Gravity predominates over ventilatory pattern in the prevention of ventilator-associated pneumonia

Gianluigi Li Bassi, Joan Daniel Marti, Lina Saucedo, Montserrat Rigol, Ignasi Roca, Maria Cabanas, Laura Muñoz, Otavio Tavares Ranzani, Valeria Giunta, Nestor Luque, Mariano Esperatti, Albert Gabarrus, Laia Fernandez, Mariano Rinaudo, Miguel Ferrer, Jose Ramirez, Jordi Vila, Antoni Torres

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

OBJECTIVE:: In the semirecumbent position, gravity-dependent dissemination of pathogens has been implicated in the pathogenesis of ventilator-associated pneumonia. We compared the preventive effects of a ventilatory strategy, aimed at decreasing pulmonary aspiration and enhancing mucus clearance versus the Trendelenburg position. DESIGN:: Prospective randomized animal study. SETTING:: Animal research facility, University of Barcelona, Spain. SUBJECTS:: Twenty-four Large White-Landrace pigs. INTERVENTIONS:: Pigs were intubated and on mechanical ventilation for 72 hours. Following surgical preparation, pigs were randomized to be positioned: 1) in semirecumbent/prone position, ventilated with a duty cycle (TITTOT) of 0.33 and without positive end-expiratory pressure (control); 2) as in the control group, positive end-expiratory pressure of 5cm H2O and TITTOT to achieve a mean expiratory-inspiratory flow bias of 10L/min (treatment); 3) in Trendelenburg/prone position and ventilated as in the control group (Trendelenburg). Following randomization, Pseudomonas aeruginosa was instilled into the oropharynx. MEASUREMENTS AND MAIN RESULTS:: Mucus clearance rate was measured through fluoroscopic tracking of tracheal markers. Microspheres were instilled into the subglottic trachea to assess pulmonary aspiration. Ventilator-associated pneumonia was confirmed by histological/microbiological studies. The mean expiratory-inspiratory flow in the treatment, control, and Trendelenburg groups were 10.7±1.7, 1.8±3.7 and 4.3±2.8L/min, respectively (p <0.001). Mucus clearance rate was 11.3±9.9mm/min in the Trendelenburg group versus 0.1±1.0 in the control and 0.2±1.0 in the treatment groups (p = 0.002). In the control group, we recovered 1.35% ± 1.24% of the instilled microspheres per gram of tracheal secretions, whereas 0.22% ± 0.25% and 0.97% ± 1.44% were recovered in the treatment and Trendelenburg groups, respectively (p = 0.031). Ventilator-associated pneumonia developed in 66.67%, 85.71%, and 0% of the animals in the control, treatment, and Trendelenburg groups (p <0.001). CONCLUSIONS:: The Trendelenburg position predominates over expiratory flow bias and positive end-expiratory pressure in the prevention of gravity-dependent translocation of oropharyngeal pathogens and development of ventilator-associated pneumonia. These findings further substantiate the primary role of gravity in the pathogenesis of ventilator-associated pneumonia.

Original languageEnglish
JournalCritical Care Medicine
Volume42
Issue number9
DOIs
Publication statusPublished - 2014

Fingerprint

Ventilator-Associated Pneumonia
Gravitation
Head-Down Tilt
Positive-Pressure Respiration
Mucus
Prone Position
Control Groups
Swine
Microspheres
Therapeutics
Lung
Oropharynx
Random Allocation
Trachea
Artificial Respiration
Spain
Pseudomonas aeruginosa

Keywords

  • mechanical ventilation
  • mucus clearance
  • semirecumbent position
  • ventilator-associated pneumonia

ASJC Scopus subject areas

  • Critical Care and Intensive Care Medicine

Cite this

Gravity predominates over ventilatory pattern in the prevention of ventilator-associated pneumonia. / Li Bassi, Gianluigi; Marti, Joan Daniel; Saucedo, Lina; Rigol, Montserrat; Roca, Ignasi; Cabanas, Maria; Muñoz, Laura; Ranzani, Otavio Tavares; Giunta, Valeria; Luque, Nestor; Esperatti, Mariano; Gabarrus, Albert; Fernandez, Laia; Rinaudo, Mariano; Ferrer, Miguel; Ramirez, Jose; Vila, Jordi; Torres, Antoni.

In: Critical Care Medicine, Vol. 42, No. 9, 2014.

Research output: Contribution to journalArticle

Li Bassi, G, Marti, JD, Saucedo, L, Rigol, M, Roca, I, Cabanas, M, Muñoz, L, Ranzani, OT, Giunta, V, Luque, N, Esperatti, M, Gabarrus, A, Fernandez, L, Rinaudo, M, Ferrer, M, Ramirez, J, Vila, J & Torres, A 2014, 'Gravity predominates over ventilatory pattern in the prevention of ventilator-associated pneumonia', Critical Care Medicine, vol. 42, no. 9. https://doi.org/10.1097/CCM.0000000000000487
Li Bassi, Gianluigi ; Marti, Joan Daniel ; Saucedo, Lina ; Rigol, Montserrat ; Roca, Ignasi ; Cabanas, Maria ; Muñoz, Laura ; Ranzani, Otavio Tavares ; Giunta, Valeria ; Luque, Nestor ; Esperatti, Mariano ; Gabarrus, Albert ; Fernandez, Laia ; Rinaudo, Mariano ; Ferrer, Miguel ; Ramirez, Jose ; Vila, Jordi ; Torres, Antoni. / Gravity predominates over ventilatory pattern in the prevention of ventilator-associated pneumonia. In: Critical Care Medicine. 2014 ; Vol. 42, No. 9.
@article{de1a391fdf1e4a0694ada1f1bbbf1326,
title = "Gravity predominates over ventilatory pattern in the prevention of ventilator-associated pneumonia",
abstract = "OBJECTIVE:: In the semirecumbent position, gravity-dependent dissemination of pathogens has been implicated in the pathogenesis of ventilator-associated pneumonia. We compared the preventive effects of a ventilatory strategy, aimed at decreasing pulmonary aspiration and enhancing mucus clearance versus the Trendelenburg position. DESIGN:: Prospective randomized animal study. SETTING:: Animal research facility, University of Barcelona, Spain. SUBJECTS:: Twenty-four Large White-Landrace pigs. INTERVENTIONS:: Pigs were intubated and on mechanical ventilation for 72 hours. Following surgical preparation, pigs were randomized to be positioned: 1) in semirecumbent/prone position, ventilated with a duty cycle (TITTOT) of 0.33 and without positive end-expiratory pressure (control); 2) as in the control group, positive end-expiratory pressure of 5cm H2O and TITTOT to achieve a mean expiratory-inspiratory flow bias of 10L/min (treatment); 3) in Trendelenburg/prone position and ventilated as in the control group (Trendelenburg). Following randomization, Pseudomonas aeruginosa was instilled into the oropharynx. MEASUREMENTS AND MAIN RESULTS:: Mucus clearance rate was measured through fluoroscopic tracking of tracheal markers. Microspheres were instilled into the subglottic trachea to assess pulmonary aspiration. Ventilator-associated pneumonia was confirmed by histological/microbiological studies. The mean expiratory-inspiratory flow in the treatment, control, and Trendelenburg groups were 10.7±1.7, 1.8±3.7 and 4.3±2.8L/min, respectively (p <0.001). Mucus clearance rate was 11.3±9.9mm/min in the Trendelenburg group versus 0.1±1.0 in the control and 0.2±1.0 in the treatment groups (p = 0.002). In the control group, we recovered 1.35{\%} ± 1.24{\%} of the instilled microspheres per gram of tracheal secretions, whereas 0.22{\%} ± 0.25{\%} and 0.97{\%} ± 1.44{\%} were recovered in the treatment and Trendelenburg groups, respectively (p = 0.031). Ventilator-associated pneumonia developed in 66.67{\%}, 85.71{\%}, and 0{\%} of the animals in the control, treatment, and Trendelenburg groups (p <0.001). CONCLUSIONS:: The Trendelenburg position predominates over expiratory flow bias and positive end-expiratory pressure in the prevention of gravity-dependent translocation of oropharyngeal pathogens and development of ventilator-associated pneumonia. These findings further substantiate the primary role of gravity in the pathogenesis of ventilator-associated pneumonia.",
keywords = "mechanical ventilation, mucus clearance, semirecumbent position, ventilator-associated pneumonia",
author = "{Li Bassi}, Gianluigi and Marti, {Joan Daniel} and Lina Saucedo and Montserrat Rigol and Ignasi Roca and Maria Cabanas and Laura Mu{\~n}oz and Ranzani, {Otavio Tavares} and Valeria Giunta and Nestor Luque and Mariano Esperatti and Albert Gabarrus and Laia Fernandez and Mariano Rinaudo and Miguel Ferrer and Jose Ramirez and Jordi Vila and Antoni Torres",
year = "2014",
doi = "10.1097/CCM.0000000000000487",
language = "English",
volume = "42",
journal = "Critical Care Medicine",
issn = "0090-3493",
publisher = "Lippincott Williams and Wilkins",
number = "9",

}

TY - JOUR

T1 - Gravity predominates over ventilatory pattern in the prevention of ventilator-associated pneumonia

AU - Li Bassi, Gianluigi

AU - Marti, Joan Daniel

AU - Saucedo, Lina

AU - Rigol, Montserrat

AU - Roca, Ignasi

AU - Cabanas, Maria

AU - Muñoz, Laura

AU - Ranzani, Otavio Tavares

AU - Giunta, Valeria

AU - Luque, Nestor

AU - Esperatti, Mariano

AU - Gabarrus, Albert

AU - Fernandez, Laia

AU - Rinaudo, Mariano

AU - Ferrer, Miguel

AU - Ramirez, Jose

AU - Vila, Jordi

AU - Torres, Antoni

PY - 2014

Y1 - 2014

N2 - OBJECTIVE:: In the semirecumbent position, gravity-dependent dissemination of pathogens has been implicated in the pathogenesis of ventilator-associated pneumonia. We compared the preventive effects of a ventilatory strategy, aimed at decreasing pulmonary aspiration and enhancing mucus clearance versus the Trendelenburg position. DESIGN:: Prospective randomized animal study. SETTING:: Animal research facility, University of Barcelona, Spain. SUBJECTS:: Twenty-four Large White-Landrace pigs. INTERVENTIONS:: Pigs were intubated and on mechanical ventilation for 72 hours. Following surgical preparation, pigs were randomized to be positioned: 1) in semirecumbent/prone position, ventilated with a duty cycle (TITTOT) of 0.33 and without positive end-expiratory pressure (control); 2) as in the control group, positive end-expiratory pressure of 5cm H2O and TITTOT to achieve a mean expiratory-inspiratory flow bias of 10L/min (treatment); 3) in Trendelenburg/prone position and ventilated as in the control group (Trendelenburg). Following randomization, Pseudomonas aeruginosa was instilled into the oropharynx. MEASUREMENTS AND MAIN RESULTS:: Mucus clearance rate was measured through fluoroscopic tracking of tracheal markers. Microspheres were instilled into the subglottic trachea to assess pulmonary aspiration. Ventilator-associated pneumonia was confirmed by histological/microbiological studies. The mean expiratory-inspiratory flow in the treatment, control, and Trendelenburg groups were 10.7±1.7, 1.8±3.7 and 4.3±2.8L/min, respectively (p <0.001). Mucus clearance rate was 11.3±9.9mm/min in the Trendelenburg group versus 0.1±1.0 in the control and 0.2±1.0 in the treatment groups (p = 0.002). In the control group, we recovered 1.35% ± 1.24% of the instilled microspheres per gram of tracheal secretions, whereas 0.22% ± 0.25% and 0.97% ± 1.44% were recovered in the treatment and Trendelenburg groups, respectively (p = 0.031). Ventilator-associated pneumonia developed in 66.67%, 85.71%, and 0% of the animals in the control, treatment, and Trendelenburg groups (p <0.001). CONCLUSIONS:: The Trendelenburg position predominates over expiratory flow bias and positive end-expiratory pressure in the prevention of gravity-dependent translocation of oropharyngeal pathogens and development of ventilator-associated pneumonia. These findings further substantiate the primary role of gravity in the pathogenesis of ventilator-associated pneumonia.

AB - OBJECTIVE:: In the semirecumbent position, gravity-dependent dissemination of pathogens has been implicated in the pathogenesis of ventilator-associated pneumonia. We compared the preventive effects of a ventilatory strategy, aimed at decreasing pulmonary aspiration and enhancing mucus clearance versus the Trendelenburg position. DESIGN:: Prospective randomized animal study. SETTING:: Animal research facility, University of Barcelona, Spain. SUBJECTS:: Twenty-four Large White-Landrace pigs. INTERVENTIONS:: Pigs were intubated and on mechanical ventilation for 72 hours. Following surgical preparation, pigs were randomized to be positioned: 1) in semirecumbent/prone position, ventilated with a duty cycle (TITTOT) of 0.33 and without positive end-expiratory pressure (control); 2) as in the control group, positive end-expiratory pressure of 5cm H2O and TITTOT to achieve a mean expiratory-inspiratory flow bias of 10L/min (treatment); 3) in Trendelenburg/prone position and ventilated as in the control group (Trendelenburg). Following randomization, Pseudomonas aeruginosa was instilled into the oropharynx. MEASUREMENTS AND MAIN RESULTS:: Mucus clearance rate was measured through fluoroscopic tracking of tracheal markers. Microspheres were instilled into the subglottic trachea to assess pulmonary aspiration. Ventilator-associated pneumonia was confirmed by histological/microbiological studies. The mean expiratory-inspiratory flow in the treatment, control, and Trendelenburg groups were 10.7±1.7, 1.8±3.7 and 4.3±2.8L/min, respectively (p <0.001). Mucus clearance rate was 11.3±9.9mm/min in the Trendelenburg group versus 0.1±1.0 in the control and 0.2±1.0 in the treatment groups (p = 0.002). In the control group, we recovered 1.35% ± 1.24% of the instilled microspheres per gram of tracheal secretions, whereas 0.22% ± 0.25% and 0.97% ± 1.44% were recovered in the treatment and Trendelenburg groups, respectively (p = 0.031). Ventilator-associated pneumonia developed in 66.67%, 85.71%, and 0% of the animals in the control, treatment, and Trendelenburg groups (p <0.001). CONCLUSIONS:: The Trendelenburg position predominates over expiratory flow bias and positive end-expiratory pressure in the prevention of gravity-dependent translocation of oropharyngeal pathogens and development of ventilator-associated pneumonia. These findings further substantiate the primary role of gravity in the pathogenesis of ventilator-associated pneumonia.

KW - mechanical ventilation

KW - mucus clearance

KW - semirecumbent position

KW - ventilator-associated pneumonia

UR - http://www.scopus.com/inward/record.url?scp=84906789995&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84906789995&partnerID=8YFLogxK

U2 - 10.1097/CCM.0000000000000487

DO - 10.1097/CCM.0000000000000487

M3 - Article

C2 - 24979484

AN - SCOPUS:84906789995

VL - 42

JO - Critical Care Medicine

JF - Critical Care Medicine

SN - 0090-3493

IS - 9

ER -