Sodium nitroprusside infusion does not dilate cerebral resistance vessels during hypothermic cardiopulmonary bypass

A. T. Rogers, Donald Prough, G. P. Gravlee, R. C. Roy, S. A. Mills, D. A. Stump, J. Phipps, R. L. Royster, C. L. Taylor

Research output: Contribution to journalArticle

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Abstract

This study determined whether sodium nitroprusside (SNP) changes cerebral vascular resistance during stable, hypothermic cardiopulmonary bypass (CPB). Cerebral blood flow (CBF) was measured using Xenon clearance in 39 patients anesthetized with fentanyl. In 25 patients (group 1), CBF was measured before and during infusion of SNP at a rate sufficient to reduce mean arterial pressure (MAP) ~ 20%. In 14 other patients (group 2), CBF was measured before and during simultaneous infusion of SNP and phenylephrine; SNP was continued at a rate that had reduced MAP ~20% while phenylephrine was added in a dose sufficient to restore MAP to preinfusion levels. Patients within each group were randomized to maintenance of Pa(CO2) ~ 40 mmHg (groups 1a and 2a), uncorrected for body temperature, or to maintenance of Pa(CO2) ~ 50 mmHg (groups 1b and 2b). The following variables were maintained within a narrow range: nasopharyngeal temperature (26-29° C), pump oxygenator flow (1.7-2.5 1·min-1·m-2), Pa(O2) (150-300 mmHg), and Hct (22-28 vol%). In each patient, controlled variables varied no more than ±5% between measurements. In group 1a (Pa(CO2) ~ 40 mmHg), MAP was 86 ± 9 mmHg (mean ± SD) before and 65 ± 8 mmHg during SNP infusion (P < 0.0001). CBF was 12 ±3 ml·100 g-1·min-1 before and 10 ± 2 ml·100-1·min-1 during SNP infusion (P < 0.01). In group 1b (Pa(CO2) ~ 55 mmHg), MAP was 86 ± 11 mmHg before and 66 ± 13 mmHg during SNP infusion (P < 0.0001). CBF changed from 22 ± 10 to 16 ± 6 ml·100 g-1·min-1 (P < 0.05). In group 2a (Pa(CO2) ~ 40 mmHg), MAP was 71 ± 10 mmHg before and 73 ± 9 mmHg during the combined SNP-phenylephrine infusion (P = not significant). CBF was 12 ± 2 ml·100 g-1·min-1 before and 10 ± 1 ml·100 g-1·min-1 during the combined infusion (P < 0.05). In group 2b (Pa(CO2) ~ 50 mmHg), MAP was 74 ± 8 mmHg before and 71 ± 4 mmHg during the combined infusion (P = ns). CBF was 18 ± 5 ml·100 g-1·min-1 before and 15 ± 5 ml·100 g-1·min-1 during the combined infusion (P < 0.01). The decrease in CBF was statistically similar in each group and was comparable to that previously reported to occur as a function of the duration of stable hypothermic CPB. Restoration of MAP by phenylephrine during continued SNP infusion did not result in either a relative or absolute CBF increase. During nonpulsatile, hypothermic CPB, SNP does not produce primary cerebral vasodilation in humans anesthetized with fentanyl.

Original languageEnglish (US)
Pages (from-to)820-826
Number of pages7
JournalAnesthesiology
Volume74
Issue number5
StatePublished - 1991
Externally publishedYes

Fingerprint

Cerebrovascular Circulation
Nitroprusside
Cardiopulmonary Bypass
Arterial Pressure
Phenylephrine
Fentanyl
Maintenance
Oxygenators
Xenon
Body Temperature
Vasodilation
Vascular Resistance

Keywords

  • Alpha-adrenergic agonists: phenylephrine
  • Anesthesia: cardiovascular
  • Anesthetic techniques: deliberate hypotension
  • Brain: cerebral blood flow
  • Cardiopulmonary bypass
  • Cerebral oxygen consumption
  • Hypothermia: induced
  • Pharmacology: nitroprusside
  • Surgery: cardiac
  • Sympathetic nervous system

ASJC Scopus subject areas

  • Anesthesiology and Pain Medicine

Cite this

Rogers, A. T., Prough, D., Gravlee, G. P., Roy, R. C., Mills, S. A., Stump, D. A., ... Taylor, C. L. (1991). Sodium nitroprusside infusion does not dilate cerebral resistance vessels during hypothermic cardiopulmonary bypass. Anesthesiology, 74(5), 820-826.

Sodium nitroprusside infusion does not dilate cerebral resistance vessels during hypothermic cardiopulmonary bypass. / Rogers, A. T.; Prough, Donald; Gravlee, G. P.; Roy, R. C.; Mills, S. A.; Stump, D. A.; Phipps, J.; Royster, R. L.; Taylor, C. L.

In: Anesthesiology, Vol. 74, No. 5, 1991, p. 820-826.

Research output: Contribution to journalArticle

Rogers, AT, Prough, D, Gravlee, GP, Roy, RC, Mills, SA, Stump, DA, Phipps, J, Royster, RL & Taylor, CL 1991, 'Sodium nitroprusside infusion does not dilate cerebral resistance vessels during hypothermic cardiopulmonary bypass', Anesthesiology, vol. 74, no. 5, pp. 820-826.
Rogers, A. T. ; Prough, Donald ; Gravlee, G. P. ; Roy, R. C. ; Mills, S. A. ; Stump, D. A. ; Phipps, J. ; Royster, R. L. ; Taylor, C. L. / Sodium nitroprusside infusion does not dilate cerebral resistance vessels during hypothermic cardiopulmonary bypass. In: Anesthesiology. 1991 ; Vol. 74, No. 5. pp. 820-826.
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abstract = "This study determined whether sodium nitroprusside (SNP) changes cerebral vascular resistance during stable, hypothermic cardiopulmonary bypass (CPB). Cerebral blood flow (CBF) was measured using Xenon clearance in 39 patients anesthetized with fentanyl. In 25 patients (group 1), CBF was measured before and during infusion of SNP at a rate sufficient to reduce mean arterial pressure (MAP) ~ 20{\%}. In 14 other patients (group 2), CBF was measured before and during simultaneous infusion of SNP and phenylephrine; SNP was continued at a rate that had reduced MAP ~20{\%} while phenylephrine was added in a dose sufficient to restore MAP to preinfusion levels. Patients within each group were randomized to maintenance of Pa(CO2) ~ 40 mmHg (groups 1a and 2a), uncorrected for body temperature, or to maintenance of Pa(CO2) ~ 50 mmHg (groups 1b and 2b). The following variables were maintained within a narrow range: nasopharyngeal temperature (26-29° C), pump oxygenator flow (1.7-2.5 1·min-1·m-2), Pa(O2) (150-300 mmHg), and Hct (22-28 vol{\%}). In each patient, controlled variables varied no more than ±5{\%} between measurements. In group 1a (Pa(CO2) ~ 40 mmHg), MAP was 86 ± 9 mmHg (mean ± SD) before and 65 ± 8 mmHg during SNP infusion (P < 0.0001). CBF was 12 ±3 ml·100 g-1·min-1 before and 10 ± 2 ml·100-1·min-1 during SNP infusion (P < 0.01). In group 1b (Pa(CO2) ~ 55 mmHg), MAP was 86 ± 11 mmHg before and 66 ± 13 mmHg during SNP infusion (P < 0.0001). CBF changed from 22 ± 10 to 16 ± 6 ml·100 g-1·min-1 (P < 0.05). In group 2a (Pa(CO2) ~ 40 mmHg), MAP was 71 ± 10 mmHg before and 73 ± 9 mmHg during the combined SNP-phenylephrine infusion (P = not significant). CBF was 12 ± 2 ml·100 g-1·min-1 before and 10 ± 1 ml·100 g-1·min-1 during the combined infusion (P < 0.05). In group 2b (Pa(CO2) ~ 50 mmHg), MAP was 74 ± 8 mmHg before and 71 ± 4 mmHg during the combined infusion (P = ns). CBF was 18 ± 5 ml·100 g-1·min-1 before and 15 ± 5 ml·100 g-1·min-1 during the combined infusion (P < 0.01). The decrease in CBF was statistically similar in each group and was comparable to that previously reported to occur as a function of the duration of stable hypothermic CPB. Restoration of MAP by phenylephrine during continued SNP infusion did not result in either a relative or absolute CBF increase. During nonpulsatile, hypothermic CPB, SNP does not produce primary cerebral vasodilation in humans anesthetized with fentanyl.",
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author = "Rogers, {A. T.} and Donald Prough and Gravlee, {G. P.} and Roy, {R. C.} and Mills, {S. A.} and Stump, {D. A.} and J. Phipps and Royster, {R. L.} and Taylor, {C. L.}",
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TY - JOUR

T1 - Sodium nitroprusside infusion does not dilate cerebral resistance vessels during hypothermic cardiopulmonary bypass

AU - Rogers, A. T.

AU - Prough, Donald

AU - Gravlee, G. P.

AU - Roy, R. C.

AU - Mills, S. A.

AU - Stump, D. A.

AU - Phipps, J.

AU - Royster, R. L.

AU - Taylor, C. L.

PY - 1991

Y1 - 1991

N2 - This study determined whether sodium nitroprusside (SNP) changes cerebral vascular resistance during stable, hypothermic cardiopulmonary bypass (CPB). Cerebral blood flow (CBF) was measured using Xenon clearance in 39 patients anesthetized with fentanyl. In 25 patients (group 1), CBF was measured before and during infusion of SNP at a rate sufficient to reduce mean arterial pressure (MAP) ~ 20%. In 14 other patients (group 2), CBF was measured before and during simultaneous infusion of SNP and phenylephrine; SNP was continued at a rate that had reduced MAP ~20% while phenylephrine was added in a dose sufficient to restore MAP to preinfusion levels. Patients within each group were randomized to maintenance of Pa(CO2) ~ 40 mmHg (groups 1a and 2a), uncorrected for body temperature, or to maintenance of Pa(CO2) ~ 50 mmHg (groups 1b and 2b). The following variables were maintained within a narrow range: nasopharyngeal temperature (26-29° C), pump oxygenator flow (1.7-2.5 1·min-1·m-2), Pa(O2) (150-300 mmHg), and Hct (22-28 vol%). In each patient, controlled variables varied no more than ±5% between measurements. In group 1a (Pa(CO2) ~ 40 mmHg), MAP was 86 ± 9 mmHg (mean ± SD) before and 65 ± 8 mmHg during SNP infusion (P < 0.0001). CBF was 12 ±3 ml·100 g-1·min-1 before and 10 ± 2 ml·100-1·min-1 during SNP infusion (P < 0.01). In group 1b (Pa(CO2) ~ 55 mmHg), MAP was 86 ± 11 mmHg before and 66 ± 13 mmHg during SNP infusion (P < 0.0001). CBF changed from 22 ± 10 to 16 ± 6 ml·100 g-1·min-1 (P < 0.05). In group 2a (Pa(CO2) ~ 40 mmHg), MAP was 71 ± 10 mmHg before and 73 ± 9 mmHg during the combined SNP-phenylephrine infusion (P = not significant). CBF was 12 ± 2 ml·100 g-1·min-1 before and 10 ± 1 ml·100 g-1·min-1 during the combined infusion (P < 0.05). In group 2b (Pa(CO2) ~ 50 mmHg), MAP was 74 ± 8 mmHg before and 71 ± 4 mmHg during the combined infusion (P = ns). CBF was 18 ± 5 ml·100 g-1·min-1 before and 15 ± 5 ml·100 g-1·min-1 during the combined infusion (P < 0.01). The decrease in CBF was statistically similar in each group and was comparable to that previously reported to occur as a function of the duration of stable hypothermic CPB. Restoration of MAP by phenylephrine during continued SNP infusion did not result in either a relative or absolute CBF increase. During nonpulsatile, hypothermic CPB, SNP does not produce primary cerebral vasodilation in humans anesthetized with fentanyl.

AB - This study determined whether sodium nitroprusside (SNP) changes cerebral vascular resistance during stable, hypothermic cardiopulmonary bypass (CPB). Cerebral blood flow (CBF) was measured using Xenon clearance in 39 patients anesthetized with fentanyl. In 25 patients (group 1), CBF was measured before and during infusion of SNP at a rate sufficient to reduce mean arterial pressure (MAP) ~ 20%. In 14 other patients (group 2), CBF was measured before and during simultaneous infusion of SNP and phenylephrine; SNP was continued at a rate that had reduced MAP ~20% while phenylephrine was added in a dose sufficient to restore MAP to preinfusion levels. Patients within each group were randomized to maintenance of Pa(CO2) ~ 40 mmHg (groups 1a and 2a), uncorrected for body temperature, or to maintenance of Pa(CO2) ~ 50 mmHg (groups 1b and 2b). The following variables were maintained within a narrow range: nasopharyngeal temperature (26-29° C), pump oxygenator flow (1.7-2.5 1·min-1·m-2), Pa(O2) (150-300 mmHg), and Hct (22-28 vol%). In each patient, controlled variables varied no more than ±5% between measurements. In group 1a (Pa(CO2) ~ 40 mmHg), MAP was 86 ± 9 mmHg (mean ± SD) before and 65 ± 8 mmHg during SNP infusion (P < 0.0001). CBF was 12 ±3 ml·100 g-1·min-1 before and 10 ± 2 ml·100-1·min-1 during SNP infusion (P < 0.01). In group 1b (Pa(CO2) ~ 55 mmHg), MAP was 86 ± 11 mmHg before and 66 ± 13 mmHg during SNP infusion (P < 0.0001). CBF changed from 22 ± 10 to 16 ± 6 ml·100 g-1·min-1 (P < 0.05). In group 2a (Pa(CO2) ~ 40 mmHg), MAP was 71 ± 10 mmHg before and 73 ± 9 mmHg during the combined SNP-phenylephrine infusion (P = not significant). CBF was 12 ± 2 ml·100 g-1·min-1 before and 10 ± 1 ml·100 g-1·min-1 during the combined infusion (P < 0.05). In group 2b (Pa(CO2) ~ 50 mmHg), MAP was 74 ± 8 mmHg before and 71 ± 4 mmHg during the combined infusion (P = ns). CBF was 18 ± 5 ml·100 g-1·min-1 before and 15 ± 5 ml·100 g-1·min-1 during the combined infusion (P < 0.01). The decrease in CBF was statistically similar in each group and was comparable to that previously reported to occur as a function of the duration of stable hypothermic CPB. Restoration of MAP by phenylephrine during continued SNP infusion did not result in either a relative or absolute CBF increase. During nonpulsatile, hypothermic CPB, SNP does not produce primary cerebral vasodilation in humans anesthetized with fentanyl.

KW - Alpha-adrenergic agonists: phenylephrine

KW - Anesthesia: cardiovascular

KW - Anesthetic techniques: deliberate hypotension

KW - Brain: cerebral blood flow

KW - Cardiopulmonary bypass

KW - Cerebral oxygen consumption

KW - Hypothermia: induced

KW - Pharmacology: nitroprusside

KW - Surgery: cardiac

KW - Sympathetic nervous system

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