Hemodynamic response to positive end-expiratory pressure and prone position in COVID-19 ARDS

Mechanical ventilation with positive end-expiratory pressure (PEEP) may prevent venous air embolism in the sitting position because cerebral venous pressure (Pcev) could be increased by the PEEP-induced increase in right atrial pressure (Pra). Whereas it is clear that there is a linear transmission of the PEEP-induced increase in Pra to Pcev while the dog is in the prone position, the mechanism of the transmission with the dog in the head-elevated position is unclear. We tested the hypothesis that a Starling resistor-type mechanism exists in the jugular veins when the head is elevated. In one group of dogs, increasing PEEP linearly increased Pcev with the dog in the prone position (head at heart level, slope = 0.851) but did not increase Pcev when the head was elevated. In another group of dogs, an external chest binder was used to produce a larger PEEP-induced increase in Pra. Further increasing Pra increased Pcev only after Pra exceeded a pressure of 19 mmHg (break pressure). This sharp inflection in the upstream (Pcev)-downstream (Pra) relationship suggests that this may be caused by a Starling resistor-type mechanism. We conclude that jugular venous collapse serves as a significant resistance in the transmission of Pra to Pcev in the head-elevated position.

Download Full-text

Prone position and positive end-expiratory pressure in acute respiratory distress syndrome*

Critical Care Medicine ◽

10.1097/01.ccm.0000094216.49129.4b ◽

2003 ◽

Vol 31 (12) ◽

pp. 2719-2726 ◽

Cited By ~ 56

Author(s):

Marc Gainnier ◽

Pierre Michelet ◽

Xavier Thirion ◽

Jean-Michel Arnal ◽

Jean-Marie Sainty ◽

...

Keyword(s):

Acute Respiratory Distress Syndrome ◽

Respiratory Distress Syndrome ◽

Respiratory Distress ◽

Prone Position ◽

Distress Syndrome ◽

Positive End Expiratory Pressure

Download Full-text

Comparison of Intra-Abdominal Pressure Among 3 Prone Positional Apparatuses After Changing From the Supine to the Prone Position and Applying Positive End-Expiratory Pressure in Healthy Euvolemic Patients

Journal of Neurosurgical Anesthesiology ◽

10.1097/ana.0000000000000257 ◽

2017 ◽

Vol 29 (1) ◽

pp. 14-20 ◽

Cited By ~ 6

Author(s):

Eugene Kim ◽

Hyun-Chang Kim ◽

Young-Jin Lim ◽

Chi-Heon Kim ◽

Seil Sohn ◽

...

Keyword(s):

Prone Position ◽

Abdominal Pressure ◽

Positive End Expiratory Pressure

Download Full-text

Continuous negative abdominal pressure: mechanism of action and comparison with prone position

Journal of Applied Physiology ◽

10.1152/japplphysiol.01125.2017 ◽

2018 ◽

Vol 125 (1) ◽

pp. 107-116 ◽

Cited By ~ 3

Author(s):

Takeshi Yoshida ◽

Doreen Engelberts ◽

Gail Otulakowski ◽

Bhushan Katira ◽

Niall D. Ferguson ◽

...

Keyword(s):

Lung Injury ◽

Prone Position ◽

Mechanism Of Action ◽

Respir Crit ◽

Vertical Gradient ◽

Lung Compliance ◽

Pleural Pressure ◽

Abdominal Pressure ◽

Prone Positioning ◽

Positive End Expiratory Pressure

We recently reported that continuous negative abdominal pressure (CNAP) could recruit dorsal atelectasis in experimental lung injury and that oxygenation improved at different transpulmonary pressure values compared with increases in airway pressure (Yoshida T, Engelberts D, Otulakowski G, Katira BH, Post M, Ferguson ND, Brochard L, Amato MBP, Kavanagh BP. Am J Respir Crit Care Med 197: 534–537, 2018). The mechanism of recruitment with CNAP is uncertain, and its impact compared with a commonly proposed alternative approach to recruitment, prone positioning, is not known. We hypothesized that CNAP recruits lung by decreasing the vertical pleural pressure (Ppl) gradient (i.e., difference between dependent and nondependent Ppl), thought to be one mechanism of action of prone positioning. An established porcine model of lung injury (surfactant depletion followed by ventilator-induced lung injury) was used. CNAP was applied using a plexiglass chamber that completely enclosed the abdomen at a constant negative pressure (−5 cmH2O). Lungs were recruited to maximal positive end-expiratory pressure (PEEP; 25 cmH2O) and deflated in steps of PEEP (2 cmH2O, 10 min each). CNAP lowered the Ppl in dependent but not in nondependent lung, and therefore, in contrast to PEEP, it narrowed the vertical Ppl gradient. CNAP increased respiratory system compliance and oxygenation and appeared to selectively displace the posterior diaphragm caudad (computerized tomography images). Compared with prone position without CNAP, CNAP in the supine position was associated with higher arterial partial pressure of oxygen and compliance, as well as greater homogeneity of ventilation. The mechanism of action of CNAP appears to be via selective narrowing of the vertical gradient of Ppl. CNAP appears to offer physiological advantages over prone positioning. NEW & NOTEWORTHY Continuous negative abdominal pressure reduces the vertical gradient in (dependent vs. nondependent) pleural pressure and increases oxygenation and lung compliance; it is more effective than prone positioning at comparable levels of positive end-expiratory pressure.

Download Full-text

Hemodynamic response to positive end-expiratory pressure following right atrium-pulmonary artery bypass (Fontan procedure)

Journal of Thoracic and Cardiovascular Surgery ◽

10.1016/s0022-5223(19)38412-0 ◽

1984 ◽

Vol 87 (6) ◽

pp. 856-861 ◽

Cited By ~ 64

Author(s):

Donald B. Williams ◽

Paul D. Kiernan ◽

Michael P. Metke ◽

H. Michael Marsh ◽

Gordon K. Danielson

Keyword(s):

Pulmonary Artery ◽

Right Atrium ◽

Artery Bypass ◽

Fontan Procedure ◽

Hemodynamic Response ◽

Positive End Expiratory Pressure

Download Full-text

Effects of positive end-expiratory pressure strategy in supine and prone position on lung and chest wall mechanics in acute respiratory distress syndrome

Annals of Intensive Care ◽

10.1186/s13613-018-0434-2 ◽

2018 ◽

Vol 8 (1) ◽

Cited By ~ 11

Author(s):

Mehdi Mezidi ◽

Francisco José Parrilla ◽

Hodane Yonis ◽

Zakaria Riad ◽

Stephan H. Böhm ◽

...

Keyword(s):

Acute Respiratory Distress Syndrome ◽

Respiratory Distress Syndrome ◽

Respiratory Distress ◽

Chest Wall ◽

Prone Position ◽

Distress Syndrome ◽

Positive End Expiratory Pressure ◽

Chest Wall Mechanics

Download Full-text

Effects of positive end-expiratory pressure on intraoperative core temperature in patients undergoing posterior spine surgery: prospective randomised trial

Journal of International Medical Research ◽

10.1177/0300060517734678 ◽

2017 ◽

Vol 46 (3) ◽

pp. 984-995

Author(s):

Hyungseok Seo ◽

Je Do Son ◽

Hyung-Chul Lee ◽

Hyung-Min Oh ◽

Chul-Woo Jung ◽

...

Keyword(s):

Prone Position ◽

Core Temperature ◽

Spine Surgery ◽

Randomised Trial ◽

Positive End Expiratory Pressure ◽

Peripheral Vasoconstriction ◽

Related Data ◽

Prospective Randomised Trial ◽

Intraoperative Hypothermia ◽

Posterior Spine Surgery

Objective Positive end-expiratory pressure (PEEP) causes carotid baroreceptor unloading, which leads to thermoregulatory peripheral vasoconstriction. However, the effects of PEEP on intraoperative thermoregulation in the prone position remain unknown. Methods Thirty-seven patients undergoing spine surgery in the prone position were assigned at random to receive either 10 cmH2O PEEP (Group P) or no PEEP (Group Z). The primary endpoint was core temperature 180 minutes after intubation. Secondary endpoints were delta core temperature (difference in core temperature between 180 minutes and immediately after tracheal intubation), incidence of intraoperative hypothermia (core temperature of <36°C), and peripheral vasoconstriction-related data. Results The median [interquartile range] core temperature 180 minutes after intubation was 36.1°C [35.9°C–36.2°C] and 36.0°C [35.9°C–36.4°C] in Groups Z and P, respectively. The delta core temperature and incidences of intraoperative hypothermia and peripheral vasoconstriction were not significantly different between the two groups. The peripheral vasoconstriction threshold (36.2°C±0.5°C vs. 36.7°C±0.6°C) was lower and the onset of peripheral vasoconstriction (66 [60–129] vs. 38 [28–70] minutes) was slower in Group Z than in Group P. Conclusions Intraoperative PEEP did not reduce the core temperature decrease in the prone position, although it resulted in an earlier onset and higher threshold of peripheral vasoconstriction.

Download Full-text

Effects of prone position and positive end-expiratory pressure on lung perfusion and ventilation*

Critical Care Medicine ◽

10.1097/ccm.0b013e31818094a9 ◽

2008 ◽

Vol 36 (8) ◽

pp. 2373-2380 ◽

Cited By ~ 22

Author(s):

Jean-Christophe Richard ◽

Fabienne Bregeon ◽

Nicolas Costes ◽

Didier L. E. Bars ◽

Christian Tourvieille ◽

...

Keyword(s):

Prone Position ◽

Lung Perfusion ◽

Positive End Expiratory Pressure

Download Full-text

Electrical impedance tomography to titrate positive end-expiratory pressure in COVID-19 acute respiratory distress syndrome

Critical Care ◽

10.1186/s13054-020-03414-3 ◽

2020 ◽

Vol 24 (1) ◽

Author(s):

François Perier ◽

Samuel Tuffet ◽

Tommaso Maraffi ◽

Glasiele Alcala ◽

Marcus Victor ◽

...

Keyword(s):

Acute Respiratory Distress Syndrome ◽

Respiratory Distress Syndrome ◽

Respiratory Distress ◽

Electrical Impedance Tomography ◽

Prone Position ◽

Electrical Impedance ◽

Distress Syndrome ◽

Positive End Expiratory Pressure ◽

Impedance Tomography ◽

Best Peep

Abstract Rationale Patients with coronavirus disease-19-related acute respiratory distress syndrome (C-ARDS) could have a specific physiological phenotype as compared with those affected by ARDS from other causes (NC-ARDS). Objectives To describe the effect of positive end-expiratory pressure (PEEP) on respiratory mechanics in C-ARDS patients in supine and prone position, and as compared to NC-ARDS. The primary endpoint was the best PEEP defined as the smallest sum of hyperdistension and collapse. Methods Seventeen patients with moderate-to-severe C-ARDS were monitored by electrical impedance tomography (EIT) and evaluated during PEEP titration in supine (n = 17) and prone (n = 14) position and compared with 13 NC-ARDS patients investigated by EIT in our department before the COVID-19 pandemic. Results As compared with NC-ARDS, C-ARDS exhibited a higher median best PEEP (defined using EIT as the smallest sum of hyperdistension and collapse, 12 [9, 12] vs. 9 [6, 9] cmH2O, p < 0.01), more collapse at low PEEP, and less hyperdistension at high PEEP. The median value of the best PEEP was similar in C-ARDS in supine and prone position: 12 [9, 12] vs. 12 [10, 15] cmH2O, p = 0.59. The response to PEEP was also similar in C-ARDS patients with higher vs. lower respiratory system compliance. Conclusion An intermediate PEEP level seems appropriate in half of our C-ARDS patients. There is no solid evidence that compliance at low PEEP could predict the response to PEEP.

Download Full-text