This year has brought a new challenge to Intensive Care Medicine. The current influenza
A (H1N1) pandemic may have a disproportionate effect on the provision of Intensive
Care services in Europe. These challenges cause many anxieties for practicing clinicians,
both as to what to expect, how to practice and what support or help they will be given.
In this statement from the European Society of Intensive Care Medicine (ESICM), we
aim to describe some of the facts, the fears and the areas where scientific societies
can help to improve our understanding of these problems and at the same time reduce
the impact of these issues for our members and their patients.
The facts
In 2009, a new acute respiratory disease emerged in Mexico, secondary to a swine-origin
influenza A (H1N1) virus (S-OIV). Public health agencies did their best to contain
the dissemination of the disease; however, unfortunately these efforts failed, and
on the 11 June, the World Health Organization (WHO) declared the first flu pandemic
since 1968. The disease spread rapidly across the globe. In the southern hemisphere,
Intensive Care faced an unprecedented challenge with as many as 25% of all ICU patients
in Australia and New Zealand having either suspected or confirmed S-OIV by the middle
of August [1]. In the Northern hemisphere, the first wave of the pandemic had a very
heterogeneous impact, with the USA, Canada, England and Spain being especially affected.
By the end of August, virtually all countries had reported cases, and many had also
reported deaths.
Very early, it became clear that a significant number of deaths were preceded or caused
by rapidly developing acute respiratory failure often refractory to conventional mechanical
ventilation. Although the vast majority of individuals had a mild illness, similar
to seasonal flu, it was observed that certain groups not usually at increased risk
of complications or death from seasonal influenza were at special risk for S-OIV.
These groups include the pregnant or recent postpartum [2], the obese and the young
[3–5]. Three predominant syndromes have been reported [1, 6] to be associated with
life-threatening situations:
acute viral pneumonitis with bilateral pulmonary infiltrates [“flu A”-associated acute
respiratory distress syndrome (FLAA-ARDS)];
secondary bacterial pneumonia;
viral exacerbation of airflow limitation.
FLAA-ARDS, the most commonly described of these syndromes, was associated with a very
high mortality. Multiple organ dysfunction syndrome (MODS) developed rapidly in up
to 75% of the patients [6], despite the fact that most of these died due to refractory
hypoxaemia apparently resistant to the use of measures such as high frequency oscillation
and extra-corporeal membrane oxygenation (ECMO) [7]. Approximately half went on to
develop life-threatening super-added infections [6], which were especially common
in those with co-existing morbid obesity, diabetes mellitus, immunosuppression, malignancy
and chronic lung disease [1].
The fears
Previous influenza pandemics occurred in 1918 (H1N1 strain), 1957 (H2N2 strain) and
1968 (H3N2 strain), resulting in very significant levels of morbidity and mortality.
This was especially the case in the pandemic of 1918–1919, which caused major social
disruption following the First World War. Today, we can be more optimistic as this
current pandemic is unique in respect of two important issues:
The state of public preparedness for a pandemic is well in excess of anything previously
seen. This has developed following the emergence of severe acute respiratory syndrome
(SARS) [8] and the threat of avian flu (H5N1). Major plans have therefore been developed
in many countries that could be now implemented [9, 10].
Since the previous pandemics, Intensive Care Medicine has evolved to enable the treatment
of very sick patients presenting with an acute respiratory illness, and we have now
new and better antibiotics and antivirals. Modern techniques of mechanical ventilation
together with protocols for the support and treatment of multiple organ failure may
reduce the overall mortality of these conditions.
Despite the existing plans, the biggest unknown factor remains the overall impact
that the pandemic will have both on the health and on the economy. Epidemiologists
have been modeling likely scenarios, but the models are notoriously inaccurate early
on in a pandemic phase [11]. Using an attack rate ranging from 10 to 30% of the population
with a hospital admission rate close to 1% and a case-fatality rate close to 0.14%,
as in seasonal flu (an hypothesis supported by preliminary data [1]), the pandemic
may have a major impact on health services and ICM in particular. Some models have
predicted critical care demand at the peak surge of the pandemic to be well in excess
of 100% of available facilities, even in the most developed countries [11]. This is
of considerable concern to practicing Intensivists. Increasing intensive care support
by a factor of two without additional skilled and trained specialists and without
the usual range or technical facilities and support services may well force us to
ventilate more patients than normal, but this would not be ‘quality critical care.’
If this increased surge was to occur, then the numbers of patients presenting would
be well in excess of the available capacity to provide them with quality care. This
will necessitate triage. The ethics of triage have been discussed several times [12–15],
but the concerns as to whether the ethical or legal framework will ultimately support
clinicians faced with these tribulations remain. Practicing for a greater good, rather
than what is best for an individual patient, may be the pragmatic answer to the problem,
but clinicians are rightly concerned that this may lead to future complaint and legal
or professional censure. Unfortunately, many national governmental authorities have
failed to address these concerns with clear and open guidance.
The resources
In response to these uncertainties, many groups have started to develop more sophisticated
plans based on better data. These plans are now being fed from data acquired by global
registries, such as the H1N1 registry, commissioned and developed by the European
Society of Intensive Care Medicine (www.h1n1registry.org). Data from this registry
will allow real-time trends to be seen and witnessed, which hopefully will enable
us to adjust our resources and facilities to be able to cope with a predicted second
surge of the disease. Ultimately, more sophisticated analysis will allow us to develop
more accurate models for future pandemics that may occur.
In these models, we need to take into account the specificities of this pandemic and
the fact that it predominantly affects the young. In many countries the numbers of
pediatric intensive care (PICU) beds are at a level far below that of the adult specialty.
In addition, PICU has centralized its service in many countries, with the implication
that many smaller hospitals no longer have significant skill bases or equipment to
care for these children. This may well result in a significant number of young patients
being cared for in an adult environment. Even disregarding the problems of putting
young patients into an adult unit, the skill and knowledge gap is huge, and this needs
to be rapidly addressed to prepare for this eventuality. The close links that exist
between the ESICM and the European Society of Paediatric and Neonatal Intensive Care
(ESPNIC) will undoubtedly prove to be an important asset to mount a coordinated and
efficient response to the current threat.
Even today, many questions remain unanswered, and our understanding of many facets
of this pandemic is poor [16]. We still know little with regards the pathogenesis
or the optimal treatment of the disease. The definition of patients-at-risk remains
unclear, and the indications, optimal doses and duration of therapy are not certain.
We need better information with regards to the impact of the vaccine in the spread
of the pandemic, the use of anti-viral agents, the risks and benefits of steroids
or the importance of pre-emptive antimicrobial therapy. To answer those questions
(and many others), several registries and collaborative studies have been initiated.
On the back of these registries, together with the established trials groups [such
as the European Critical Care Research Network (ECCRN) Trial Group], we hope to be
able to initiate and coordinate collaborative interventional research that will increase
our knowledge base of this problem.
We contend that such research efforts can and must happen in real time, as the pandemic
develops. Indeed, history has shown us that when faced with the most severe of challenges,
we usually manage to cope. This often takes courage as well as ingenuity and innovation.
Despite the adversities faced and the challenges of working long and stressful shifts,
research continues and knowledge base advances. During the SARS crisis in 2002 [17,
18], guidelines for treatment were generated as fast as the disease spread [19], and
research output was maintained or even increased. Facing the threat of being infected
themselves, clinical teams, often overwhelmed with clinical duties, kept collecting
and analyzing data, enabling them to test the best approaches to decrease the morbidity
and the mortality of SARS. We would like to thank publicly all of our colleagues that
have used their time and efforts to increase our knowledge of this disease, in order
to minimize its worldwide impact and to achieve better outcomes for all of our patients.
We are certain that the same will happen now.
Despite all of our doubts and the existence of huge heterogeneities between countries,
or even regions within countries, the knowledge and availability of ICM is now greater
than ever before. It is the duty of scientific societies such as ESICM to foster the
development and the dissemination of new knowledge. It is our duty to demonstrate
that with this new knowledge Intensivists will be able to improve the outcome of their
patients.