Introduction
The burden of cardiovascular disease within a progressively ageing
population has resulted in a shift in the demographic of cardiac surgery
patients to include those that are older, increasingly frail and
presenting with multiple co-morbidities (1), (2).
Despite a higher risk profile, mortality post-cardiac surgery remains
low, due to continued advances in peri-operative care(3). However, the complex nature of these patients
means they are likely to encounter a longer and more complicated
post-operative course, often involving a prolonged length of stay (LOS)
in intensive care (ITU). Prolonged ITU stay has been reported as
occurring in 4-11% of cardiac patients (4) with other
sources citing it to be as high as 36%(5). This poses
both clinical and ethical issues as a very small proportion of patients
are consuming an extremely high level of both human and financial
resources. Care of the critically ill requires a high level of
expenditure of time, money and resources; this includes specialist
staff, one to one nursing care and sophisticated equipment and
treatments (6). Critical care units across the UK are
running at, or near full, capacity whilst also struggling with staffing
shortages (7). Lack of critical care bed availability
often leads to cancellation of procedures, extension of waiting lists
and compromised patient safety, thereby reducing operational performance
across all areas of cardiac surgery and directly affecting patient care.
Williams et al . (8) identified a
disproportionate usage of ITU beds in their study and concluded that the
poor outcomes that have been reported after prolonged ITU stays may
indicate it is neither beneficial to the patient nor cost effective.
This is echoed by Gaudino et al. (9) who
commented that although life-saving treatment should not be withheld,
resources should be allocated wisely to consider those waiting for
treatment.
It is widely accepted that short-term outcomes for those with a
prolonged LOS in ITU are poor, with higher rates of in-hospital
mortality (10% vs 0.6%) and morbidity (10), (11).
Additionally, both physical and cognitive impairments have been reported
in those who have survived admission to an ICU, symptoms of which can
persist for years following discharge, with more recent classification
under the term ‘post-intensive care syndrome’ or PICS(12) . Post-operative delirium in intensive care is a
common occurrence in cardiac surgery patients
(26-52%(13)) and there is evidence to suggest that
those who experience delirium are at higher risk of long-term cognitive
dysfunction (14). This is compounded by the growing
number of elderly patients undergoing surgery, with 37% of critically
unwell adults over the age of 65 having pre-existing cognitive
impairments such as dementia and depression (14). PICS
also encompasses physical impairments; muscle weakness as a result of
critical care admission occurs in 40% of adult patients and in a small
number of cases persists beyond discharge, resulting in poor functional
ability and reduced quality of life. The mental health repercussions of
ITU admission are perhaps the most marked, with 30% of patients
experiencing depression, 70% anxiety and up to 50% demonstrating
symptoms of post-traumatic stress disorder (14).
Poorer outcomes for those with prolonged intensive care stay, increasing
demand for critical care and a lack of resources has resulted in the
development of enhanced recovery programmes. Enhanced recovery after
surgery (ERAS) or ‘fast track’ programmes are a multidisciplinary
approach that covers the entire patient journey (pre, intra and
post-operatively) and have been designed to limit psychological and
physiological stress in surgical patients in order to promote faster
recovery (15). Techniques include thorough preparation
for surgery through patient assessment and education, minimally invasive
surgical techniques, optimal fluid management and pain control and the
early promotion of oral nutrition and mobilisation post-operatively(16). ERAS was first implemented in colorectal surgery
but its usage has spread to other specialities including cardiac
surgery. The implementation of enhanced recovery pathways in cardiac
surgery has been found to reduce not only LOS in hospital but also ITU
LOS, post-operative complications and cost (17).
Coleman et al.( 18) reported
that although patient demographics, lifestyle and disease severity were
similar between the ERAS and the control groups, the ERAS patients had
better understanding of coronary artery disease, shorter fasting and
water deprivation times, increased engagement with physiotherapy and
improved physical performance post-operatively. Williams et al.(19) saw a reduction in post-operative LOS by one day
in the ERAS group and a reduction in intensive care unit LOS from 43 to
28 hours. Evidence demonstrating the positive effects of ERAS programmes
within cardiac surgery, however, remains limited in comparison to other
surgical specialties, and, as a consequence, ERAS is not yet widely
implemented.
As a result of worse short-term clinical outcomes for patients with
prolonged ITU stay, discharge from hospital was, until recently,
considered the key measure of success. However, there has been a shift
towards long-term outcomes, functional recovery and quality of life
(QoL) as measures of surgical quality. There is now a body of primary
research into long-term post-operative outcomes for cardiac patients
with a focus on prolonged ICU stay, but it lacks consolidation. It is
the aim of this review, therefore, to compare and critique the findings
of multiple studies and provide an overview of the best available
research on this topic in order to determine the long-term effects of
prolonged ITU stay, and to inform and influence clinical practice in
this area. Better understanding of the outcomes of this demographic of
patients will also promote informed decision making for those
considering cardiac surgery and allow clinicians to make more accurate
decisions regarding treatment options, resource allocation and medical
priorities. However in order to do so, greater understanding of
prognosis, long-term survival and QoL is required.