Incorporating electrical impedance tomography to transpulmonary pressure-guided PEEP in severe ARDS with pneumothorax and multiple cavitations: a case report

Pneumothorax is a potentially fatal complication in patients with acute respiratory distress syndrome (ARDS), presenting challenges in determining the optimal positive end-expiratory pressure (PEEP) level to prevent atelectasis without exacerbating the pneumothorax. This case report describes the successful application of transpulmonary pressure and electrical impedance tomography (EIT) at the bedside to guide PEEP selection in a patient with ARDS complicated by pneumothorax due to methicillin-resistant Staphylococcus aureus infection. By using minimal PEEP to maintain positive end-expiratory transpulmonary pressure and visualizing lung reopening with EIT, the optimal PEEP level was reaffirmed, even if traditionally considered high. The patient’s condition improved, and successful weaning from the ventilator was achieved, leading to a transfer out of the intensive care unit.Clinical trial registration: https://clinicaltrials.gov/show/NCT04081142, identifier NCT04081142

The effect of blood transfusion on sublingual microcirculation in critically ill patients: A scoping review

Purpose: To investigate the effects of red blood cell (RBC) transfusion on sublingual microcirculation in critically ill patients. Methods: Systematic strategy was conducted to search studies that measured sublingual microcirculation before and after transfusion in critically ill patients. This review was reported according to the Preferred Reporting Items for Systematic Review and Meta-Analyses Scoping Review Extension. Results: The literature search yielded 114 articles. A total of 11 studies met the inclusion criteria. Observational evidence showed diffusive capacity of the microcirculation significantly improved in intraoperative and anemic hematologic patients after transfusion, while the convective parameters significantly improved in traumatic patients. RBC transfusion improved both diffusive and convective microcirculatory parameters in hypovolemic hemorrhagic shock patients. Most of the studies enrolled septic patients showed no microcirculatory improvements after transfusion. The positive effects of the leukoreduction were insufficiently supported. The effects of the storage time of the RBCs were not conclusive. The majority of the evidence supported a negative correlation between baseline proportion of perfused vessels (PPV) and changes in PPV. Conclusions: This scoping review has catalogued evidence that RBC transfusion differently improves sublingual microcirculation in different populations. The existing evidence is not sufficient to conclude the effects of the leukoreduction and storage time of RBCs

Prevalence and prognosis of respiratory pendelluft phenomenon in mechanically ventilated ICU patients with acute respiratory failure: a retrospective cohort study

BACKGROUND: Respiratory pendelluft phenomenon, defined as intrapulmonary gas redistribution caused by asynchronous alveolar ventilation, could be potentially harmful by inducing lung injury. The aim of the present study was to investigate its prevalence and prognosis in intensive care unit (ICU) patients with acute respiratory failure (ARF). METHODS: This was a retrospective observational study on 200 mechanically ventilated ARF patients treated in a tertiary ICU. The presence of pendelluft was determined using electrical impedance tomography (EIT) within 48 h after admission. Its amplitude was defined as the impedance difference between the sum of all regional tidal impedance variation and the global tidal impedance variation. A value above 2.5% (the 95th percentile from 30 healthy volunteers) was considered confirmative for its occurrence. RESULTS: Pendelluft was found in 61 patients (39 in 94 patients with spontaneous breathing, 22 in 106 receiving controlled ventilation), with an overall prevalence of 31%. Existence of spontaneous breathing and higher global inhomogeneity index were associated with pendelluft. Patients with pendelluft had a longer ICU length of stay [10 (6, 14) vs. 7 (4, 11) days; median (lower, upper quartile); p = 0.022] and shorter 14-day ventilator-free days [8 (1, 10) vs. 10 (6, 12) days; p = 0.015]. Subgroup survival analysis suggested the association between pendelluft and longer ventilation duration, which was significant only in patients with PaO(2)/FiO(2) ratio below 200 mmHg (log-rank p = 0.042). ICU mortality did not differ between the patients with and without pendelluft. CONCLUSIONS: Respiratory pendelluft occurred often in our study group and it was associated with longer ventilation duration. Early recognition of this phenomenon should trigger interventions aimed at alleviating pendelluft. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13613-022-00995-w

Whole‐process respiratory management strategies based on electrical impedance tomography in a pregnant woman with diffuse alveolar hemorrhage induced by systemic lupus erythematosus under veno‐venous extracorporeal membrane oxygenation

Abstract Electrical impedance tomography (EIT) as a bedside, noninvasive, radiation‐free technology, could quantify alveolar collapse and over‐distension and provide real‐time ventilation images of lungs. Clinical studies have shown potential benefit in reducing lung injury by EIT to guide mechanical ventilation setting in acute respiratory distress syndrome (ARDS). The respiratory management of ARDS with venous−venous extracorporeal membrane oxygenation (VV ECMO) remains a challenge for ICU doctors. Moreover, EIT has gained great interests in the respiratory management in VV ECMO therapy. Here, EIT was used for respiratory management in the presented case of a 36‐year‐old gravida with systemic lupus erythematosus, who developed severe hypoxia caused by diffuse alveolar hemorrhage. Although the patient received mechanical ventilation, VV ECMO was further used for the refractory respiratory failure. EIT was applied to titrate positive end‐expiratory pressure (PEEP), guide prone position and early mobilization, dynamic evaluating lung development during ECMO therapy. She was successfully rescued after comprehensive therapy. In summary, an EIT‐guided whole‐process respiratory management strategy that included PEEP titration, prone position, early mobilization, and dynamic lung ventilation monitoring was proposed. This case demonstrated that EIT‐guided whole‐process respiratory management strategy was feasible in the respiratory failure patient with VV ECMO therapy