Correlation between the hysteresis of the pressure-volume curve and the recruitment-to-inflation ratio in patients with coronavirus disease 2019.

BACKGROUND: Since the response to lung recruitment varies greatly among patients receiving mechanical ventilation, lung recruitability should be assessed before recruitment maneuvers. The pressure-volume curve (PV curve) and recruitment-to-inflation ratio (R/I ratio) can be used bedside for evaluating lung recruitability and individualing positive end-expiratory pressure (PEEP). Lung tissue recruitment on computed tomography has been correlated with normalized maximal distance (NMD) of the quasi-static PV curve. NMD is the maximal distance between the inspiratory and expiratory limb of the PV curve normalized to the maximal volume. However, the relationship between the different parameters of hysteresis of the quasi-static PV curve and R/I ratio for recruitability is unknown. METHODS: We analyzed the data of 33 patients with severe coronavirus disease 2019 (COVID-19) who received invasive mechanical ventilation. Respiratory waveform data were collected from the ventilator using proprietary acquisition software. We examined the relationship of the R/I ratio, quasi-static PV curve items such as NMD, and respiratory system compliance (Crs). RESULTS: The median R/I ratio was 0.90 [interquartile range (IQR), 0.70-1.15] and median NMD was 41.0 [IQR, 37.1-44.1]. The NMD correlated significantly with the R/I ratio (rho = 0.74, P < 0.001). Sub-analysis showed that the NMD and R/I ratio did not correlate with Crs at lower PEEP (- 0.057, P = 0.75; and rho = 0.15, P = 0.41, respectively). On the contrary, the ratio of Crs at higher PEEP to Crs at lower PEEP (Crs ratio (higher/lower)) moderately correlated with NMD and R/I ratio (rho = 0.64, P < 0.001; and rho = 0.67, P < 0.001, respectively). CONCLUSIONS: NMD of the quasi-static PV curve and R/I ratio for recruitability assessment are highly correlated. In addition, NMD and R/I ratio correlated with the Crs ratio (higher/lower). Therefore, NMD and R/I ratio could be potential indicators of recruitability that can be performed at the bedside.

Veno-venous extracorporeal membrane oxygenation and prone ventilation for therapeutic management of COVID-19.

BACKGROUND: The efficacy and safety of the combined use of veno-venous extracorporeal membrane oxygenation (ECMO) and prone ventilation are currently not known for coronavirus disease 2019 (COVID-19). CASE PRESENTATION: We report two cases in which the combination of veno-venous ECMO and prone ventilation for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pneumonia were successfully carried out. Both patients had developed severe respiratory failure due to SARS-CoV-2 pneumonia, thus requiring veno-venous ECMO. Prone ventilation was also administered safely. CONCLUSION: Oxygenation and lung compliance gradually improved during prone ventilation, and both patients were successfully extubated. For patients with severe SARS-CoV-2 pneumonia who require veno-venous ECMO, the use of prone ventilation could be beneficial, and should be considered.

Gasping during refractory out-of-hospital cardiac arrest is a prognostic marker for favourable neurological outcome following extracorporeal cardiopulmonary resuscitation: a retrospective study.

BACKGROUND: Gasping during cardiac arrest is associated with favourable neurological outcomes for out-of-hospital cardiac arrest. Moreover, while extracorporeal cardiopulmonary resuscitation (ECPR) performed for refractory cardiac arrest can improve outcomes, factors for favourable neurological outcomes remain unknown. This study aimed to examine whether gasping during cardiac arrest resuscitation during transport by emergency medical services (EMS) was independently associated with a favourable neurological outcome for patients who underwent ECPR. This retrospective study was based on medical records of all adult patients who underwent ECPR due to refractory cardiac arrest. The primary endpoint was neurologically intact survival at discharge. The study was undertaken at Sapporo Medical University Hospital, a tertiary care centre approved by the Ministry of Health, Labour and Welfare, located in the city of Sapporo, Japan, between January 2012 and December 2018. RESULTS: Overall, 166 patients who underwent ECPR were included. During transportation by EMS, 38 patients exhibited gasping, and 128 patients did not. Twenty patients who exhibited gasping during EMS transportation achieved a favourable neurological outcome (20/38; 52.6%); 14 patients who did not exhibit gasping achieved a favourable neurological outcome (14/128; 10.9%). Gasping during transportation by EMS was independently associated with favourable neurological outcome irrespective of the type of analysis performed (multiple logistic regression analysis, odds ratio [OR] 9.52; inverse probability of treatment weighting using propensity score, OR 9.14). CONCLUSIONS: The presence of gasping during transportation by EMS was independently associated with a favourable neurological outcome in patients who underwent ECPR. The association of gasping with a favourable neurological outcome in patients with refractory cardiac arrest suggests that ECPR may be considered in such patients.

Usefulness of venoarterial extracorporeal membranous oxygenation for fatal cibenzoline succinate poisoning.

BACKGROUND: The effect of venoarterial extracorporeal membranous oxygenation (V-A ECMO), plasma exchange (PE), and direct hemoperfusion (DHP) for fatal cibenzoline succinate poisoning is unclear. We report a rare case of severe cibenzoline succinate poisoning along with cardiac arrest, wherein the patient was managed with V-A ECMO, PE, and DHP. We also measured the blood levels of cibenzoline succinate frequently. CASE PRESENTATION: A 51-year-old woman had a refractory cardiac arrest after cibenzoline succinate ingestion. We initiated V-A ECMO, PE, and DHP. Plasma exchange did not improve clinical manifestations. Her clinical condition improved during DHP, but there was no evidence about removal of drugs. On day 3, DHP and ECMO were terminated. On day 9, she was transferred to another hospital without arrhythmia recurrence. CONCLUSION: Venoarterial ECMO is effective in cases of cibenzoline succinate poisoning-related cardiac dysfunction or cardiac arrest. No evidence was obtained for the effects of PE and DHP.

Successful use of veno-arterial extracorporeal membrane oxygenation for septic cardiomyopathy in a patient with pre-existing chronic heart failure.

BACKGROUND: Indications for using veno-arterial extracorporeal membrane oxygenation (V-A ECMO) in sepsis cases remain unclear. CASE PRESENTATION: A 66-year-old man with pre-existing chronic heart failure developed severe pneumonia resulting in refractory septic shock. He was diagnosed with septic cardiomyopathy based on depressed left ventricular ejection fraction and a dilated left ventricle based on a transthoracic echocardiogram. We initiated V-A ECMO on day 3 because the shock did not respond to conventional therapy. The patient's hemodynamics improved, and his infection was reduced. He recovered fully and was discharged on day 107 with his cardiac function restored to its baseline. CONCLUSION: Septic cardiomyopathy is a form of reversible myocardial dysfunction. Veno-arterial extracorporeal membrane oxygenation should be considered for septic cardiomyopathy with intractable circulatory failure. Pre-existing chronic heart failure is not a contraindication for VA-ECMO.

The prognostic value of agonal respiration in refractory cardiac arrest: a case series of non-shockable cardiac arrest successfully resuscitated through extracorporeal cardiopulmonary resuscitation.

BACKGROUND: Agonal respiration following out-of-hospital cardiac arrest is associated with favorable neurological outcomes. Resuscitation using extracorporeal membrane oxygenation could contribute to achieving favorable neurological outcomes in patients with refractory cardiac arrest. CASE PRESENTATION: We report two cases of refractory cardiac arrest with non-shockable rhythms and agonal respiration; both patients were successfully resuscitated through extracorporeal cardiopulmonary resuscitation (ECPR). Both patients were breathing spontaneously upon arrival. One patient was asystolic and the other experienced pulseless electrical activity followed by ventricular fibrillation. Agonal respiration was observed in both and ECPR was implemented, leading to a favorable neurological outcome at discharge. CONCLUSION: The presence of agonal respiration has the potential to confer a favorable neurological outcome in patients with refractory cardiac arrest if maintained, even when the initial cardiac rhythm is not shockable. In these cases, resuscitation should not be abandoned, and ECPR should be considered.

Successful resuscitation for cardiac arrest due to severe accidental hypothermia accompanied by mandibular rigidity: a case of cold stiffening mimicking rigor mortis.

BACKGROUND: In cases of severe accidental hypothermia, it was recommended that resuscitation should be continued until the patient has rewarmed, as hypothermia itself can preserve cerebral function, and hypothermic cardiac arrest is reversible. During cardiopulmonary resuscitation for normothermic patients, muscle rigidity suggests the initiation of postmortem changes such as rigor mortis and can lead to the termination of resuscitation. Currently, the prognosis of cardiac arrest due to severe accidental hypothermia accompanied by rigidity is unknown. CASE PRESENTATION: A 29-year-old woman was found unresponsive near a snowy mountain trail. Upon discovery, she was found to be in cardiac arrest with an initial asystole rhythm and exhibited mandibular rigidity. On admission, her core temperature was 22 °C. Although cardiac arrest continued, and she showed no response to normal resuscitation, blood gas analysis revealed that her initial serum potassium level was 5.4 mmol/L. Extracorporeal membrane oxygenation (ECMO) for systemic perfusion and rewarming was initiated. After ECMO was introduced, return of spontaneous circulation was achieved. She showed no neurological impairments at discharge. CONCLUSIONS: Muscle rigidity does not rule out the possibility of resuscitation in patients with severe accidental hypothermia under cardiac arrest. Serum potassium levels may assist in deciding whether ECMO should be introduced, even if a patient is in asystole. This knowledge may help emergency physicians to save the lives of such patients.