Effect of Trendelenburg position during prone ventilation in fifteen COVID-19 patients. Observational study

Background Prone position ventilation has shown to improve oxygenation and mortality in severe ARDS. The data of prone position ventilation during severe ARDS secondary to COVID-19 have shown similar benefit in oxygenation and mortality. Usually, patient placed in prone position are placed flat or in reverse Trendelenburg positioning to decrease risk of aspiration and abdominal girth compressing the chest. To date, no studies are available to compare the effects of positioning the bed in different angles during the prone position ventilation. Methods An observational study in fifteen patients with severe ARDS secondary to COVID-19 who were placed in the prone position for the first time. All the patients were sedated and chemically paralyzed with no spontaneous effort. All patients were ventilated with the pressure-controlled mode with set PEEP according to the pressure-volume curves. Five patients had esophageal balloon manometry to estimate pleural pressures and trans-pulmonary pressures. Patients were initially placed in reverse Trendelenburg position and later in Trendelenburg position. Tidal volume and respiratory compliance were observed for 30 minutes after bed positioning has been achieved. Tidal volume and total respiratory compliance in both Trendelenburg and reverse Trendelenburg position were compared. Ventilator settings were not changed during the observation. No patients were suspected of increased intra-cranial or intra-ocular pressures. T-test was done to compare the values. Results Tidal volume significantly increased by 80.26 ± 23.4 ml/breath (95% CI 37.7 - 122.9) from 391.3 ± 52.7 to 471.6 ± 60.9 (20.5%) P 0.001. The respiratory system compliance significantly increased by 4.9 ml/cmH2O (95% CI 1.4 - 8.4) from 34.6 ± 4.7 to 39.5 ± 4.6 (14%) P 0.001. Of the five patients with esophageal balloon, the lung compliance significantly increased by 16.7 ml/cmH2O (95% CI 12.8 – 20.6) from 66.6 ± 1.7 to 83.3 ± 3.3 (25%) P 0.001. The chest wall compliance had small but non-significant increase by 1.5 ml/cmH2O (95% CI -1.3 – 4.3) from 65 ± 1.4 to 66.5 ± 2.3 (2%) P 0.085. Conclusion In this study, statistically significant increase in tidal volume, lung and respiratory system compliance were observed in patients placed in the Trendelenburg position during prone position ventilation. The results reflect the effect of body positioning during prone position ventilation. These effects may be the reflection of altered ventilation distribution throughout the lungs and change in pleural pressure as well as trans-pulmonary pressure during body positioning. More studies need to be done to confirm and examine this phenomenon. Precautions should be taken as this maneuver can increase the intra-cranial and intra-ocular pressures. Keywords: COVID-19, Trendelenburg, Reverse Trendelenburg, ARDS

Download Full-text

Effect of changes in lung volume on respiratory system compliance in newborn infants

Journal of Applied Physiology ◽

10.1152/jappl.1989.67.3.1192 ◽

1989 ◽

Vol 67 (3) ◽

pp. 1192-1197 ◽

Cited By ~ 14

Author(s):

F. Ratjen ◽

R. Zinman ◽

A. R. Stark ◽

L. E. Leszczynski ◽

M. E. Wohl

Keyword(s):

Tidal Volume ◽

Respiratory System ◽

Lung Volume ◽

Newborn Infants ◽

Face Mask ◽

Flow Volume ◽

Respiratory System Compliance ◽

Tidal Breathing ◽

Volume Changes ◽

Passive Flow

Total respiratory system compliance (Crs) at volumes above the tidal volume (VT) was studied by use of the expiratory volume clamping (EVC) technique in 10 healthy sleeping unsedated newborn infants. Flow was measured with a pneumotachograph attached to a face mask and integrated to yield volume. Volume changes were confirmed by respiratory inductance plethysmography. Crs measured by EVC was compared with Crs during tidal breathing determined by the passive flow-volume (PFV) technique. Volume increases of approximately 75% VT were achieved with three to eight inspiratory efforts during expiratory occlusions. Crs above VT was consistently greater than during tidal breathing (P less than 0.0005). This increase in Crs likely reflects recruitment of lung units that are closed or atelectatic in the VT range. Within the VT range, Crs measured by PFV was compared with that obtained by the multiple-occlusion method (MO). PFV yielded greater values of Crs than MO (P less than 0.01). This may be due to braking of expiratory airflow after the release of an occlusion or nonlinearity of Crs. Thus both volume recruitment and airflow retardation may affect the measurement of Crs in unsedated newborn infants.

Download Full-text

The prone position is associated with a decrease in respiratory system compliance in healthy anaesthetized infants

Pediatric Anesthesia ◽

10.1046/j.1460-9592.2001.00646.x ◽

2001 ◽

Vol 11 (3) ◽

pp. 291-296 ◽

Cited By ~ 12

Author(s):

Robin G. Cox ◽

Alastair Ewen ◽

Bevin B. Bart

Keyword(s):

Prone Position ◽

Respiratory System ◽

Respiratory System Compliance

Download Full-text

Effect of Body Posture on Lung Ventilation and Oxygenation During Carbon Dioxide Pneumoperitoneum in Rabbit

Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca Veterinary Medicine ◽

10.15835/buasvmcn-vm:2020.0028 ◽

2021 ◽

Vol 78 (1) ◽

pp. 89

Author(s):

Iulia MELEGA ◽

Cosmina DEJESCU ◽

Mădălina DRAGOMIR ◽

Cecilia DANCIU ◽

Florica MATEI ◽

...

Keyword(s):

Body Position ◽

Peak Inspiratory Pressure ◽

Lung Ventilation ◽

Dynamic Compliance ◽

Inspiratory Pressure ◽

Trendelenburg Position ◽

Carbon Dioxide Pneumoperitoneum ◽

Respiratory Compliance ◽

The Creation ◽

Reverse Trendelenburg Position

This study was conducted to investigate the influence of body position on respiratory compliance and oxygenation during iatrogenic pneumoperitoneum in the rabbit. The peak inspiratory pressure, dynamic compliance, static compliance and arterial gas parameters were calculated and measured 10 min before and 30 min after the creation of pneumoperitoneum with the patient in the horizontal position, 30 min after placing the patient in the Trendelenburg position and 30 min after placing the patient in the reversed Trendelenburg position. Following the creation of pneumoperitoneum and Trendelenburg positioning, there was a significant increase in peak inspiratory pressure while dynamic and static respiratory compliance decreased. Similarly, arterial oxygenation increased during Trendelenburg position while arterial carbon pressure remained within limits during all positions. Overall, the reverse Trendelenburg position did not improve ventilation, neither the oxygenation. However, this position showed to be more appropriate because may reduce the risk of lung injury associated with high-pressure ventilation during pneumoperitoneum.

Download Full-text

Driving pressure is not associated with mortality in mechanically ventilated patients without ARDS

Critical Care ◽

10.1186/s13054-019-2698-9 ◽

2019 ◽

Vol 23 (1) ◽

Cited By ~ 10

Author(s):

Michael J. Lanspa ◽

Ithan D. Peltan ◽

Jason R. Jacobs ◽

Jeffrey S. Sorensen ◽

Lori Carpenter ◽

...

Keyword(s):

Tidal Volume ◽

Language Processing ◽

Respiratory System ◽

Linear Models ◽

Cohort Analysis ◽

Driving Pressure ◽

Respiratory System Compliance ◽

Mechanically Ventilated ◽

Volume Ventilation ◽

Comorbidity Index

Abstract Background In patients with acute respiratory distress syndrome (ARDS), low tidal volume ventilation has been associated with reduced mortality. Driving pressure (tidal volume normalized to respiratory system compliance) may be an even stronger predictor of ARDS survival than tidal volume. We sought to study whether these associations hold true in acute respiratory failure patients without ARDS. Methods This is a retrospectively cohort analysis of mechanically ventilated adult patients admitted to ICUs from 12 hospitals over 2 years. We used natural language processing of chest radiograph reports and data from the electronic medical record to identify patients who had ARDS. We used multivariable logistic regression and generalized linear models to estimate associations between tidal volume, driving pressure, and respiratory system compliance with adjusted 30-day mortality using covariates of Acute Physiology Score (APS), Charlson Comorbidity Index (CCI), age, and PaO2/FiO2 ratio. Results We studied 2641 patients; 48% had ARDS (n = 1273). Patients with ARDS had higher mean APS (25 vs. 23, p < .001) but similar CCI (4 vs. 3, p = 0.6) scores. For non-ARDS patients, tidal volume was associated with increased adjusted mortality (OR 1.18 per 1 mL/kg PBW increase in tidal volume, CI 1.04 to 1.35, p = 0.010). We observed no association between driving pressure or respiratory compliance and mortality in patients without ARDS. In ARDS patients, both ΔP (OR1.1, CI 1.06–1.14, p < 0.001) and tidal volume (OR 1.17, CI 1.04–1.31, p = 0.007) were associated with mortality. Conclusions In a large retrospective analysis of critically ill non-ARDS patients receiving mechanical ventilation, we found that tidal volume was associated with 30-day mortality, while driving pressure was not.

Download Full-text

Prone Positioning May Increase Lung Overdistension in COVID-19-Induced ARDS

10.21203/rs.3.rs-990841/v1 ◽

2021 ◽

Author(s):

Michal Otáhal ◽

Mikuláš Mlček ◽

João Batista Borges ◽

Glasiele Cristina Alcala ◽

Dominik Hladík ◽

...

Keyword(s):

Prone Position ◽

Respiratory System ◽

Supine Position ◽

Body Position ◽

Prone Positioning ◽

Respiratory System Compliance ◽

Lung Collapse ◽

Impedance Tomography ◽

Regional Lung ◽

Lung Overdistension

Abstract Background: Real-time effects of changing body position and positive end-expiratory pressure (PEEP) on regional lung overdistension and collapse in individual patients remain largely unknown and not timely monitored. The aim of this study was to individualize PEEP in supine and prone body positions seeking to reduce lung collapse and overdistension in mechanically ventilated patients with coronavirus disease (COVID-19)-induced acute respiratory distress syndrome (ARDS). We hypothesized that prone positioning with bedside titrated PEEP would provide attenuation of both overdistension and collapse.Methods: In this prospective observational study, patients with COVID-19-induced ARDS under mechanical ventilation were included. We used electrical impedance tomography (EIT) with decremental PEEP titration algorithm (PEEPEIT-titration), which provides information on regional lung overdistension and collapse, along with global respiratory system compliance, to individualize PEEP and body position. PEEPEIT-titration in supine position straightaway followed by PEEPEIT-titration in prone position were performed. Immediately before each PEEPEIT-titration, the same lung recruitment maneuver was performed: 2 min of PEEP 24 cmH2O and driving pressure of 15 cmH2O.Results: Forty-two PEEPEIT-titration were performed in ten patients (21 pairs supine and prone positions). We have found larger % of overdistension along the PEEP titration in prone than supine position (P = 0.042). A larger % of collapse along the PEEP titration was found in supine than prone position (P = 0.037). A smaller respiratory system compliance was found in prone than supine position (P < 0.0005).Conclusions: In patients with COVID-19-induced ARDS, prone body position, when compared with supine body position, decreased lung collapse at low PEEP levels, but increased lung overdistension at PEEP levels greater than 10 cm H2O.Trial registration number: NCT04460859

Download Full-text