The ROX index can be a useful tool for the triage evaluation of COVID-19 patients with dyspnoea

NEWS2, S/F-ratio and ROX-index at emergency department for the prediction of adverse outcomes in COVID-19 patients: An external validation study

BACKGROUND

In the context of the COVID-19 pandemic, the early and accurate identification of patients at risk of deterioration was crucial in overcrowded and resource-limited emergency departments. This study conducts an external validation for the evaluation of the performance of the National Early Warning Score 2 (NEWS2), the S/F ratio, and the ROX index at ED admission in a large cohort of COVID-19 patients from Colombia, South America, assessing the net clinical benefit with decision curve analysis.

METHODS

A prospective cohort study was conducted on 6907 adult patients with confirmed COVID-19 admitted to a tertiary care ED in Colombia. The study evaluated the diagnostic performance of NEWS2, S/F ratio, and ROX index scores at ED admission using the area under the receiver operating characteristic curve (AUROC) for discrimination, calibration, and decision curve analysis for the prediction of intensive care unit admission, invasive mechanical ventilation, and in-hospital mortality.

RESULTS

We included 6907 patients who presented to the ED with confirmed SARS-CoV-2 infection from March 2020 to November 2021. Mean age was 51 (35-65) years and 50.4% of patients were males. The rate of intensive care unit admission was 28%, and in-hospital death was 9.8%. All three scores have good discriminatory performance for the three outcomes based on the AUROC. S/F ratio showed miscalibration at low predicted probabilities and decision curve analysis indicated that the NEWS2 score provided a greater net benefit compared to other scores across at a 10% threshold to decide ED admission at a high-level of care facility.

CONCLUSIONS

The NEWS2, S/F ratio, and ROX index at ED admission have good discriminatory performances in COVID-19 patients for the prediction of adverse outcomes, but the NEWS2 score has a higher net benefit underscoring its clinical utility in optimizing patient management and resource allocation in emergency settings.

Comparison of Prognostic Scores for Patients with COVID-19 Presenting with Dyspnea in the Emergency Department

BACKGROUND

Easy-to-use bedside risk assessment is crucial for patients with COVID-19 in the overcrowded emergency department (ED).

OBJECTIVE

The aim of this study was to explore the prognostic ability of ratio of percutaneous oxygen saturation (SpO2) to fraction of inspired oxygen (FiO2) (S/F); ratio of SpO2/FiO2 to respiratory rate (ROX); National Early Warning Score (NEWS); quick Sequential Organ Failure Assessment (qSOFA); and confusion, respiratory rate, blood pressure, and age ≥ 65 years (CRB-65) in patients with COVID-19 presenting with dyspnea to the ED.

METHODS

In this retrospective observational study, clinical and demographic details of patients with COVID-19 were obtained at ED admission. S/F, ROX, NEWS, CRB-65, and qSOFA scores were calculated at the time of ED arrival. Accuracy of these five indices to predict the need for invasive mechanical ventilation (IMV) within 48 h, intensive care unit (ICU) admission, and early (7-day) mortality were determined using receiver operating characteristic curves.

RESULTS

A total of 375 patients were included in this study. Fifty patients (13.3%) required IMV within 48 h and 58 patients (15.5%) were transferred to the ICU. Seven-day mortality was 6.7% and 28-day mortality was 18.1%. Among all five scores determined from patient data on ED admission, ROX, S/F, and NEWS presented greater discriminatory performance than CRB-65 and qSOFA in predicting IMV within 48 h, ICU admission, and early mortality.

CONCLUSIONS

Emergency physicians can effectively use S/F, ROX, and NEWS scores for rapid risk stratification of patients with COVID-19 infection. Moreover, from the perspective of simplicity and ease of calculation, we recommend the use of the S/F ratio.

A new non-invasive index for the prediction of endotracheal intubation in patients with SARS COVID-19 infection, in the emergency department, pilot study

BACKGROUND

In the current context of the SARS COVID-19 pandemic, where the main cause of death is respiratory failure, and since early recognition would allow timely measures to be implemented and probably improve outcomes, it is important to have tools that allow the emergency room to predict quickly and without the use of large resources which will need invasive mechanical ventilation. This study proposes using a new predictive index of noninvasive characteristics, based on the relationship between oxygenation and work of breathing measured by ultrasound-assessed diaphragmatic function, for the need for invasive mechanical ventilation in patients with SARS-COV2 infection who are admitted to the emergency department.

METHODS

A prospective predictive cohort study was performed, collecting all patients admitted to the emergency room with respiratory failure (not severe or in imminent respiratory arrest) and a confirmed diagnosis of SARS-CoV-2 pneumonia. Diaphragmatic excursion measurements were taken within the first 24 h after admission to the department. The relationship between diaphragmatic excursion and SAFI was calculated, establishing the ultrasound diaphragmatic excursion So2/FiO2 index (U.D.E.S.I). The index's performance was determined by analysis of sensitivity, specificity, and area under the curve (AUC).

RESULTS

This pilot study analyzed the first 100 patients enrolled and found in-hospital mortality of 19%, all patients who died required mechanical ventilation, the right index showed a specificity of 82.4% with a sensitivity of 76.9%, likewise for the left index an overall specificity of 90.5% with a sensitivity of 65.3% was found. The ideal cut-off point for the right index is 1.485, and for the left index, the threshold point was 1.856. AUC of the right index is 0.798 (0.676-0.920) and of the left index 0.793 (0.674-0.911), when comparing them no significant differences were found between these values p = 0.871.

CONCLUSION

The relationship of So2/FiO2 and diaphragm excursion measured by both right and left ultrasound could predict the need for mechanical ventilation of the patient with COVID-19 pneumonia in the emergency room and could constitute a valuable tool since it uses noninvasive parameters and is easily applicable at the patient's bedside. However, a more extensive study is needed to validate these preliminary results.

A Review of Coronavirus Disease 2019 in Pregnancy

Pregnancy is an independent risk factor for morbidity and mortality in coronavirus disease 2019 (COVID-19) with increased rates of operative delivery, intensive care unit admission, and mechanical ventilation as well as a possible increased risk of death, independent of other risk factors, compared with nonpregnant women with COVID-19. Furthermore, pregnancy outcomes are worse in those with COVID-19 with increased risk for preeclampsia, venous thromboembolism, preterm birth, miscarriage, and stillbirth compared with pregnant women without COVID-19. Importantly, pregnant women of nonwhite ethnicity appear to be at greater risk of severe COVID-19, necessitating improved access to care and closer monitoring in these women. The management of COVID-19 in pregnancy is largely similar to that in nonpregnant people; however, there is an important emphasis on multidisciplinary team involvement to ensure favorable outcomes in both mother and baby. Similarly, vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is safe in pregnancy and improves maternal and neonatal outcomes.

Value of Rox Index to Predict Intubation and Intensive Care Unit Outcome in Patients with Respiratory Failure

BACKGROUND

Recent literature suggests that the respiratory rate oxygenation (ROX) index may be a useful parameter in predicting intubation indication in hypoxemic patients.

OBJECTIVE

In this study, we evaluated the accuracy of the ROX index in predicting intubation, length of stay in the ICU, and mortality in ICU patients with hypoxemic respiratory failure with and without hypercapnia.

METHODS

Single-centre retrospective cohort study of 290 patients, with a preliminary diagnosis of respiratory failure, who were treated with low flow oxygen systems. Demographics, medical history, clinical, laboratory, treatment, and prognostic data were obtained from the electronic records of the hospital. The ROX index was calculated at the time of ICU admission.

RESULTS

Thirty-seven percent of non-hypercapnic and 69% of hypercapnic patients were intubated (p:0.005). In hypercapnic patients, ROX: 6.9 had highest sensitivity (81%) and specificity (65%) values for intubation (p:0.005). In non-hypercapnic patients, ROX: 6.2 had the highest sensitivity (81%) and specificity (40%) values. While 11% of hypercapnic patients and 30% of non-hypercapnic patients were died (p:0.05), 22% of hypercapnic patients and 33% of non-hypercapnic patients stayed in the ICU longer than 14 days (p:0.044). The highest sensitivity and specificity values were found for mortality in hypercapnic patients; for ROX value of 5.94 (sensitivity:86%, specificity:61%) and for ICU stay longer than 14 days; for ROX value of 7.4 (sensitivity:71%, specificity:68%).

CONCLUSION

Results of our study suggest that ROX index calculated during ICU admission can be helpful in predicting intubation indication and length of ICU stay in patients with respiratory failure and hypercapnia may influence the cutoff values.

Performance of non-invasive respiratory function indices in predicting clinical outcomes in patients hospitalized for COVID-19 pneumonia in medical and sub-intensive wards: a retrospective cohort study

Coronavirus disease 2019 (COVID-19) is a newly recognized infectious disease which can lead to acute respiratory distress syndrome requiring ventilatory support and intensive care unit admission. The aim of our study is to evaluate the performance of two non-invasive respiratory function indices (the ROX index and the SatO2/FiO2 ratio), as compared to the traditional PaO2/FiO2 ratio, in predicting a clinically relevant composite outcome (death or intubation) in hospitalized patients for COVID-19 pneumonia. Four hospital centers in Northern Italy conducted an observational retrospective cohort study during the first wave of COVID-19 pandemic. Four hundred and fifty-six patients with COVID-19 pneumonia admitted to medical or sub-intensive wards were enrolled. Clinical, laboratory, and respiratory parameters, for the calculation of different indices, were measured at hospital admission. In medical wards (Verona and Padua) the PaO2/FiO2 ratio, ROX index and SatO2/FiO2 ratio were able to predict intubation or death with good accuracy (AUROC for the PaO2/FiO2 ratio, ROX index and SatO2/FiO2 ratio of 75%, 75% and 74%, respectively). Regarding sub-intensive wards (Milan and Mantua), none of the three respiratory function indices was significantly associated with the composite outcome. In patients admitted to medical wards for COVID-19 pneumonia, the ROX index and the SatO2/FiO2 ratio demonstrated not only good performance in predicting intubation or death, but their accuracy was comparable to that of the PaO2/FiO2 ratio. In this setting, where repeated arterial blood gas tests are not always feasible, they could be considered a reliable alternative to the invasive PaO2/FiO2 ratio.

Silent hypoxia is not an identifiable characteristic in patients with COVID-19 infection

Background

Methods

Results

Conclusions

ROX index and SpO2/FiO2 ratio for predicting high-flow nasal cannula failure in hypoxemic COVID-19 patients: A multicenter retrospective study

BACKGROUND

The ratio of oxygen saturation (ROX) index, defined as the ratio of oxygen saturation (SpO2)/fraction of inspired oxygen (FiO2) to respiratory rate, can help identify patients with hypoxemic respiratory failure at high risk for intubation following high-flow nasal cannula (HFNC) initiation; however, whether it is effective for predicting intubation in coronavirus disease 2019 (COVID-19) patients receiving HFNC remains unknown. Moreover, the SpO2/FiO2 ratio has been assessed as a prognostic marker for acute hypoxemic respiratory failure. This study aimed to determine the utility of the ROX index and the SpO2/FiO2 ratio as predictors of failure in COVID-19 patients who received HFNC.

METHODS

This multicenter study was conducted in seven university-affiliated hospitals in Korea. Data of consecutive hospitalized patients diagnosed with COVID-19 between February 10, 2020 and February 28, 2021 were retrospectively reviewed. We calculated the ROX index and the SpO2/FiO2 ratio at 1 h, 4 h, and 12 h after HFNC initiation. The primary outcome was HFNC failure defined as the need for subsequent intubation despite HFNC application. The receiver operating characteristic curve analysis was used to evaluate discrimination of prediction models for HFNC failure.

RESULTS

Of 1,565 hospitalized COVID-19 patients, 133 who received HFNC were analyzed. Among them, 63 patients (47.4%) were successfully weaned from HFNC, and 70 (52.6%) were intubated. Among patients with HFNC failure, 32 (45.7%) died. The SpO2/FiO2 ratio at 1 h after HFNC initiation was an important predictor of HFNC failure (AUC 0.762 [0.679-0.846]). The AUCs of SpO2/FiO2 ratio at 4 h and ROX indices at 1 h and 4 h were 0.733 (0.640-0.826), 0.697 (0.597-0.798), and 0.682 (0.583-0.781), respectively. Multivariable analysis showed that the patients aged ≥70 years are 3.4 times more likely to experience HFNC failure than those aged <70 years (HR 3.367 [1.358-8.349], p = 0.009). The SpO2/FiO2 ratio (HR 0.983 [0.972-0.994], p = 0.003) at 1 h was significantly associated with HFNC failure.

CONCLUSIONS

The SpO2/FiO2 ratio following HFNC initiation was an acceptable predictor of HFNC failure. The SpO2/FiO2 ratio may be a good prognostic marker for predicting intubation in COVID-9 patients receiving HFNC.

Evaluation of the response to prone positioning in awake patients with COVID-19

ABSTRACT This study aims to evaluate the acute effects of the responses to prone positioning (PP) in awake patients with COVID-19. A prospective, single-centered study, using supplemental oxygen, was conducted with 32 awake patients with COVID-19. The response to PP was performed for 30 minutes. According to their tolerance, the patients were instructed to daily remain in PP. The variables for oxygen saturation (SpO2), heart rate, respiratory rate, ROX index and intensive care unit (ICU) admission rate were registered. In total, 25 patients (78.1%) responded to PP, with 13 (40.6%) showing persistent response and 12 (37.5%) showing transient response. Seven patients (21.9%) did not respond. Patients with persistent and transient responses increased SpO2 (p<0.001) and ROX index (p=0.001 and p<0.001, respectively), and reduced heart rate (p=0.01 and p=0.02, respectively), and respiratory rate (p=0.003 and p=0.001, respectively). The variables were similar in patients who did not respond to PP. The ICU admission rate of patients who had persistent or transient response, or did not respond was 30.8% (4/13), 41.7% (5/12), and 57.1% (4/7), respectively. The patients who responded to PP showed reduced heart and respiratory rates and increased ROX index, without interfering in the hospitalization rate.

Avaliação da resposta à posição prona em pacientes acordados com COVID-19

RESUMO O objetivo deste estudo foi avaliar os efeitos agudos dos tipos de resposta à posição prona (PP) em pacientes acordados com COVID-19. Realizou-se um estudo prospectivo, unicêntrico, com 32 pacientes acordados com COVID-19, e com uso de oxigênio suplementar. A resposta à posição prona foi feita durante 30 minutos. Após o teste, os pacientes foram orientados a permanecer na PP diariamente, de acordo com a tolerância de cada um. As variáveis saturação de oxigênio (SpO2), frequência cardíaca, frequência respiratória, índice ROX e taxa de internação na unidade de terapia intensiva (UTI) foram registradas. Um total de 25 pacientes (78,1%) responderam à PP, sendo que 13 (40,6%) apresentaram resposta persistente e 12 (37,5%) transitória. Sete pacientes (21,9%) não responderam. Os pacientes com respostas persistente e transitória tiveram aumento da SpO2 (p<0,001) e do índice ROX (p=0,001 e p<0,001, respectivamente), e redução das frequências cardíaca (p=0,01 e p=0,02, respectivamente) e respiratória (p=0,003 e p=0,001, respectivamente). Não houve diferença em nenhuma das variáveis nos pacientes que não responderam à PP. A taxa de internação na UTI dos pacientes que apresentaram resposta persistente, transitória ou que não responderam foi de 30,8% (4/13), 41,7% (5/12) e 57,1% (4/7), respectivamente. Conclui-se que os pacientes que responderam à PP apresentaram redução das frequências cardíaca e respiratória e aumento do índice ROX, sem interferir na taxa de internação.

The Respiratory Rate-Oxygenation Index predicts failure of post-extubation high-flow nasal cannula therapy in intensive care unit patients: a retrospective cohort study

Objective

To investigate the applicability of the Respiratory Rate-Oxygenation Index to identify the risk of high-flow nasal cannula failure in post-extubation pneumonia patients.

Methods

This was a 2-year retrospective observational study conducted in a reference hospital in Bogotá, Colombia. All patients in whom post-extubation high-flow nasal cannula therapy was used as a bridge to extubation were included in the study. The Respiratory Rate-Oxygenation Index was calculated to assess the risk of post-extubation high-flow nasal cannula failure.

Results

A total of 162 patients were included in the study. Of these, 23.5% developed high-flow nasal cannula failure. The Respiratory Rate-Oxygenation Index was significantly lower in patients who had high-flow nasal cannula failure [median (IQR): 10.0 (7.7 - 14.4) versus 12.6 (10.1 - 15.6); p = 0.006]. Respiratory Rate-Oxygenation Index > 4.88 showed a crude OR of 0.23 (95%CI 0.17 - 0.30) and an adjusted OR of 0.89 (95%CI 0.81 - 0.98) stratified by severity and comorbidity. After logistic regression analysis, the Respiratory Rate-Oxygenation Index had an adjusted OR of 0.90 (95%CI 0.82 - 0.98; p = 0.026). The area under the Receiver Operating Characteristic curve for extubation failure was 0.64 (95%CI 0.53 - 0.75; p = 0.06). The Respiratory Rate-Oxygenation Index did not show differences between patients who survived and those who died during the intensive care unit stay.

Conclusion

The Respiratory Rate-Oxygenation Index is an accessible tool to identify patients at risk of failing high-flow nasal cannula post-extubation treatment. Prospective studies are needed to broaden the utility in this scenario.