A preliminary investigation into maximal expiratory pressures in some village children.

A clinical mercury sphygmomanometer was used to measure Maximal Expiratory Pressure (MEP) in 29 boys (mean age 8 +/- 1.4 yr) and 21 girls (mean age 7.6 +/- 1.5 yr) of a village in interior Maharashtra. The values of 70.6 +/- 13.4 mmHg SD for the boys and 61.9 +/- 18.9 mmHg for the girls were quite comparable to the respiratory pressures reported elsewhere in literature, even though the subjects were apparently poorly nourished. There was no statistical difference between the MEPs of boys and girls. The MEP was positively and significantly (P<0.01) correlated to height (r=0.51) and weight (r=0.05) in the boys. The MEP denoting respiratory muscle strength also correlated positively with handgrip power used to represent non-respiratory muscle strength (r=0.34) (P>0.05). The simple, reproducible method of measuring MEP as described may be useful for measuring this important physiological parameter at the bedside in children whose respiratory muscle function needs to be evaluated.

Lung functions with spirometry: an Indian perspective--II: on the vital capacity of Indians.

Spirometry has been used in India since 1929 to evaluate vital capacity. The mean value for this parameter has changed slightly for the better over about eight decades. It is currently recorded at about 21.8 ml/cm height for males and about 18 ml/cm height for females, the difference between the two sexes being statistically significant throughout the period studied. The vital capacity reaches its peak at about 30 years of age in both Indian men and women and declines there after. There is no significant statistical difference in the vital capacities of subjects from different regions of India. Composite regressions have been generated for use as reference equations for estimating. Vital capacity of Indians is lower than that of Caucasians, but the age related decline is much greater for Caucasians.

Lung functions with spirometry: an Indian perspective--I. Peak expiratory flow rates.

Peak expiratory flow rate is an effective measure of effort dependent airflow. It is relatively a simple procedure, and may be carried out in the field using portable instruments. The average PEFR of healthy young Indian males and females is around 500 and 350 lpm respectively. The PEFR reaches a peak at about 18-20 years, maintains this level up to about 30 years in males, and about 40 years in females, and then declines with age. Common regression equations for Indians enveloping major studies from various parts of the country have been formulated. Indian PEFR values compare favourably with other ethnic groups such as Americans and Europeans.

Heart rate and blood pressure responses of left-handers and right-handers to autonomic stressors.

We hypothesized that cerebral dominance may contribute to differences in cardio-vascular responses of right-handers (RH) and left-handers (LH) to autonomic stressors. We tested this hypothesis by exposing 14 RH, and 14 LH males to category I tests in which the hand and cerebral cortex were involved in performing the test viz.--i) Cold pressor test (CPT), ii) Handgrip dynamometry (HGD) and; category II (no use of hand)--i) Orthostatic Tolerance Test (OTT), ii) Valsalva Manuever (VM), iii) Controlled Breathing Test for sinus arrhythmia (SA) in a random sequence, and measured their heart rate (HR/min) and blood pressure (MAP mmHg). All subjects had similar resting HR and MAP values, and responded to the category I interventions with increased HR and BP. The absolute HR values of LH and RH did not differ significantly during the interventions. However, the increase in HR from control induced by the CPT, and the HGD was greater for LH (P<0.05). Also, LH showed a greater decrease in HR and MAP in the recovery phase (P<0.05). The VAS scores for degree of discomfort during the CPT were similar for both the groups. During the OTT, the increase in HR was more in RH (P<0.05). The Valsalva ratios for LH and RH were similar. Our findings suggest that the autonomic control over the cardio-vascular system may be different in LH and RH, and that this imbalance could be attributable to a variation in cerebral dominance.