the effect of time from last food intake on arterial blood gases: implication on reference values

arterial blood gas parameters were analyzed in forty-nine healthy persons (31 males, 18 females) to detemine reference values fo these parameters and their relation to the time from last food intake to arterial puncture (t). the mean ± standard deviation of arterial oxygen pressure, arterial carbon dioxide pressure and ph at core body temperature were 84.4±7.0 mmhg (male: 83.0±6.5, female: 86.7±73), 37.7±2.8 mmhg (male: 38.5±2.7, female: 36.2±2.4) respectively 7.41±0.02 (male: 7.41±0.02 female: 7.42±0.03). the mean pco2 was lower in comparison with most of the studies at sea level. the difference between males and females was significant in pco2 and ph (p=0.004, p=0.02 respectively) but in was not significant in po2 (p=0.07). the pco2 and ph had no statistically significant relatioship with age (p=0.42, p=0.25 respectively). the relationship between po2 with age, pco2 and t was significant (p=0.02, p=0.017, and p=0.019 respectively). the best linear predictive equation was: po2= 1.28 ao2-29.4 for t 10hours þ ao2 = 0.21(baro-47) – (1.2pco2