key: cord-0829489-v8ouh3oz authors: Mateos-Rodríguez, Alonso; Ortega-Anselmi, Justo; Candel-González, Francisco Javier; Canora-Lebrato, Jesús; Fragiel-Saavedra, Marcos; Hernández-Píriz, Alba; Behzadi-Koocahni, Navid; González-del Castillo, Juan; Pérez-Alonso, Antonio; de la Cruz-Conty, María Luisa; García-de Casasola, Gonzalo; Marco-Martínez, Javier; Zapatero-Gaviria, Antonio title: Alternative CPAP methods for the treatment of secondary serious respiratory failure due to pneumonia by COVID-19() date: 2021-01-22 journal: Med Clin (Engl Ed) DOI: 10.1016/j.medcle.2020.09.003 sha: afbb5cb4c1a36ea29af1b699aba95884b0fdf5b5 doc_id: 829489 cord_uid: v8ouh3oz INTRODUCTION: The use of devices that provide continuous positive pressure in the airway has shown improvement in various pathologies that cause respiratory failure. In the COVID 19 pandemic episode the use of these devices has become widespread, but, due to the shortage of conventional CPAP devices, alternative devices have been manufactured. The objective of this study is to describe the use of these devices, as well as their efficacy. MATERIAL AND METHODS: Data are collected from patients admitted for Pneumonia due to COVID 19 at the IFEMA Field Hospital. Data are collected from 23 patients with respiratory failure and need for ventilatory support. RESULTS: Study carried out on a total of 23 patients, dated admission to IFEMA. Alternative CPAP was used in five patients (21.7%), while ventilatory support with a reservoir mask or Ventimask Venturi effect was used in the remaining 18 patients (78.3%). A progressive increase in saturation is observed in those patients in whom alternative CPAP was used (from 94% on average to 98% and 99% on average after 30 and 60 min with the mask, respectively), although this change was not significant (p = 0.058 and p = 0.122 respectively). No significant change in RF was observed at the beginning and end of the measurement in patients who used alternative CPAP (p = 0.423), but among those who did not use alternative CPAP (p = 0.001). A statistically significant improvement in the variable oxygen saturation / fraction inspired by oxygen is observed in patients who used alternative CPAP (p = 0.040) CONCLUSION: The use of these devices has helped the ventilatory work of several patients by improving their oxygenation parameters. To better observe the evolution of patients undergoing this therapy and compare them with patients with other types of ventilatory support, further studies are necessary. Palabras clave: COVID 19 Insuficiencia respiratoria CPAP Metodos alternativos de cpap para el tratamiento de insuficiencia respiratoria grave secundaria a neumonia por COVID 19 r e s u m e n Introducción: El uso de dispositivos que aportan presión positiva continua en la vía aérea ha demostrado mejoría en diversas patologías que producen insuficiencia respiratoria. En el episodio de pandemia por COVID 19 el uso de estos dispositivos se ha generalizado, pero, debido a la escasez de dispositivos convencionales de CPAP, se han fabricado dispositivos alternativos. El objetivo de este estudio es describir el uso de estos dispositivos, así como su eficacia. Material y métodos: Se recogen datos de pacientes ingresados por Neumonía por COVID 19 en el Hospital de campaña de IFEMA. Se recogen datos de pacientes con insuficiencia respiratoria y necesidad de soporte ventilatorio. Resultados: Estudio realizado sobre un total de 23 pacientes, con fecha ingreso en IFEMA. Se empleó CPAP alternativa en cinco pacientes (21,7%), mientras que en los 18 pacientes restantes (78,3%) se usó soporte ventilatorio con mascarilla reservorio o Ventimask efecto Venturi. Se observa un aumento progresivo de la saturación en aquellos pacientes en los que se empleó CPAP alternativa (de 94% de promedio a 98% y 99% de promedio tras 30 y 60 minutos con la máscara, respectivamente), aunque este cambio no resultó significativo (p = 0,058 y p = 0,122 respectivamente). No se observó un cambio significativo de frecuencia respiratoria al inicio y final de la medición en pacientes que usaron CPAP alternativa (p = 0,423) pero si entre los que no la usaron (p = 0,001). Se observa una mejoría estadísticamente significativa en la variable Saturación de oxigeno / Fracción inspirado de oxígeno en los pacientes que usaron CPAP alternativa (p = 0,040) Conclusión: El uso de estos dispositivos ha ayudado al trabajo ventilatorio de varios pacientes mejorando sus parámetros de oxigenación. Para observar mejor la evolución de los pacientes sometidos a esta terapia y compararlos con pacientes con otro tipo de soporte ventilatorio, son necesarios más estudios en los que se aleatorice su uso. © 2020 Publicado por Elsevier España, S.L.U. Applying continuous positive airway pressure (CPAP) results in the deployment or recruitment of partially or totally collapsed alveolar units, improves lung compliance, and increases transpulmonary pressure and functional residual capacity. This implies improved respiration, as well as gas exchange. 1 At the haemodynamic level, applying CPAP results in decreased pre-load and post-load (by reducing venous return and left ventricular wall systolic pressure), with a slight decrease in systolic blood pressure and cardiac output in patients with normal heart function. In patients suffering from heart failure with increased pulmonary capillary pressure and hypervolaemia, the cardiac output may increase. 2 When CPAP is compared to conventional oxygenation systems, it shows a significant reduction in the need for intubation (50-60%) as well as lower in-hospital mortality (40-47%), and it is considered the oxygen therapy system of choice for many pathologies. 3 Recently, a study 4 suggested that the use of a CPAP device would limit the spread of the virus into the room air. Its use has also been indicated to avoid or delay admission to the intensive care unit (ICU) 5 and various publications have reported the usefulness of CPAP in acute lung oedema [6] [7] [8] and its application in the emergency department. 9 The European Society for Intensive Care Medicine has recommended the use of CPAP in patients with acute respiratory failure due to COVID-19. 10, 11 However, during the COVID-19 pandemic when the healthcare system has been under extreme demand, there have been times when there have not been enough conventional CPAP systems available on the market to treat these patients. To ensure ventilatory support to patients with acute respiratory failure secondary to COVID-19, various alternative systems were developed that were capable of producing CPAP. The devices in use have been modified throughout this opening gambit against the disease. The most popular alternative devices were developed by professionals from the ICUs of the Príncipe de Asturias University Hospital and the Henares University Hospital. The elements used for their assembly are similar, namely: In the case of the first device, the T-piece connecting the various elements is manufactured with 3 D printers, specifically designed for this device. Manufacturing has been carried out by Hewlett Packard ® . The objective of this study is to verify the efficacy of these devices in the clinical and respiratory status of the patients to whom they are applied. Our hypothesis is that the use of these alternative devices improves the patient's ventilatory status more quickly than conventional oxygen therapy. It is a descriptive observational study in which clinicalepidemiological data are collected from patients of legal age who were treated at the IFEMA Field Hospital, with an admission date between 24 March and 28 April, for pneumonia due to SARS CoV-2 and who developed respiratory failure (oxygen saturation [SatO2] < 93 and oxygen saturation/fraction of inspired oxygen [SatO2/FiO2] < 300), and who required the use of a reservoir mask or a Venturi effect Ventimask, as well as alternative CPAP devices. The following variables were collected: The compilation of the variables was obtained from the computer system where the patient clinical records were logged. There was no clear directive for the use of the alternative CPAP. It was used in cases of respiratory failure refractory to conventional oxygen therapy with a partial pressure of oxygen index (PaO2)/RR lower than 150. Patients were divided into two groups: those who were given conventional oxygen therapy exclusively; and those who were given alternative CPAP. The possible association between the patient characteristics (demographic data, risk factors, and drug treatment) and the use of alternative CPAP was studied using Pearson's chi-square test and/or Fisher's exact test, while possible differences in terms of biochemical parameters were analysed with the Student's t-test. The abovementioned analyses were carried out with the SPSS V.20 program (IBM Inc., Chicago, Il., USA), and statistically significant associations/differences were considered to exist when the p-value was below 0.05. Furthermore, linear regression was used to compare the changes (difference between the initial and final values after the use of oxygen therapy) of SatO2, RR and the oxygen saturation analysis (SpO2)/FiO2 among patients who used CPAP and those who did not use this alternative. For this, the R lme4 package, version 3.4 (RCoreTeam, 2017) was used. 12 All patients who met the inclusion criteria and agreed to participate in the study filled out an informed consent form. Said document collected the most important information of the study about the patient, the possible adverse effects, confidentiality and the right to withdraw at any time. The study has received a positive opinion from the Clinical Research and Ethics Committee of the San Carlos Clinical University Hospital. A total of 23 patients were recruited. 52.2% (n = 12) were males, and the sex of one patient was not available. The mean age was 63 years (standard deviation [SD] = 11.3), the youngest patient was 44 years old and the oldest patient was 85 years old. The personal history of the patients was as follows: 52.2% (n = 12) had arterial hypertension, 13.0% (n = 3) had diabetes mellitus, 26.1% (n = 6) were obese, only 8.7% (n = 2) suffered from ischemic heart disease, 21.7% (n = 5) chronic kidney disease, 13% (n = 3) were smokers and 26.1% (n = 6) suffered from lung disease, this being, specifically, asthma in four patients, COPD in two, and obstructive sleep apnea syndrome (OSAS) in one patient. The onset of symptoms in all recruited patients was between 16 March and 12 April. The mean values of the biochemical parameters (and SD) were the following: D-dimer = 2,053 ng/dL (3,178.8); IL-6 = 29.3 pg/mL (21.0); ferritin = 1,052 g/L (537.7). The medicinal products used as treatment for COVID-19 were the following: hydroxychloroquine for 100% study patients; lopinavir/ritonavir 56.5% (n = 13); tocilizumab 60.9% (n = 14); corticosteroids 95.7% (n = 22); antibiotics were azithromycin in 82.6% (n = 19) and ceftriaxone in 13.0% (n = 3). Alternative CPAP was used in five patients (21.7%), but was not used in the other 18 (78.3%). Table 1 shows the temporal sequence of the ventilatory support of the recruited patients. The overall mean initial SatO2 was 96% (2.25). The SatO2 prior to the use of CPAP in the patients in whom this alternative was used, was two percentage units lower (95% CI between -0.13 and 4.75) than the initial saturation registered in the rest of the patients ( Table 2) . A progressive increase in SatO2 was observed in those patients in whom alternative CPAP was used, from an initial average of 94% to a mean saturation of 98 and 99% after 30 and 60 min, respectively. After removal of the device, the mean saturation of these patients was 96% (2.08), while that recorded at the same time in non-CPAP patients was 95% (1.44), with the increase achieved with CPAP being significantly higher (p = 0.013). The overall mean initial RR was 22 rpm (5.51). The CPAP group was seven units (95% CI between 0.1 and 12.0) higher than that registered in patients who did not go on to receive this alternative ( Table 2) . After the use of the CPAP, the RR remained at values similar to the initial values (final mean =27 rpm, SD = 9.64), while the RR registered in the rest of the patients who did not go on to receive this alternative decreased to a mean of 15 rpm (p = 0.033) ( Table 2) . The overall baseline SpO2/FiO2 was 164.38 (104.22). The CPAP group was 74.8 units (95% CI between 11.3 and 138.2), so it was lower than that registered in patients who did not go on to receive this alternative (Table 2 ). After the use of CPAP, the mean SpO2/FiO2 went up to 186.73 units, reaching a final value of 293.33 (75.04), similar to that reached in the rest of the patients who did not go on to receive the alternative (mean = 299.50, SD = 106.91), so both approaches were equally useful in restoring SpO2/FiO2 (p = 0.759) ( Table 2) . One patient had a sensation of moderate dyspnea and two had mild dyspnea prior to being given the alternative CPAP, and the other two patients who used CPAP did not report a sensation of dyspnea. The CPAP used in all cases had a valve in the lower part (alternative CPAP type A) and the PEEP averaged 9.50 cm H2O, with an SD of 1.12; mask tolerance was good in all five cases and, none of the patients with alternative CPAP required the administration of opioids. We found no significant differences in relation to the personal history between patients who received alternative CPAP and those who did not (Table 3) . On the other hand, an association was observed between patients with high ferritin levels and the use of the alternative CPAP (Table 4) . No association between the drugs used to treat the infection and the need for alternative ventilatory support was found (Table 5 ). Based on our data, it appears that the use of the alternative CPAP improves the ventilatory status of patients with respiratory failure refractory to conventional oxygen therapy. In patients with acute respiratory distress syndrome, heterogeneity in the filling of the lung parenchyma leads to the appearance of both distended and collapsed areas. Protective ventilation strategies based on the use of low volumes have shown, in this context, an increase in survival. To distend the lung, in addition to using the PEEP, recruitment manoeuvres are used, although this is still under debate. 13 To develop this PEEP, the use of non-invasive mechanical ventilation is ideal. 9 However, the high number of patients with severe respiratory failure and the lack of non-invasive ventilation devices imposed the use of alternative CPAPs that were capable of producing this PEEP. A priori, the patients who were given the CPAP did not have a different saturation than the rest. In the case series, it is observed that these devices were indicated for respiratory work, because the initial saturation levels were similar in both groups, but the respiratory rate differed, being much higher in the alternative CPAP group prior to its use. Even so, after a while, the SatO2 increased in the alternative CPAP group and decreased in the other group, contrary to the respiratory rate that remained on a similar level. If we unite the SatO2/FiO2 variables, it is seen that there is significant improvement in the patients who were given the alternative CPAP. The usefulness of SatO2/FiO2 is comparable to PaO2/FiO2 (PAFi) for the diagnosis of respiratory distress. 14, 15 SpO2/FiO2 has proved to be comparable to PAFi in patients with ventilatory function deterioration and can be a reliable indicator of the need for escalating the ventilatory support. Patients with a relationship between the SatO2 and an FiO2 lower than 100 or 200 should be candidates for this type of therapy. Another interesting fact is that no relationship was found between the use of ventilatory support and previous pathologies. If we look for a relationship in the laboratory levels of the patients whose ventilatory levels were worst, we find only one association, namely ferritin. Higher ferritin values prove to have a worse prognosis, as shown by other recently published studies. 16 The most important limitations of the study are that the sample size was reduced due to the closure of the field hospital, and the heterogeneity in the retrospective data collection as dynamic changes were made in the hospital every day. The use of these devices has helped to reduce the ventilatory work of several patients, improving their oxygenation parameters. More studies are needed to better observe the evolution of patients undergoing this therapy and to compare them with patients given another type of ventilatory support. The use of devices invented on the flyby healthcare professionals has been the result of wellunderstood improvisation and the need to adapt to the times we are living through. Recent articles 17 have shown the same difficulties we encountered, and which have been overcome thanks to the contribution of many professionals from different healthcare levels. This is one more example of everything that has happened in recent weeks. This article has not received funding. Physiological response of hypoxemic patients to different modes of noninvasive ventilation Cardiac and respiratory effects of continuous positive airway pressure and noninvasive ventilation in acute cardiac pulmonary edema Noninvasive Ventilation in Acute Cardiogenic Pulmonary EdemaSystematic Review and Meta-analysis Minimise nosocomial spread of 2019-nCoV when treating acute respiratory failure The use of helmets to deliver non-invasive continuous positive airway pressure in hypoxemic acute respiratory failure A 64-year old man who sustained many episodes of acute cardiogenic pulmonary edema successfully treated with Boussignac continuous positive airway pressure: A case report Implementation of Boussignac continuous positive airway pressure in the coronary care unit: experiences and attitudes Boussignac continuous positive airway pressure for the managemet of acute cardiogenic pulmonary edema: prospective study with a retrospective control group Boussignac continuous positive airway pressure device in the emergency care of acute cardiogenic pulmonary oedema: a randomized pilot study Surviving Sepsis Campaign: Guidelines on the Management of Critically Ill Adults with Coronavirus Disease 2019 (COVID-19). European Society of Intensive Care Medicine Soporte respiratorio en el paciente adulto con insuficiencia respiratoria aguda secundaria a COVID-19 en urgencias y emergencias Fitting Linear Mixed-Effects Models Using lme4 Alveolar recruitment maneuvers in respiratory distress síndrome Clinical Characteristics and Outcomes Are Similar in ARDS Diagnosed by Oxygen Saturation/Fio2 Ratio Compared With Pao2/Fio2 Ratio Comparison of the spo2/fio2 ratio and the pao2/fio2 ratio in patients with acute lung injury or acute respiratory distress syndrome Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study. The lancet Epidemia por COVID-19 en Madrid: crónica de un reto The authors declare that they have no conflict of interest. Dr Federico Gordo of the HU Henares and Dr María Trascasa of the HU Príncipe de Asturias, and their teams, for sharing their alternative CPAP innovations with the IFEMA Field Hospital.