Table 3.
Assessment of potential predictors of suction-related changes in heart rate.
| Predictors | Suction-Related Change in HR (n = 17) |
No Suction-Related Change in HR (n = 118) |
OR 1 (95% CI) | p 2 | pNL 4 |
|---|---|---|---|---|---|
| Categorical | |||||
| Female | 6 (35%) | 26 (22%) | 1.93 (0.51–7.33) | 0.33 | |
| Amniotic fluid | (n = 115) | 0.10 | |||
| Clear | 6 (35%) | 61 (53%) | 1 (ref) | ||
| Slight | 2 (12%) | 14 (12%) | 1.45 (0.26–8.15) | 0.67 | |
| Thick/Blood | 9 (53%) | 40 (35%) | 2.29 (0.69–7.53) | 0.17 | |
| Catheter (vs. bulb) | 3 (18%) | 32 (27%) | 0.58 (0.16–2.02) | 0.39 | |
| Ventilation prior to SE | 8 (47%) | 60 (51%) | 0.86 (0.28–2.66) | 0.79 | |
| Stimulation prior to SE | 13 (76%) | 75 (64%) | 1.86 (0.56–6.16) | 0.31 | |
| Continuous | |||||
| Gestational Age (weeks) | 39 (38, 39) n = 15 | 38 (36, 39) n = 114 | 1.37 (0.98–1.93) | 0.066 | 0.095 |
| Birthweight (g) | 2780 (2530, 3320) | 3100 (2730, 3350) | 0.080 3 | 0.043 | |
| First observed HR (bpm) | 74 (58, 123) | 72 (52, 131) | 0.96 (0.85–1.07) | 0.45 | 0.089 |
| Time post delivery to initiation of SE (sec) | 113 (64, 160) | 103 (54, 183) | 0.12 3 | 0.047 | |
| HR prior to SE (bpm) | 144 (129, 155) | 137 (89, 170) | 0.003 3 | 0.001 | |
| Duration of SE (sec) | 18 (10, 23) | 14 (7, 23) | 1.02 (0.99–1.04) | 0.14 | 0.98 |
There were 54 infants in the sample (20 deaths). Some infants contributed more than one observation. 1 Odds ratios (OR) with 95% confidence interval (CI) for suction-related changes in HR from logistic regression allowing for clustering of suctioning events within infants, given per 100 g for BW, per 10 bpm for first-observed HR, and per 10 sec for time post delivery. 2 p-value from Wald test of overall effect of variable (3 while allowing for non-linear effect), 4 p-value from Wald test of non-linear effect of continuous variable. The estimated effect of HR prior to SE is illustrated in Figure 4. Sec = seconds, HR = heart rate, bpm = beats per minute, SE = suction event.