The following blood gases obtained at 8am and 10 am from a patient admitted to the ICU with Grade V Subarachnoid hemorrhage. Between the two sets of arterial blood gases a procedure was performed. Changes in gas tensions were not accompanied by changes in haemodynamic parameters.
|
Time |
8 AM |
10 AM |
|
FiO2 |
0.3 |
1.0 |
|
pH |
7.41 |
7.06 |
|
PCO2 |
39 mm Hg (5.2 kPa) |
108 mm Hg (14.4 kPa) |
|
PO2 |
103 mm Hg (13.7 (kPa) |
425 mm Hg (56.6 kPa) |
|
Peak airway |
24 cm water |
0 cm water |
|
Tidal |
650 ml |
0 ml |
15.1 What procedure was performed? Give reasons.
Apnoea test (as peak pressure has dropped to zero and there is no recordable TV. Not likely to be bronchoscopy as peak pressures are high during bronchoscopy
This patient is not breathing, and is demonstrating no respiratory drive in spite of a ridiculously high CO2. The 100% FiO2 suggests that an apnoea test for brain death is in progress.
Ropper, Allan H., Sean K. Kennedy, and Lisa Russell. "Apnea testing in the diagnosis of brain death: clinical and physiological observations." Journal of neurosurgery 55.6 (1981): 942-946.