Development and Validation of the Neonatal Risk Estimate Score for Children Using Extracorporeal Respiratory Support.

OBJECTIVE: To develop and validate the Neonatal Risk Estimate Score for Children Using Extracorporeal Respiratory Support, which estimates the risk of in-hospital death for neonates prior to receiving respiratory extracorporeal membrane oxygenation (ECMO) support. STUDY DESIGN: We used an international ECMO registry (2008-2013); neonates receiving ECMO for respiratory support were included. We divided the registry into a derivation sample and internal validation sample, by calendar date. We chose candidate variables a priori based on published evidence of association with mortality; variables independently associated with mortality in logistic regression were included in this parsimonious model of risk adjustment. We evaluated model discrimination with the area under the receiver operating characteristic curve (AUC), and we evaluated calibration with the Hosmer-Lemeshow goodness-of-fit test. RESULTS: During 2008-2013, 4592 neonates received ECMO respiratory support with mortality of 31%. The development dataset contained 3139 patients treated in 2008-2011. The Neo-RESCUERS measure had an AUC of 0.78 (95% CI 0.76-0.79). The validation cohort had an AUC = 0.77 (0.75-0.80). Patients in the lowest risk decile had an observed mortality of 7.0% and a predicted mortality of 4.4%, and those in the highest risk decile had an observed mortality of 65.6% and a predicted mortality of 67.5%. CONCLUSIONS: Neonatal Risk Estimate Score for Children Using Extracorporeal Respiratory Support offers severity-of-illness adjustment for neonatal patients with respiratory failure receiving ECMO. This score may be used to adjust patient survival to assess hospital-level performance in ECMO-based care.

Development and validation of the pediatric risk estimate score for children using extracorporeal respiratory support (Ped-RESCUERS).

PURPOSE: To develop and validate the Pediatric Risk Estimation Score for Children Using Extracorporeal Respiratory Support (Ped-RESCUERS). Ped-RESCUERS is designed to estimate the in-hospital mortality risk for children prior to receiving respiratory extracorporeal membrane oxygenation (ECMO) support. METHODS: This study used data from an international registry of patients aged 29 days to less than 18 years who received ECMO support from 2009 to 2014. We divided the registry into development and validation datasets by calendar date. Candidate variables were selected for model inclusion if the variable independently changed the mortality risk by at least 2 % in a Bayesian logistic regression model with in-hospital mortality as the outcome. We characterized the model's ability to discriminate mortality with the area under curve (AUC) of the receiver operating characteristic. RESULTS: From 2009 to 2014, 2458 non-neonatal children received ECMO for respiratory support, with a mortality rate of 39.8 %. The development dataset contained 1611 children receiving ECMO support from 2009 to 2012. The model included the following variables: pre-ECMO pH, pre-ECMO arterial partial pressure of carbon dioxide, hours of intubation prior to ECMO support, hours of admission at ECMO center prior to ECMO support, ventilator type, mean airway pressure, pre-ECMO use of milrinone, and a diagnosis of pertussis, asthma, bronchiolitis, or malignancy. The validation dataset included 438 children receiving ECMO support from 2013 to 2014. The Ped-RESCUERS model from the development dataset had an AUC of 0.690, and the validation dataset had an AUC of 0.634. CONCLUSIONS: Ped-RESCUERS provides a novel measure of pre-ECMO mortality risk. Future studies should seek external validation and improved discrimination of this mortality prediction tool.

Long-term sensorineural hearing loss induces functional changes in the rat auditory nerve.

Loss of cochlear hair cells in the rat initiates degenerative change within the primary auditory neurons (ANs) of the cochlea. These degenerative changes include loss of peripheral processes, demyelination and ultimately cell death. This pathology will affect the biophysical processes involved in action potential generation and propagation to an electrical stimulus via a cochlear implant. We measured the response properties of ANs, with particular reference to their refractory behaviour, in normal, short- (9 weeks) and long-term (> 52 weeks) deafened rats. AN loss was moderate in the short-term and severe in the long-term deafened animals. AN activity was elicited using a brief electrical stimulus delivered via a bipolar electrode array implanted into the cochlea. The general response properties of ANs recorded from deafened cochleae were similar to those observed in normal cochleae, i.e. a monotonic increase in the probability of firing and a decrease in response latency and temporal jitter with increasing stimulus intensity. However, the absolute refractory period was significantly prolonged in animals deaf for > 12 months (P = 0.0026). Deafened animals also exhibited a highly significant increase in threshold compared with normal controls (P < 0.001). These functional changes have implications for recipients of cochlear implants and potential therapies directed toward halting or reversing AN pathology.