Short term evaluation of respiratory effort by premature infants supported with bubble nasal continuous airway pressure using Seattle-PAP and a standard bubble device.

BACKGROUND: Almost one million prematurely born infants die annually from respiratory insufficiency, predominantly in countries with limited access to respiratory support for neonates. The primary hypothesis tested in the present study was that a modified device for bubble nasal continuous positive airway pressure (Bn-CPAP) would provide lower work of spontaneous breathing, estimated by esophageal pressure-rate products. METHODS: Infants born <32 weeks gestation and stable on Bn-CPAP with FiO2 <0.30 were studied within 72 h following delivery. Esophageal pressures during spontaneous breathing were measured during 2 h on standard Bn-CPAP, then 2 h with Bn-CPAP using a modified bubble device presently termed Seattle-PAP, which produces a different pattern of pressure fluctuations and which provided greater respiratory support in preclinical studies, then 2 h on standard Bn-CPAP. RESULTS: All 40 infants enrolled completed the study and follow-up through 36 wks post menstrual age or hospital discharge, whichever came first. No infants were on supplemental oxygen at completion of follow-up. No infants developed pneumothoraces or nasal trauma, and no adverse events attributed to the study were observed. Pressure-rate products on the two devices were not different, but effort of breathing, assessed by areas under esophageal pressure-time curves, was lower with Seattle-PAP than with standard Bn-CPAP. CONCLUSION: Use of Seattle-PAP to implement Bn-CPAP lowers the effort of breathing exerted even by relatively healthy spontaneously breathing premature neonates. Whether the lower effort of breathing observed with Seattle-PAP translates to improvements in neonatal mortality or morbidity will need to be determined by studies in appropriate patient populations.

Development and validation of a simple algorithm for initiation of CPAP in neonates with respiratory distress in Malawi.

BACKGROUND: Low-cost bubble continuous positive airway pressure (bCPAP) systems have been shown to improve survival in neonates with respiratory distress, in developing countries including Malawi. District hospitals in Malawi implementing CPAP requested simple and reliable guidelines to enable healthcare workers with basic skills and minimal training to determine when treatment with CPAP is necessary. We developed and validated TRY (T: Tone is good, R: Respiratory Distress and Y=Yes) CPAP, a simple algorithm to identify neonates with respiratory distress who would benefit from CPAP. OBJECTIVE: To validate the TRY CPAP algorithm for neonates with respiratory distress in a low-resource setting. METHODS: We constructed an algorithm using a combination of vital signs, tone and birth weight to determine the need for CPAP in neonates with respiratory distress. Neonates admitted to the neonatal ward of Queen Elizabeth Central Hospital, in Blantyre, Malawi, were assessed in a prospective, cross-sectional study. Nurses and paediatricians-in-training assessed neonates to determine whether they required CPAP using the TRY CPAP algorithm. To establish the accuracy of the TRY CPAP algorithm in evaluating the need for CPAP, their assessment was compared with the decision of a neonatologist blinded to the TRY CPAP algorithm findings. RESULTS: 325 neonates were evaluated over a 2-month period; 13% were deemed to require CPAP by the neonatologist. The inter-rater reliability with the algorithm was 0.90 for nurses and 0.97 for paediatricians-in-training using the neonatologist's assessment as the reference standard. CONCLUSIONS: The TRY CPAP algorithm has the potential to be a simple and reliable tool to assist nurses and clinicians in identifying neonates who require treatment with CPAP in low-resource settings.

A high-value, low-cost bubble continuous positive airway pressure system for low-resource settings: technical assessment and initial case reports.

Acute respiratory infections are the leading cause of global child mortality. In the developing world, nasal oxygen therapy is often the only treatment option for babies who are suffering from respiratory distress. Without the added pressure of bubble Continuous Positive Airway Pressure (bCPAP) which helps maintain alveoli open, babies struggle to breathe and can suffer serious complications, and frequently death. A stand-alone bCPAP device can cost $6,000, too expensive for most developing world hospitals. Here, we describe the design and technical evaluation of a new, rugged bCPAP system that can be made in small volume for a cost-of-goods of approximately $350. Moreover, because of its simple design--consumer-grade pumps, medical tubing, and regulators--it requires only the simple replacement of a <$1 diaphragm approximately every 2 years for maintenance. The low-cost bCPAP device delivers pressure and flow equivalent to those of a reference bCPAP system used in the developed world. We describe the initial clinical cases of a child with bronchiolitis and a neonate with respiratory distress who were treated successfully with the new bCPAP device.

Tracheostomy placement in infants with bronchopulmonary dysplasia: safety and outcomes.

Optimizing the timing and safety for the placement of a tracheostomy in infants with bronchopulmonary dysplasia (BPD) has not been determined. The purpose of the present study was to describe the data from a single institution about the efficacy and safety of tracheostomy placement in infants with BPD needing long-term respiratory support. We established a service line for the comprehensive care of infants with BPD and we collected retrospective clinical data from this service line. We identified patients that had a trachostomy placed using the local Vermont-Oxford database, and obtained clinical data from chart reviews. We identified infants who had a tracheostomy placed for the indication of severe BPD only. Safety and respiratory efficacy was assessed by overall survival to discharge and the change in respiratory supportive care from just before placement to 1-month post-placement. Twenty-two patients (750 ± 236 g, 25.4 ± 2.1 weeks gestation) had a tracheostomy placed on day of life 177 ± 74 which coincided with a post-conceptual age of 51 ± 10 weeks. At placement these infants were on high settings to support their lung disease. The mean airway pressure (MAP) was 14.3 ± 3.3 cmH(2) O, the peak inspiratory pressure was 43.7 ± 8.0 cmH(2) O, and the FiO(2) was 0.51 ± 0.13. The mean respiratory severity score (MAP × FiO(2) ) 1 month after tracheostomy was significantly (P = 0.03) lower than prior to tracheostomy. Survival to hospital discharge was 77%. All patients with tracheostomies that survived were discharged home on mist collar supplemental oxygen. In conclusion, the high survival rate in these patients with severe BPD and the decreased respiratory support after placement of a tracheostomy suggests that high ventilatory pressures should not be a deterrent for placement of a tracheostomy. Future research should be aimed at determining optimal patient selection and timing for tracheostomy placement in infants with severe BPD.

Transcatheter elimination of left-to-right shunts in infants with bronchopulmonary dysplasia is feasible and safe.

OBJECTIVE: To test the hypothesis that transcatheter elimination of left-to-right (L-R) cardiac shunts in former premature infants with bronchopulmonary dysplasia (BPD) is feasible, safe, and is associated with an improvement in respiratory status. DESIGN: Retrospective case review. PATIENTS: Twelve patients with BPD who underwent an attempt at transcatheter closure of an L-R shunt lesion within the first year of life at a single center. Median weight was 5.4 kg and median age was 6 months. Fifteen L-R shunt lesions included patent ductus arteriosus (n = 1), atrial septal defect (ASD) (n = 9), and aortopulmonary collaterals (n = 5). OUTCOME MEASURES: Echocardiographic and clinical markers were collected before and after intervention as well as procedural variables including successful elimination of the shunt and procedural complications. RESULTS: The L-R shunts were successfully occluded in 11/12 (91.6%) patients without any significant procedural adverse event. The ASD closure group demonstrated a decrease in right heart size after the procedure. All patients required respiratory support prior to, and 1 month after, the procedure while only 5/10 (50%) required respiratory support at 12 months of age (P = .0129). There was no change in the median weight percentile over time. CONCLUSION: Transcatheter occlusion of L-R shunts can be performed safely and effectively in children with BPD. Further studies may clarify the role of such therapy in improvement in respiratory physiology over time.

Myocardial tissue Doppler changes in patients with bronchopulmonary dysplasia.

OBJECTIVE: To determine whether tissue Doppler measurements provide sensitive measures of right ventricular function that correlate with the severity of bronchopulmonary dysplasia (BPD). STUDY DESIGN: 21 subjects (6 control subjects with no/mild BPD, 7 patients with moderate BPD, and 8 patients with severe BPD) underwent limited echocardiograms with standard M-mode, mitral and tricuspid inflow velocities, and tissue Doppler features measured. BPD severity was scored by using the NICHD/NHLBI/ORD workshop rating scale by physicians blinded to the echocardiogram results. Groups were compared by using 1-way analysis of variance with post-hoc testing and linear regression. RESULTS: Patients with moderate BPD had a higher early Doppler inflow velocity to the early tissue Doppler velocity ratio (E/E' ratio; P = .03), corresponding to increased end diastolic pressure, compared with patients with no/mild BPD. Patients with severe BPD had a higher E/E' ratio (P = .004) than patients with no/mild BPD. Linear regression demonstrated a correlation between BPD category and right ventricle E/E' (P = .007, R(2) = 0.33) and left ventricular myocardial performance index (P = .02, R(2) = 0.28). CONCLUSION: Increasing right ventricle E/E' ratio correlates with clinical severity of BPD. Abnormal left ventricular myocardial performance index was noted to correlate with the grade of BPD. Further longitudinal studies of tissue Doppler echocardiographic assessment of cardiac function in premature infants with BPD are needed.

Spatiotemporal characteristics of acid refluxate and relationship to symptoms in premature and term infants with chronic lung disease.

BACKGROUND AND OBJECTIVES: The prevalence of gastroesophageal reflux (GER) is high among infants with chronic lung disease (CLD), and the associated pathogenic mechanisms are not clear. The relationship of symptoms to the extent or duration of acid reflux events (AREs) is not well known in preterm or term infants. Our aim was to evaluate the relationship between spatial (height) and temporal (duration) characteristics of AREs (pH <4.0) with symptoms in CLD. We tested the hypothesis that in infants with CLD, AREs into the pharynx are associated with increased symptom occurrence and delayed clearance. METHODS: Nine infants born at 29.8 +/- 5.5 wk gestation (mean +/- SD, range 24.7-39.0 wk) with CLD were evaluated for GER at 49.7 +/- 8.0 wk postmenstrual age (mean +/- SD, range 39.9-67.4 wk). Esophageal manometry was first performed to determine the nares-lower esophageal sphincter (LES) distance. A pH-impedance probe was placed at 87% of the nares-LES distance, and a recording was performed for about 24 h at cribside. Symptoms (respiratory, sensory, and movement) were documented by nurses that were blinded to the pH-impedance recordings. A symptom was considered associated with an ARE if it occurred 2 min before, during, or 2 min after the ARE. The proximal extent and associated clearance mechanisms were correlated with symptom sensitivity index (SSI = number of AREs with symptoms/total AREs *100). Multiple logistic regression methods, analysis of variance (ANOVA) models, and chi(2) tests were performed. Data are described as median, mean +/- SD, or %. RESULTS: A total of 511 AREs, based on pH-Impedance methods, were analyzed from 203 h of recordings in the nine infants. The distal esophagus was the maximal height reached in 80% of AREs (P < 0.001, compared to other esophageal segments). Overall 33% of the AREs were associated with symptoms, and an SSI of 77% was noted with high AREs into the pharynx. The average acid clearance time was prolonged with symptomatic AREs versus nonsymptomatic AREs by 3.5-fold (P < 0.001). CONCLUSIONS: The occurrence and frequency of symptoms with AREs depend on the most proximal extent of the ARE and the acid clearance time.