Don't drown the "down lung"

Oxygen toxicity during one-lung ventilation: is it time to re-evaluate our practice?

Lung cancer remains one of the leading causes of cancer-related mortality. Surgical resection remains the mainstay of non-small cell lung cancer therapy, but an increasing number of patients receive preoperative adjuvant chemotherapy that may predispose these patients to unique organ toxicities. This chemotherapy, along with exposure to high oxygen concentrations, may combine to increase the risk of reactive oxygen species-mediated lung injury. Continued efforts are needed to improve overall outcome in these patients, including a reevaluation of our management of oxygen therapy.

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.

Pneumonectomy in children for destroyed lung and the long-term consequences

OBJECTIVES

Destroyed lung introduces irreversible changes in lung parenchyma. This condition is uncommon in children. Operative intervention is essential for children in this state. We demonstrate our experience with this condition and report on the respective long-term results.

METHOD

Seventeen children who underwent pneumonectomy for destroyed lung during a 15-year period were retrospectively analyzed. Long-term results were detected in 13 patients.

RESULTS

Seventeen children underwent pneumonectomy. Five children were female (29.4%), and 12 children were male (70.5%). The median age of the study group children was 9.1 years (3-16 years). Sputum was the most common presenting symptom (n = 13, 76.4%). Bronchiectasis (n = 11), tuberculosis (n = 4), and necrotizing lung disease (n = 2) were the main underlying conditions. Destroyed lung was detected on the left side in 14 children (82.4%) and on the right side in 3 children (17.6%). Main bronchial stenosis was found in 4 children and mucosal thickening or congestion in 5 children. The median length of hospital stay was 15.5 days. The mortality rate was 11.7% (n = 2), and the morbidity rate was 23.5% (n = 4). Follow-up information was available for 13 patients, and this ranged from 1 year to 12 years (median 5.2 years). The respiratory capacity and scoliosis level of the patients were examined.

CONCLUSIONS

Although pneumonectomy is considered a difficult procedure in children, its use for destroyed lung resolves complications and improves a patient's quality of life. In time, the remaining lung expands to compensate for the loss of the removed lung. Children grew and developed normally after pneumonectomy. Patients tend not to have major skeletal deformation as the result of pneumonectomy in the short term.

Pathophysiology of Postpneumonectomy Pulmonary Edema

Pulmonary edema is a rare, potentially fatal complica tion associated with major resection of the lung, usually pneumonectomy. Although pulmonary edema in this setting can often be attributed to a variety of causes such as cardiac failure, bacterial pneumonia, and fluid overload, the specific syndrome of postpneumonec tomy pulmonary edema (PPE) occurs in the absence of these factors. PPE remains a diagnosis of exclusion, and its pathophysiology is poorly understood. Overzealous perioperative fluid administration has traditionally been implicated in clinical cases of postpneumonectomy pulmonary edema, but there is a body of evidence suggesting several other potential mechanisms. These include increases in cardiac output secondary to cat echolamine release, interruption of mediastinal lym phatic drainage, endothelial injury secondary to release of humoral factors or stretching of intercellular junc tions, hyperinflation, and other unknown factors.

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.

Postpneumonectomy pulmonary edema. A retrospective analysis of incidence and possible risk factors

OBJECTIVE

To analyze the incidence of postpneumonectomy pulmonary edema (PPE) and to determine potential risk factors for PPE.

MATERIAL AND METHODS

A group of 197 patients was studied retrospectively, and the incidence of PPE was recorded over a 5-year period. Preoperative, perioperative, and postoperative clinical data were collected, and preoperative and postoperative chest radiographs were reviewed. A scoring system was used to distinguish between premanifest and manifest PPE. Postpneumonectomy patients with pulmonary edema, with no clinically evident cause, were considered to have PPE.

RESULTS

The incidence of premanifest PPE was 12.2% (n = 24), and that of manifest PPE was 2.5% (n = 5). Mortality in the group of patients who developed manifest PPE was 100%. Two significant perioperative associations were found in the PPE group. One was the administration of fresh frozen plasma (FFP) transfusions (relative risk, 4.3; 95% confidence interval, 1.3 to 14.4 corrected for age and sex), while the other was higher mechanical ventilation pressures during surgery (relative risk, 3.0; 95% confidence interval, 1.2 to 7.3).

CONCLUSION

Our data suggest that FFP transfusions form an important risk factor for PPE. The mechanism may be an increased permeability of the pulmonary vessels due to an immunologic reaction after multiple FFP transfusions. The significantly higher mechanical ventilation pressures we found in the PPE group may be explained as an early sign of the development of PPE.

Acute lung injury following lung resection: is one lung anaesthesia to blame?

Further examination of the parameters of oxidative stress, perioperative changes in the vasoregulatory mechanisms of the pulmonary circulation, and characterisation of the endothelial insult that probably occurs in all patients undergoing lung resection is necessary if the operative conditions under which lung surgery is carried out are to be optimised. Perhaps, then, more insight might be gained into how to improve preservation of lungs for transplantation and how to protect the lung from significant injury following resection.