2. Many things to review:
Rapid Flu swab for H1N1?
Paralysis in the first 24 hours in patients with ARDS?
Permissive hypercapnia while using low VT vent.?
Prone positioning when low VT vent. is no longer
working?
Steroids for ARDS 2/2 Influenza?
Extracorporeal membrane oxygenation use in patients
with severe ARDS?
5. Indications
Hypoxemic respiratory failure with PaO2/FiO2 of <100 mmHg
If failed optimization of the ventilator settings
Hypercapnic respiratory failure with an arterial pH less than 7.20
Refractory cardiogenic shock
Cardiac arrest
Failure to wean from cardiopulmonary bypass after cardiac surgery
As a bridge to either cardiac transplantation or placement of a ventricular
assist device
Extracorporeal life support organization.
6. ECMO in ARDS
1974-1994 NIH sponsored trial
VA-ECMO vs. Conventional vent.
Survival was low in both arms: 9.5% vs. 8.3%
1986: Morris reported a randomized control trial PCIR
vent vs. extracorporeal Co2 removal
No difference in survival 42% vs. 33%
7. Newer Data
PubMed search: ECMO and ARDS
Clinical trials in adults: 18
Up-to-Date: 11 studies
The authors believe there is survival benefit when
implemented in patients with severe ARDS, but the
editors and other reviewers think the survival benefit may
not be 2/2 the ECMO, but instead 2/2 the care received
a the center where ECMO is done.
8. Efficacy and economicassessment ofconventional
ventilatory support versusextracorporealmembrane
oxygenation forsevereadult respiratory failure(CESAR):
amulticentrerandomised controlled trial
GilesJPeek,MirandaMugford,RavindranathTiruvoipati,AndrewWilson,ElizabethAllen,MariammaMThalanany,ClareLHibbert,
AnnTruesdale,Felicity Clemens,NicolaCooper,RichardKFirmin,DianaElbourne,for theCESARtrialcollaboration
Summary
Background Severe acute respiratory failure in adults causes high mortality despite improvements in ventilation
techniques and other treatments (eg, steroids, prone positioning, bronchoscopy, and inhaled nitric oxide). We aimed
to delineate the safety, clinical e cacy, and cost-e ectiveness of extracorporeal membrane oxygenation (ECMO)
compared with conventional ventilation support.
Methods In this UK-based multicentre trial, we used an independent central randomisation service to randomly
assign 180adults in a1:1ratiotoreceive continued conventional managementor referral toconsideration for treatment
by ECMO. Eligible patients were aged 18–65 years and had severe (Murray score >3· 0 or pH <7· 20) but potentially
reversible respiratory failure. Exclusion criteria were: high pressure (>30 cm H O of peak inspiratory pressure) or
high FiO (>0· 8) ventilation for more than 7 days; intracranial bleeding; any other contraindication to limited
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page1330
Department ofCardiothoracic
Surgery (GJPeekMD,
RKFirminMBBS) and
Department ofExtracorporeal
MembraneOxygenation
9. CESAR
Randomized clinical trial
180 patients
Conventional management
Referral to consideration for treatment with ECMO
Included if:
18-65 years old
Severe but reversible resp. failure (Murray score >3 or
pH<7.20)
Exclusion: High pressure or FIO2 for >7 days, ICH, or
contraindication to heparin.
The primary outcome was death or severe disability at 6
months after randomization or before discharge from
hospital.
14. Specifics
Cohort study
ECMO-referred patients
H1N1-ralated ARDS referred, accepted and transferred to
1 of 4 ECMO centers in the UK during H1N1 pandemic
of 2009-2010.
Both referred and non-ECMO referred patients were
matched using data from a Swine Flu Triage study.
Survival to hospital discharge
15.
16. The Question Remains
Is it the ECMO or is it the center with ECMO that
benefits the patient most?
17. Conclusion
W/out a good randomized control trial of ECMO vs.
conventional ventilation
If patient develops ARDS refractory to conventional
ventilation referral to a center with ECMO (earlier
rather than later) will probably benefit the patient.
This may be most beneficial in patients who are young,
have ARDS 2/2 H1N1 or other viral PNA, and who have
few co-morbidities.
Hinweis der Redaktion
Mecahnical cardiopulm support used for prolonged time periods ~3-10 days
The goal of therapy is to minimize ventilator-induced lung injury while allowing additional time to treat the underlying disease process and to permit recovery from acute injury.
During ECMO, blood is drained from the native vascular system, circulated outside the body by a mechanical pump, and reinfused into the circulation. While outside the body, the blood passes through an oxygenator and heat exchanger. In the oxygenator, hemoglobin becomes fully saturated with oxygen, while carbon dioxide (CO2) is removed. Oxygenation is determined by flow rate, where elimination of CO2 can be controlled by adjusting the rate of countercurrent gas flow through the oxygenator
VA: Blood is extracted from the RA and returned to the arterial system: Provides both cardiac and pulmonary support
.
Veno venous : Blood is extracted from the vena cava or RA and returned to the RA, THUS THE PATIENT MUST PROVIDE THE HD.
CANNULAS ARE USALLY PLACED IN THE RIGHT COMMON FEMORAL FOR EXTRAXTION AND THE RIGHT IJ FOR INFUSION
Although this porcedure sounds simple. The act of placing very large bore cannulas in these locations comes with considerable risk and must be performed under the guidence of a CT surgeon.
The guidelines for indications foe use of ECMO are publised by the Extracorporeal life support organization. Generally ECMO could be considered in patients who are sufferinf from at least one of the following.
The use of this technique in adults comes from well described data on infants/neonates which has shown a mortaliy benefit when used in the setting of resp failure and lung transplant. Unfortunately this mortality benefit has yet to be convincingly confirmed in adult.
Ealry Publications of Clinical research trial using ECMO in adults with ARDS yilded poor results. As an axample
Given the negative results from these trials, enthusiasm for the use of ECMO in adult respiratory failure waned in the 1980s, Advances in overall ICU care, ventilator management and ECMO technology render these early trial results not applicable to current practice.
After doing a Pubmed search using the words ECMo and ARDS then limited the search to clinical trials in adults. 18 papers are found. After briefly reviewing them in addition to reviweing the uptodate article written by Dr, Jonathan Haft a profsssoer of caridac surgery at the university of michigan, and Dr. Robert Bartlett who is a professor emeritus at the same.
11 of these show promising results
8 of these studies were observtional, but consistantly found a slighlty beter survival rate than those published in the past.
The last two I believe has spurred a debate about where the survival benefit comes from.
Interestingly, when reading the uptodate article on this topic the recommendation for ECMO in ARDS states of note the seciton editor for this article was our own Dr. Parsons.
Lets look at why.
To date this is thonly randomized clincal control trial to date which has compared our current conventional ventilation to ECMO.
high pressure (&gt;30 cm H2O of peak inspiratory pressure) or high FiO2 (&gt;0·8) ventilation for more than 7 days; intracranial bleeding; any other contraindication to limited heparinisation; or any contraindication to continuation of active treatment
The group referred to the ECMO center had significantly increased survival without disability at six months compared to conventional management (63 versus 47 percent
Twenty five percent of the patients referred for ECMO were not managed with ECMO because 6 died before transfer to the ECMO center and 24% reovered with the conventional ventilation protocol used by the ECMO center.
Additionally another potential limitation of this study was in the use of the murray lung injury score.
The main disadvantage to the Murray score, especially in the conduct of large clinical studies, is that pulmonary compliance is not routinely measured. A significant deficiency of the Murrary score is that cardiogenic pulmonary edema is not excluded
The other artice published 2011 pertained to ARDS 2/2 H1N1.
AcohortstudyinwhichECMO-referredpatientswere defined as all patients with H1N1-related ARDS who were referred, accepted, and trans- ferred to 1 of the 4 adult ECMO centers in the United Kingdom during the H1N1 pan- demic in winter 2009-2010. The ECMO-referred patients and the non–ECMO-referred patients were matched using data from a concurrent, longitudinal cohort study (Swine Flu Triage study) of critically ill patients with suspected or confirmed H1N1. Detailed demo- graphic, physiological, and comorbidity data were used in 3 different matching tech- niques (individual matching, propensity score matching, and GenMatch matching).
Evern after adjusting the data through three different level of matching there was a survival benefit 23.7 versus 52.5 percent
But again in this study ~15% of patients referrred to an ecmo center were managed with conventiaonal ventilation
Eighty five percent of the patients referred to an ECMO center were managed with ECMO, while the others improved with conventional ventilation
Of note since the 2009 epidemic referal for ECMO in the setting of H1N1 has increased from 100 cases per year to 400, not because there is more data but because like our patient those referred are very young w/out significanct co morbidity who develop progound hypoxemia in the setting of a very stiff lung. Refractory to conventionalt therapy,
Or is it that I we standardize conventiional therapy patients do better?