## 3 Results  
The research question was constructed following the PICO format (population/patient, intervention, comparator, and outcomes/outcomes). It was detailed as, \"adults with acute respiratory distress syndrome subject to invasive mechanical ventilation in an ICU (P), prone decubitus technique (I), not applicable (C), effectiveness, pressure ulcer care, changes in the patient's respiratory physiology, and recommended duration to achieve greater survival and effectiveness (0)\" (Figure 1). Below is a table that shows the search strategy used to select 21 articles (Table 1). The total number of valid articles is summarized in the Appendix A (Table A1). To determine if the PP position is effective in treating patients with ARDS due to COVID-19 disease, it is observed how PP is a strategy in ARDS, owing to the absolute conformity in the studies found in this regard [23; 24; 25]. This effectiveness is achieved in conjunction with IMV, in moderate to severe ARDS, from the second or third pronation cycle and performing prolonged cycles (about two continuous days) [25; 26; 27]. Mortality and survival are also two parameters that increase, even though there was a study carried out in 2015 that does not support the first index reviewed [27; 28]. This may be because of the fact that this procedure has never been so needed for patients with respiratory disease until the COVID-19 pandemic, which has led to its massive use and has prompted the conducting of numerous investigations in this regard [29; 30]. In those patients who ended up dying or needing alternative therapies (ECMO), PP has not been effective [31; 32]. This may be because of the fact that there are cases of ARDS that present an unchangeable or \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Item Criteria** & \
\begin{tabular}{c} **Google** \\ **Scholar** \\ \end{tabular} &
\begin{tabular}{c} **Medline/** \\ **Pubmed** \\ \end{tabular} & **Scielo** & **Dialnet** & **WOS** & **Total** \\ \hline Identified & 67 & 87 & 8 & 7 & 4 & 173 \\ Duplicates & 17 & 23 & 4 & 4 & 1 & 46 \\ Title & 19 & 22 & 5 & 2 & 1 & 49 \\ \hline Abstract & 4 & 9 & 1 & 1 & 1 & 16 \\ Text complete & 6 & 12 & 3 & 1 & 1 & 23 \\ Valid & 6 & 12 & 2 & 1 & 1 & 21 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Databases consulted. Figure 1: Flow diagram. barely modifiable prognosis with such therapy [33; 34]. It would be advisable to carry out studies in this regard to identify which cases do not respond to this strategy in order to implement it or find another strategy that is effective in order to avoid death [35; 36]. Regarding the nursing care carried out in the critical patient prone by COVID-19, it is observed that the appearance of pressure ulcers is inevitable in patients prone due to the COVID-19 disease. The risk and severity of this type of injury in pronated patients seem higher than patients in other body positions. This secondary pathology is due to the severity of the disease and the workload to which ICU personnel are subjected [37]. These professionals during the pandemic have been overwhelmed and have not had the same time to apply preventive care for pressure ulcers in these patients [38; 39]. A patient immobilized for a long time in any body position, without receiving sufficient attention, would have the same risk and severity of pressure ulcers as those obtained in these patients [40]. The rest of the articles show heterogeneous recommendations regarding the treatment of pressure ulcers, as has happened so far with pressure ulcers that appear from other body positions [40; 41]. It is concluded that there is a lack of studies that determine standardized measures of care for the development and treatment of pressure ulcers in the prone patient [42]. To identify the physiological benefits of the PP position [43; 44], it can be concluded that the main respiratory benefit achieved with the prone position is the improvement of blood oxygenation [44].