The use of extracorporeal membrane oxygenation in severe necrotizing soft tissue infections complicated by septic shock

Extracorporeal Membrane Oxygenation for Septic Shock in Adults and Children: A Narrative Review

Refractory septic shock is associated with a high risk of death. Circulatory support in the form of veno-arterial extracorporeal membrane oxygenation (VA ECMO) may function as a bridge to recovery, allowing for the treatment of the source of the sepsis. Whilst VA ECMO has been accepted as the means of hemodynamic support for children, in adults, single center observational studies show survival rates of only 70-90% for hypodynamic septic shock. The use of VA ECMO for circulatory support in hyperdynamic septic shock with preserved cardiac output or when applied late during cardio-pulmonary resuscitation is not recommended. With unresolving septic shock and a loss of ventriculo-arterial coupling, stress cardiomyopathy often develops. If the cardiac index (CI) approaches subnormal levels (CI < 2.5 L/min m-2) that do not match low systemic vascular resistance with a resulting loss of vital systemic perfusion pressure, VA ECMO support should be considered. A further decrease to the level of cardiogenic shock (CI < 1.8 L/min m-2) should be regarded as an indication for VA ECMO insertion. For patients who maintain a normal-to-high CI as part of their refractory vasoparalysis, VA ECMO support is justified in children and possibly in patients with a low body mass index. Extracorporeal support for septic shock should be limited to high-volume ECMO centers.

Venoarterial extracorporeal membrane oxygenation for group B streptococcal toxic shock syndrome: A case report and literature review

RATIONALE

Streptococcal toxic shock syndrome (STSS) rapidly leads to refractory shock and multiple organ failure. The mortality rate among patients with STSS is 40%; however, most deaths occur within a few days of onset. Venoarterial extracorporeal membrane oxygenation (VA-ECMO) may help avoid acute death in adult patients with STSS. However, the effectiveness of VA-ECMO is unclear. In this study, we report a case of group B STSS, which was successfully treated with VA-ECMO despite cardiopulmonary arrest (CPA) owing to rapidly progressive refractory shock.

PATIENT CONCERNS

A 60-year-old woman was hospitalized because of diarrhea and electrolyte abnormalities owing to chemoradiation therapy for rectal cancer. A sudden deterioration of her condition led to CPA. Conventional cardiopulmonary resuscitation was immediately performed but was ineffective. Therefore, VA-ECMO was initiated. Contrast-enhanced computed tomography revealed duodenal perforation. Hence, septic shock owing to peritonitis was diagnosed, and emergency surgery was performed under VA-ECMO. However, the patient had progressive multiple organ failure and required organ support therapy in the intensive care unit (ICU).

DIAGNOSES

On day 2 in the ICU, blood and ascites fluid culture tests revealed beta-hemolytic streptococci, and the patient was finally diagnosed as having STSS caused by Streptococcus agalactiae.

INTERVENTIONS

Clindamycin was added to meropenem, vancomycin, and micafungin, which had been administered since the sudden deterioration. In addition, VA-ECMO, mechanical ventilation, blood purification therapy, and treatment for disseminated intravascular coagulation were continued.

OUTCOMES

Thereafter, hemodynamics improved rapidly, and the patient was weaned off VA-ECMO on day 5 of ICU admission. She was transferred to a general ward on day 22 in the ICU.

LESSONS

In patients with fatal STSS and rapid progressive refractory shock or CPA, VA-ECMO may help to avoid acute death and improve prognosis by ameliorating tissue oxygenation and providing extra time to treat invasive streptococcal infection.

Extracorporeal Life Support in Pregnancy: A Systematic Review

Background The use of extracorporeal life support (ECLS) has expanded to include unique populations such as peripartum women. This systematic review aims to (1) quantify the number of cases and indications for ECLS in women during the peripartum period reported in the literature and (2) report maternal and fetal complications and outcomes associated with peripartum ECLS. Methods and Results This review was registered in PROSPERO (CRD42018108142). MEDLINE, Embase, and CINAHL were searched for case reports, case series, and studies reporting cases of ECLS during the peripartum period that reported one or more of the following outcomes: maternal survival, maternal complications, fetal survival, and/or fetal complications. Qualitative assessment of 221 publications evaluated the number of cases, clinical details, and maternal and fetal outcomes of ECLS during the peripartum period. There were 358 women included and 68 reported fetal outcomes in cases where the mother was pregnant at the time of cannulation. The aggregate maternal survival at 30 days was 270 (75.4%) and at 1 year was 266 (74.3%); fetal survival was 44 (64.7%). The most common indications for ECLS overall in pregnancy included acute respiratory distress syndrome 177 (49.4%), cardiac failure 67 (18.7%), and cardiac arrest 57 (15.9%). The most common maternal complications included mild to moderate bleeding 66 (18.4%), severe bleeding requiring surgical intervention 48 (13.4%), and intracranial neurologic morbidity 19 (5.3%). The most commonly reported fetal complications included preterm delivery 33 (48.5%) and neonatal intensive care unit admission 19 (27.9%). Conclusions Reported rates of survival in ECLS in pregnant and postpartum women are high and major complications relatively low.

Extracorporeal Membrane Oxygenation for Adults With Refractory Septic Shock

Because of a severe dysregulation of the host response to infection, septic shock may induce a profound imbalance between oxygen consumption and delivery, which in some cases may be refractory to conventional support measures. In this setting, extracorporeal membrane oxygenation (ECMO) may help to restore this ratio. Indeed, in neonates and children, this technique is already established as a valid salvage therapy. In spite of the rapid growth in the use of ECMO in recent years, the evidence of its benefits in adult patients is weak, particularly in cases of refractory septic shock. Nevertheless, several case series have reported good outcomes in selected cases with specific management. Here we explore the links between sepsis and ECMO, starting with the basic biology underlying the two entities. We then review the published literature on the use of extracorporeal support in adult patients with septic shock and finally conclude with a review of the key points of management that can optimize the results after this critical situation.

Duration of veno-arterial extracorporeal life support (VA ECMO) and outcome: an analysis of the Extracorporeal Life Support Organization (ELSO) registry

Background

Veno-arterial extracorporeal membrane oxygenation (VA ECMO) is an effective rescue therapy for severe cardiorespiratory failure, but morbidity and mortality are high. We hypothesised that survival decreases with longer VA ECMO treatment. We examined the Extracorporeal Life Support Organization (ELSO) registry for a relationship between VA ECMO duration and in-hospital mortality, and covariates including indication for support.

Methods

All VA runs from the ELSO database from 2002 to 2012 were extracted. Multiple runs and non-VA runs were excluded. Runs were categorized into diagnostic groups. Logistic regression for analysis of the effect of duration on outcome, and multivariate regression for diagnosis and other baseline factors were performed. Non-linear models including piecewise logistic models were fitted.

Results

There were 2699 runs analysed over 14,747 days. Logistic regression analysis of the effect of duration on outcome, and multivariate regression analysis of diagnosis and other baseline factors were performed. In-hospital survival was 41.4% (95% CI 39.6–43.3). 75% of patients were supported for less than 1 week and 96% for less than 3 weeks. Median duration (4 days IQR 2.0–6.8) was greater in survivors (4.1 (IQR 2.5–6.7) vs 3.8 (IQR 1.7–7.0) p = 0.002). The final multivariate model demonstrated increasing survival to day 4 (OR 1.53 (95% CI 1.37–1.71) p < 0.001), decreasing from day 4 to 12 (OR 0.86 (95% CI 0.81–0.91), p < 0.001) with no significant change thereafter (OR 0.98 (95% CI 0.94–1.02), p = 0.400).

Conclusions

ECMO for 4 days or less is associated with higher mortality, likely reflecting early treatment failure. Survival is highest when patients are weaned on the fourth day of ECMO but likely decreases into the second week. While this does not suggest weaning at this point will produce better outcomes, it does reflect the likely time course of ECMO as a bridge in severe shock. Patients with some underlying conditions (like myocarditis and heart transplantation) achieve better outcomes despite longer support duration. These findings merit prospective study for the development of prognostic models and weaning strategies.

Predictors of survival in adults undergoing extracorporeal membrane oxygenation with severe infections

BACKGROUND

To identify novel factors associated with the survival of septic adults receiving extracorporeal membrane oxygenation (ECMO) to improve patient selection and outcomes.

METHODS

Cases were identified from our ECMO registry from 2001 to 2011 if they were ≥16 years and received ECMO for life-threatening sepsis.

RESULTS

A total of 151 adults with a median (25th-75th percentile) age of 51 (37-63) years were analyzed. Pneumonia (50%), myocarditis (20%), and primary bloodstream infections (15%) were the main types of infection, caused by predominantly nonfermentative Gram-negative bacteria (NFGNB) (26%), Enterobacteriaceae (24%), and Gram-positive cocci (21%). The in-hospital mortality of patients with NFGNB, enteric, and Gram-positive bacterial pneumonias were 100%, 68%, and 14%, respectively. Using the Cox-proportional hazards model, we found that age >75 years (hazard ratio [HR], 1.98, 95% confidence interval [95% CI], 1.30-3.02), pre-ECMO dialysis (HR, 3.20, 95% CI, 1.34-7.63), longer door-to-ECMO intervals (HR, 1.01, 95% CI, 1.00-1.02), venoarterial mode (HR, 2.58, 95% CI, 1.55-4.21), and fungal (HR, 2.83, 95% CI, 1.36-5.88) and NFGNB sepsis (HR, 2.48, 95% CI, 1.44-4.27) were associated with mortality. Gram-positive sepsis (HR, 0.20, 95% CI, 0.08-0.57), myocarditis (HR, 0.12, 95% CI, 0.06-0.27), pneumonia (HR, 0.54, 95% CI, 0.30-0.90), and effective empirical antimicrobial therapy were predictive of survival (HR, 0.57, 95% CI, 0.37-0.89); all P < .05. Excluding the 67 heavily premorbid patients, we found that 54% survived ECMO and 42% survived to discharge, with significantly more survivors with door-to-ECMO times of ≤96 hours than >96 hours (59% vs 15%, P < .0001).

CONCLUSIONS

Better outcomes were associated with door-to ECMO times of 96 hours or less, for Gram-positive rather than Gram-negative sepsis, and for pneumonia rather than primary bloodstream infections.

A review of sepsis-induced cardiomyopathy

Sepsis-induced cardiomyopathy is a reversible myocardial dysfunction that typically resolves in 7–10 days. It is characterized by left ventricular dilatation and depressed ejection fraction. However, many uncertainties exist regarding the mechanisms, characteristics, and treatments of this condition. Therefore, this review attempts to summarize our current knowledge of sepsis-induced cardiomyopathy.

Successful Use of Extracorporeal Membrane Oxygenation in an Adult Patient With Toxic Shock-Induced Heart Failure

Cardiomyopathy secondary to toxic shock syndrome (TSS) is an uncommon but potentially life-threatening problem. We report the case of a 51-year-old male who presented with profound cardiogenic shock and multiorgan failure that could not be managed by conventional therapy with intravenous fluids, vasopressors and inotropes. Venoarterial extracorporeal membrane oxygenation (VA ECMO) was instituted as a bridge to recovery. After administration of antibiotics and intravenous immunoglobulin, the patient’s condition improved and he was successfully weaned off ECMO after 6 days. The patient recovered from multiorgan failure, and left ventricular ejection fraction improved from <10% pre-ECMO to 65% 8 months after discharge. This case supports the view that VA ECMO can be used successfully to support vital organ perfusion in patients with profound but reversible cardiomyopathy attributed to TSS.

Necrotizing Soft Tissue Infections: Surgeon's Prospective

Necrotizing soft tissue infections (NSTIs) are fulminant infections of any layer of the soft tissue compartment associated with widespread necrosis and systemic toxicity. Delay in diagnosing and treating these infections increases the risk of mortality. Early and aggressive surgical debridement with support for the failing organs significantly improves the survival. Although there are different forms of NSTIs like Fournier's gangrene or clostridial myonecrosis, the most important fact is that they share common pathophysiology and principles of treatment. The current paper summarizes the pathophysiology, clinical features, the diagnostic workup required and the treatment principles to manage these cases.

Temporary extracorporeal circulatory support and pulmonary embolectomy for catastrophic amniotic fluid embolism

Amniotic fluid embolism is usually a life-threatening complication of an otherwise healthy pregnancy. Medical management of the coagulopathy and cardiovascular collapse is challenging and is often unsuccessful. We present a case and advocate the use of temporary circulatory support and pulmonary embolectomy in what would otherwise have been a fatal scenario.