated with visceral ischemic complications. Surface cooling in infant pigs with ventricular septal defects results in increased systemic vascular resistance and unchanged pulmonary vascular resistance with increased left-to-right shunting and a maldistribution of blood flow away from the viscera and kidneys. This study was to determine whether nitroprusside ameliorates the deleterious effects of increased systemic vascular resistance during hypothermia in infant pigs with ventricular septal defects. Nine neonatal pigs (4 weeks, 4 kg) had experimental ventricular septal defects resulting in a 2.3 ± 0.3 : 1 shunt. Systemic and pulmonary vascular resistances were determined by the flow probe and microsphere techniques. Systemic and pulmonary blood flow distributions were measured by the microsphere technique. Left-to-right shunt ratios were determined by oximetry, flow probe, and microsphere. The pigs were cooled to 28°C and measurements were made at 37°, 32°, and 28° C. We found that nitroprusside abolishes the deleterious effects of surface cooling by blocking the rise of systemic vascular resistance without significant changes in aortic pressure. As a result, the animals maintained control pulmonary-to-systemic flow levels and maintained control levels of oxygen delivery while showing a decline in oxygen consumption. Additionally, the vasodilatory effect allowed the animals to cool twice as fast as animals without nitroprusside. Regional blood flow distribution as percent cardiac output and absolute tissue flow were protected during surface cooling. This technique may have a role in cardiac operations on infants with left-to-right shunts.

UR - http://www.scopus.com/inward/record.url?scp=0023176324&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0023176324&partnerID=8YFLogxK

M3 - Article

VL - 93

SP - 647

EP - 657

JO - Journal of Thoracic and Cardiovascular Surgery

JF - Journal of Thoracic and Cardiovascular Surgery

SN - 0022-5223

IS - 5

ER -