Post-pneumonectomy pulmonary edema: analysis and risk factors

Respiratory failure following pulmonary resection

Improvements in the perioperative management of the patient undergoing pulmonary resections have reduced postoperative complication rates steadily in the last several decades. However, postresection respiratory failure, particularly lung injury with no discernible cause, remains a major cause of morbidity and mortality. Because the incidence of this entity is relatively low, the terminology, pathogenesis, and optimal management are poorly delineated in the literature. The purpose of this review is to describe the criteria used to define postresection lung injury, discuss the possible etiologic factors, and outline currently available treatment strategies.

Incidence and Risk Factors for Lung Injury After Lung Cancer Resection

BACKGROUND

Lung injury, defined as acute hypoxemia accompanied by radiographic pulmonary infiltrates without a clearly identifiable cause, is a major cause of morbidity and mortality after major anatomic pulmonary resection. Our objective was to identify the incidence and risk factors for the development of postoperative lung injury.

METHODS

A retrospective case-control study of consecutive patients undergoing resection for lung cancer at a single institution was performed. The severity of lung injury was defined using the American European Consensus Conference on ARDS (acute respiratory distress syndrome) criteria and the National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0 (http://ctep.cancer.gov/reporting/ctc.html). Patients with lung injury were compared with matched control patients, based on age, sex, and extent of resection, for examination of a priori defined risk factors.

RESULTS

From January 2001 to June 2004, 1,428 patients underwent attempted curative lung cancer resection. Postoperative lung injury occurred in 76 (5.3%) cases, 44 (3.1%) of which met criteria for acute lung injury or acute respiratory distress syndrome. After matching, there were no differences between cases and control patients with respect to use of induction therapy, perioperative transfusions, or tumor laterality. After univariate and multivariate analysis, increasing perioperative fluid administration and decreasing postoperative predicted lung function were significant risk factors for the development of lung injury. The overall mortality for patients with lung injury was 25%, compared with 2.6% for the control group.

CONCLUSIONS

Lung injury after lung resection has a high mortality. Lower predicted postoperative lung function, especially diffusion capacity, in combination with greater perioperative fluid administration were significant predictors of postoperative lung injury.

Determinanten des insensiblen Flüssigkeitsverlustes

Accurate perioperative fluid balance is the basis of a targeted infusion regimen. However, neither the initial status nor perioperative changes of the fluid compartments can be reliably measured in daily routine. In particular, insensible losses are not consistently assessed, so that substitution therapy is generally empirical. The object of this paper is to communicate the scientific data on this topic. Preoperative fasting (10 h) does not per se cause intravascular hypovolemia. In adults, total basal evaporation by way of the skin and airways and of any wounds during major abdominal interventions is usually less than 1 ml/kg/h. An inconstant fluid and protein shift towards the interstitial space perioperatively seems to be associated with hypervolemia, which suggests it should be preventable. The decisive factor in this context seems to be deterioration of the endothelial glycocalyx, whose further patho-physiological impact is currently only partially known. Clinical studies have revealed a link between fluid restriction and improved outcome after major abdominal surgery.

Inhaled nitric oxide does not prevent postpneumonectomy pulmonary edema in pigs

OBJECTIVE

Increase in lung permeability is an inevitable consequence of pneumonectomy in relation to inflammatory injury and increased perfusion flow. We tested whether inhaled nitric oxide, a potent vasodilatator and anti-inflammatory agent, prevents postpneumonectomy edema in the first 24 hours after pneumonectomy in pigs.

METHODS

We assessed hemodynamics, gas exchange, extravascular lung water estimated with the double-indicator dilution method, and lung neutrophil sequestration measured on the basis of lung myeloperoxidase activity at 1 and 24 hours after left pneumonectomy in 14 pigs randomly assigned to inhaled nitric oxide (10 ppm) or control groups.

RESULTS

Extravascular lung water content markedly increased at 1 and 24 hours after pneumonectomy, with no difference between the 2 groups. Hemodynamics did not differ between the 2 groups. Myeloperoxidase activity was higher and PaO2 values were lower in the nitric oxide group compared with in the control group.

CONCLUSIONS

Over the 24 hours after pneumonectomy, intraoperative inhaled nitric oxide levels neither improved gas exchange nor attenuated accumulation of lung water. On the contrary, they were associated with an increase in lung neutrophil sequestration and deterioration of arterial oxygenation, suggesting the occurrence of an early and toxic effect of nitric oxide.

Complications of Pulmonary Resection: Postpneumonectomy Pulmonary Edema and Postpneumonectomy Syndrome

Bassed on the authors' review of the unusual variants of PPS and the body of published experience, a revision of the current classification scheme for PPS into a more comprehensive form is justified as follows: (1) by the nature of obstruction; and (2) by the time of onset. This classification encompasses early and late symptom onset, as well as considering both airway and vascular compression. This scheme argues in favor of an expanded cardiac work-up in addition to the measures outlined previously for airway assessment. Althought PPS remains a rare clinical entity, the refinement in the understanding of this condition and the evolution of treatment options have vastly improved patient outcomes. A careful evaluation of the patient must be done before embarking on treatment owing to the numerous etiologies for progressive dyspnea in the pneumonectomy patient.

Postoperative acute respiratory distress syndrome development in the thoracic surgery patient

Acute respiratory distress syndrome (ARDS) in the thoracic surgery patient is a dreaded complication that occurs in 4% to 5% of pneumonectomies. This peculiar syndrome is indistinct from other forms of ARDS yet is associated with an exceedingly higher mortality rate. Current management parallels ARDS treatment of other etiologies.

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.

Edema pulmonar pós-pneumonectomia

A pneumonectomia, embora seja tecnicamente simples, está associada a alta incidência de complicações (cerca de 60%). As complicações respiratórias correspondem a aproximadamente 15% deste total. A mortalidade global dessa cirurgia é de 8,6%, mas em presença de complicações respiratórias, a taxa de mortalidade chega a 30%. O edema pulmonar pós-pneumonectomia é uma complicação rara (3% a 5%), mas muito grave, sendo fatal na maioria dos casos. Foi descrito pela primeira vez há pouco mais de vinte anos mas, apesar da gravidade alarmante, pouco sabemos acerca de sua fisiopatologia, embora muitas hipóteses tenham sido levantadas. Uma vez instalado, nenhuma medida é comprovadamente eficaz no seu tratamento. Vários fatores de risco estão associados ao aparecimento do edema pulmonar pós-pneumonectomia, dentre os quais a sobrecarga hídrica, que foi o primeiro fator evitado. Entretanto, muitos trabalhos mostram não haver relação direta entre o volume recebido e o desenvolvimento do edema. A prevenção é a melhor forma de evitá-lo e deve ser realizada de maneira multifatorial, envolvendo toda a equipe médica, desde o momento da anestesia até os cuidados cirúrgicos e na terapia intensiva. No entanto, tão importante quanto a prevenção, é a suspeita clínica precoce, identificando os pacientes em risco para essa grave complicação.

Progress in Postoperative ICU Management

The clinical case presented in this article illustrates how many of the more recent advances in the management of critically ill patients apply to current clinical practice. Simple cost-effective general measures (eg, optimal sterile precautions during procedures; hand washing; early goal-directed resuscitation with appropriate fluids, inotropes, and antibiotics; and surgical source control of infected foci) still should form the basis of clinical practice, however. There has been renewed interest in blood transfusion therapy and its associated risks. Lower tidal volume ventilation now is practiced almost universally in patients with ARDS, and several new selective pulmonary vasodilators have extended the armamentarium when taking care of these patients. High-frequency oscillatory ventilation and ECMO remain challenging options in patients with refractory hypoxemia. Appropriate patient selection is important when corticosteroid therapy is considered. Tight blood glucose control and monitoring improve outcome and should be part of ICU care of septic patients. The role of the PAC is controversial. Other techniques to measure cardiac output, hemodynamics, and perfusion are available and should be considered. Sedation and analgesia form an integral part of critical care. Because of its immediate and long-term risks, neuromuscular blockade should be used sparingly and only when all other options have been exhausted. Ongoing education regarding sedation protocols and the effect of sedation on outcome is needed among physicians and nurses caring for these patients.

Risk Factors for Acute Lung Injury After Thoracic Surgery for Lung Cancer

Acute lung injury (ALI) may complicate thoracic surgery and is a major contributor to postoperative mortality. We analyzed risk factors for ALI in a cohort of 879 consecutive patients who underwent pulmonary resections for non-small cell lung carcinoma. Clinical, anesthetic, surgical, radiological, biochemical, and histopathologic data were prospectively collected. The total incidence of ALI was 4.2% (n = 37). In 10 cases, intercurrent complications (bronchopneumonia, n = 5; bronchopulmonary fistula, n = 2; gastric aspiration, n = 2; thromboembolism, n = 1) triggered the onset of ALI 3 to 12 days after surgery, and this was associated with a 60% mortality rate (secondary ALI). In the remaining 27 patients, no clinical adverse event preceded the development of ALI-0 to 3 days after surgery-that was associated with a 26% mortality rate (primary ALI). Four independent risk factors for primary ALI were identified: high intraoperative ventilatory pressure index (odds ratio, 3.5; 95% confidence interval, 1.7-8.4), excessive fluid infusion (odds ratio, 2.9; 95% confidence interval, 1.9-7.4), pneumonectomy (odds ratio, 2.8; 95% confidence interval, 1.4-6.3), and preoperative alcohol abuse (odds ratio, 1.9; 95% confidence interval, 1.1-4.6). In conclusion, we describe two clinical forms of post-thoracotomy ALI: 1). delayed-onset ALI triggered by intercurrent complications and 2). an early form of ALI amenable to risk-reducing strategies, including preoperative alcohol abstinence, lung-protective ventilatory modes, and limited fluid intake.

IMPLICATIONS

In an observational study including all patients undergoing lung surgery, we describe two clinical forms of acute lung injury (ALI): a delayed-onset form triggered by intercurrent complications and an early form associated with preoperative alcohol consumption, pneumonectomy, high intraoperative pressure index, and excessive fluid intake over the first 24 h.

Asymmetric ARDS following pulmonary resection: CT findings initial observations

PURPOSE

To investigate whether asymmetric distribution of acute respiratory distress syndrome (ARDS) following lobectomy is due to compensatory hyperexpansion of the residual lung within the hemithorax operated on and to discern if this distribution reflects true asymmetry of the disease process.

MATERIALS AND METHODS

Retrospective review of the intensive care unit database was performed over a period of 6 years to identify all cases of lung injury following lung surgery that satisfied the American-European consensus criteria for ARDS. Time to onset following surgery, time of subsequent computed tomographic (CT) examination, patient age and sex, and nature of surgery were recorded, as well as eventual patient status (ie, death or discharge). Availability of both preoperative and postoperative CT scans was required for inclusion for further analysis. These images were analyzed on a commercial CT workstation for the volume of lung resected and the pre- and postoperative volume and density of each lung. Expected postoperative densities (preoperative density adjusted for volume) were compared with observed postoperative densities.

RESULTS

Review disclosed 583 patients who underwent lobectomy or segmentectomy. Seventeen patients (2.9%) developed postoperative ARDS. Nine of these patients had pre- and postoperative CT scans available for analysis. In eight of nine cases, density increased more in the nonoperated lung than in the operated lung (P =.01). The degree of density increase in the nonoperated lung was significantly greater (305 mg/mL; range, 48-449 mg/mL) than that in the operated lung (13 mg/mL; range, -198 to 231 mg/mL; P <.001).

CONCLUSION

Following lobectomy, there appears to be a truly asymmetric form of ARDS rather than compensatory hyperexpansion of the residual lung on the operated side.

Can pneumonectomy for non-small cell lung cancer be avoided? An audit of parenchymal sparing lung surgery

BACKGROUND

Lung cancer resection rates are suboptimal in the UK. Pneumonectomy has a higher perioperative mortality risk than lobectomy. To increase resection rates and improve outcomes we have implemented a policy of parenchymal sparing surgery for tumours involving a main stem bronchus.

METHODS

In a prospective 4 year study of 119 consecutive patients operated upon by a single surgeon the perioperative course, pathology and survival were compared for 81 patients undergoing pneumonectomy and 38 patients in whom pneumonectomy was avoided by bronchoplastic+/-angioplastic procedures.

RESULTS

The rate of pneumonectomy decreased significantly with increasing experience with parenchymal sparing surgery (R(2)=0.98, P<0.001) with 21 of the last 30 patients (70%) avoiding pneumonectomy. There were no significant inter-group differences in patient characteristics, perioperative course or outcome. One-year survival was 64% after pneumonectomy and 73% after sleeve lobectomy. However the perioperative loss of respiratory function was significantly lower in the patients in whom pneumonectomy was avoided (P=0.0003).

CONCLUSIONS

Pneumonectomy can be avoided in a large proportion of patients with non-small cell lung cancer of a main stem bronchus without adversely affecting outcome but with preservation of lung function

Acute lung injury and acute respiratory distress syndrome after pulmonary resection

BACKGROUND

In this study we investigate the frequency and mortality of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) after pulmonary resection.

METHODS

Patients that underwent pulmonary resection at the Royal Brompton Hospital between 1991 and 1997 were included. The case notes of all patients developing postoperative complications were retrospectively reviewed.

RESULTS

The overall combined frequency of ALI and ARDS was 3.9%. The frequency was higher in patients over 60 years of age, males and those undergoing resection for lung cancer. ALI/ARDS caused 72.5% of the total mortality after resection in this series.

CONCLUSIONS

In our experience ALI and ARDS are major causes of mortality after lung resection.

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.