Post-lung resection pulmonary edema: a case for aggressive management

Balanced Chest Drainage Prevents Post-Pneumonectomy Pulmonary Oedema

BACKGROUND

Pneumonectomy in the adult patient is associated with a mortality of 1-9%. Death is often due to post pneumonectomy pulmonary oedema (PPPO). The use of balanced chest drainage system (BCD) in the setting of post pneumonectomy has been reported to be of benefit in the prevention of PPPO. This study seeks to compare the incidence of PPPO in patients who underwent pneumonectomy and whose empty pleural space was managed either with CRD or BCD.

METHODS

This retrospective observational cohort study involved 98 patients who were operated on by one surgeon at Liverpool Hospital, Sydney, Australia from 1997 to 2019. The patients were divided into two groups according to the era in which they had their pneumonectomy. Group 1 consisted of 18 patients managed with clamp-release drainage between 1997 and 2002. Group 2 consisted of 80 patients managed with balanced chest drainage between 2003 and 2019. The primary outcomes of interest were the development of PPPO and death. Demographic and clinico-pathological variables between the groups were compared including whether the phrenic nerve was sacrificed, volume of infused intraoperative fluid, duration of single lung ventilation, intraoperative tidal volumes, agents of anaesthetic induction and maintenance, mean urine output in the first 4 postoperative hours, institution of a postoperative 1.5 L fluid restriction, total chest drainage, day of chest drain removal, presence of radiological postoperative mediastinal shift, post-pneumonectomy pulmonary oedema and death. Group characteristics were compared using t-test and chi-squared for continuous and categorical variables respectively. Univariate and multivariate analysis was also undertaken using the Firth method of logistic regression for rare occurrences in a stepwise fashion.

RESULTS

Through univariate analysis, balanced chest drainage, postoperative fluid restriction and intraoperative fluid infusion showed significant effect on PPPO. Through multivariate analysis, balanced chest drainage was found to have independent protective value for PPPO and mortality.

CONCLUSION

Compared with clamp-release drainage, balanced chest drainage results in a lower incidence of post-pneumonectomy pulmonary oedema and death.

Post-operative pulmonary complications after thoracotomy

Pulmonary complications are a major cause of morbidity and mortality in the post-operative period after thoracotomy. The type of complications and the severity of complications depend on the type of thoracic surgery that has been performed as well as on the patient's pre-operative medical status. Risk stratification can help in predicting the possibility of the post-operative complications. Certain airway complications are more prone to develop with thoracic surgery. Vocal cord injuries, bronchopleural fistulae, pulmonary emboli and post-thoracic surgery non-cardiogenic pulmonary oedema are some of the unique complications that occur in this subset of patients. The major pulmonary complications such as atelectasis, bronchospasm and pneumonia can lead to respiratory failure. This review was compiled after a search for search terms within 'post-operative pulmonary complications after thoracic surgery and thoracotomy' on search engines including PubMed and standard text references on the subject from 2000 to 2015.

Management of Postoperative Respiratory Failure

Despite best efforts, postoperative complications such as postoperative respiratory failure may occur and prompt recognition of the process and management is required. Postoperative respiratory failure, such as postoperative pneumonia, postpneumonectomy pulmonary edema, acute respiratory distress-like syndromes, and pulmonary embolism, are associated with high morbidity and mortality. The causes of these complications are multifactorial and depend on preoperative, intraoperative, and postoperative factors, some of which are modifiable. The article identifies some of the risk factors, causes, and treatment strategies for successful management of the patient with postoperative respiratory failure.

Acute respiratory distress syndrome after pulmonary resection

Postoperative acute respiratory distress syndrome (ARDS) is a recognized complication of pulmonary resection. It is characterized by the acute onset of hypoxemia with radiographic infiltrates consistent with pulmonary edema, without elevations in the pulmonary capillary wedge pressure. Many studies suggest that around 2-5 % of patients develop some degree of lung injury, and the mortality from ARDS following pulmonary resection remains high. ARDS following thoracotomy and lung resection has a miserable prognosis, with overall hospital mortality rates over 25 %. The present review evaluates the evidence available in the literature tracking perioperative mortality and morbidity as well as the pathogenesis and management of ARDS in patients undergoing pulmonary resection.

Idiopathic postpneumonectomy pulmonary edema: Hyperinflation of the remaining lung is a potential etiologic factor, but the condition can be averted by balanced pleural drainage

OBJECTIVES

Idiopathic postpneumonectomy pulmonary edema is a leading cause of mortality after pneumonectomy. Postoperative hyperinflation of the remaining lung is an etiologic factor. We have demonstrated avoidance of postpneumonectomy pulmonary edema solely by changing management of the pneumonectomy space to a balanced drainage system. In sheep, we tested the following hypothesis: (1) Postoperative induced hyperinflation of the remaining lung can cause postpneumonectomy pulmonary edema. (2) A balanced drainage system can prevent its development.

METHODS

We performed 37 right-sided pneumonectomies in adult sheep. In experiment 1, after surgery, 10 sheep had continuous suction (5 kPa) applied through an intercostal catheter placed in the empty hemithorax to induce mediastinal shift and hyperinflation of the left lung without adverse hemodynamic sequelae. In experiment 2, 27 sheep were randomly allocated into 3 equal groups regarding management of the residual empty right hemithorax: balanced drainage, no intercostal drainage, and clamp-release intercostal underwater drainage. A fourth group of 9 sheep served as a sham controls placebo with the same anesthetic and a right thoracotomy.

RESULTS

All sheep tolerated surgery without adverse event. In experiment 1, there was significant mediastinal shift at necropsy in all sheep and 60% (n = 6) had postpneumonectomy pulmonary edema develop in the left lung (P = .023 vs sham). In experiment 2, incidences of postpneumonectomy pulmonary edema were as follows: 0 in balanced group (P = .057 vs other groups), 3 (30%) in no-drainage group, and 3 (30%) in clamp-release group. Only the 12 sheep with postpneumonectomy pulmonary edema had respiratory distress; the rest had uneventful recoveries.

CONCLUSION

In a sheep model of postpneumonectomy pulmonary edema, hyperinflation from mediastinal shift is an etiologic factor. A balanced drainage system averts postpneumonectomy pulmonary edema. This is the first time such a causal relationship has been demonstrated, supporting our continued use of balanced drainage after pneumonectomy.

Accuracy and limits of transpulmonary dilution methods in estimating extravascular lung water after pneumonectomy

STUDY OBJECTIVES

The measurement of extravascular lung water index by double indicator (EVLWIdi) or the measurement of extravascular lung water index by transpulmonary thermodilution (EVLWItt) could be useful after pneumonectomy. Since pulmonary blood flow and volume are altered after pneumonectomy, the validity of these methods is uncertain. This study has compared measurements of EVLWIdi and EVLWItt with measurement of extravascular lung water index by gravimetry (EVLWIg) in a porcine model of pulmonary edema induced after right pneumonectomy.

DESIGN

Randomized laboratory study.

SETTING

Animal research laboratory.

SUBJECTS

Twenty-seven female pigs; mean weight, 35 +/- 5 kg (+/- SD).

INTERVENTIONS

The pigs were anesthetized, placed on mechanical ventilation, and allocated to a two-lung group (n = 10) or a right pneumonectomy group (n = 17). EVLWIdi and EVLWItt were measured at baseline, 60 min after pneumonectomy, and 60 min after IV injection of oleic acid (OA).

MEASUREMENTS AND RESULTS

There was a good correlation between EVLWIg and EVLWIdi values (r = 0.96, p < 0.0001 in the two-lung group; and r = 0.81, p = 0.02 in the pneumonectomy group). EVLWIdi underestimated EVLWIg in the two-lung group (- 3 mL/kg; 95% confidence interval [CI], - 7 to + 2 mL/kg) and in the pneumonectomy group (- 0.9 mL/kg; 95% CI, - 3.3 to + 1.5 mL/kg). After pneumonectomy, EVLWItt decreased in mean by 27% and increased in mean by 70% after OA acid. There was a good correlation between EVLWIg and EVLWItt values (r = 0.96, p < 0.0001 in the two-lung group; and r = 0.90, p < 0.0001 after pneumonectomy). EVLWItt slightly overestimated gravimetric value in the two-lung group (+ 1.5 mL/kg; 95% CI, - 1.5 to + 4.2 mL/kg) and largely overestimated gravimetric value after pneumonectomy (+ 5 mL/kg; 95% CI, + 3.4 to + 6.8 mL/kg).

CONCLUSION

Double-indicator and transpulmonary thermodilution methods could be useful in monitoring extravascular lung water index (EVLWI) after pneumonectomy, but transpulmonary thermodilution largely overestimates EVLWI.

Pathophysiology and management of one-lung ventilation

The ability to manage OLV effectively in patients with significant pulmonary disease is increasing. Knowledge of pulmonary ventilation and perfusion physiology, improvements in the ability to prevent and treat hypoxia, and a thorough grasp of traditional and novel ventilatory techniques may promote improved perioperative outcomes.

Acute lung injury and acute respiratory distress syndrome after pulmonary resection

The occurrence of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) after thoracic surgery are perplexing and persistent problems. Variously described as postpneumonectomy pulmonary edema, noncardiogenic pulmonary edema, and postlung resection pulmonary edema, ALI and ARDS may be considered a single entity, with ALI being the less severe form of ARDS. It is characterized by the acute onset of hypoxemia with radiographic infiltrates consistent with pulmonary edema, without elevations in the pulmonary capillary wedge pressure. Although this syndrome does not occur frequently and is usually without identifiable cause, the mortality is high. However, the phenomenon has not been rigorously studied owing to the low incidence, with primarily retrospective case series reported. Thus, the nomenclature, risks, and pathogenesis are not well defined. Interest in this syndrome has recently been renewed as the rate of other perioperative complications has declined. ALI/ARDS is reviewed with a focus on potential etiologies and the spectrum of available interventions.

Post-pneumonectomy pulmonary edema: is anesthesia to blame?

Post-pneumonectomy pulmonary edema is a major cause of early mortality following lung resection surgery. It is not clear whether this complication is caused by excessive perioperative intravenous fluid as was previously thought. The recent demonstration of increased pulmonary capillary permeability of the lung following a pneumonectomy suggests measures to try and decrease the incidence of this highly lethal syndrome. These measures include the judicious use of intravenous crystalloids, avoidance of lung hyperinflation and efforts to minimize the pulmonary artery pressure.