ECMO for refractory cardiorespiratory failure due to meningococcal disease

Venoarterial Extracorporeal Membrane Oxygenation Versus Conventional Therapy in Severe Pediatric Septic Shock

OBJECTIVES

The role of venoarterial extracorporeal membrane oxygenation in the treatment of severe pediatric septic shock continues to be intensely debated. Our objective was to determine whether the use of venoarterial extracorporeal membrane oxygenation in severe septic shock was associated with altered patient mortality, morbidity, and/or length of ICU and hospital stay when compared with conventional therapy.

DESIGN

International multicenter, retrospective cohort study using prospectively collected data of children admitted to intensive care with a diagnosis of severe septic shock between the years 2006 and 2014.

SETTING

Tertiary PICUs in Australia, New Zealand, Netherlands, United Kingdom, and United States.

PATIENTS

Children greater than 30 days old and less than 18 years old.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of 2,452 children with a diagnosis of sepsis or septic shock, 164 patients met the inclusion criteria for severe septic shock. With conventional therapy (n = 120), survival to hospital discharge was 40%. With venoarterial extracorporeal membrane oxygenation (n = 44), survival was 50% (p = 0.25; CI, -0.3 to 0.1). In children who suffered an in-hospital cardiac arrest, survival to hospital discharge was 18% with conventional therapy and 42% with venoarterial extracorporeal membrane oxygenation (Δ = 24%; p = 0.02; CI, 2.5-42%). Survival was significantly higher in patients who received high extracorporeal membrane oxygenation flows of greater than 150 mL/kg/min compared with children who received standard extracorporeal membrane oxygenation flows or no extracorporeal membrane oxygenation (82%, 43%, and 48%; p = 0.03; CI, 0.1-0.7 and p < 0.01; CI, 0.2-0.7, respectively). Lengths of ICU and hospital stay were significantly longer for children who had venoarterial extracorporeal membrane oxygenation.

CONCLUSIONS

The use of venoarterial extracorporeal membrane oxygenation in severe pediatric sepsis is not by itself associated with improved survival. However, venoarterial extracorporeal membrane oxygenation significantly reduces mortality after cardiac arrest due to septic shock. Venoarterial extracorporeal membrane oxygenation flows greater than 150 mL/kg/min are associated with almost twice the survival rate of conventional therapy or standard-flow extracorporeal membrane oxygenation.

Factors associated with survival in pediatric extracorporeal membrane oxygenation--a single-center experience

AIM

We aimed to examine outcomes of extracorporeal membrane oxygenation (ECMO) therapy in the pediatric population and identify pre-ECMO and on-ECMO characteristics that are associated with survival.

METHODS

We retrospectively reviewed the ECMO records at our institution between 1999 and 2008 and selected pediatric patients who were cannulated for respiratory failure or hemodynamic instability resistant to conventional interventions. We recorded details of pre-ECMO clinical characteristics, including blood gas variables and mechanical ventilatory support, and details of ECMO therapy including survival off ECMO and to hospital discharge. Predictors of survival were analyzed using logistic regression modeling and a prediction algorithm was developed.

RESULTS

Of the 445 ECMO runs, data from 58 consecutive patients were analyzed: 57% were successfully decannulated, and 48% survived to discharge from the hospital. The cohort included 32 (55%) female patients, 22 postoperative patients (38%), and 15 (26%) with an immunosuppressive condition, with a median age of 5 years and weight 19.5 kg, The mean duration of pre-ECMO respiratory support was 3 days, in the form of high-frequency oscillatory ventilation (n = 28, 48%) and conventional mechanical ventilation (n = 13, 22%). The median duration (interquartile range) of ECMO support was 142 hours (60, 321) or 5.9 days. Pre-ECMO pH above 7.2 (P < .001) and oxygenation index below 35 (P = .021) were associated with the highest survival rates. Pre-ECMO PaCO(2) and duration of mechanical ventilation were not associated with survival.

CONCLUSIONS

Based on our results, ECMO therapy should be considered early in children with oxygenation index greater than 35 with worsening metabolic status. The restriction of ECMO based on ventilator days alone needs to be revisited in this era of lung protective ventilation.

Reduction in case fatality rate from meningococcal disease associated with improved healthcare delivery

BACKGROUND AND AIMS

The case fatality rate from meningococcal disease (MD) has remained relatively unchanged in the post antibiotic era, with 20-50% of patients who develop shock still dying. In 1992 a new paediatric intensive care unit (PICU) specialising in MD was opened. Educational information was disseminated to local hospitals, and a specialist transport service was established which delivered mobile intensive care. The influence of these changes on mortality of children with MD was investigated.

METHODS

A total of 331 consecutive children with meningococcal disease admitted to the PICU between 1992 and 1997 were studied. Severity of the disease on admission was assessed using the paediatric risk of mortality (PRISM) score. Logistic regression analysis was used to correct for clinical severity, age, and sex; death was the outcome, and year of admission, a temporal trend variable, was the primary exposure.

RESULTS

The case fatality rate fell year on year (from 23% in 1992/93 to 2% in 1997) despite disease severity remaining largely unchanged. After adjustment for age, sex, and disease severity, the overall estimate for improvement in the odds of death was 59% per year (odds ratio for the yearly trend 0.41).

CONCLUSIONS

A significant improvement in outcome for children admitted with MD to a PICU has occurred in association with improvements in initial management of patients with MD at referring hospitals, use of a mobile intensive care service, and centralisation of care in a specialist unit.

Do new strategies in meningococcemia produce better outcomes?

Meningococcal septic shock (MSS) has high mortality and morbidity rates. In addition to the traditional prompt antibiotics and respiratory and circulatory support, new treatment strategies have been proposed.

AGAINST THE INFLAMMATORY CASCADE

Immunotherapy, such as antiserum to Escherichia coli J5 and human antilipid A monoclonal antibodies/centoxin (HA-1A), did not significantly alter the mortality rate of MSS; we are awaiting the results of the bactericidal/permeability-increasing protein multicenter trial. Two series reported the effects of hemofiltration and hemodiafiltration in MSS, but the true benefits remain unknown.

TO TREAT HEMOSTATIC ABNORMALITIES

In MSS, heparin is still controversial and antithrombin concentrate use has been reported in only one child. Several case reports on protein C and recombinant tissue plasminogen activator have been published; the efficacy (improvement in shock and organ dysfunction and reduction in amputation rate) and safety (intracerebral hemorrhage with recombinant tissue plasminogen activator) of these treatments need further evaluation. Blood and plasma exchange appear to be safe and are supposed to reduce mortality, but it is difficult to draw firm conclusions from published studies. Finally, local application of medicinal leeches has been reported to improve purpuric lesions.

TO INDUCE VASODILATION

Prostacyclin, or epoprostenol, infusion, sodium nitroprussiate infusion, sympathetic blockade, and topical nitroglycerin have been reported to improve distal perfusion; however, these reports are all anecdotal.

OTHER STRATEGIES

Improvement in limb perfusion was achieved after hyperbaric oxygenation in patients with purpura fulminans caused by different pathogens. Most authors recommend monitoring of compartment pressures and performing fasciotomy as indicated. Finally, extracorporeal membrane oxygenation was recently proposed to support seven children with intractable MSS.

CONCLUSIONS

There is no proof that unconventional treatments have a significant impact on outcome in MSS; prospective multicenter trials are needed. At present, early recognition of meningococcal sepsis and appropriate treatment seem to be the optimal methods of improving outcome. Efforts to find an effective meningococcal vaccine must be continued.

Recognition, treatment and complications of meningococcal disease

Meningococcal disease remains a major cause of death in young children. A decrease in mortality requires recognition and treatment of the disease at a number of stages in the illness. Life-threatening meningococcal disease usually presents as septicaemia rather than meningitis. The cardinal feature of meningococcal septicaemia is the purpuric rash. Many parents recognise the rash and seek medical advice because of it. When primary care physicians recognise the rash, the administration of parenteral penicillin may decrease mortality. However, antibacterials are not given promptly if there is no rash or if the disease presents in an atypical form. In hospital, antibacterial therapy with a third-generation cephalosporin should be given. Disease severity needs to be assessed by a valid method, such as the Glasgow Meningococcal Septicaemia Prognostic Score (GMSPS). This can identify those patients who need intensive care and/or might benefit from new therapies. The 2 life-threatening complications are septic shock and meningoencephalitis with raised intracranial pressure. Despite numerous case reports of success with potential new treatments, none has been proven safe and/or effective by controlled trials. Although it is tempting to focus on new treatments, the early recognition of severe meningococcal disease by parents, primary care physicians and junior hospital doctors is equally, if not more, important as a potential means of decreasing mortality.