The Ventilatory and Oxygen Costs in the Anesthetized Rhesus Monkey of Inhaling Drugs Used in the Therapy and Diagnosis of Asthma

Abstract

We examined in male Rhesus monkeys the effects on oxygen consumption (VO2), carbon dioxide production (VCO2), minute ventilation (VE), heart and respiratory rates, and functional residual capacity (FRC) of breathing normal saline (NS), salbutamol (albuterol), methacholine (MCh), sodium cromoglycate (SCG), epinephrine (adrenaline), and terbutaline in doses commonly prescribed to human infants and children. We studied 10 anesthetized and intubated monkeys with a mean age and weight of 6.0 yr and 9.1 kg, respectively. VO2 increased over control, by 46.5% after salbutamol (p less than 0.0005), 25% after methacholine (p less than 0.001), 13.2% after epinephrine (p less than 0.01), and 16% after terbutaline (p less than 0.001), but it did not increase after either SCG or NS. VE increased by 82% after MCh and salbutamol (p less than 0.001), less dramatically after epinephrine and terbutaline at 50.5 and 31.5% (p less than 0.02 and p less than 0.001), respectively, and not at all after SCG and NS. Heart rate response was greatest after salbutamol, and nodal and ventricular arrhythmias were noted in four of 10 monkeys after MCh challenge. FRC did not change significantly except after salbutamol, where there was a small rise of 1.8 ml/kg (p less than 0.05).