High-frequency percussive ventilation facilitates weaning from extracorporeal membrane oxygenation in adults

© 2018 American Society of Extra-Corporeal Technology. All Rights Reserved. Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is an invaluable rescue therapy for patients suffering from cardiopulmonary arrest, but it is not without its drawbacks. There are cases where patients recover their cardiac function, yet they fail to wean to mechanical conventional ventilation (MCV). The use of high-frequency percussive ventilation (HFPV) has been described in patients with acute respiratory failure (RF) who fail MCV. We describe our experience with five patients who underwent VA-ECMO for cardiopulmonary arrest who were successfully weaned from VA-ECMO with HFPV after failure to wean with MCV. Weaning trials of HFPV a day before decannulation or at the time of separation from VA-ECMO were conducted. Primary endpoint data collected include pre- and post-HFPV partial pressures of oxygen (PaO2) and PaO2/FIO2(P/F) ratios measured at 2 and 24 hours after institution of HFPV. Additional periprocedural data points were collected including length of time on ECMO, hospital stay, and survival to discharge. Four of five patients were placed on VA-ECMO subsequent to percutaneous coronary intervention. One patient had cardiac arrest secondary to RF. Mean PaO2(44 ± 15.9 mmHg vs. 354 ± 149 mmHg, p \u3c .01) and mean P/F ratio (44 ± 15.9 vs. 354 ± 149, p \u3c .01) increased dramatically at 2 hours after the initiation of HFPV. Theimprovementinmean PaO2and P/F ratio was durable at 24 hours whether or not the patient was returned to MCV (n = 3) or remained on HFPV (n = 2) (44 ± 15.9 mmHg vs. 131 ± 68.7 mmHg, p = .036 and 44 ± 15.9 vs. 169 ± 69.9, p \u3c .01, respectively). Survival to discharge was 80%. The data presented suggest that HFPV may be used as a strategy to shorten time on ECMO, thereby reducing the negative effects of the ECMO circuit and improving its cost efficacy

A comparison of existing risk prediction models in patients undergoing venoarterial extracorporeal membrane oxygenation

© 2020 The Author(s) Background: Patients undergoing consideration for venoarterial extracorporeal membrane oxygenation (VA-ECMO) require an immediate risk profile assessment in the setting of incomplete information. A number of survival prediction models for critically ill patients and patients undergoing elective cardiac surgery or institution of VA-ECMO support have been designed. We assess the ability of these models to predict outcomes in a cohort of patients undergoing institution of VA-ECMO for cardiogenic shock or cardiac arrest. Methods: Fifty-one patients undergoing institution of VA-ECMO support were retrospectively analyzed. APACHE II, SOFA, SAPS II, Encourage, SAVE, and ACEF scores were calculated. Their ability to predict outcomes were assessed. Results: Indications for ECMO support included postcardiotomy shock (25%), ischemic etiologies (39%), and other etiologies (36%). Pre-ECMO arrest occurred in 73% and 41% of patients underwent cannulation during arrest. Survival to discharge was 39%. Three survival prediction model scores were significantly higher in nonsurvivors to discharge than surivors; the Encourage score (25.4 vs 20; p =.04), the APACHE II score (23.6 vs 19.2; p =.05), and the ACEF score (3.1 vs 1.8; p =.03). In ROC analysis, the ACEF score demonstrated the greatest predictive ability with an AUC of 0.7. Conclusions: A variety of survival prediction model scores designed for critically ill ICU and VA-ECMO patients demonstrated modest discriminatory ability in the current cohort of patients. The ACEF score, while not designed to predict survival in critically ill patients, demonstrated the best discriminatory ability. Furthermore, it is the simplest to calculate, an advantage in the emergent setting

High-Frequency Percussive Ventilation Rescue Therapy in Morbidly Obese Patients Failing Conventional Mechanical Ventilation.

Morbidly obese patients with respiratory failure who do not improve on conventional mechanical ventilation (CMV) often undergo rescue therapy with extracorporeal membrane oxygenation (ECMO). We describe our experience with high-frequency percussive ventilation (HFPV) as a rescue modality.In a retrospective analysis from 2009 to 2016, 12 morbidly obese patients underwent HFPV after failing to wean from CMV. Data were collected regarding demographics, cause of respiratory failure, ventilation settings, and hospital course outcomes. Our end point data were pre- and post-HFPV partial pressure of arterial oxygen and PaO2 to fraction of inspired oxygen (PF) ratios measured at initiation, 2, and 24 hours.Twelve morbidly obese patients required HFPV for respiratory failure. Causes of respiratory failure overlapped and included cardiogenic pulmonary edema (n = 8), pneumonia (n = 5), septic shock (n = 5), and asthma (n = 1). After HFPV initiation, mean fraction of inspired oxygen FiO2 was tapered from 98% to 82% and 66% at 2 and 24 hours, respectively. Mean PaO2 increased from 60.9 mm Hg before HFPV to 175.1 mm Hg ( P \u3c .05) at initiation of HFPV, then sustained at 129.5 mm Hg ( P \u3c .05) and 88.1 mm Hg ( P \u3c .005) at 2 and 24 hours, respectively. Mean PF ratio improved from 66.1 before HFPV to 180.3 ( P \u3c .05), 181.0 ( P \u3c .05) and 148.9 ( P \u3c .0005) at initiation, 2, and 24 hours, respectively. The improvement in mean PaO2 and PF ratios was durable at 24 hours whether or not the patient was returned to CMV (n = 10) or remained on HFPV (n = 2). Survival to discharge was 66.7%.In our cohort of morbidly obese patients, HFPV was successfully utilized as a rescue therapy precluding the need for ECMO. Despite our small sample size, HFPV should be considered as a rescue therapy in morbidly obese patients failing CMV prior to the initiation of ECMO. Our retrospective analysis supports consideration for HFPV as another form of rescue therapy for obese patients with refractory hypoxemia and respiratory failure who are not improving with CMV

The Effect of Acute Limb Ischemia on Mortality in Patients Undergoing Femoral Venoarterial Extracorporeal Membrane Oxygenation

© 2019 Elsevier Inc. Background: Extracorporeal membrane oxygenation (ECMO) is a life-saving modality increasingly used in the management cardiopulmonary failure. However, ECMO itself is not without major complications. Mortality remains high, and morbidity such as stroke, renal failure, and acute limb threatening ischemia (ALI) are common among surviving patients. We analyzed the effect of one of these complications, ALI, on the survival of patients receiving venoarterial ECMO (VA ECMO) with femoral cannulation. Methods: Patients with cardiopulmonary failure supported by VA ECMO inserted through femoral cannulation at two institutions from December 2010 to December 2017 were enrolled in this study. Data were collected retrospectively. Our primary outcome was ALI and its effect on hospital mortality. Secondary outcomes included six-month mortality, length of hospital stay, and other complications (stroke and renal failure); multivariate logistic regression analysis was used to identify predictors of ALI and hospital mortality. Results: There were 71 patients included in this study. The overall VA ECMO hospital mortality was 53.5%. ALI was seen in 14 (19.7%) patients. Of these, four (5.6%) patients had fasciotomy, four patients (5.6%) had thrombectomy, and one underwent arterial repair (1.4%). Five additional patients (7.0%) with ALI expired and had no vascular intervention. None of the demographic and clinical characteristics significantly correlated with ALI except for stroke and renal failure requiring new-onset hemodialysis (HD). The rate of hospital and 6-month mortality in patients with and without vascular complications were 78.6%, 92.3% and 47.4%, 57.4%, respectively (P = 0.042 and P = 0.023). Multivariate analysis correlated hospital and six-month mortality with ALI, stroke, and new-onset HD. Conclusions: ALI correlates with higher mortality in VA ECMO patients with femoral cannulation. Although some of the contributing factors to mortality in these patients are related to the consequences of cardiopulmonary failure, strong efforts should be made to avoid ALI after femoral VA ECMO cannulation

A Simple Scoring System to Predict Survival after Venoarterial Extracorporeal Membrane Oxygenation

Patients undergoing consideration for venoarterial extracorporeal membrane oxygenation (VA ECMO) require an immediate risk profile assessment in the setting of incomplete or no information. A retrospective cohort study of 100 patients undergoing VA ECMO placement at three institutions was carried out. Variables strongly associated with survival to discharge were used to calculate a risk stratification score. Indications for VA ECMO support included postcardiotomy shock (24%), ischemic etiologies (33%), nonischemic cardiomyopathy (32%), and other etiologies (11%). Pre-VA ECMO arrest occurred in 69%, and 30% of patients underwent cannulation during arrest. Survival to discharge was 38%. Three variables demonstrated a strong trend toward predicting survival to discharge: lactate \u3e10 mmol/L (p = .054), albumin /dL (p = .062), and platelet count /uL (p = .064), and these variables were included in a scoring system. The extremes of age and duration of pre-VA ECMO ventilation were associated with a dismal prognosis and were also included. These five variables were used to construct a mortality prediction score. A score of 0 was associated with 10% expected mortality, whereas a score of 4+ was associated with 100% expected mortality. Mortality increased in a stepwise fashion with increasing scores. The expected mortality closely paralleled the observed mortality. A simple scoring system composed of easily collected variables may help predict mortality. However, it is not intended to replace an experienced clinician\u27s judgment, but to enhance it