Mechanical ventilation stands as a life-saving intervention in the management of respiratory failure. However, it carries the risk of ventilator-induced lung injury. Despite the adoption of lung-protective ventilation strategies, including lower tidal volumes and pressure limitations, mortality rates remain high, leaving room for innovative approaches. The concept of mechanical power has emerged as a comprehensive metric encompassing key ventilator parameters associated with the genesis of ventilator-induced lung injury, including volume, pressure, flow, resistance, and respiratory rate. While numerous animal and human studies have linked mechanical power and ventilator-induced lung injury, its practical implementation at the bedside is hindered by calculation challenges, lack of equation consensus, and the absence of an optimal threshold. To overcome the constraints of measuring static respiratory parameters, dynamic mechanical power is proposed for all patients, regardless of their ventilation mode. However, establishing a causal relationship is crucial for its potential implementation, and requires further research. The objective of this review is to explore the role of mechanical power in ventilator-induced lung injury, its association with patient outcomes, and the challenges and potential benefits of implementing a ventilation strategy based on mechanical power.

BACKGROUND: Noninvasive respiratory support modalities are common alternatives to mechanical ventilation in acute hypoxemic respiratory failure. However, studies historically compare noninvasive respiratory support to conventional oxygen rather than mechanical ventilation. In this study, we compared outcomes in patients with acute hypoxemic respiratory failure treated initially with noninvasive respiratory support to patients treated initially with invasive mechanical ventilation.
METHODS: This is a retrospective observational cohort study between January 1, 2018 and December 31, 2019 at a large healthcare network in the United States. We used a validated phenotyping algorithm to classify adult patients (≥18 years) with eligible International Classification of Diseases codes into two cohorts: those treated initially with noninvasive respiratory support or those treated invasive mechanical ventilation only. The primary outcome was time-to-in-hospital death analyzed using an inverse probability of treatment weighted Cox model adjusted for potential confounders. Secondary outcomes included time-to-hospital discharge alive. A secondary analysis was conducted to examine potential differences between noninvasive positive pressure ventilation and nasal high flow.
RESULTS: During the study period, 3177 patients met inclusion criteria (40% invasive mechanical ventilation, 60% noninvasive respiratory support). Initial noninvasive respiratory support was not associated with a decreased hazard of in-hospital death (HR: 0.65, 95% CI: 0.35-1.2), but was associated with an increased hazard of discharge alive (HR: 2.26, 95% CI: 1.92-2.67). In-hospital death varied between the nasal high flow (HR 3.27, 95% CI: 1.43-7.45) and noninvasive positive pressure ventilation (HR 0.52, 95% CI 0.25-1.07), but both were associated with increased likelihood of discharge alive (nasal high flow HR 2.12, 95 CI: 1.25-3.57; noninvasive positive pressure ventilation HR 2.29, 95% CI: 1.92-2.74).
CONCLUSIONS: These data show that noninvasive respiratory support is not associated with reduced hazards of in-hospital death but is associated with hospital discharge alive.

Two cases of neonatal splenic hemorrhage with acute cardiorespiratory failure are described in this report. The first case involves a full-term neonate who was found unresponsive without any witnesses and could not be successfully resuscitated. A postmortem diagnosis revealed a splenic hemorrhage. Second case is an extremely premature neonate who experienced a witnessed cardiovascular collapse on the 14th day of life. Rapid cardiovascular support was administered, resulting in a positive outcome. While splenic hemorrhage is commonly associated with traumatic events, these cases highlight the need of considering spontaneous splenic hemorrhages as a potential cause of acute neonatal compromise, even in the absence of birth-related trauma (e.g., asphyxia, prolonged labor, clavicle fractures, brachial plexus injuries). This report emphasizes the importance of including splenic hemorrhage timely in the differential diagnosis of neonatal cardiorespiratory instability, especially in the absence of more common diagnoses, and discusses the challenges associated with its recognition and treatment.

Blastomycosis can result in lung injury with high mortality rates. The literature on veno-venous extracorporeal membrane oxygenation (VV-ECMO) used as a rescue therapy is limited to case reports and small case series collected over extended time periods. This report describes the clinical course and post-hospitalization outcomes among patients with blastomycosis-induced respiratory failure requiring VV-ECMO in the most recent time frame. The data were collected retrospectively from the health records of eight patients with blastomycosis-induced respiratory failure admitted to a tertiary care center between 2019 and 2023. The mean time from the start of mechanical ventilation to ECMO initiation was 57 h. All patients survived to ECMO decannulation, and seven of them survived to hospital discharge. All six patients whose post-discharge follow-up information was available were weaned from mechanical ventilation and lived at home while two required supplemental oxygen. This includes a case where the provision of adequate ECMO support was challenging due to the patient\'s morbid obesity. The most common residual imaging abnormalities included pulmonary infiltrates and pneumatoceles. The study demonstrates the feasibility of VV-ECMO as a rescue therapy in patients with blastomycosis-related refractory respiratory failure. Rapid initiation of ECMO support in eligible patients may have contributed to the good outcomes.

Hepatopulmonary syndrome (HPS) poses a significant challenge in liver transplant patients, affecting between 10% and 30% of candidates. Historically, HPS was considered a contraindication for liver transplantation due to its association with high mortality rates. However, recent studies have shown improvements in pulmonary function post-transplant, leading to the inclusion of these patients as candidates. Despite this progress, approximately one-fifth of liver transplant recipients develop severe postoperative hypoxia, further complicating their clinical course and contributing to increased mortality. The management of post-transplant HPS involves various strategies, including extracorporeal membrane oxygenation (ECMO), although its use remains infrequently reported. Theoretical models suggest that oxygenation typically improves within 10 days post-transplant, while resolution of HPS may take 6-12 months, making ECMO an attractive possibility as a bridge to recovery in this population. We present a case were ECMO was used in this context.

This article reviews the current evidence base for racial and ethnic disparities related to acute respiratory failure. It discusses the prevailing and most studied mechanisms that underlay these disparities, analytical challenges that face the field, and then uses this discussion to frame future directions to outline next steps for developing disparities-mitigating solutions.

Presentation of congenital diaphragmatic hernia in adulthood is rare. Further, most cases are attributable to Bochdalek and Morgagni hernias with central tendon hernias being particularly uncommon. We report a case of central congenital diaphragmatic hernia in an adult presenting as large intestinal obstruction and respiratory failure. Open repair of the hernia was performed, which brought about the resolution of the patient\'s symptoms. This case report highlights the possibility for congenital diaphragmatic hernia to present in adulthood and the importance of early diagnosis and treatment in these situations.

BACKGROUND: Positive end-expiratory pressure (PEEP) is a crucial component of mechanical ventilation to improve oxygenation in critically ill patients with respiratory failure. The interaction between abdominal and thoracic compartment pressures is known well. Especially in intra-abdominal hypertension, lower PEEP may cause atelectotrauma by repetitive opening and closing of alveoli.
OBJECTIVE: In this study, it was aimed to investigate the effect of PEEP adjustment according to the intra-abdominal pressure (IAP) on oxygenation and clarify possible harms.
METHODS: Patients older than 18 were mechanically ventilated due to hypoxemic respiratory failure and had normal IAP (<15 mmHg) included in the study. Patients with severe cardiovascular dysfunction were excluded. The following PEEP levels were applied: PEEPzero of 0 cmH2O, PEEPIAP/2 = 50% of IAP, and PEEPIAP = 100% of IAP. After a 30-minute equilibration period, arterial blood gases and mean arterial pressures were measured.
RESULTS: One hundred thirty-eight patients (mean age 66.5 ± 15.9, 56.5% male) enrolled on the study. The mean IAP was 9.8 ± 3.4. Seventy-nine percent of the patients\' PaO2/FiO2 ratio was under 300 mmHg. Figure 1 shows the change in PaO2/FiO2 ratio, PaCO2, PPlato, and MAP of the patients according to the PEEP levels. Overall increases were detected in the PaO2/FiO2 ratio (P < 0.001) and Pplato (P < 0.001), while PaCO2 and MAP did not change after increasing PEEP gradually. Pairwise analyses revealed differences in PaO2/FiO2 between PEEPzero (186.4 [85.7-265.8]) and PEEPIAP/2 (207.7 [101.7-292.9]) (t = -0.77, P < 0.001), between baseline and PEEPIAP (236.1 [121.4-351.0]) (t = -1.7, P < 0.001), and between PEEPIAP/2 and PEEPIAP (t = -1.0, P < 0.001). Plato pressures were in the safe range (<30 cmH2O) at all three PEEP levels (PEEPzero = 12 [10-15], PEEPIAP/2 = 15 [13-18], PEEPIAP = 17 [14-22]).
CONCLUSIONS: In patients with acute hypoxemic respiratory failure and mechanically ventilated, PEEP adjustment according to the IAB improves oxygenation, especially in the settings of the limited source where other PEEP titration methods are absent.

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BACKGROUND: We evaluated the influence of different partial carbon dioxide pressure (PaCO2) levels on organ perfusion in patients with respiratory failure receiving pressure-support ventilation with veno-venous extracorporeal membrane oxygenation (V-V ECMO).
METHODS: In this twelve patients prospective study, ECMO gas-flow was decreased from baseline (PaCO2 < 40 mmHg) until PaCO2 increased by 5-10 mmHg (High-CO2 phase). Resistance indices of gut, spleen, and snuffbox artery, the peripheral perfusion index (PPI), and heart rate variability were measured at baseline and High-CO2 phase.
RESULTS: When PaCO2 increased from 36 (36-37) mmHg at baseline to 42 (41-43) mmHg in the High-CO2 phase (p < 0.001), PPI decreased significantly (p = 0.026). The snuffbox artery (p = 0.022), superior mesenteric artery (p = 0.042), and spleen (p = 0.012) resistance indices increased significantly. The root mean square of successive differences (RMSSD) decreased from 19.5(18.1-22.7) to 15.9(14.4-18.6) ms (p = 0.034), and the ratio of low-frequency to high-frequency components(LF/HF) increased from 0.47 ± 0.23 to 0.70 ± 0.38 (p = 0.013).
CONCLUSIONS: High PaCO2 might cause decreased peripheral tissue and visceral organ perfusion through autonomic nervous system in patients with respiratory failure undergoing PSV with V-V ECMO.