The physiotherapist plays an integral role in the management of patients in respiratory intensive care units (ICU). However, while their care of mechanically-ventilated patients is an established one, their role during weaning is less well documented (Bruton, Conway, et al.1999). Respiratory failure is caused by the failure to ventilate sufficiently, occurring in various patient types, for example: exacerbation of COPD, Acute-Respiratory-Distress-Syndrome or spinal cord injuries. Invasive ventilation provides full ventilatory support to the critically ill patient in the ICU and should maintain or improve alveolar ventilation (Pilbeam 1992) and reduce the work of breathing. It is universally understood that, 'weaning is a process' and not an event (Boles, Bion, et al. 2006). Stiller (2000) states the defined role that physiotherapists play in this process varies considerably from one unit to the next, depending on factors such as country, tradition, staffing levels, training, and expertise. The physiotherapist has various roles in this process: secretion clearance, respiratory muscle training, exercise, transfer training, identifying readiness for extubation, weaning strategies, appropriate respiratory management and application of NIV. Potential roles will be discussed in this essay to raise awareness of the key skills which could be exploited in order to professionally develop the weaning process and improve treatment and outcomes for ventilated patients. The purpose of this essay is to endeavour to justify certain roles and potential roles of physiotherapy in the process of weaning, reviewing existing evidence to justify treatment interventions and roles whilst making recommendations for potential future assessment.
One of the most commonly used interventions by ICU physiotherapists for the intubated patient is manual-hyperinflation (MH). Gooselink, Bott, et al. (2008) states; 'the aims of MH are to prevent pulmonary atelectasis, re-expand collapsed alveoli, improve oxygenation, improve lung compliance and facilitate movement of airway secretions towards the central airways'. While there is a lack of substantive evidence for MH, Gooselink, Bott, et al. (2008), Denehy (1999) and Choi and Jones (2005) have all proposed that administered correctly and in correlation with other techniques such as positioning, expiratory vibrations and suctioning it can be efficacious in clearing secretions and reducing airway resistance in the intubated patient, specifically patients with ventilator associated pneumonia (Choi and Jones 2005). In a small study carried out by Hodgson, Denehy, et al. (1996) as cited by Denehy (1999) the amount of secretions expelled was measured in ventilated critically ill patients receiving MH and positioning as opposed to those not. They presented that when MH was used there was a significant increase in the wet weight of secretions produced. Gooselink, Bott, et al. (2008) and Hodgson, Denehy, et al. (1996) present positive findings justifying the benefits of MH in the weaning process. King and Morrell (1992) demonstrated that seventy eight percent of the senior ICU physiotherapists included in their survey, considered sputum clearance to be the main benefit of MH in the ventilated patient, thus proving MH 's importance in the physiotherapeutic management of weaning.
There are possible gaps in the administration of MH as Jones (2002) proposed that in order for MH to clear secretions, a peak expiratory flow needs to be reached which depends on effective technique of delivery .This would spark the idea that physiotherapists could potentially educate members of the multidisciplinary team in correct use of MH and the importance of consent and communication. As there is conflicting evidence to justify the use of MH, this should encourage future research into its benefits in the weaning process.
With patient progress, focus is on trying to involve their participation. Deep breathing exercises and cough technique are directed by the physiotherapist as part of the Active-Cycle-of-Breathing-Techniques treatment. Percussion and vibrations are also used by many but again, evidence of effectiveness is sparse (Ambrosino and Clini 2005).
Increased lung volumes are necessary for the patient to attempt some independent secretion clearance. Ambrosino and Clini (2005, pp.1098) presented that, 'upright positioning should be adopted to improve lung volumes and decrease work of breathing in patients who are being weaned from mechanical ventilation,' whereas they found that prone positioning was suited for patients with ARDS. Physiotherapeutic positioning again would be beneficial when correlated with secretion management due to its favourable effect on ventilation.
Mobilization presents the opportunity to move secretions, aid clearance and work the patient physically to regain some independence. Mobilization is an evolving concept in ICU treatment; it can progress from passive/active exercises, sit out of bed, gradual standing with the tilt table, stand and walk. A survey to determine the role of physiotherapists in European ICU's found that all physiotherapists were involved in mobilization of critically ill patients regularly, indicating the benefits of physiotherapy-led mobilization (Norrenburg and Vincent 2000). Ambrosino and Clini (2005) state the importance of mobilization for muscle strength and function, but it also increases the work of breathing hence incorporating respiratory muscle function. In a study by Partsch (2002) as cited by Gooselink, Bott, et al. (2008, pp.1190) supports this idea as they stated 'mobilization refers to physical activity sufficient to elicit acute physiological effects that enhance ventilation, central and peripheral perfusion, circulation, muscle metabolism and alertness…' all evidence of the important role of the physiotherapist when treating an intubated patient. McWilliams and Pantelides (2008) suggest that early mobilization can significantly decrease length of stay in ICU, further supporting Gooselink, Bott, et al. (2008). One can conclude that overall physical health of the patient may be improved and weaning times decreased the sooner the physiotherapist begins mobilization.
Non-Invasive-Ventilation (NIV) is a mode of positive pressure therapy often used in the weaning and extubation process by physiotherapists. NIV permits the early removal of the endotracheal tube and is administered via nasal or facial mask. It is conceivably the 'bridge' between invasive ventilation and spontaneously breathing. Spontaneous breathing trials assess if a patient is suitable for discontinuation of invasive ventilation. This can be done by; putting the patient on a minimal pressure support with PEEP, CPAP, or a T-Piece. If the patient tolerates the trial length and maintains a stable respiratory status then extubation should begin. NIV is a less intrusive method of supporting the patient's respiratory system whilst also preserving the patient's ability to cough and speak. Burns, Adhikari, et al. (2009) cited that similar to invasive therapy, NIV can reduce respiratory rate, augment tidal volume and improve gas exchange in COPD patients. Nava, Ambrosino et al. (1998) conducted a prospective randomised study to evaluate the use of NIV as a weaning approach in patients with respiratory failure due to COPD. Despite this being a small and short study, the results were favourable for physiotherapist use of NIV as the group of patients weaned with NIV Pressure-Support-Ventilation had a significantly lower rate of failure than the control group of invasive weaning. Extubation sparks the clinical dilemma of when NIV should be used. Boles, Bion, et al. (2006) states, ' the effectiveness of NIV remains to be determined,' similarly to Jiang, Kao, et al.(1999), that due to a lack of evidence, NIV should not be routine following extubation but rather that physiotherapists should only use NIV if the patient is considered at risk of developing post-extubation respiratory complications. One may conclude that further research is required but perhaps patients suffering from COPD may benefit from longer NIV treatment due to their vulnerable respiratory system.
Regarding the potential roles of the physiotherapist in weaning a patient from invasive ventilation to spontaneously breathing, there are numerous techniques that could, and, perhaps, should be applied based on expertise and knowledge. Perhaps the most simple but hypothetically the most effective would be for the physiotherapist to have more influence on the weaning process and the decisions that are made; when weaning should begin, weaning strategies, mode of ventilation and whether NIV is appropriate. Moran, Bradley, et al. (2005) found through a survey of Physiotherapists that 90 percent were involved in the management but only 50 percent were involved in the implementation of NIV, showing potential for greater physiotherapy involvement. Evidence based practice is the forefront approach to all health professional treatment due to high costs in the health service. Jones (2000) states, 'physiotherapy interventions must be demonstrably cost effective, so that patient outcome at least balances man power costs.' A potential role that physiotherapists could fulfil would be to research into longer outcome results as there is currently a lack of evidence to show long term quality of life outcomes for post ventilated ICU patients. Having this evidence could strongly justify physiotherapeutic management in the weaning process.
A potential role of the physiotherapist could be with adequate time and resources, to train all members of the ICU multidisciplinary team on certain practical treatments to ensure consistency of delivery. Such training could be provided for MH, open/closed suctioning, transfers and identifying the 'window of opportunity' as to when to begin weaning, a key factor in terms of outcomes and opportunities. Delaying weaning once a patient is medically fit, such as at the weekend due to less staff, leads to increased stay in ICU, increased time on MV, poorer outcome measures than those liberated earlier which ultimately leads to higher costs in a cost-inflated health service (Boles, Bion, et al. 2006). Potentially physiotherapist could undertake observation periods so to not miss this 'window of opportunity'. With correct identification, the consequent reduction in costs could fund weekend ICU physiotherapists to ensure weaning is proceeded as indicated and the process to spontaneously breathing is speeded.
Pulmonary rehabilitation is another potential role for the physiotherapist in the weaning process which can also prevent the adverse effects of bed rest. Current low levels of funding and staffing render it unfeasible as a regular treatment method during and after the weaning process. The Chartered-Society-of-Physiotherapists (2003) states that the benefits of pulmonary rehab are: decrease in the sensation of dyspnoea, improved exercise tolerance, improved peripheral muscle strength, reduction in anxiety and depression, and a decrease in length of hospital stay. One can deduce that a specifically designed pulmonary rehab protocol to suit the ICU could be established to assist weaning. This Pulmonary rehabilitation could continue once liberated on an out-patient basis to aid outcomes and quality of life for the patient. Nava, Ambrosino,et al. (1998) supports this idea, suggesting a comprehensive rehabilitation programme, consisting of leg and arm mobilization, respiratory muscle training and early ambulation may facilitate weaning in COPD patients. This ICU-adapted pulmonary rehab can simply progress from passive to active movements to more functional activities such as the use of the bike pedal in bed. These exercises place a greater demand on the respiratory muscles which in turn helps to re-train them to the demands that will be required for successful weaning. A study by Chiang, Wang, et al (2006) as cited by Gooselink, Bott, et al. (2008, pp.1191) showed that upper and lower limb training improved strength but more significantly increased the amount of ventilator-free time and improved functional outcomes in patients requiring prolonged invasive ventilation, more evidence justifying the use of pulmonary rehabilitation in weaning. Clearly a lack of sufficient funding and adequate staffing poses the greatest threat to the proposal, and to any progression in the physiotherapeutic treatment of invasively ventilated patients.
In conclusion, the role of the physiotherapist in the process of weaning a patient from invasive ventilation to spontaneously breathing is a vital part of the spectrum of MDT treatment. Recent studies are beginning to evaluate and justify this, and must continue. With further research and studies, physiotherapy in ICU'S may evolve and weaning therefore avail of the expertise and specialist techniques of the physiotherapist. This essay hints at a few of these possibilities, but with further research, perhaps a more practical/physical approach to weaning could be established to speed the weaning process, as opposed to the current pharmaceutical/physician - led approach.
