Page 104 - Physiological based CPAP for preterm infants at birth Tessa Martherus

Chapter 4
Rescue Interventions
In the first 30 min after birth, 11 lambs received 9 additional dosages of caffeine and/or 13 periods of iPPV via the nasal prongs. Lambs were ventilated with an inflation rate of 50 (30-50) bpm and inter-breath variability of 11 (8-40) % for a duration of 3:08 (2:27-9:22) min (Table 3). On 5/9 (56%) occasions, caffeine improved breathing and increased mean PBF.
On the 10/13 (77%) occasions that iPPV was deemed successful, the first inflation was transmitted to the lungs after 4 (2-29) s and increased breathing rate, mean PBF, heart rate, SaO2, and AaDO2 (Table 3). In 3/13 (23%) animals, ventilation did not reach the lungs and intubation was required.
Table 3. Successful rescue interventions Before
1 minute after
27 (18-49)
88 (52-101) 290 (143-319) 63 (38-86)
71 (48-76) 159 (139-201)
34 (25-53)
40 (31-76)
287 (234-436)
77 (51-102)
71 (66-81)
165 (137-208) 6.631 (6.587-6.706) 149 (120-161)
90 (44-99)
197 (154-445)
P-value
0.043 0.893 0.043 0.345 0.225 0.345
0.005 0.037 0.015 0.009 0.005 0.009 0.115 0.575 0.005 0.017
Caffeine (n=4)
Breathing rate (bpm) Inter-breath variability (%) PBF (mL/min)
CBF (mL/min)
BAP (mmHg)
Heart rate (bpm)
iPPV (n=10)
Breathing rate (bpm) Inter-breath variability (%) PBF (mL/min)
CBF (mL/min)
BAP (mmHg)
Heart rate (bpm)
pH
PaCO2 (mmHg)
SaO2 (%)
AaDO2 (mmHg)
9 (3-15)
89 (68-109) 197 (61-264) 68 (40-86)
79 (47-96) 135 (107-163)
13 (7-22)
97 (57-122)
115 (91-183)
38 (26-69)
46 (40-56)
104 (81-123)
6.724 (6.631-6.806) 137 (126-162)
12 (3-32)
497 (454-544)
Data is presented as median (Q1-Q3). Interventions were deemed successful if breathing improved after caffeine administration (4/9) or if lambs continued on CPAP after iPPV (10/13).
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