Postoperative acute respiratory distress syndrome development in the thoracic surgery patient

Acute Respiratory Distress Syndrome in Cancer Patients

Acute respiratory distress syndrome (ARDS) is a heterogeneous form of acute, diffuse lung injury that is characterized by dysregulated inflammation, increased alveolar-capillary interface permeability, and non-cardiogenic pulmonary edema. In the general population, the incidence and mortality associated with ARDS over the last two decades have steadily declined in parallel with optimized approaches to pneumonia and other underlying causes of ARDS as well as increased utilization of multimodal treatment strategies that include lung-protective ventilation. In the cancer settings, significant declines in the incidence and mortality of ARDS over the past two decades have also been reported, although these rates remain significantly higher than those in the general population. Epidemiologic studies identify infection, including disseminated fungal pneumonias, as a major underlying cause of ARDS in the cancer setting. More than half of cancer patients who develop ARDS will not survive to hospital discharge. Those who do survive often face a protracted and often incomplete recovery, resulting in significant long-term physical, psychological, and cognitive sequelae. The residual organ dysfunction and poor functional status after ARDS may delay or preclude subsequent cancer treatments. As such, close collaboration between the critical care physicians and oncology team is essential in identifying and reversing the underlying causes and optimizing treatments for cancer patients with ARDS. This chapter reviews the diagnosis and common causes of ARDS in cancer and gives an update on the general management principles for cancer patients with ARDS in the ICU.

Venovenous Extracorporeal Membrane Oxygenation for Postoperative Acute Respiratory Distress Syndrome

Background

Extracorporeal membrane oxygenation (ECMO) has recently attracted interest as a treatment for severe acute respiratory distress syndrome (ARDS). However, the outcomes of this procedure in post-surgical settings have not yet been characterized. In this study, we evaluated the outcomes of ECMO in patients with severe postoperative ARDS.

Methods

From January 2007 to December 2012, a total of 69 patients (aged 58.3±11.5 years, 23 females) who underwent venovenous ECMO to treat severe postoperative ARDS were reviewed. Of these patients, 22 (31.9%) had undergone cardiothoracic surgery, 32 (46.4%) had undergone liver transplantation, and 15 (21.7%) had undergone other procedures.

Results

Thirty-four patients (49.3%) were successfully weaned from ECMO, while the other 35 patients (50.7%) died on ECMO support. Among the 34 patients who were successfully weaned from ECMO, 21 patients (30.4%) eventually died before discharge from the hospital, resulting in 13 hospital survivors (18.8%). Multivariable analysis showed that the duration of pre-ECMO ventilation was a significant independent predictor of death (odds ratio [OR], 2.25; 95% confidence interval [CI], 1.29 to 3.90; p=0.004), whereas the concomitant use of continuous venovenous hemodialysis (CVVHD) was associated with improved survival (OR, 0.55; 95% CI, 0.31 to 0.97; p=0.038).

Conclusion

Although the overall survival rate of patients treated with ECMO for postoperative ARDS was unfavorable, ECMO offered an invaluable opportunity for survival to patients who would not have been expected to survive using conventional therapy. CVVHD may be beneficial in improving the outcomes of such patients, whereas a prolonged duration of pre-ECMO ventilator support was associated with poor survival.

Pulmonary radiofrequency ablation complicated by acute respiratory distress syndrome

The authors present a case of a patient with rectal adenocarcinoma and lung metastasis undergoing elective radiofrequency (RF) ablation of a large, refractory pulmonary metastasis. The mass was located in the left upper lobe, invading the left hilum. The patient experienced shortness of breath following the procedure and shortly after extubation. This shortness of breath progressed over 4 days, when the patient developed acute respiratory distress syndrome (ARDS). The patient suffered from complications related to respiratory support and expired 9 days after RF ablation. Possible mechanisms of ARDS development following pulmonary ablation are discussed.