Oxygen Delivery Using a Neonatal Self-inflating Resuscitation Bag: Effect of Oxygen Flow
ABSTRACT OBJECTIVE:We evaluated the effect of oxygen (O2) flow rate on the corresponding delivered fraction of oxygen (FiO2) during positive pressure ventilation (PPV) when using a neonatal self-inflating bag (SIB).METHODS:Fifteen health care professionals administered PPV at a respiratory rate of 40 to 60 breaths per minute and at peak inspiratory pressures of 25 and 35 cm H2O to a manikin by using a SIB with reservoir connected to an O2 source equipped with a flowmeter (flow rates: 0-10 L/min). The FiO2 corresponding to each flow rate was measured at the inflow to the facial mask for 60 seconds.RESULTS:In total, 2520 FiO2 data points were collected. At every O2 flow rate, the FiO2 gradually increased from time 0 seconds to time 60 seconds, both at 25 cm H2O and at 35 cm H2O. After 1 minute of PPV at 25 cm H2O, the delivered FiO2 was 31.5% ± 2.1% and 43.1% ± 3.1% at O2 flow rates of 0.1 and 0.5 L/min, respectively. After 1 minute of PPV at 35 cm H2O, the delivered FiO2 was 29.4% ± 2.0% and 42.1% ± 4.6% at O2 flow rates of 0.1 and 0.5 L/min, respectively. At all O2 flow rates >5 L/min, the delivered FiO2 was >85% and >95%, after 1 minute of PPV at 25 and 35 cm H2O, respectively.CONCLUSIONS:Delivered FiO2 during PPV depends on 3 factors: oxygen flow rate, peak inspiratory pressures, and time elapsed. These data can be used to develop a scheme correlating the oxygen flow rate and the corresponding delivered FiO2 when using a neonatal SIB.
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ABSTRACT: Objective To test whether 4 commonly used self-inflating bags with a reservoir in situ can reliably deliver different oxygen concentrations (21%-100%) using a portable oxygen cylinder with flows of <= 5 L/min. Study design Four self-inflating bags (from Laerdal, Ambu, Parker Healthcare, and Mayo Healthcare) were tested to provide positive pressure ventilation to a manikin at 60 inflations/min by 4 operators. Oxygen delivery was measured for 2 minutes, combining oxygen flows (0.25, 0.5, 1, 5 L/min) and peak inspiratory pressures (PIPs 2025, 35-40 cmH(2)O). Results Combinations (n = 128) were performed twice. Oxygen delivery depended upon device, oxygen flow, and PIP. All self-inflating bags delivered mean oxygen concentrations of <40% with 0.25 L/min, regardless of PIP. Three self-inflating bags delivered <= 40% with flow 0.5 L/min at PIP 35-40 cmH(2)O, whereas all delivered >40% at PIP 2025 cmH(2)O. With 1 L/min, 3 self-inflating bags delivered 40%-60% at PIP 35-40 cmH(2)O and all delivered >60% at PIP 20-25 cmH(2)O. With 5 L/min, all self-inflating bags delivered close to or 100%, regardless of PIP. Differences in oxygen delivery between self-inflating bags were statistically significant (P < .001) even when differences were not clinically important. Conclusion Self-inflating bags with a reservoir in situ can deliver a variety of oxygen concentrations without a blender, from <40% with 0.25 L/min oxygen flow to 100% with 5 L/min. The adjustment of oxygen flow may be a useful method of titrating oxygen in settings where air-oxygen blenders are unavailable.Journal of Pediatrics 05/2014; 165(2). DOI:10.1016/j.jpeds.2014.04.020 · 3.74 Impact Factor
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ABSTRACT: Background: The recent newborn resuscitation guidelines have recommended that a pulse oximeter and oxygen blender be used to keep oxygen saturation (SpO2) within the target range. However, an oxygen blender and compressed air are not generally available in delivery rooms. Objectives: To determine whether using low-flow oxygen at 0.5-1 liters/min for positive pressure ventilation (PPV) via a self-inflating bag (SIB) without a reservoir is effective and able to maintain SpO2 within the target range. Methods: Infants with a gestational age (GA) ≤32 weeks who initially required PPV after birth were enrolled. PPV was performed with low-flow oxygen at 0.5-1 liters/min via an SIB without a reservoir, and the flow was adjusted in a stepwise manner (from 0.5 to 0.8 to 1 liters/min) to keep SpO2 in the target range. If the heart rate was still <100/min or SpO2 was <70% at 3 min or chest compression was needed, then 100% oxygen was provided. Results: Forty-seven infants were enrolled in the study with a median (interquartile range) GA and birth weight of 28 (27-30) weeks and 1,060 (770-1,360) g, respectively. Twelve infants were initially intubated and switched to 100% oxygen (n = 12) due to ineffective ventilation, which occurred predominately in lower GA infants with intrapartum fetal distress. Thirty infants were successfully resuscitated with low-flow oxygen PPV (success rate 85.7%, 30/35), and >80% of their SpO2 distribution during PPV was between the 3rd and 97th percentiles of the reference range. Conclusion: Low-flow oxygen for PPV via an SIB used in this study should be sufficient for providing oxygen in resuscitation of preterm infants as long as adequate ventilation is evident. This technique is simple and could be useful in a resource-limited setting. © 2014 S. Karger AG, Basel.Neonatology 07/2014; 106(3):216-221. DOI:10.1159/000362918 · 2.37 Impact Factor