Correction of blood pH attenuates changes in hemodynamics and organ blood flow during permissive hypercapnia

Victor J. Cardenas, Joseph B. Zwischenberger, Weike Tao, Phuong Dung J Nguyen, Tyrus Schroeder, Lillian D. Traber, Daniel L. Traber, Akhil Bidani

Research output: Contribution to journalArticle

72 Citations (Scopus)

Abstract

Objectives: To determine whether changes in cardiac output, regional blood flow, and intracranial pressure during permissive hypercapnia are blood pH- dependent and can be attenuated by correction of intravascular acidemia. Design: Prospective, controlled study. Setting: Research laboratory. Subjects: Female Marino ewes. Interventions: Animals were instrumented with a pulmonary artery catheter, femoral arterial and venous catheters, a catheter in the third cerebral ventricle, and ultrasonic flow probes on the left carotid, superior mesenteric, and left renal arteries 1 wk before experimentation. At initiation of the protocol, ewes underwent endotracheal intubation and mechanical ventilation under general anesthesia. Minute ventilation was reduced to induce hypercapnia with a target PaCO2 of 80 torr (10.7 kPa). In the pH-uncorrected group (n = 6), arterial blood pH was allowed to decreased without treatment. In the pH-corrected group (n = 5), 14.4 mEq/kg of sodium bicarbonate was given intravenously as a bolus to correct arterial blood pH toward a target arterial pH of 7.40 (dose calculated by the Henderson-Hasselbalch equation). Measurements and Main Results: Arterial blood pH, PCO2, cardiac output, intracranial pressure, end carotid, superior mesenteric, and renal artery blood flow rates were measured at normocapnic baseline and at every hour during hypercapnia for 6 hrs. In the pH-uncorrected group, arterial blood pH decreased from 7.41 ± 0.03 at normocapnia to 7.14 ± 0.01 (p < .01 vs. normocapnia) as blood PCO2 increased to 01.2 ± 1.8 torr (10.8 ± 0.2 kPa). In the pH-corrected group, arterial blood pH was 7.42 ± 0.02 at normocapnia and was maintained at 7.37 ± 0.01 while PaCO2 was increased to 50.3 ± 0.9 torr (10.7 ± 0.1 kPa). Significant increases in cardiac output occurred with the initiation of hypercapnia for both groups (pH-uncorrected group: 4.3 ± 0.6 L/min at normocapnia va. 6.8 ± 1.0 L/min at 1 hr [p < .05]; pH-corrected group: 4.1 ± 0.4 at normocapnia vs. 5.7 ± 0.4 L/min at 1 hr [p < .05]). However, this increase was sustained only in the uncorrected group. Changes in carotid and mesenteric artery blood flow rates, as a percent of baseline values, showed sustained significant increases in the pH-uncorrected groups (p < .05) and only transient (carotid at 1 hr) or no (superior mesenteric) significant change in the pH-corrected groups. Conversely, significant increases in renal artery blood flow were seen only in the pH-uncorrected group during the last 2 hrs of the experiment (p < .05). Organ blood flow, as a percent of cardiac output, did not change significantly in either group. Intracranial pressure increased significantly in the pH-uncorrected group (9.0 ± 1.5 mm Hg at normocapnia va. 26.8 ± 5.1 st 1 hr, p < .05), and remained increased, while showing no significant change in the pH-corrected group (8.5 ± 1.6 mm Hg at normocapnia to 7.7 ± 4.2 st 1 hr). Conclusions: Acute hypercapnia, induced within 1 hr, is associated with significant increases in cardiac output, organ blood flow, and intracranial pressure. These changes can be significantly attenuated by correction of blood pH with the administration of sodium bicarbonate, without adverse effects on hemodynamics.

Original languageEnglish (US)
Pages (from-to)827-834
Number of pages8
JournalCritical Care Medicine
Volume24
Issue number5
DOIs
StatePublished - May 1996

Fingerprint

Hypercapnia
Hemodynamics
Cardiac Output
Intracranial Pressure
Renal Artery
Sodium Bicarbonate
Catheters
Renal Circulation
Blood Pressure
Cerebral Ventricles
Third Ventricle
Mesenteric Arteries
Superior Mesenteric Artery
Intratracheal Intubation

Keywords

  • acidosis, respiratory
  • acute respiratory failure
  • adult respiratory distress syndrome
  • bicarbonate
  • critical illness
  • hemodynamics
  • hypercapnia
  • mechanical ventilation
  • pH

ASJC Scopus subject areas

  • Critical Care and Intensive Care Medicine

Cite this

Cardenas, V. J., Zwischenberger, J. B., Tao, W., Nguyen, P. D. J., Schroeder, T., Traber, L. D., ... Bidani, A. (1996). Correction of blood pH attenuates changes in hemodynamics and organ blood flow during permissive hypercapnia. Critical Care Medicine, 24(5), 827-834. https://doi.org/10.1097/00003246-199605000-00017

Correction of blood pH attenuates changes in hemodynamics and organ blood flow during permissive hypercapnia. / Cardenas, Victor J.; Zwischenberger, Joseph B.; Tao, Weike; Nguyen, Phuong Dung J; Schroeder, Tyrus; Traber, Lillian D.; Traber, Daniel L.; Bidani, Akhil.

In: Critical Care Medicine, Vol. 24, No. 5, 05.1996, p. 827-834.

Research output: Contribution to journalArticle

Cardenas, VJ, Zwischenberger, JB, Tao, W, Nguyen, PDJ, Schroeder, T, Traber, LD, Traber, DL & Bidani, A 1996, 'Correction of blood pH attenuates changes in hemodynamics and organ blood flow during permissive hypercapnia', Critical Care Medicine, vol. 24, no. 5, pp. 827-834. https://doi.org/10.1097/00003246-199605000-00017
Cardenas, Victor J. ; Zwischenberger, Joseph B. ; Tao, Weike ; Nguyen, Phuong Dung J ; Schroeder, Tyrus ; Traber, Lillian D. ; Traber, Daniel L. ; Bidani, Akhil. / Correction of blood pH attenuates changes in hemodynamics and organ blood flow during permissive hypercapnia. In: Critical Care Medicine. 1996 ; Vol. 24, No. 5. pp. 827-834.
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title = "Correction of blood pH attenuates changes in hemodynamics and organ blood flow during permissive hypercapnia",
abstract = "Objectives: To determine whether changes in cardiac output, regional blood flow, and intracranial pressure during permissive hypercapnia are blood pH- dependent and can be attenuated by correction of intravascular acidemia. Design: Prospective, controlled study. Setting: Research laboratory. Subjects: Female Marino ewes. Interventions: Animals were instrumented with a pulmonary artery catheter, femoral arterial and venous catheters, a catheter in the third cerebral ventricle, and ultrasonic flow probes on the left carotid, superior mesenteric, and left renal arteries 1 wk before experimentation. At initiation of the protocol, ewes underwent endotracheal intubation and mechanical ventilation under general anesthesia. Minute ventilation was reduced to induce hypercapnia with a target PaCO2 of 80 torr (10.7 kPa). In the pH-uncorrected group (n = 6), arterial blood pH was allowed to decreased without treatment. In the pH-corrected group (n = 5), 14.4 mEq/kg of sodium bicarbonate was given intravenously as a bolus to correct arterial blood pH toward a target arterial pH of 7.40 (dose calculated by the Henderson-Hasselbalch equation). Measurements and Main Results: Arterial blood pH, PCO2, cardiac output, intracranial pressure, end carotid, superior mesenteric, and renal artery blood flow rates were measured at normocapnic baseline and at every hour during hypercapnia for 6 hrs. In the pH-uncorrected group, arterial blood pH decreased from 7.41 ± 0.03 at normocapnia to 7.14 ± 0.01 (p < .01 vs. normocapnia) as blood PCO2 increased to 01.2 ± 1.8 torr (10.8 ± 0.2 kPa). In the pH-corrected group, arterial blood pH was 7.42 ± 0.02 at normocapnia and was maintained at 7.37 ± 0.01 while PaCO2 was increased to 50.3 ± 0.9 torr (10.7 ± 0.1 kPa). Significant increases in cardiac output occurred with the initiation of hypercapnia for both groups (pH-uncorrected group: 4.3 ± 0.6 L/min at normocapnia va. 6.8 ± 1.0 L/min at 1 hr [p < .05]; pH-corrected group: 4.1 ± 0.4 at normocapnia vs. 5.7 ± 0.4 L/min at 1 hr [p < .05]). However, this increase was sustained only in the uncorrected group. Changes in carotid and mesenteric artery blood flow rates, as a percent of baseline values, showed sustained significant increases in the pH-uncorrected groups (p < .05) and only transient (carotid at 1 hr) or no (superior mesenteric) significant change in the pH-corrected groups. Conversely, significant increases in renal artery blood flow were seen only in the pH-uncorrected group during the last 2 hrs of the experiment (p < .05). Organ blood flow, as a percent of cardiac output, did not change significantly in either group. Intracranial pressure increased significantly in the pH-uncorrected group (9.0 ± 1.5 mm Hg at normocapnia va. 26.8 ± 5.1 st 1 hr, p < .05), and remained increased, while showing no significant change in the pH-corrected group (8.5 ± 1.6 mm Hg at normocapnia to 7.7 ± 4.2 st 1 hr). Conclusions: Acute hypercapnia, induced within 1 hr, is associated with significant increases in cardiac output, organ blood flow, and intracranial pressure. These changes can be significantly attenuated by correction of blood pH with the administration of sodium bicarbonate, without adverse effects on hemodynamics.",
keywords = "acidosis, respiratory, acute respiratory failure, adult respiratory distress syndrome, bicarbonate, critical illness, hemodynamics, hypercapnia, mechanical ventilation, pH",
author = "Cardenas, {Victor J.} and Zwischenberger, {Joseph B.} and Weike Tao and Nguyen, {Phuong Dung J} and Tyrus Schroeder and Traber, {Lillian D.} and Traber, {Daniel L.} and Akhil Bidani",
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doi = "10.1097/00003246-199605000-00017",
language = "English (US)",
volume = "24",
pages = "827--834",
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issn = "0090-3493",
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TY - JOUR

T1 - Correction of blood pH attenuates changes in hemodynamics and organ blood flow during permissive hypercapnia

AU - Cardenas, Victor J.

AU - Zwischenberger, Joseph B.

AU - Tao, Weike

AU - Nguyen, Phuong Dung J

AU - Schroeder, Tyrus

AU - Traber, Lillian D.

AU - Traber, Daniel L.

AU - Bidani, Akhil

PY - 1996/5

Y1 - 1996/5

N2 - Objectives: To determine whether changes in cardiac output, regional blood flow, and intracranial pressure during permissive hypercapnia are blood pH- dependent and can be attenuated by correction of intravascular acidemia. Design: Prospective, controlled study. Setting: Research laboratory. Subjects: Female Marino ewes. Interventions: Animals were instrumented with a pulmonary artery catheter, femoral arterial and venous catheters, a catheter in the third cerebral ventricle, and ultrasonic flow probes on the left carotid, superior mesenteric, and left renal arteries 1 wk before experimentation. At initiation of the protocol, ewes underwent endotracheal intubation and mechanical ventilation under general anesthesia. Minute ventilation was reduced to induce hypercapnia with a target PaCO2 of 80 torr (10.7 kPa). In the pH-uncorrected group (n = 6), arterial blood pH was allowed to decreased without treatment. In the pH-corrected group (n = 5), 14.4 mEq/kg of sodium bicarbonate was given intravenously as a bolus to correct arterial blood pH toward a target arterial pH of 7.40 (dose calculated by the Henderson-Hasselbalch equation). Measurements and Main Results: Arterial blood pH, PCO2, cardiac output, intracranial pressure, end carotid, superior mesenteric, and renal artery blood flow rates were measured at normocapnic baseline and at every hour during hypercapnia for 6 hrs. In the pH-uncorrected group, arterial blood pH decreased from 7.41 ± 0.03 at normocapnia to 7.14 ± 0.01 (p < .01 vs. normocapnia) as blood PCO2 increased to 01.2 ± 1.8 torr (10.8 ± 0.2 kPa). In the pH-corrected group, arterial blood pH was 7.42 ± 0.02 at normocapnia and was maintained at 7.37 ± 0.01 while PaCO2 was increased to 50.3 ± 0.9 torr (10.7 ± 0.1 kPa). Significant increases in cardiac output occurred with the initiation of hypercapnia for both groups (pH-uncorrected group: 4.3 ± 0.6 L/min at normocapnia va. 6.8 ± 1.0 L/min at 1 hr [p < .05]; pH-corrected group: 4.1 ± 0.4 at normocapnia vs. 5.7 ± 0.4 L/min at 1 hr [p < .05]). However, this increase was sustained only in the uncorrected group. Changes in carotid and mesenteric artery blood flow rates, as a percent of baseline values, showed sustained significant increases in the pH-uncorrected groups (p < .05) and only transient (carotid at 1 hr) or no (superior mesenteric) significant change in the pH-corrected groups. Conversely, significant increases in renal artery blood flow were seen only in the pH-uncorrected group during the last 2 hrs of the experiment (p < .05). Organ blood flow, as a percent of cardiac output, did not change significantly in either group. Intracranial pressure increased significantly in the pH-uncorrected group (9.0 ± 1.5 mm Hg at normocapnia va. 26.8 ± 5.1 st 1 hr, p < .05), and remained increased, while showing no significant change in the pH-corrected group (8.5 ± 1.6 mm Hg at normocapnia to 7.7 ± 4.2 st 1 hr). Conclusions: Acute hypercapnia, induced within 1 hr, is associated with significant increases in cardiac output, organ blood flow, and intracranial pressure. These changes can be significantly attenuated by correction of blood pH with the administration of sodium bicarbonate, without adverse effects on hemodynamics.

AB - Objectives: To determine whether changes in cardiac output, regional blood flow, and intracranial pressure during permissive hypercapnia are blood pH- dependent and can be attenuated by correction of intravascular acidemia. Design: Prospective, controlled study. Setting: Research laboratory. Subjects: Female Marino ewes. Interventions: Animals were instrumented with a pulmonary artery catheter, femoral arterial and venous catheters, a catheter in the third cerebral ventricle, and ultrasonic flow probes on the left carotid, superior mesenteric, and left renal arteries 1 wk before experimentation. At initiation of the protocol, ewes underwent endotracheal intubation and mechanical ventilation under general anesthesia. Minute ventilation was reduced to induce hypercapnia with a target PaCO2 of 80 torr (10.7 kPa). In the pH-uncorrected group (n = 6), arterial blood pH was allowed to decreased without treatment. In the pH-corrected group (n = 5), 14.4 mEq/kg of sodium bicarbonate was given intravenously as a bolus to correct arterial blood pH toward a target arterial pH of 7.40 (dose calculated by the Henderson-Hasselbalch equation). Measurements and Main Results: Arterial blood pH, PCO2, cardiac output, intracranial pressure, end carotid, superior mesenteric, and renal artery blood flow rates were measured at normocapnic baseline and at every hour during hypercapnia for 6 hrs. In the pH-uncorrected group, arterial blood pH decreased from 7.41 ± 0.03 at normocapnia to 7.14 ± 0.01 (p < .01 vs. normocapnia) as blood PCO2 increased to 01.2 ± 1.8 torr (10.8 ± 0.2 kPa). In the pH-corrected group, arterial blood pH was 7.42 ± 0.02 at normocapnia and was maintained at 7.37 ± 0.01 while PaCO2 was increased to 50.3 ± 0.9 torr (10.7 ± 0.1 kPa). Significant increases in cardiac output occurred with the initiation of hypercapnia for both groups (pH-uncorrected group: 4.3 ± 0.6 L/min at normocapnia va. 6.8 ± 1.0 L/min at 1 hr [p < .05]; pH-corrected group: 4.1 ± 0.4 at normocapnia vs. 5.7 ± 0.4 L/min at 1 hr [p < .05]). However, this increase was sustained only in the uncorrected group. Changes in carotid and mesenteric artery blood flow rates, as a percent of baseline values, showed sustained significant increases in the pH-uncorrected groups (p < .05) and only transient (carotid at 1 hr) or no (superior mesenteric) significant change in the pH-corrected groups. Conversely, significant increases in renal artery blood flow were seen only in the pH-uncorrected group during the last 2 hrs of the experiment (p < .05). Organ blood flow, as a percent of cardiac output, did not change significantly in either group. Intracranial pressure increased significantly in the pH-uncorrected group (9.0 ± 1.5 mm Hg at normocapnia va. 26.8 ± 5.1 st 1 hr, p < .05), and remained increased, while showing no significant change in the pH-corrected group (8.5 ± 1.6 mm Hg at normocapnia to 7.7 ± 4.2 st 1 hr). Conclusions: Acute hypercapnia, induced within 1 hr, is associated with significant increases in cardiac output, organ blood flow, and intracranial pressure. These changes can be significantly attenuated by correction of blood pH with the administration of sodium bicarbonate, without adverse effects on hemodynamics.

KW - acidosis, respiratory

KW - acute respiratory failure

KW - adult respiratory distress syndrome

KW - bicarbonate

KW - critical illness

KW - hemodynamics

KW - hypercapnia

KW - mechanical ventilation

KW - pH

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