Efficacy of prone position in acute respiratory distress syndrome patients: A pathophysiology-based review

Abstract

Acute respiratory distress syndrome (ARDS) is a syndrome with heterogeneous underlying pathological processes. It represents a common clinical problem in intensive care unit patients and it is characterized by high mortality. The mainstay of treatment for ARDS is lung protective ventilation with low tidal volumes and positive end-expiratory pressure sufficient for alveolar recruitment. Prone positioning is a supplementary strategy available in managing patients with ARDS. It was first described 40 years ago and it proves to be in alignment with two major ARDS pathophysiological lung models; the "sponge lung" - and the "shape matching" -model. Current evidence strongly supports that prone positioning has beneficial effects on gas exchange, respiratory mechanics, lung protection and hemodynamics as it redistributes transpulmonary pressure, stress and strain throughout the lung and unloads the right ventricle. The factors that individually influence the time course of alveolar recruitment and the improvement in oxygenation during prone positioning have not been well characterized. Although patients' response to prone positioning is quite variable and hard to predict, large randomized trials and recent meta-analyses show that prone position in conjunction with a lung-protective strategy, when performed early and in sufficient duration, may improve survival in patients with ARDS. This pathophysiology-based review and recent clinical evidence strongly support the use of prone positioning in the early management of severe ARDS systematically and not as a rescue maneuver or a last-ditch effort.

Protective effects of the suppressed NF‐κB/TLR4 signaling pathway on oxidative stress of lung tissue in rat with acute lung injury

“…There are also a number of risk factors for the occurrence of ALI, including inflammation, infection, multiple transfusions, sepsis, smoke inhalation, pneumonia, acute pancreatitis, near‐drowning aspiration of gastric contents, and severe trauma . Currently, the only method of treatment for lung diseases is the use of lung protective ventilation with positive end‐expiratory pressure and low tidal volumes, as there is insufficiency in pharmacological therapies for preventing injury or promoting repair . Although there have been a number of therapeutic interventions recognized over the past couple of years, the occurrence of ALI cases has increased from approximately 1.5 to 75 cases per a 100 000 population, while the mortality of patients diagnosed with ARDS has reached 40% .…”

“…5 Currently, the only method of treatment for lung diseases is the use of lung protective ventilation with positive end-expiratory pressure and low tidal volumes, as there is insufficiency in pharmacological therapies for preventing injury or promoting repair. 6,7 Although there have been a number of therapeutic interventions recognized over the past couple of years, the occurrence of ALI cases has increased from approximately 1.5 to 75 cases per a 100 000 population, while the mortality of patients diagnosed with ARDS has reached 40%. 8,9 Based on this information, urgency in in discovering newer and more accurate biomarkers is imminent in order to help provide a better diagnosis along with a positive prognosis of ALI.…”

Management of Acute Respiratory Distress Syndrome in a Child With Adenovirus Pneumonia: Case Report and Literature Review

“…iNO (20 ppm) was initiated; and dobutamine was replaced with milrinone (0.5 mcg/kg/min) due to increased pulmonary artery outlet pressure. The child was placed in prone position due to refractory ARDS for the initial 12-hour period, according to current recommendations reviewed by Koulouras et al 4 On the fifth day of evolution, with no clinical improvement, methylprednisolone was used as an adjuvant measure at a dose of 4 mg/kg/day and maintained for 48 hours. Respiratory acidosis and hypoxemia persisted, with average arterial oxygen saturation (SatO 2 ) of 77% and pCO 2 >100 mmHg, radiological worsening, and bilateral interstitial pulmonary veiling.…”

Gas Exchange of prone positioning in influenza pneumonia-related acute respiratory distress syndrome: A multicenter retrospective cohort study in Taiwan

“…The survival benefit of prone positioning was confirmed in the PROSEVA study in 2013 [12] showed decreased 28-day and 90-day mortality and increased ventilator-free day only if the patients had fair lung protective strategy and longer prone positioning duration. The mechanisms of improvement oxygenation including making more homogenous ventilation, decreasing ventilationperfusion mismatch, avoiding ventilator induced lung injury, and decreasing compression by heart or abdomen [13].…”