head injury, ventilatory status
Ventilatory Status Early After Head Injury
The ventilatory status of patients within the first few hours following head injury has not been well established. We prospectively studied 63 patients who presented to an urban trauma center with varying severity of head injury to determine whether any trend toward hypo-or hyperventilation existed within the first two hours following injury. Arterial blood gas analysis done on emergency presentation showed that 14 patients with severe head injury (Glasgow coma scale ~ 4) had mean pH values of 7.29 and mean PaC02 of 41.86 torr. IWenty patients categorized as moderate head injury had mean pH values of 7.38 with a mean PaC02 of 34.1 torr. T~venty-nine patients with GCS >I 12 had mean pH and PaC02 values of 7.4 and 31.8 torr, respectively. These differences in pH and PaC02 were statistically significant between the GCS groups with mild and severe head injury (P ~ .01 pH), (P = .05 PC02), and could not be explained on the basis of hypoxemia, blood alcohol level, hypotension, or associated chest injury. It is concluded that patients with severe craniocerebral trauma show an early trend toward hypercapnea and acidosis. Immediate control of airway and assisted ventilation is necessary in order to reduce PaC02 to optimal levels in patients with severe head injury.