Critical care medicine
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Critical care medicine · Apr 1981
Factors affecting heated transcutaneous PO2 and unheated transcutaneous PO2 in preterm infants.
The authors evaluated transcutaneous PCO2 (PtcCO2) and PO2 (PtcO2) electrodes in 25 infants. Their diagnosis were severe hyaline membrane disease (HMD) (18), aspiration syndrome (3), severe hydrops, (3) persistent fetal circulation (6), and the others, congenital pneumonia, congenital plural effusion, pulmonary hemorrhage. In most all, the cardiovascular system was compromised, i.e., PDA with congestive heart failure and shock. ⋯ The data were analyzed first dividing all the paired arterial and transcutaneous gas tensions into those with and without cardiovascular drugs (dopamine, isoproterenol), and second, the paired values were divided into those taken (a) during severe acidosis (pH less than 7.25), (b) hypotension (less than 2 SD) of normal, and (c) hypotension and acidosis. These data show: (1) the unheated PtcCO2 and heated PtcO2 accurately correlated with the simultaneous arterial measurements: (2) PtcCO2 reflects tissue PCO2; (3) drugs affect both the PtcCO2 and PtcO2; (4) elevated PtcCO2 dissociating from the simultaneous PaCO2 in neonates with cardiovascular compromise results from decreased tissue perfusion. These data suggest that transcutaneous gas sensors perform dual functions; first, as gas monitors in patients without cardiovascular alterations, and second, in patients with cardiovascular compromise, PtcCO2 reflected tissue perfusion and PtcCO2 monitored oxygen delivery to the tissues.
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Critical care medicine · Apr 1981
Mechanism of action of epinephrine in resuscitation from asphyxial arrest.
To determine the relative importance of the alpha and beta adrenergic effects of epinephrine in resuscitation, 32 dogs were studied in four groups. Group A (alpha blocked) received phenoxybenzamine, 70 mg/kg; group B (beta blocked), propranolol 5 mg/kg; group C (alpha and beta blocked) both drugs; and group D (control), no drug. ⋯ The difference in successful resuscitation of the alpha blocked animals and the not alpha blocked animals is statistically significant (P less than or equal to 0.01). It is concluded that the efficacy of epinephrine in aiding resumption of spontaneous circulation from asphyxial arrest is due to alpha adrenergic receptor stimulation and that beta receptor stimulation is not important in determining outcome.