Evaluation of Oxygenation in 129 Proning Sessions in 34 Mechanically Ventilated COVID-19 Patients

Analysis of Statistics Utilized in Primary Articles in the Journal of Intensive Care Medicine: A Prelude to Practical Pedagogy in Biostatistics

BackgroundBiostatistics is an increasing focus in current medical school curricula. This study evaluated the statistical methods utilized in a high-impact factor medical Journal to develop a guide to those statistics that can be applied to facilitate the interpretation of data for practicing physicians, fellows, residents, and medical students.MethodsIn Part 1 of our tandem manuscripts, the 100 most recent primary articles from February 2021 to December 2021 were analyzed from the Journal of Intensive Care Medicine. The evaluation consisted of study temporality, study design, types of descriptor variables, and types of statistical tests.ResultsRetrospective studies were most common (75/100, 75%), followed by prospective studies (23/100, 23%). The most popular designs were cohort (82/100, 82%), followed by case series (9/100, 9%), randomized control trials (4/100, 4%), and case-control (3/100, 3%). The most commonly utilized descriptor variables were frequency and proportion (100/100, 100%), followed by median (74/100, 74%) and mean (71/100, 71%). The chi-square test was the most frequently used statistical test (59/100, 59%), while logistic regression (48/100, 48%), Mann-Whitney-U (46/100, 46%), and two-sample independent t-test (40/100, 40%) also were popular.ConclusionThis review revealed that retrospective and cohort studies were utilized most frequently. The chi-square test was used in the majority of studies, while logistic regression was also popular. This information can help determine areas in which supplemental training will be most beneficial to improve the understanding of statistical methods in medical journals by practicing physicians, fellows, residents, and medical students. As an outgrowth of this study, we have developed a practical guide to relevant statistical methods, serving as Part 2 of these tandem manuscripts.

The effect of prone positioning on ventilator parameters, blood gas levels, and ventilator-associated pneumonia in intensive care unit patients: a randomized controlled trial

OBJECTIVES

This study was planned to compare the prone position and non-prone position groups and to evaluate arterial blood gas results, mechanical ventilator values and ventilator-associated pneumonia (VAP) status before, during, and after patients were brought back to the non-prone position.

DESIGN

This study is a randomized controlled trial with a parallel-group design and a 1:1 allocation ratio. A block randomisation method was used to ensure balanced allocation between two groups.

SETTING

The research was conducted in the 14-bed and 26-bed general ICUs of two private hospitals on the European side of Istanbul.

PARTICIPANTS

The 94 eligible participants were randomly divided into two groups. 52 participants were assigned to the prone position group, while 42 participants were assigned to the non-prone position group, which served as the control group. In the end, 40 participants were in each group.

INTERVENTION

The intervention involved placing patients in the prone position and monitoring their arterial blood gas results, mechanical ventilator values, and VAP status at multiple stages: before, during, and after returning them to the non-prone position. Each patient was followed for a minimum of 5 days.

RESULTS

The majority of the participants were male (51.2%) and aged 45-64 (48.8%). The comparison of experimental and control groups indicated statistically significant difference in saturation, FiO₂, inspiratory-expiratory tidal volume, and blood gas levels of the patients in the treatment group (p = 0.001; p < 0.01).

CONCLUSIONS

The change in the experimental group was greater than in the control group. In conclusion, the mechanical ventilator parameters and blood gas levels of the patients in the treatment group were better than those of the patients in the control group. It is recommended as an effective practice in patients receiving prone position mechanical ventilation (MV).

CLINICAL TRIAL REGISTRATION NUMBER AND REGISTRATION DATE

NCT05760716/ March 6, 2023 (This trial was registered retrospectively at ClinicalTrials.gov (Registration Number: NCT05760716) after its completion due to demanded revisions. The integrity of the data and adherence to the study protocol were ensured throughout. The trial adhered to ethical standards (ethics committee approval, informed consent) even if it was not registered prospectively).

Physiological response to prone positioning in intubated adults with COVID-19 acute respiratory distress syndrome: a retrospective study

Background

COVID-19 related acute respiratory distress syndrome (ARDS) has specific characteristics compared to ARDS in other populations. Proning is recommended by analogy with other forms of ARDS, but few data are available regarding its physiological effects in this population. This study aimed to assess the effects of proning on oxygenation parameters (PaO2/FiO2 and alveolo-arterial gradient (Aa-gradient)), blood gas analysis, ventilatory ratio (VR), respiratory system compliance (CRS) and estimated dead space fraction (VD/VT HB). We also looked for variables associated with treatment failure.

Methods

Retrospective monocentric study of intubated COVID-19 ARDS patients managed with an early intubation, low to moderate positive end-expiratory pressure and early proning strategy hospitalized from March 6 to April 30 2020. Blood gas analysis, PaO2/FiO2, Aa-gradient, VR, CRS and VD/VT HB were compared before and at the end of each proning session with paired t-tests or Wilcoxon tests (p < 0.05 considered as significant). Proportions were assessed using Fischer exact test or Chi square test.

Results

Forty-two patients were included for a total of 191 proning sessions, median duration of 16 (5–36) hours. Considering all sessions, PaO2/FiO2 increased (180 [148–210] vs 107 [90–129] mmHg, p < 0.001) and Aa-gradient decreased (127 [92–176] vs 275 [211–334] mmHg, p < 0.001) with proning. CRS (36.2 [30.0–41.8] vs 32.2 [27.5–40.9] ml/cmH2O, p = 0.003), VR (2.4 [2.0–2.9] vs 2.3 [1.9–2.8], p = 0.028) and VD/VT HB (0.72 [0.67–0.76] vs 0.71 [0.65–0.76], p = 0.022) slightly increased. Considering the first proning session, PaO2/FiO2 increased (186 [165–215] vs 104 [94–126] mmHg, p < 0.001) and Aa-gradient decreased (121 [89–160] vs 276 [238–321] mmHg, p < 0.001), while CRS, VR and VD/VT HB were unchanged. Similar variations were observed during the subsequent proning sessions. Among the patients who experienced treatment failure (defined as ICU death or need for extracorporeal membrane oxygenation), fewer expressed a positive response in terms of oxygenation (defined as increase of more than 20% in PaO2/FiO2) to the first proning (67 vs 97%, p = 0.020).

Conclusion

Proning in COVID-19 ARDS intubated patients led to an increase in PaO2/FiO2 and a decrease in Aa-gradient if we consider all the sessions together, the first one or the 4 subsequent sessions independently. When considering all sessions, CRS increased and VR and VD/VT HB only slightly increased.

Prone ventilation in intubated COVID-19 patients: a systematic review and meta-analysis

BACKGROUND

The efficacy and safety profiles of prone ventilation among intubated Coronavirus Disease 2019 (COVID-19) patients remain unclear. The primary objective was to examine the effect of prone ventilation on the ratio of arterial partial pressure of oxygen to fraction of inspired oxygen (PaO2/FiO2) in intubated COVID-19 patients.

METHODS

Databases of MEDLINE, EMBASE and CENTRAL were systematically searched from inception until March 2021. Case reports and case series were excluded.

RESULTS

Eleven studies (n = 606 patients) were eligible. Prone ventilation significantly improved PaO2/FiO2 ratio (studies: 8, n = 579, mean difference 46.75, 95% CI 33.35‒60.15, p < 0.00001; evidence: very low) and peripheral oxygen saturation (SpO2) (studies: 3, n = 432, mean difference 1.67, 95% CI 1.08‒2.26, p < 0.00001; evidence: ow), but not the arterial partial pressure of carbon dioxide (PaCO2) (studies: 5, n = 396, mean difference 2.45, 95% CI 2.39‒7.30, p = 0.32; evidence: very low), mortality rate (studies: 1, n = 215, Odds Ratio 0.66, 95% CI 0.32‒1.33, p = 0.24; evidence: very low), or number of patients discharged alive (studies: 1, n = 43, Odds Ratio 1.49, 95% CI 0.72‒3.08, p = 0.28; evidence: very low).

CONCLUSION

Prone ventilation improved PaO2/FiO2 ratio and SpO2 in intubated COVID-19 patients. Given the substantial heterogeneity and low level of evidence, more randomized- controlled trials are warranted to improve the certainty of evidence, and to examine the adverse events of prone ventilation.

Administration of enteral nutrition and gastrointestinal complications in Covid-19 critical patients in prone position

Background

The prone position (PP) used in the treatment of critically ill patients infected with SARS-CoV-2, may be a barrier to enteral nutrition (EN). This study aimed to analyze the effectiveness and complications of EN in the PP, as well as clinical outcomes.

Methods

Prospective cohort study with patients in EN and coronavirus disease 2019 (COVID-19), on mechanical ventilation (MV), which whom needed or not PP. Gastrointestinal intolerances (GII) related to PP were evaluated, and correlated with possible confounding factors. EN, days on MV, Intensive Care Unit (ICU) length of stay, hospital length of stay, ventilator-associated pneumonia (VAP) and mortality were analyzed. The data were evaluated daily and compared prone group (PG=57) and supine group (SG=69).

Results

The PP was associated with GII (P=0.000) and presented in 32 patients (26,44%) with no difference among groups. Association between epinephrine (P=0.003), vasopressin (P=0.018), and GII was observed. There was no difference between the total volume of enteral nutrition (TVEN) infused in the groups. However, the mean EN infused for the days when the patient was on PP was (70.0% ± 31.5) and for the days in supine position was (74.8% ± 27.3), P= 0.006. The PG had a longer time on MV (P=0.005) and ICU (P=0.003) and PP was associated with VAP (P=<0.001). The infused TVEN showed no association with VAP (P=0.09).

Conclusion

PP was a determining factor in GII and proved to be a risk factor for VAP, but the EN protocol seems to have ensured an adequate EN supply in PP and be a safe alternative.

Evaluation of the efficiency and complications of the consecutive proning in COVID-19 ICU: a retrospective study

Purpose

We aimed to evaluate and compare the efficacy and complications of three consecutive prone positions (PP) in COVID-19 ICU.

Materials and method

Patients with ARDS and placed in PP for 3 times (PP1, PP2, PP3) consecutively were included. Arterial blood gases (ABG), partial pressure of arterial oxygen/fraction of inspired oxygen (PaO₂/FiO₂) ratios, partial pressure of carbondioxide (PaCO₂), PEEP, and FiO₂ were recorded before (bPP), during (dPP), and after (aPP) every prone positioning. Eye, skin, nerve, and tube complications related to PP were collected.

Results

In all positions, PaO₂ value during PP was significantly higher than PaO₂ before and after prone position (p = 0.001). PaO₂ values were similar in all (PP1, PP2, PP3) bPP arterial blood gases. We found difference in PaO₂ values during prone position between the first (PP1) and second proning (PP2). When each prone was evaluated within itself, PaO₂/FiO₂ increases after proning compared to before proning. PaO₂/FiO₂ during PP were higher compared to before proning ones. PaO₂/FiO₂ during PP1 was significantly higher compared to during PP3 (p = 0.005). In PP3, PEEP values bPP, dPP, and aPP were significantly higher than PEEP values after the second prone (p = 0.02, p = 0.001, p = 0.01). In the third prone, PaCO₂ levels were higher than in PP1 and PP2. There were eye complications in 13, tube-related complications in 10, skin complications in 30, and nerve damage in 1 patient.

Conclusion

We believe that a more careful decision should be made after the second prone position in patients who have to be placed in sequential prone position.

Prone position in COVID 19-associated acute respiratory failure

PURPOSE OF REVIEW

Prone position has been widely used in the COVID-19 pandemic, with an extension of its use in patients with spontaneous breathing ('awake prone'). We herein propose a review of the current literature on prone position in mechanical ventilation and while spontaneous breathing in patients with COVID-19 pneumonia or COVID-19 ARDS.

RECENT FINDINGS

A literature search retrieved 70 studies separating whether patient was intubated (24 studies) or nonintubated (46 studies). The outcomes analyzed were intubation rate, mortality and respiratory response to prone. In nonintubated patient receiving prone position, the main finding was mortality reduction in ICU and outside ICU setting.

SUMMARY

The final results of the several randomized control trials completed or ongoing are needed to confirm the trend of these results. In intubated patients, observational studies showed that responders to prone in terms of oxygenation had a better survival than nonresponders.

Effect of prone positioning on oxygenation and static respiratory system compliance in COVID-19 ARDS vs. non-COVID ARDS

Background

Prone positioning is recommended for patients with moderate-to-severe acute respiratory distress syndrome (ARDS) receiving mechanical ventilation. While the debate continues as to whether COVID-19 ARDS is clinically different from non-COVID ARDS, there is little data on whether the physiological effects of prone positioning differ between the two conditions. We aimed to compare the physiological effect of prone positioning between patients with COVID-19 ARDS and those with non-COVID ARDS.

Methods

We retrospectively compared 23 patients with COVID-19 ARDS and 145 patients with non-COVID ARDS treated using prone positioning while on mechanical ventilation. Changes in PaO₂/FiO₂ ratio and static respiratory system compliance (Crs) after the first session of prone positioning were compared between the two groups: first, using all patients with non-COVID ARDS, and second, using subgroups of patients with non-COVID ARDS matched 1:1 with patients with COVID-19 ARDS for baseline PaO₂/FiO₂ ratio and static Crs. We also evaluated whether the response to the first prone positioning session was associated with the clinical outcome.

Results

When compared with the entire group of patients with non-COVID ARDS, patients with COVID-19 ARDS showed more pronounced improvement in PaO₂/FiO₂ ratio [adjusted difference 39.3 (95% CI 5.2–73.5) mmHg] and static Crs [adjusted difference 3.4 (95% CI 1.1–5.6) mL/cmH₂O]. However, these between-group differences were not significant when the matched samples (either PaO₂/FiO₂-matched or compliance-matched) were analyzed. Patients who successfully discontinued mechanical ventilation showed more remarkable improvement in PaO₂/FiO₂ ratio [median 112 (IQR 85–144) vs. 35 (IQR 6–52) mmHg, P = 0.003] and static compliance [median 5.7 (IQR 3.3–7.7) vs. − 1.0 (IQR − 3.7–3.0) mL/cmH₂O, P = 0.006] after prone positioning compared with patients who did not. The association between oxygenation and Crs responses to prone positioning and clinical outcome was also evident in the adjusted competing risk regression.

Conclusions

In patients with COVID-19 ARDS, prone positioning was as effective in improving respiratory physiology as in patients with non-COVID ARDS. Thus, it should be actively considered as a therapeutic option. The physiological response to the first session of prone positioning was predictive of the clinical outcome of patients with COVID-19 ARDS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-021-01819-4.

Bloodstream Infection Risk, Incidence, and Deaths for Hospitalized Patients during Coronavirus Disease Pandemic

Hospital-acquired infections are emerging major concurrent conditions during the coronavirus disease (COVID-19) pandemic. We conducted a retrospective review of hospitalizations during March‒October 2020 of adults tested by reverse transcription PCR for severe acute respiratory syndrome coronavirus 2. We evaluated associations of COVID-19 diagnosis with risk for laboratory-confirmed bloodstream infections (LCBIs, primary outcome), time to LCBI, and risk for death by using logistic and competing risks regression with adjustment for relevant covariates. A total of 10,848 patients were included in the analysis: 918 (8.5%) were given a diagnosis of COVID-19, and 232 (2.1%) had LCBIs during their hospitalization. Of these patients, 58 (25%) were classified as having central line‒associated bloodstream infections. After adjusting for covariates, COVID-19‒positive status was associated with higher risk for LCBI and death. Reinforcement of infection control practices should be implemented in COVID-19 wards, and review of superiority and inferiority ranking methods by National Healthcare Safety Network criteria might be needed.

Effect of prone position on respiratory parameters, intubation and death rate in COVID-19 patients: systematic review and meta-analysis

Prone position (PP) is known to improve oxygenation and reduce mortality in COVID-19 patients. This systematic review and meta-analysis aimed to determine the effects of PP on respiratory parameters and outcomes. PubMed, EMBASE, ProQuest, SCOPUS, Web of Sciences, Cochrane library, and Google Scholar were searched up to 1st January 2021. Twenty-eight studies were included. The Cochran's Q-test and I2 statistic were assessed heterogeneity, the random-effects model was estimated the pooled mean difference (PMD), and a meta-regression method has utilized the factors affecting heterogeneity between studies. PMD with 95% confidence interval (CI) of PaO2/FIO2 Ratio in before-after design, quasi-experimental design and in overall was 55.74, 56.38, and 56.20 mmHg. These values for Spo2 (Sao2) were 3.38, 17.03, and 7.58. PP in COVID-19 patients lead to significantly decrease of the Paco2 (PMD: - 8.69; 95% CI - 14.69 to - 2.69 mmHg) but significantly increase the PaO2 (PMD: 37.74; 95% CI 7.16-68.33 mmHg). PP has no significant effect on the respiratory rate. Based on meta-regression, the study design has a significant effect on the heterogeneity of Spo2 (Sao2) (Coefficient: 12.80; p < 0.001). No significant associations were observed for other respiratory parameters with sample size and study design. The pooled estimate for death rate and intubation rates were 19.03 (8.19-32.61) and 30.68 (21.39-40.75). The prone positioning was associated with improved oxygenation parameters and reduced mortality and intubation rate in COVID-19 related respiratory failure.