Fluid Balance Predicts Need for Intubation in Subjects With Respiratory Failure Initiated on High-Flow Nasal Cannula

Abstract

Background: High Flow Nasal Cannula (HFNC) has gained widespread use for acute hypoxemic respiratory failure on the basis of recent publications demonstrating fewer intubations and perhaps lower mortality in certain situations. However, a subset of patients initiated on HFNC for respiratory failure ultimately do require intubation. Our goal is to identify patient level features predictive of this outcome. Materials and methods: This is a retrospective cohort study of patients with hypoxemic respiratory failure treated with HFNC. Individuals were described as having "succeeded" (if weaned from HFNC) or "failed" (if they required intubation). A variety of easily measurable variables were evaluated for their ability to predict intubation risk, analyzed via a multivariate logistic regression model. Results: Of a total of 74 subjects, 42 "succeeded" and 32 "failed." Net fluid balance in the first 24 hours after HFNC initiation was significantly lower in the success group (-33 ± 80 vs. +72 ± 117 mL / h, p <0.01). An adjusted model finds only fluid balance and the previously described Respiratory Rate-Oxygenation (ROX) index (a ratio of the oxygen saturation (SpO 2) divided by the fraction of inspired oxygen (FiO 2) to the respiratory rate (RR), [SpO 2 /FiO 2 ]/RR) at 12 hours as significant predictors of successful weaning (negative fluid balance adjusted OR 0.77 [0.62-0.96] for-10 mL/Hr increments, p = 0.02; ROX adjusted OR 1.72 p <0.01). Conclusions: Negative fluid balance while on HFNC discriminates well between those who will require intubation versus those who will be successfully weaned.

Boas Práticas No Cuidado Ao Doente Crítico Submetido a Oxigenoterapia De Alto Fluxo Por Cânula Nasal

“…A aplicação do índice de ROX apresenta-se assim como uma ferramenta bastante útil, na promoção da segurança do doente submetido a OAFCN. Varipapa et al (2021), num estudo onde foram incluídos 74 doentes com IRA hipoxémica de etiologias variadas submetidos a OAFCN, procurou aferir o impacto do balanço hídrico na falha da OAFCN (necessidade de intubação endotraqueal). Verificou-se que valores negativos de balanço hídrico (50ml/h) foram promotores de um desmame ventilatório bem sucedido, uma vez que apenas 12,5% dos doentes que cumpriram este requisito foram intubados (independentemente da etiologia da insuficiência respiratória).…”

Noninvasive respiratory support in the emergency department: Controversies and state‐of‐the‐art recommendations

“…Several studies have identified factors either associated with or predictive of failure for both NIPPV and NHF that all generally involve indices of work of breathing or severity of hypoxemia in some form or another. 57,[68][69][70]97,[105][106][107][108][109][110] The ROX index [(SpO 2 /FiO 2 )/respiratory rate], was derived and validated to determine whether a patient is likely to succeed or fail NHF. 111 Values > 4.88 have fairly good predictive value for not requiring intubation, whereas values < 2.85 at 2 h, < 3.47 at 6 h, and < 3.85 at 12 h were predictors of NHF failure, 111 leaving a large uninformative middle range of values.…”

“…Predicting failure using widely available clinical data is challenging. Several studies have identified factors either associated with or predictive of failure for both NIPPV and NHF that all generally involve indices of work of breathing or severity of hypoxemia in some form or another 57,68–70,97,105–110 . The ROX index [(SpO 2 /FiO 2 )/respiratory rate], was derived and validated to determine whether a patient is likely to succeed or fail NHF 111 .…”