Relationship of thyroid hormone patterns to survival in canine hemorrhagic shock

6 of 13 dogs subjected to 1 h of hemorrhagic shock (BP = 45-50 mm Hg) died during the first convalescent day. Nonsurvivors had lower baseline plasma concentrations of total and free T4 and T3, as well as rT3, and higher T3 uptake values. During shock, dogs that died had significantly lower plasma levels of total and free T4 and T3 and higher T3 uptake. In general, intergroup differences were accentuated during resuscitation. After volume replenishment, indices of thyroid function had stabilized or improved in survivors, but were still deteriorating in dogs that ultimately died. There were no consistent hemodynamic differences between the two groups. Thus, parameters of thyroid metabolism appear to be good prognostic indicators in canine hemorrhagic shock.