Evaluation of hypoxic brain injury with spinal fluid enzymes, lactate, and pyruvate.

OBJECTIVE: To investigate the prognostic importance in neurologic recovery of the lumbar cerebrospinal fluid (CSF) variables creatine kinase (CK) and brain-type creatine kinase isoenzyme (CK-BB), lactate dehydrogenase (LDH) and its isoenzymes (LDH 1-5), CSF acid phosphatase, beta-D-N-acetylglucosaminidase activity, and CSF lactate, pyruvate, sodium, potassium, and calcium concentrations in patients who experienced cardiac arrest.

DESIGN: Prospective clinical study with blood and CSF samples collected 4, 28, 76, and 172 hrs after resuscitation.

SETTING: Medical ICU in a university hospital.

PATIENTS: Twenty consecutive victims of out-of-hospital cardiac arrest. Eight patients recovered neurologically and 12 patients remained comatose or neurologically disabled until death.

MEASUREMENTS AND MAIN RESULTS: CSF CK, CK-BB, LDH, and LDH isoenzyme 1-3 concentrations in all disabled patients were markedly increased at 76 hrs after the resuscitation. However, these variables were not changed in the recovered subjects. Patients (n = 7) with a mean CSF CK level of 25 +/- 33 (SD) U/L, CK-BB 23 +/- 33 U/L, and CSF lactate 3.8 +/- 0.9 mmol/L at 28 hrs after cardiac arrest remained unconscious and died. In the recovered patients, the mean CSF CK concentration was 2.0 +/- 1.5 U/L (p less than .001) and CSF lactate concentration 2.5 +/- 0.5 mmol/L (p less than .002). The lactate concentration was highest at 4 hrs after resuscitation, declining thereafter. Patients with a mean CSF total LDH level of 609 +/- 515 U/L and acid phosphatase 2.4 +/- 1.2 U/L 76 hrs after resuscitation died without regaining consciousness. In the recovered patients, the mean total CSF LDH activity was 82 +/- 58 U/L (p = .003) and CSF acid phosphatase was 0.8 +/- 0.5 U/L (p = .01) 76 hrs after resuscitation.

CONCLUSIONS: CSF CK, CK-BB, and CSF lactate concentrations reflect a patient's outcome most reliably when measured within 28 to 76 hrs of the cardiac arrest. Similarly, CSF LDH, its isoenzymes 1-3, and CSF acid phosphatase concentrations, when measured at 76 hrs, can be used to monitor the patient's outcome after cardiac arrest. When correlated with Glasgow Coma Scale scores, the closest negative correlation was again seen in CSF CK and CK-BB at 28 and 76 hrs, as well as in LDH, LDH1-3, and acid phosphatase values at 76 hrs. The negative correlation between CSF lactate and Glasgow Coma Scale scores was most distinct at 28 hrs.