Hong Kong Physiotherapy Journal
Volume 18, Issue 2 , Pages 47-52, August 2012

Evidence-Based Physiotherapy in Intensive Care

  • Alice Jones, PhD, FACP, MPhil, MSc, Cert PT

      Affiliations

    • Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong.
    • Corresponding Author InformationReprint requests and correspondence to: Alice Jones, Associate Professor, Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.

Received 30 December 1999

Article Outline

Abstract: 

The aim of this paper is to arouse physical therapist awareness of the necessity for evidence-based practice in the intensive care environment. This article summarizes findings from an intex{et search of physiotherapy-related clinical trials over the last 10 years. The feasibility of performing randomized-controlled trials and the role of the physical therapist in the intensive care environment are discussed. Therapists are encouraged to consider appropriate casemix and outcome measures when adducing evidence to support or dispute the effect of a physiotherapeutic technique.

Key words: evidence-based, intensive care, physiotherapy

 

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Introduction 

Intensive care units (ICUs)&nre amongst the most expensive areas of hospital activity [1], and have been criticized for unproven efficacy with regard to outcome measures. It has been alleged that a large proportion of intensive care resources are either invested in patients with poor outcomes or squandered on the observation of low-risk patients [1]. Seventy percent of high-cost intensive care patients die during their admission [2], and the resources required to care for 8% of the highcost admissions to ICUs are equivalent to 92% of the resources necessary to provide care for low-cost patients [2].

Undoubtedly, it is difficult for physiotherapists in ICUs to justify their existence when the discipline of intensive care itself has been challenged by administrators' rationalization of limited healthcare resources. Economic constriction over the last 2 years, particularly in South-East Asia, has resulted in a significant restriction of hospital budgets. As a consequence, a phenomenon called “no referral for physiotherapy” has recently emerged in some ICUs in Hong Kong and the United Kingdom. Patients in the ICU are no longer being referred for physiotherapy treatment, because referrers believe there is insufficient evidence to prove the efficacy of physiotherapy. As the pressure on the economy increases, the decision-making process, which determines the resource allocation to intensive care practice has changed from an expert opinion to an evidence-based judgment. One may ask, Why should evidence be required to satisfy fiscal rationalists? Quite simply, government health organizations represent the mandate of the people to ensure that taxation revenue generates the maximum health-care mileage. Measurable outcome improvement is demanded for a continued allocation of resources. An intensive care physiotherapy service is part of that resource allocation, and as such, physiotherapy interventions must be demonstrably costeffective, so that patient outcome at least balances manpower costs.

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What evidence is required? 

Evidence-based medicine has been defined as the integration of individual clinical expertise with the best available external clinical evidence from systematic research [3]. Neither definition alone is sufficient for the practice of good medicine. Without external evidence, clinical practice may become dated, and yet at the same time, evidence of the highest probity may be inapplicable or inappropriate for an individual patient [3]. A framework for comparative evaluation of evidential spectra was devised by the United States Preventive Services Task Force (Table 1) [4]. Applying this rating system to some commonly quoted studies of physiotherapy interventions in intensive care (Table 2) [5, 6, 7, 8, 9, 10], it is obvious that although many of these studies produced favourable results for physiotherapy, none were randomized–controlled trials (RCTs) and all can be validly criticized for observer bias.

Table 1. United States Preventive Services Task Force's rating of quality of evidence [4]
CategoryDescription
IEvidence obtained from a systematic review of all relevant randomized–controlled trials
IIEvidence obtained from at least one properly-designed randomized–controlled trial
III–iEvidence obtained from well-designed controlled trials without randomization
III–iiEvidence obtained from well-designed cohort or case–control analytic studies preferably from more than one centre
III–iiiEvidence obtained from multiple time series with or without the intervention, plus dramatic results in uncontrolled experiments
IVOpinions of respected authorities, based on clinical experience, descriptive studies, or reports of expert committees
Table 2. Commonly quoted (uncontrolled, non-randomized) studies of physiotherapy treatments in the intensive care unit

•Radiological improvement without hypoxaemia demonstrated in mechanically ventilated patients who received chest physiotherapy [5]

•Chest physiotherapy was shown to be equally effective when compared with therapeutic bronchoscopy in the treatment of acute lobar atelectasis in patients in the intensive care unit [6, 7]

•Improvement in total lung/thorax compliance was demonstrated following chest physiotherapy/manual inflation [7, 8]

•The effect of chest physiotherapy in the management of intensive care patients with pneumonia [9, 10]

The scientific literature commonly records conflicting views regarding the effectiveness of physiotherapy in different patient groups. For example, Mackenzie states that “pneumonia may be difficult to diagnose (in adults) and may, in the early stages, respond favourably to chest physiotherapy” [11]. In contrast, Phelan's view is that “physiotherapy has an extremely limited role in the management of infants and children with pneumonia. It should not be used at all during acute stages and if resolution is rapid” [12]. Although referring to different patient groups, these types of contradictory analyses are further supported by the Cochrane Library's review of bronchopulmonary hygiene physical therapy (BHPT) in chronic obstructive pulmonary disease (COPD) and bronchiectasis. Fiscal rationalization also motivated this review, because BHPT was viewed by few health authorities as labour intensive and expensive. Furthermore, BHPT supposedly posed some potential patient risks, and the relative benefit of different techniques was yet to be determined [13].

An initial trawl of the Cochrane Airways Group database revealed 95 trials for analysis, which after applying exclusion criteria filtering, resulted in only seven RCTs [14, 15, 16, 17, 18, 19, 20]. Even these trials were criticized for their small sample size and moderate quality [13]. Although physiotherapy treatment was shown to improve pulmonary clearance (as measured by sputum production and radioisotope clearance), there was no significant improvement in pulmonary function. Understandably, the BHPT review concluded that there was insufficient evidence to support or refute administration of BHPT to patients with acute and stable COPD, chronic bronchitis, or bronchiectasis [13].

In view of current derisory perceptions of pulmonary physical therapy, an internet-based investigation of published physiotherapy research specifically related to intensive therapy was undertaken. Two common indices, MEDLINE™ [21], and the Cumulative Index to Nursing and Allied Health Literature (CINAHL®) [22] were searched; limited to the English language and using the terms ‘physiotherapy OR physical therapy AND intensive care’. The MEDLINE™ search produced 44 articles for the period 1989 to 1999. Abstract examination showed 21 of the articles were not related to physiotherapy techniques, eight were review papers and one was a letter. Of the remaining 14 physiotherapy-related clinical trials, only six were RCTs. There were more articles in the CINAHL® index and the search was limited to the period between 1993 and December 1998. Applying the same search terms, 99 articles were disclosed and of these there were only three RCTs in the 29 physiotherapy-related studies. From a total of 143 articles, about one-third (47) were not physiotherapy-related and a third (53) were reviews or discussion papers. Nearly all of the remaining clinical trials (43) fell into Class III evidence categories because they failed to incorporate a randomized, controlled design. The resultant strength of any recommendation, for or against the use of a technique, could at best, only be weak or moderate.

A brief summary of the conclusions drawn from the clinical trials and evidence in support of physiotherapy is shown in Table 3 [23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33]. Paediatric research mostly focused on the use of assessment tools and motor development, however, there were a number of negative reports on the value of chest physiotherapy. Chest physiotherapy increased skin blood flow in neonates (signifying pain and discomfort) [34], but failed to prevent atelectasis [35]. Furthermore, direct tracheobronchial suctioning was reportedly superior to physiotherapy in the treatment of post-extubation atelectasis in premature infants [36].

Table 3. A summary of physiotherapy findings from clinical trials reported during the last 10 years

•Respiratory physiotherapy interventions increase oxygen demand and induce stress [23, 24, 25]

•Haemodynamic changes are unavoidable during a physiotherapy intervention [26, 27], but that often these manoeuvers are still considered to be safe [28, 29]

•Early mobilization is important and the effectiveness of incentive spirometry is debatable [30]

•Improvement in airway resistance and compliance after suctioning [31]

•Reduction of intrapulmonary shunt after abdominal surgery with additional (evening) physiotherapy [32]

•Improvement in the 6-minute-walk distance and maximum inspiratory mouth pressure in patients with chronic obstructive pulmonary disease requiring mechanical ventilation after comprehensive early pulmonary rehabilitation [33]

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Demand for evidence 

Questioning accepted practice, which has not been based on high quality evidence, has led to a robust interrogation of the role of respiratory physiotherapy. Campbell and colleagues in 1975 were the first to dispute the efficacy of chest physiotherapy, when they reported that percussion caused a reduction in the forced expired volume in one second (FEV1.0)[37]. A number of provocative reviews followed in the literature: “Does Chest Physical Therapy Work?” [38]; “Chest Physiotherapy: Time for Reappraisal” [39], and “Chest Physiotherapy — May be Harmful in Some Patients” [40]. However, scientific rigour does not necessarily guarantee logical conclusions. In 1996, Alexander and colleagues demonstrated in a RCT that patients who were allocated to discontinue chest physiotherapy received 45% fewer treatments compared with the control group. This represented an estimated cost saving of US$319,000 with no increase in mortality or length of hospital stay [41]. The authors concluded that, chest physiotherapy is frequently dispensed inappropriately. While this study may demonstrate a financial benefit, the second arm of the conclusion does not necessarily follow. Failure to determine statistical power has resulted in two flaws in this study. First, the outcome measures chosen, namely, hospital stay and mortality rate, are the least sensitive measures of the impact of physiotherapy, except in desperately-ill patients. It is, therefore, not surprising to find that there is no difference between the patient groups for these criteria in a patient cohort that lacks a strong indication for chest physiotherapy in the first place [42]. Second, cost estimates were based on the number of treatments rather than treatment-duration, and may not reflect the true costs of care. For example, a physiotherapist could assess a patient and conclude that the most appropriate ‘treatment’ is instruction on exercises to be conducted at home or advice on daily living, which may require only five minutes of the physiotherapist's time. Many of the negative reports on the efficacy of chest physiotherapy result from the mismatching of the patient condition with the physiotherapy technique [43] because of the lack of definition of treatment components, making evaluation of a specific technique difficult.

The absence of high-quality evidence has provided ammunition for the ‘prosecutors’ of physiotherapy, resulting in broad unsubstantiated statements disparaging the effectiveness of chest physiotherapy [39].

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Feasibility of randomized–controlled trials in physiotherapy research 

To provide rigorous scientifically-sound evidence, RCTs are the gold standard, however, these trials are often not feasible because they are either too costly, or their conduct raises serious ethical issues [44]. Additionally, clinical practice itself is complex, multi-faceted, deep and situational, and singular scientific analysis may not be appropriate. The efficacy of physiotherapy is often influenced by the quality of the patient-therapist interaction, plus factors such as experience, intuition, motivation, purpose, judgement, and value, all of which constitute soft data, but are major impact factors in determining patient-valued outcomes, such as, quality-of-life [44]. Although these soft measures may appear to be of minimal benefit to a ventilated patient per se, they may provide considerable comfort to the patient's relatives and form an integral component of an advanced healthcare system. It is true that physiotherapy often fails to provide hard data or criteria that are easily measurable, particularly in the ICU environment where there are so many confounding variables. It is often difficult to determine the primary contributing factor to a favourable treatment outcome when a patient receives more than one therapeutic intervention. While physiotherapists may very much wish to produce top class evidence, there is also the ethical issue of withdrawing some historical intervention, believed to be beneficial to the patient. If future funding allocation is based on evidence of efficacy, and if that evidence is not of the highest rank, physiotherapy as a specialty runs the risk of not being as highly regarded as competing disciplines — with resultant absorption.

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The role of physiotherapists in intensive care units 

It is generally believed that physiotherapy is useful in the management of patients with excessive secretions [45]. Fifty-three of 54 intensive care directors surveyed (14 from the United Kingdom, 20 from Australia, 8 from Canada, 6 from South Africa, and 6 from Hong Kong) considered secretion-mobilization to be the primary role of the physiotherapist in the ICU [46]. Alarmingly, in response to a “yes” and “no” closed-ended question, 57% of these intensive care directors considered that the physiotherapist's work could be covered by other disciplines. Pulmonary physiotherapists should see their role extending beyond being a ‘secretion mobilizer’, to include techniques that maximize tissue oxygen delivery, improve lung volume, and maintain musculoskeletal function without causing detriment to a patient's cardiopulmonary function. A physiotherapist's knowledge of human anatomy, respiratory and muscle physiology, biomechanics and body movement science, together with psychologically-polished clinical skills, makes physiotherapy a particularly appropriate discipline to rehabilitate and motivate the patient. Furthermore, the physiotherapist has a significant role in educating patients and relatives in the value of self-care. If patients are aware of how to maximise their lung function, cough effectively, and self-administer pulmonary hygiene, the physiotherapist will not be required to perform secretion-mobilization techniques. This does not mean that the physiotherapist has no healthcare role, but rather, a different role to play.

Regardless of the intrinsic value of soft data, hard evidence of physiotherapy effectiveness will still be required. To provide this evidence, physiotherapists must show that they are capable of adapting their role to the different temporal requirements of the disease process. To combine clinical experience and expertise with external clinical evidence, physiotherapy research should focus on matching the case-mix to the therapeutic manoeuver and using appropriate outcome measures. Techniques for mobilizing sputum will not work if there is no sputum.

In the ICU environment, there are still many issues relating to physiotherapy that have not been adequately investigated. For example, the relationship between breathing pattern, work of breathing and ventilator weaning; the effect of manual inflation and mobilization exercises on oxygen consumption; and sensory input and positioning of patients with acute head and chest injury. To ensure the results are worth the effort, trials should attempt to produce the best quality evidence possible (Table 4).

Table 4. Procedures to consider when undertaking a clinical trial

•Identify an appropriate patient cohort

•Identify the role of physiotherapy in the management of this type of patient

•Employ a specific technique to achieve a specific objective

•Perform a power analysis on the parameter of interest and determine sample size

•Allocate patients randomly to groups

•Include a control group

•Separate the operator and the assessor, and ensure blinding

•Measure appropriate outcome parameters
−physiological (temporal)

−psychological

−global/individual


•Involve multiple centres

The future, however, looks brighter. Nowadays, most physiotherapy students embrace a research culture during their clinical training, because many more of their teachers are, themselves, research trained. While immediate benefit may not be demonstrable, one can expect to see a more vigorous evaluation of physiotherapy techniques by future physiotherapists with an extension of the physiotherapist's role in the ICU to that of a clinical physiologist/psychologist.

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Conclusion 

Evidence-based medicine does not necessarily exclude individual clinical expertise. Proficiency and judgement acquired through clinical experience should not be discarded just because there is no inviolable scientific evidence.

Questioning evidence in a science oriented working environment is desirable, but the question asked should be important and not trivial. One must consider the role, objective, and expected outcome of the intervention. The indicators for treatment must be present, and the patient population or condition appropriate for therapy. That is not to mention the obvious need to standardize methods and research strategies where appropriate. However, no two patients are identical and different outcomes may be desired in different circumstances.

Most studies that have reported negative efficacy of physiotherapy treatment have done no more than alert readers to redirect their energy to increase investment return, by restricting therapy to appropriate patient groups. It is important that one must not let evidence-based practice become evidence-constrained or evidence-biased practice.

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PII: S1013-7025(00)18003-0

doi:10.1016/S1013-7025(00)18003-0

Hong Kong Physiotherapy Journal
Volume 18, Issue 2 , Pages 47-52, August 2012

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