Patient-Self Inflicted Lung Injury: A Practical Review

Patients with severe lung injury usually have a high respiratory drive, resulting in intense inspiratory effort that may even worsen lung damage by several mechanisms gathered under the name “patient-self inflicted lung injury” (P-SILI). Even though no clinical study has yet demonstrated that a ventilatory strategy to limit the risk of P-SILI can improve the outcome, the concept of P-SILI relies on sound physiological reasoning, an accumulation of clinical observations and some consistent experimental data. In this review, we detail the main pathophysiological mechanisms by which the patient’s respiratory effort could become deleterious: excessive transpulmonary pressure resulting in over-distension; inhomogeneous distribution of transpulmonary pressure variations across the lung leading to cyclic opening/closing of nondependent regions and pendelluft phenomenon; increase in the transvascular pressure favoring the aggravation of pulmonary edema. We also describe potentially harmful patient-ventilator interactions. Finally, we discuss in a practical way how to detect in the clinical setting situations at risk for P-SILI and to what extent this recognition can help personalize the treatment strategy

Continuous positive airway pressure for respiratory support during COVID-19 pandemic: a frugal approach from bench to bedside

International audienceBackground We describe a frugal approach (focusing on needs, performance, and costs) to manage a massive influx of COVID-19 patients with acute hypoxemic respiratory failure (AHRF) using the Boussignac valve protected by a filter ("Filter Frugal CPAP", FF-CPAP) in and out the ICU.Methods (1) A bench study measured the impact of two filters with different mechanical properties on CPAP performances, and pressures were also measured in patients. (2) Non-ICU healthcare staff working in COVID-19 intermediate care units were trained with a video tutorial posted on a massive open online course. (3) A clinical study assessed the feasibility and safety of using FF-CPAP to maintain oxygenation and manage patients out of the ICU during a massive outbreak.Results: Bench assessments showed that adding a filter did not affect the effective pressure delivered to the patient. The resistive load induced by the filter variably increased the simulated patient's work of breathing (6-34%) needed to sustain the tidal volume, depending on the filter's resistance, respiratory mechanics and basal inspiratory effort. In patients, FF-CPAP achieved pressures similar to those obtained on the bench. The massive training tool provided precious information on the use of Boussignac FF-CPAP on COVID-19 patients. Then 85 COVID-19 patients with ICU admission criteria over a 1-month period were studied upon FF-CPAP initiation for AHRF. FF-CPAP significantly decreased respiratory rate and increased SpO(2). Thirty-six (43%) patients presented with respiratory indications for intubation prior to FF-CPAP initiation, and 13 (36%) of them improved without intubation. Overall, 31 patients (36%) improved with FF-CPAP alone and 17 patients (20%) did not require ICU admission. Patients with a respiratory rate > 32 breaths/min upon FF-CPAP initiation had a higher cumulative probability of intubation (p < 0.001 by log-rank test).Conclusion: Adding a filter to the Boussignac valve does not affect the delivered pressure but may variably increase the resistive load depending on the filter used. Clinical assessment suggests that FF-CPAP is a frugal solution to provide a ventilatory support and improve oxygenation to numerous patients suffering from AHRF in the context of a massive outbreak

Effects of Standard-Dose Prophylactic, High-Dose Prophylactic, and Therapeutic Anticoagulation in Patients With Hypoxemic COVID-19 Pneumonia The ANTICOVID Randomized Clinical Trial

International audienceIMPORTANCE Given the high risk of thrombosis and anticoagulation-related bleeding in patients with hypoxemic COVID-19 pneumonia, identifying the lowest effective dose of anticoagulation therapy for these patients is imperative. OBJECTIVES To determine whether therapeutic anticoagulation (TA) or high-dose prophylactic anticoagulation (HD-PA) decreases mortality and/or disease duration compared with standard-dose prophylactic anticoagulation (SD-PA), and whether TA outperforms HD-PA; and to compare the net clinical outcomes among the 3 strategies. DESIGN, SETTINGS, AND PARTICIPANTS The ANTICOVID randomized clinical open-label trial included patients with hypoxemic COVID-19 pneumonia requiring supplemental oxygen and having no initial thrombosis on chest computer tomography with pulmonary angiogram at 23 health centers in France from April 14 to December 13, 2021. Of 339 patients randomized, 334 were included in the primary analysis-114 patients in the SD-PA group, 110 in the HD-PA, and 110 in the TA. At randomization, 90% of the patients were in the intensive care unit. Data analyses were performed from April 13, 2022, to January 3, 2023. INTERVENTIONS Patients were randomly assigned (1:1:1) to receive either SD-PA, HD-PA, or TA with low-molecular-weight or unfractionated heparin for 14 days. MAIN OUTCOMES AND MEASURES A hierarchical criterion of all-cause mortality followed by time to clinical improvement at day 28. Main secondary outcome was net clinical outcome at day 28 (composite of thrombosis, major bleeding, and all-cause death). RESULTS Among the study population of 334 individuals (mean [SD] age, 58.3 [13.0] years; 226 [67.7%] men and 108 [32.3%] women), use of HD-PA and SD-PA had similar probabilities of favorable outcome (47.3% [95%CI, 39.9% to 54.8%] vs 52.7%[95%CI, 45.2%to 60.1%]; P = .48), as did TA compared with SD-PA (50.9% [95%CI, 43.4%to 58.3%] vs 49.1% [95%CI, 41.7%to 56.6%]; P = .82) and TA compared with HD-PA (53.5%[95%CI 45.8% to 60.9%] vs 46.5% [95%CI, 39.1% to 54.2%]; P = .37). Net clinical outcome was met in 29.8% of patients receiving SD-PA (20.2%thrombosis, 2.6%bleeding, 14.0% death), 16.4% receiving HD-PA (5.5%thrombosis, 3.6%bleeding, 11.8%death), and 20.0% receiving TA (5.5% thrombosis, 3.6% bleeding, 12.7%death). Moreover, HD-PA and TA use significantly reduced thrombosis compared with SD-PA (absolute difference, -14.7 [95%CI -6.2 to -23.2] and -14.7 [95%CI -6.2 to -23.2], respectively). Use of HD-PA significantly reduced net clinical outcome compared with SD-PA (absolute difference, -13.5; 95%CI -2.6 to -24.3). CONCLUSIONS AND RELEVANCE This randomized clinical trial found that compared with SD-PA, neither HD-PAnor TAuse improved the primary hierarchical outcome of all-cause mortality or time to clinical improvement in patients with hypoxemicCOVID-19 pneumonia; however, HD-PA resulted in significantly better net clinical outcome by decreasing the risk of de novo thrombosis

High-Dose Dexamethasone and Oxygen Support Strategies in Intensive Care Unit Patients With Severe COVID-19 Acute Hypoxemic Respiratory Failure

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