Table 1.

ICD-9 codes used for data collection

Complications	ICD-9 Codes
Hematoma	99812
Elevated ICP/Papilledema	37700 37701 37702
Post-op bleeding	99811
Other nervous system complication	99709
Accidental puncture or laceration	9982
Airway or respiratory failure	51881
Pneumonia	481 4821 48281 486 5180 99731
Post-operative infection	6820 73008 73009 73098 73099 99859 99851
Post-operative stroke	99702
Seizure	34510 3453 34540 34550 34551 34560 34580 34590 34591
Wound disruption	99830 99831 99832
Graft failure	99652
Wound infection	99859
Meningitis	3200 3201 3202 3203 3209
Other bone infection	73028
Pulmonary or air embolism	9991
Trauma	85220 85221 85226 85241 85301
Comorbid condition*	75555 74100 74101 74103 74190 74191 7420 7421 7422 7423 7424 7428 7429 7449 74601 74602 74609 7463 7464 7466 7467 74681 74685 74686 74687 74689 7469 7580 7581 7582 75831 75832 75833 75839 7585 7586 7587 75889 7589

^*acrocephalosyndactyly, anomalies of pulm valve, chromosomal abnormalities, congenital encephalocele, congenital hydrocephalus, microcephalus, other specific anomaly of brain, other specified anomalies of the nervous system, reduction deformities of brain, spinia bifida w/hydrocephalus, unspecified anomaly of face/neck, unspecified anomaly of brain/spinal cord/nervous system