The influenza A(H1N1) virus pandemic increases the number of patients admitted to intensive care unit (ICU) although they are often young and healthy [1], [2], [3]. Some of them developed a severe Acute Respiratory Distress Syndrome (ARDS), potentially fatal in adult, mortality for such patients is 30 to 58% [4]. When mechanical ventilation (low tidal volume ventilation, high PEEP) associated with usual adjuvant therapies (prone positioning, inhaled nitric oxide) fail, Extracorporeal Membrane Oxygenation (ECMO) is still possible to treat refractory hypoxemia. ECMO is based on the concept that extracorporeal support of respiration could be accomplished safely, allows the lungs to rest and heal and avoids Ventilation Induced Lung Injury (VILI) [4].
In Southern hemisphere, during the winter of 2009, a pandemic H1N1 virus emerged, and up to 30% of patients who had mechanical ventilation were treated with ECMO [1].
Some recent study showed a significant improvement in survival of patients transferred to a specialist centre for ECMO treatment compared to conventional management [4]. The benefits of ECMO seem to be better if it is initiated early, before ARDS and vicious circle of tissue hypoxia cause multiple organ failure.
The referent centre for ARDS advanced treatments and the regional emergency phone call department (Samu 13) have developed in Marseille (Provence-Alpes-Côte d’Azur [PACA] area, France) a Mobile Respiratory Assistance Unit (MRAU) which is dedicated to introduce precociously the ECMO to patient bedside and then to facilitate his inter-hospital transfer.
This system developed in PACA area (31 400 km2 surface) allows every patient (4.6 million inhabitants or nearly 8% of the French population) with severe ARDS/H1N1 to benefit of ECMO, as quickly as possible (“golden hour”) wherever his position in a 200 km around.
In practice, ECMO is proposed for patients with the following criteria: (1) proven H1N1 virus infection; and (2) severe oxygenation deficit with PaO2/FiO2 less than 70 for at least two hours with a PEEP greater than 10 cmH2O; or (3) PaO2/FiO2 between 70 and 100 with plateau pressure greater or equal to 35 cmH2O; or (4) severe respiratory acidosis with pH less or equal to 7.15 with 35 b per minute. When criteria are gathered, the local ICU calls the Samu 13 on a devoted and 24 hours a day available hotline to activate the procedure. Then, potential benefits and risks are analyzed on line with the referent centre (phone conference). This triage avoids unnecessary transfers, often at risk (cerebral hypoxia and fatal outcome), for such patients [4].
Subsequently, the Samu 13 manages the implementation of considerable resources very costly in terms of personnel, vehicles (ambulances, helicopters) and equipments [5]. After arrival of the ECMO team, veno-venous ECMO (CardioHelp© mobile pump, Maquet®, Germany) is performed by trained cardiac surgeon in the local ICU with perfusionist and anesthesiologist help. Then, the whole team provides the transfer to Marseille's referent centre.
This procedure is functional since 6 weeks and has already permitted to perform MRAU in eight different hospitals to eight patients aged from 17 to 61 years old with severe ARDS, which have complicated proven H1N1 infections (Table 1 ).
Table 1.
Outcome of patients and patients’ characteristics.
| Age (years) | Sex | Date | ICU location | Mode of transport | Time limit for arriving on site | Duration of UMAR management | Outcome |
|---|---|---|---|---|---|---|---|
| 49 | F | 31/10 | Marseille | Helicopter | 33 min | 2 h 17 | Died |
| 17 | F | 05/11 | Nice | Road | 1 h 35 | 11 h 06 | Died |
| 18 | F | 14/11 | La Ciotat | Road | 47 min | 2 h 58 | Died |
| 26 | M | 15/11 | Marseille | Road | 36 min | 7 h 40 | Weaning of ECMO |
| 61 | F | 23/11 | Martigues | Road | 50 min | 6 h 56 | Still under ECMO |
| 51 | M | 26/11 | Avignon | Road | 1 h 19 | 11 h 47 | Died |
| 21 | F | 28/11 | Marseille | Road | 31 min | 3 h 05 | Weaning of ECMO |
| 36 | F | 19/12 | Carpentras | Helicopter | 1 h 40 | 7 h 52 | Still under ECMO |
From now on, this procedure could be performed to ARDS in the whole area whatever the etiology.
Conflict of interest statement
None.
References
- 1.Australia and New Zealand Extracorporeal Membrane Oxygenation (ANZ ECMO) Influenza investigators Extracorporeal Membrane Oxygenation for 2009 Influenza A(H1N1) Acute Respiratory Distress Syndrome. JAMA. 2009;302:1888–1895. doi: 10.1001/jama.2009.1535. [DOI] [PubMed] [Google Scholar]
- 2.Perez-Padilla R., de la Rosa-Zamboni D., Ponce de Leon S., Hernandez M., Quinones-Falconi F., Bautista E., et al. Pneumonia and respiratory failure from swine-origin influenza A(H1N1) in Mexico. N Engl J Med. 2009;361:680–689. doi: 10.1056/NEJMoa0904252. [DOI] [PubMed] [Google Scholar]
- 3.Jain S., Kamimoto L., Bramley A.M., Schmitz A.M., Benoit J.R., Louie J., et al. Hospitalized patients with 2009 H1N1 influenza in the United States, April–June 2009. N Engl J Med. 2009;361:1935–1944. doi: 10.1056/NEJMoa0906695. [DOI] [PubMed] [Google Scholar]
- 4.Peek G.J., Mugford M., Tiruvoipati R., Wilson A., Allen E., Thalanany M.M., et al. Efficacy and economic assessment of conventional ventilatory support versus Extracorporeal Membrane Oxygenation for severe adult respiratory failure (CESAR): a multicentre randomised controlled trial. Lancet. 2009;374:1351–1363. doi: 10.1016/S0140-6736(09)61069-2. [DOI] [PubMed] [Google Scholar]
- 5.Schuerer D.J., Kolovos N.S., Boyd K.V., Coopersmith C.M. Extracorporeal Membrane Oxygenation: current clinical practice, coding and reimbursement. Chest. 2008;134:179–184. doi: 10.1378/chest.07-2512. [DOI] [PubMed] [Google Scholar]