Table 3.

Predictors of Poor Outcome [Death/Disability]

	Median (25th & 75th Percentile) PCO2 Values (mmHg)			Adjusted Analyses*
Measures of PCO2 Exposure	Death or Disability	No Death Disability	p-value**	OR & 95% CI***	p-value
Minimum PCO2 to 12h	22 (20 - 29)	26 (21 - 32)	0.0202	2.0 (1.1 - 3.4)	0.0151
Maximum PCO2 to 12h	48 (38 - 66)	42 (37 - 59)	0.1768	1.1 (1.0 - 1.3)	0.1423
Difference in Max. & Min. PCO2	23.5 (13 - 42)	18 (9 - 32)	0.0247	1.1 (0.9 - 1.2)	0.3986
Standard Deviation in PCO2 Measurements	10.3 (5.7-16.9)	7.8 (4.3-13.0)	0.0435	1.2 (0.9 - 1.6)	0.3169

Logistic Regression Model with Cumulative Exposure	Unadjusted Odds Ratios		Adjusted Odds Ratios
Cumulative Exposure to Hypocarbia (<35mmHg)	OR & 95%CI	p-value	OR & 95%CI	p-value
> 75th quartile (>=116 mmHg.hrs)	4.1 (1.4 - 12.5)	0.0536	6.9 (1.5 - 31.9)	0.0490
50-75th quartile (59-115 mmHg.hrs)	3.4 (1.2 - 10.1)	-	7.7 (1.8 - 33.4)	-
25-50th quartile (29-58 mmHg.hrs)	2.6 (0.9 - 7.8)	-	4.4 (1.0 - 19.4)	-
< 25th quartile (1-28 mmHg.hrs)	1.6 (0.6 - 4.8)	-	2.5 (0.6 - 10.4)	-
Initial Level of HIE – Severe vs. Moderate	6.0 (3.0 - 12.0)	<0.0001	3.4 (1.5 - 7.7)	0.0043
Study Treatment Group – Control vs Hypothermia	2.2 (1.2 - 3.9)	0.0080	3.3 (1.5 - 7.0)	0.0024
Time to Spontaneous Respiration >10min vs < 10min	8.1 (3.8 - 17.1)	<0.0001	5.0 (2.1 - 11.7)	0.0002
pH at Randomization (0.1 point decrease)	1.4 (1.2 - 1.7)	0.0009	1.5 (1.1 - 1.9)	0.0047
Days on Ventilation (1 day increase)	1.2 (1.0 - 1.2)	0.0009	1.1 (1.0 - 1.2)	0.0088
			AUC c-statistic	0.861

^*Adjusted for initial level of encephalopathy, study treatment group, time to spontaneous respiration >10 minutes, systemic pH at randomization & days on ventilation

^**Wilcoxon

^***Odds Ratios are increased odds of death/disability associated with a 10 mmHg decline in the PCO2 measure.