THE EFFECTS OF NALOXONE, ADRENALECTOMY AND HEPARIN DURING AND AFTER CPR (CARDIAC ARREST, SHOCK, STRESS RESPONSE, CATECHOLAMINES)

PETER JOSEPH FOLEY, Purdue University

Abstract

Three studies were performed to investigate the humoral response to cardiac arrest (CA) and cardiopulmonary resuscitation (CPR) in dogs. First, the effects of naloxone on the sympatho-medullary and blood gas response to and resuscitation from CA and CPR were determined. Plasma and cerebrospinal fluid (CSF) epinephrine (E), norepinephrine (NE) and blood gases were measured before, during and after 12 min of CA and CPR. The cardiac ventricles were electrically fibrillated and 30 sec later CPR was begun. After 6 min of CPR, 6 dogs received naloxone (10 mg/kg) and 6 dogs received 0.9% saline IV. E and NE increased immediately after CA and remained elevated until after resuscitation. During CPR, arterial pO(,2), pH and venous pCO(,2) increased while venous pH and pCO(,2); and arterial HCO(,3)('-) and pCO(,2) decreased. All dogs except 1 saline treated were resuscitated. Naloxone did not cause a significant change in any of the above variables. In the second study, the effects of adrenalectomy on the humoral response to and resuscitation from CA and CPR were determined. Plasma and CSF E and NE, serum cortisol (C), T(,3) and T(,4) were measured before, during and after 12 min of CA and CPR. Ten dogs were adrenalectomized (AD) and 10 dogs were sham (SH) operated. One hour after surgery, the cardiac ventricles were electronically fibrillated and 30 sec later CPR was begun. In the SH group, E and NE increased immediately after CA and remained elevated until after resuscitation. Cortisol was elevated in response to surgery and remained elevated during CPR. In the AD group, NE increased slightly in response to CA and CPR, while E and C were depressed. The E and NE in the CSF increased slightly during CPR while serum T(,3) and T(,4) did not respond in both AD and SH dogs. Nine of the 10 AD dogs died while only 4 of the 10 SH dogs died.(,) In the third study, the effects of heparin (Hep) on 24 hour survival from CA and CPR were determined. Five dogs were pretreated with Hep (1 mg/kg) and 5 dogs received 0.9% saline IV. The cardiac ventricles were electrically fibrillated and 3 min later CPR was begun. Hep did not improve 24 hour survival in spite of inhibiting the clotting mechanism. In conclusion, plasma E and NE increase dramatically in response to CA. Naloxone has no effect on this response while AD causes a significant blunting of this response.

Degree

Ph.D.

Subject Area

Anatomy & physiology|Animals

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