Introduction

The development of paediatric intensive care has contributed to improved survival rates in children with critical illnesses [68, 69]. Consequently, new disease patterns have emerged due to long-term complications and effects of the original illness and its treatment. In addition to survival and morbidity, physical and psychological sequelae, as well as the quality of life (QoL) in survivors and in their families are important outcome measures.

Historically, outcome research in paediatrics is either based on an age-specific approach, such as follow-up studies of premature infants [41, 72, 73], or on a more disease-oriented approach, such as follow-up studies in survivors of cardiothoracic surgery or trauma [15, 55, 64, 70]. These studies have shown substantial physical, psychological and neuro-cognitive sequelae, interfering with daily life and normal development. In addition, effects on parents and siblings have been shown [26]. Evaluative research of adult intensive care survivors showed the effect of intensive care treatment per se. Irrespective of the underlying illnesses, sequelae on all domains with effects on QoL were found [2, 19, 58, 75]. In multi-disciplinary paediatric intensive care unit (PICU) populations, reports on outcome are scarce [24, 25].

Based on these observations, we believe that follow-up research of paediatric intensive care survivors and their families is needed to evaluate: (1) physical sequelae and their impact during growth and development; (2) psychological sequelae in patients and their families and their impact on the QoL of patients and family members; and (3) the need for treatment and support after discharge.

The aim of this article is to provide an overview of the available literature concerning the different domains of QoL (i.e. physical, psychological and social functioning) in children surviving paediatric intensive care, including the effect on parents, and to suggest directions for future follow-up research.

Methods

To identify studies eligible for this review, we searched Medline (1966–2006), EMBASE (1974–2006), CINAHL (1982–2006), pre-CINAHL and the Cochrane Library (2006) in March 2006. In the search strategy, all terms mapped to the appropriate MeSH/EMTREE subject headings and “exploded” were used; among them were: paediatric intensive care unit (PICU), septic shock, respiratory insufficiency, meningococcal disease, central venous catheterisation, intubation, physical and psychological sequelae, post-traumatic stress disorder (PTSD), QoL, health status and long-term outcome.

Definitions

Functional health is defined as an individual’s ability to perform normal daily activities, to fulfil usual roles and to maintain health and well-being.

QoL is defined as an individual’s perception of their position in life, in the context of the culture and value systems and in relation to their goals, expectations, standards and concerns [1].

Health-related QoL (HRQoL) is defined as QoL in which a dimension of personal judgement over one’s health and disease is added [21].

Study selection

Studies were selected for review if they met two inclusion criteria: (1) study of a representative population of PICU survivors (defined as a population consisting of medical and/or surgical PICU patients <18 years old) and (2) evaluation of physical sequelae, measurement of QoL or functional health >30 days after PICU discharge. Because of the limited number of studies, the measurement tools did not need to be standardised. Studies with a retrospective and prospective design were included.

Excluded were: (1) studies in homogeneous PICU populations (e.g. survivors of cardiothoracic surgery and trauma) reporting diagnosis-related outcome in particular but not intensive care treatment as such, and (2) studies evaluating mortality only.

Results

Eligible studies and quality of the studies

Twenty-seven studies were found in which one or more aspects of long-term sequelae in PICU survivors and/or their families were described. The patient characteristics, populations, measurement tools and outcomes are described in Tables 1 and 2. The quality criteria are described in Table 3. None of the studies met all of the quality criteria. In studies describing the same outcome aspect, differences in study population, follow-up time and measurement tools make the comparison and synthesis of results difficult.

Table 1 Patient characteristics, measurement tools, physical and functional health outcome
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Table 2 Patient characteristics, measurement tools and psychological and quality of life (QoL) outcome
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Table 3 Quality assessment of reviewed studies
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Physical and neuro-cognitive sequelae (Table 1)

In 12 studies that included in total 340 patients, aspects of physical and neuro-cognitive sequelae were evaluated.

Neurological evaluation was conducted in five studies including 275 survivors. The majority of the children were neurologically normal. In the remaining children, disabilities such as hearing loss, coordination, cognition and developmental problems turned out to be severe [23, 35, 43, 53, 59].

Pulmonary evaluation was conducted in six studies including 65 patients [6, 14, 22, 30, 48, 74]. Restrictive and obstructive disease and hypoxaemia during exercise was found.

Cardiac evaluation was conducted in two studies including 23 survivors [22, 74]. No abnormalities were found, except for left ventricular hypertrophy in one child.

Renal evaluation was conducted in one study including 12 survivors [62]. In two children, glomerular filtration was impaired, one had hypertension and one had proteinuria.

Psychological sequelae (Table 2)

Various questionnaires were used. Cut-off points for the diagnosis of PTSD differed between studies but all of them showed high scores for PTSD in children and parents.

Psychological evaluation of children was conducted in five studies including 202 children [40, 50–52, 61]. Symptoms of PTSD were found in 11 of 74 evaluated children. In one study, a relation was found between invasive procedures and high scores [52].

Psychological evaluation of parents was conducted in six studies including parents of 547 children [4, 8, 20, 40, 50, 61]. Symptoms of PTSD were found in 72 of 295 evaluated parents. In some studies, a relation was found between high scores and illness severity as perceived by parents [4, 50, 61]. In one study, these high scores decreased over time [8].

Functional health and QoL (Tables 1 and 2)

Evaluation of functional health was conducted in three studies including 821 children [9, 12, 44]. The majority of the children seemed to have normal functional health; the remainder was found to be seriously impaired.

Evaluation of QoL was conducted in four studies including 1,664 children [27, 38, 47, 65]. QoL was evaluated using three different questionnaires. In the majority of children, the QoL was normal or equal to the QoL before PICU admission. In all studies, some of the children had poor QoL.

Discussion

Only 27 studies consisting of 3,444 PICU survivors met our inclusion criteria. The small numbers, heterogeneity of the studied populations and the used measurement tools, the frequent use of non-validated measurement tools and the various aspects of outcomes studied make aggregation of the data and, therefore, strong conclusive statements difficult.

Physical sequelae

The reviewed studies report distinct physical sequelae, including neurological abnormalities in PICU survivors. Standardised neurological examination of PICU survivors was validated in 1994 but very few studies have been carried out since [24, 25]. As neurological problems have a great impact on daily life, standardised evaluation and adequate support and rehabilitation seem to be relevant, similar to in NICU survivors [11, 46, 56].

Follow-up studies evaluating lung function in children are hampered by the small incidence of severe respiratory insufficiency in children [49]. In adult respiratory distress syndrome (ARDS), the recovery of lung function is shown during the first year and physical limitations seem to be partly dependent on lung function [34, 58]. In infants and children, post-natal lung growth may contribute to the improvement of lung function after critical illness. In addition to lung function, the long-term effect of small airway disease should be evaluated, for instance, in children with respiratory syncitial virus infection.

Data on the structured evaluation of cardiac and renal function in paediatric and adult ICU survivors is not available. In young children, septic shock and the need for vasoactive support of the circulation may interact with the developing myocardium and may have persistent effects on cardiac growth and function [10, 67, 77].

Complications of intensive care procedures per se, (e.g. vascular complications due to intra-vascular catheters and side-effects of ototoxic drugs and sedatives) are not evaluated [5, 18, 32, 33, 45, 54, 57, 63]. One can assume the exact incidence of physical sequelae to be higher than has been reported so far.

Psychological sequelae and functional health and QoL

In the reviewed studies, psychological sequelae have been established in 10–14% of survivors and their parents. The comparison of findings is hampered due to different measurement tools and cut-off points for the diagnosis of PTSD and various follow-up intervals. Risk factors accounting for hampered psychological outcome could be diverse (severity of illness, being removed from one’s child, having been witness to the accident, mental health, family functioning, social support, coping strategies and lack of information from the medical team) [17, 26, 29, 31]. Psychological support to improve coping strategies and prevent over-protection might improve psychological outcome in children and parents [3, 28]. Further research is essential to establish the appropriate time and extent of the psychological support needed.

Cognitive sequelae have rarely been studied in the reviewed studies. Adequate neuro-cognitive evaluation is both expensive and time-consuming. Studies in neonatal ICU survivors show substantial cognitive dysfunction with great impact on daily life [7]. Consequently, early intervention, education and rehabilitation are expected to improve daily life [11, 46].

A majority of PICU survivors seem to have unchanged functional health and good QoL. In the reviewed studies, functional health is evaluated by telephone interviews [27, 38, 47, 65]. In most of these studies, the physician rather than the child or its parents evaluates functional health. Ideal (HR)QoL questionnaires should measure all aspects of QoL and preferably be filled in by the children themselves. Proxy investigation of functional health and (HR)QoL (in children <6–8 years of age) is second best [36, 37, 39, 66]. Besides, the pre-morbid state is probably an important factor which is difficult to assess [16].

Suggestions for future follow-up research

The reviewed studies have a number of methodological limitations. Heterogeneity is the most important one. Consensus on all aspects of follow-up research is essential for well-founded conclusions. For example, structured and standardised evaluation of: (1) organ system function with a validated tool such as the Paediatric Logistic Organ Dysfunction (PELOD) score [13, 42, 60, 71]; (2) neuro-cognitive function; (3) complications of PICU treatment; and (4) (HR)QoL are warranted. Multi-centre studies as proposed by the Collaborative Pediatric Critical Care Research Network (CPCCRN) with a uniform approach will provide answers either in general PICU cohorts or in disease-oriented study groups [76].

In conclusion, this review indicates that PICU survivors and their parents may have substantial physical and psychological sequelae interacting with QoL. Because of longer life expectancy, longer follow-up time is warranted, emphasising the consequences for health care in children. We believe that paediatric intensivists and psychologists should be involved as core members of follow-up teams.