Pulmonary responses during cold induced acute pain.

Cold induced acute pain is associated with many autonomic responses of the cardiovascular system, skin conductance and pupil size. However, there are few reports suggesting changes in pulmonary function. Hence present study reports preliminary data on this. Acute pain was induced in 30 non-smoker males, 30-50 yrs of age by immersing hand in cold water and their respiratory rate (RR), tidal volume (TV), inspiratory and expiratory reserve volumes (IRV, ERV) and respective capacities, vital capacity (VC), force vital capacity (FVC), FEV1%, peak flow and flow rates at 75%, 50% and 25% of expired volume (V75,50,25) were measured. Acute pain parameters like pain threshold, tolerance and sensitivity were also recorded. Besides these, heart rate, blood pressure (systolic and diastolic), skin temperature of forehead and opposite palm were also measured. Comparisons were made between values recorded before, during and after cold induced pain. An increase in RR, RV, IC, EC, FVC, FVC%, FEV1 was observed during cold induced pain reflecting an acute state of sympathetic dominance. Positive correlations between heart rate and respiratory rate, and other respiratory with pain parameters were seen during period of induction of acute pain. Hence the study indicates that alterations in pulmonary profile form a part of multidimensional responses observed during cold induced acute pain.