Anaesthetic management and unplanned admission to intensive care after thoracic surgery

摘要

Over the past three decades, the emergence of less invasive treatments and better peri-operative anaesthetic care in thoracic surgery have contributed to better clinical outcomes, despite the increasing age of patients and their higher burden of comorbidities 1, 2. Postoperative pulmonary complications, namely acute respiratory distress syndrome, pneumonia and bronchopleural fistula, occur frequently after lung cancer resection and they are largely implicated as causes of early mortality and poor long-term survival 3. The decision to admit a patient to the intensive care unit (ICU) or the high dependency unit or the recovery area are mainly based on the type of operation, the patient's comorbidities, the institutional policy as well as the availability of beds in these settings 4. Most admissions to the ICU are planned or anticipated before the scheduled case, with the aims of preventing postoperative complications and enhancing functional recovery. Unplanned or emergency ICU admissions after surgery are much less frequent and are related to unexpected peri-operative adverse events such as severe bleeding, persistent hypoxaemia, unstable hemodynamic conditions and hypothermia or delirium. The aim of unplanned ICU admission is to reverse any organ dysfunction using enhanced monitoring and nursing care, along with fluids, drugs and organ supportive therapy. For clinicians and healthcare managers, unplanned ICU admission has become a valid indicator to assess patient safety in surgical patients and can be used in cost-effective benchmarking as well as in root cause analysis of peri-operative adverse events 5. Compared with direct or planned admission to ICU, unplanned ICU admission is associated with a significantly higher risk of death beyond the expected consequences of comorbidities, age, type of surgery and emergency status. In this issue of Anaesthesia, Shelley et al. report an incidence of 2.3% unplanned ICU admission among 7431 cases of lung resection performed in 16 UK thoracic surgical centres 6. The vast majority of patients who required unplanned ICU admission in this study also required mechanical ventilation of their lungs, although the cause(s) of respiratory failure and timing of admission to the ICU were unclear or unreported. Multivariate analysis indicated that unplanned ICU admissions were less frequent in patients receiving intravenous (i.v.) anaesthesia, compared with inhalational anaesthesia, and in patients receiving thoracic epidural analgesia, compared with other analgesic techniques, including paravertebral block (PVB). In a larger prospective dataset from the American College of Surgeons National Surgical Quality Improvement Program (n = 16,696), 3.6% of patients required unplanned re-intubation of their tracheas within 30 days after lung surgery. Interestingly, the need for postoperative invasive ventilatory support was associated with patients' frailty features (advanced age, poor functional status, low haematocrit, low albumin level) and with the severity of the surgical stress (open thoracotomy, prolonged surgery) 7. Nowadays, anaesthetists are recognised as a key member of the thoracic team as in the liver transplantation team where the anaesthetists' level of experience has been shown to influence postoperative mortality and graft failure 8. Likewise, in thoracic surgery, the application of proper lung isolation techniques and of physiologically evidence-based practices may contribute to the success of the intervention and also to improve clinical outcomes 9. From several cohort studies, we know that major postoperative pulmonary complications are strongly associated with risk factors such as pre-existing low aerobic physical fitness and inspiratory muscle weakness, as well as with intra-operative positive fluid balance and elevated inspiratory driving pressure 10, 11, all factors that could be targeted by specific interventions. Indeed, implementation of pre-operative exercise training has been e