EFFECT OF HALOTANE AND FENTANYL ON MYOCARDIAL INFARCT SIZE AND REGIONAL BLOOD FLOW DISTRIBUTION

Background We determined if a single administration of heparin or nonanticoagulant N-acetylheparin could reduce myocardial injury resulting from a 90-minute occlusion of the left circumflex coronary artery (LCX) and 6 hours of reperfusion in the anesthetized canine. Methods and Results Heparin (2 mg/kg), N-acetylheparin (2 mg/kg), or vehicle, 0.9% sodium chloride (control), was administered intravenously to separate groups of animals 2 hours before LCX occlusion. To ensure parity of LCX ischemia, only animals with ischemic zone regional blood flow < 0.16 mL/min/g tissue were included in the final analysis. Hemodynamics did not differ among the three study groups. Infarct size as a percentage of the left ventricular area at risk was obtained for each group. Myocardial infarct size was 43.0 ± 3.9% in the vehicle, 28.8 ± 5.8% in the heparin ( P < .05 vs vehicle) and 24.7 ± 4.6% ( P < .05 vs vehicle) in the N-acetylheparin-treated animals. Conclusion Pretreatment with heparin or its nonanticoagulant derivative, N-acetylheparin, provides significant protection to the regionally ischemic and reperfused canine myocardium independent of either plasma glycosaminoglycan concentration or alterations in the coagulation system.

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Systemic and Regional Blood Flow Distribution in Unanesthetized Swine and Swine Anesthetized with Halothane + Nitrous Oxide, Halothane, or Enflurane

Survey of Anesthesiology ◽

10.1097/00132586-198302000-00005 ◽

1983 ◽

Vol 27 (1) ◽

pp. 4???5

Author(s):

W. J. TRANQUILLI ◽

M. MANOHAR ◽

C. M. PARKS ◽

J. C. THURMON ◽

M. C. THEODORAKIS ◽

...

Keyword(s):

Blood Flow ◽

Nitrous Oxide ◽

Regional Blood Flow ◽

Flow Distribution ◽

Blood Flow Distribution

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Regional blood flow distribution during the Cushing response: alterations with adrenergic blockade

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1985.248.1.h98 ◽

1985 ◽

Vol 248 (1) ◽

pp. H98-H108

Author(s):

D. G. van Wylen ◽

L. G. D'Alecy

Keyword(s):

Blood Flow ◽

Cardiac Output ◽

Regional Blood Flow ◽

Flow Distribution ◽

Peripheral Tissue ◽

Systemic Hypertension ◽

Tissue Blood Flow ◽

Blood Flow Distribution ◽

Beta Receptor ◽

Cushing Response

Regional blood flow distribution (microspheres) and cardiac output (CO, thermal dilution) were measured during the Cushing response in unblocked (UB), beta-receptor-blocked (BB, 2 mg/kg propranolol iv), or alpha-receptor blocked (AB, 0.5 mg/kg + 0.5 mg X kg-1 X min-1 phentolamine iv) chloralose-anesthetized dogs. Intracranial pressure was increased to 150 mmHg by infusion of temperature-controlled artificial cerebrospinal fluid into the cisterna magna. Similar increases in mean arterial pressure were seen in UB and BB, but in AB a Cushing response could not be sustained. In UB, cerebral blood flow (CBF) decreased 50%, coronary blood flow (CoBF) increased 120%, and peripheral tissue blood flow was reduced only in the kidneys (18%) and the intestines (small 22%, large 35%). Blood flow to the other viscera, skin, and skeletal muscle was unchanged. CO (16%) and heart rate (HR, 38%) decreased, and total peripheral resistance (TPR, 68%) and stroke volume (SV, 38%) increased. In BB, CBF decreased 50%, CoBF decreased 20%, and blood flow was reduced 40-80% in all peripheral tissues. CO (69%) and HR (62%) decreased, TPR increased 366%, and SV was unchanged. We conclude that the Cushing response in UB animals combines an alpha-receptor-mediated vasoconstriction with a beta-receptor cardiac stimulation. The beta-mechanism is neither necessary nor sufficient for the hypertension. However, the combination of alpha- and beta-adrenergic mechanisms maintains cardiac output and peripheral tissue blood flow relatively constant while producing a systemic hypertension.

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