Gastrointestinal Tract Function:

As a result of burn  injury acute gastric dilation occurs, creating abdominal distention and  regurgitations. Malabsorption occurs secondary to a decrease  in blood supply and motility of the G.I.  tract. Ulceration appear on  the gastroduodenal mucosa and  a decrease  in  gastric mucus production  is apparent. Hyperacidity of gastric secretion with high level of hydrogen  ion  increase susceptibility  to curling ulcer.  

Pulmonary Function:

Hyperventilation, detectable around third day often rises  to a maximum at about five days after the bums and  then gradually declines unless other complication supervene. Oxygen consumption shows a marked  increase resulting  in decreased arterial oxygen tension, Arterial Po,  usually returns  to the  normal level spontaneously  by  the end of  first week. 

Water Evaporation:

Evaporation of water from the site of  burn occurs  due  to exudation of plasma on  the surface during first 48 hours following bum. The amount of evaporative loss may  be as high  as 6 to 18  litres per day  in  tropical condition. We  have discussed the pathophysiology of burns now let us  learn  the classification of bums.