Best practice & research. Clinical anaesthesiology
-
Surgery and general anaesthesia have direct effects on the respiratory system depending on the organ/system involved and modality of delivery, potentially leading to postoperative pulmonary complications that increase hospital morbidity, prolong hospital stay and add to health-care costs. Postoperative complications have been reported to be as high as 30% for thoracotomy and lung resection in patients with chronic obstructive pulmonary disease. ⋯ In general, preoperative optimisation of medical therapy combined with physiotherapy and early extubation and mobilisation may improve clinical outcomes in high-risk surgeries, including upper abdominal and thoracic surgery in patients with severe emphysema. Evidence from randomised controlled trials or meta-analyses is limited and most of the recommendations on perioperative physiotherapy come from either uncontrolled or non-randomised trials or from observational studies and expert opinion.
-
Best Pract Res Clin Anaesthesiol · Jun 2010
ReviewRole of non-invasive ventilation (NIV) in the perioperative period.
Anaesthesia, postoperative pain and surgery (more so if the site of the surgery approaches the diaphragm) will induce respiratory modifications: hypoxaemia, pulmonary volume decrease and atelectasis associated to a restrictive syndrome and a diaphragm dysfunction. These modifications of the respiratory function occur early after surgery and may induce acute respiratory failure (ARF). Maintenance of adequate oxygenation in the postoperative period is of major importance, especially when pulmonary complications such as ARF occur. ⋯ Evidence suggests that NIV, as a prophylactic or curative treatment, has been proven to be an effective strategy to reduce intubation rates, nosocomial infections, intensive care unit and hospital lengths of stay, morbidity and mortality in postoperative patients. However, before initiating NIV, any surgical complication must be treated. The aims of this article are (1) to describe the rationale behind the application of NIV, (2) to report indications (including induction of anaesthesia) and contraindications and (3) to offer some algorithms for safe usage of NIV in high-risk surgery patients.
-
Best Pract Res Clin Anaesthesiol · Jun 2010
ReviewNew insights into experimental evidence on atelectasis and causes of lung injury.
Development of atelectasis is common in both patients with and without lung injury during mechanical ventilation. Atelectasis might contribute to or attenuate lung injury by different possible mechanisms. ⋯ In addition, the loss of aerated lung volume due to atelectasis in mechanically ventilated patients indirectly results in increased mechanical strain of the reduced number of ventilated lung regions, if ventilation is not adequately decreased. This study discusses possible mechanisms and interactions between atelectasis formation in the lungs and the development or aggravation of acute lung injury.
-
Best Pract Res Clin Anaesthesiol · Jun 2010
ReviewMechanisms of atelectasis in the perioperative period.
Atelectasis appears in about 90% of all patients who are anaesthetised. Up to 15-20% of the lung is regularly collapsed at its base during uneventful anaesthesia prior to any surgery being carried out. Atelectasis can persist for several days in the postoperative period. ⋯ However, a combination of oxygenation and airway suctioning will most likely cause new atelectasis. Recruitment at the end of the anaesthesia followed by ventilation with 100% O2 causes new atelectasis before anaesthesia is terminated but not with ventilation with lower fraction of inspired oxygen (FIO2). Thus, recruitment must be followed by ventilation with moderate FIO2.
-
Best Pract Res Clin Anaesthesiol · Jun 2010
ReviewPerioperative tidal volume and intra-operative open lung strategy in healthy lungs: where are we going?
Tidal volumes have tremendously decreased over the last decades from <15 ml kg(-1) to approximately 6 ml kg(-1) actual body weight. Guidelines, widely agreed and used, exist for patients with acute lung injury or acute respiratory distress syndrome (ARDS). However, it is questionable if data created in patients with acute lung injury or ARDS from ventilation on intensive care units can be transferred to healthy patients undergoing surgery. ⋯ The same problem has been observed regarding the application of positive end-expiratory pressure (PEEP) and intra-operative lung recruitment. This article provides an overview of the current literature addressing the size of tidal volume, the use of PEEP and the application of the open-lung concept in patients without acute lung injury or ARDS. Pathophysiological aspects of mechanical ventilation are elucidated.