Scientific basis for postoperative respiratory care
Postoperative pulmonary complications (PPCs) following upper abdominal and thoracic surgery are common (severe PPCs 2-5%) and expensive ($52.000 per PPC). Costs (LOS increased by 2 weeks), morbidity, and mortality are higher with PPCs than with cardiac or thromboembolic complications.
Preventing and treating PPCs is a major focus of physical and respiratory therapists, using a wide variety of techniques and devices, including incentive spirometry, CPAP, PEP, intrapulmonary percussive ventilation, and chest physical therapy. The scientific evidence for these techniques is lacking and heterogenic. This article provides a critical review of the literature regarding the evidence on chest physiotherapy.
Risk factors for developing a PPC can be
- preoperative: age, smoking, COPD, immobility etc.
- intraoperative: length of surgery, general anaesthesia, type of surgery (upper abdominal) and high tidal volumes during surgery.
The combined impact of surgical trauma and anaesthesia result in reduced lung volumes, respiratory muscle dysfunction and atelectasis. Positioning, pain and pharmacologic agents can all worsen the reduction in lung volumes, characterized by substantial reductions in functional residual capacity and vital capacity. The development of atelectasis leads to hypoxemia and translocation of bacteria to the bloodstream, and may be important in creating the heterogeneous lung at risk for ventilator-induced lung injury.
Therefore, methods to increase lung volumes and improve cough have been developed and studied, such as
- incentive spirometry (no evidence, but might be helpful in setting goals with patients)
- CPAP (only effective in improving oxygenation and reduce PPCs for high risk and obese patients)
- chest physiotherapy (conflicting evidence: some research reports more frequent and severe atelectasis by causing pain and splinting, some report a decrease in PPCs with intensive administration and a mix of techniques
- PEP (evidence does not support routine use of PEP)
- IPPB (intrapulmonary percussive ventilation: no evidence for reduction of PPCs)
The author advocates for implementing a group of related treatments and practices to reduce PPCs, rather then searching for a single silver bullet. Using a system named I COUGH (for incentive spirometry, coughing and deep breathing, oral care, understanding, getting out of bed, andhead of bed elevation), this group studied over 1,500 surgical cases, with promising results in terms of multidisciplinary involvement, patient education, early mobilizaton, and reduction of PPCs.
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What is the impact and consequence of this lack of evidence for CPT on your daily practice?
> From: Branson, Respir Care 58 (11) (2016) 1974-1984. All rights reserved to The Author(s). Click here for the Pubmed summary.