Matthew Bacchetta

Extracorporeal Membrane Oxygenation for ARDS in Adults

A 41-year-old woman presents with severe community-acquired pneumococcal pneumonia. Chest radiography reveals diffuse bilateral infiltrates, and hypoxemic respiratory failure develops despite appropriate antibiotic therapy. She is intubated and mechanical ventilation is initiated with a volume- and pressure-limited approach for the acute respiratory distress syndrome (ARDS). Over the ensuing 24 hours, her partial pressure of arterial oxygen (Pao2) decreases to 40 mm Hg, despite ventilatory support with a fraction of inspired oxygen (Fio2) of 1.0 and a positive end-expiratory pressure (PEEP) of 20 cm of water. She is placed in the prone position and a neuromuscular blocking agent is administered, without improvement in her Pao2. An intensive care specialist recommends the initiation of extracorporeal membrane oxygenation (ECMO).

Extracorporeal membrane oxygenation for respiratory failure in adults

Purpose of reviewThis article reviews case series and trials that evaluated extracorporeal membrane oxygenation (ECMO) for respiratory failure and describes patient and circuit management in the modern era of ECMO support. Recent findingsIn recent years, pivotal progress has been made in the conception and construction of ECMO circuits. They are now simpler, safer, require less anticoagulation and are associated with fewer bleeding complications. The encouraging results of the efficacy and economic assessment of conventional ventilatory support versus ECMO for severe adult respiratory failure (CESAR) trial performed in the United Kingdom and good outcomes of patients who received ECMO as rescue therapy during the recent H1N1 influenza pandemic, in which the latest generation of ECMO technology was used, reignited interest in ECMO for severe acute respiratory distress syndrome (ARDS). SummaryThe latest generation of ECMO systems is more biocompatible, better performing and longer lasting. Although recent studies suggested that veno-venous ECMO might improve the outcomes of patients with ARDS, indications for ECMO use remain uncertain. Future trials of ECMO for severe ARDS should strictly control for standard-of-care mechanical ventilation strategies in the control group and early transportation on ECMO for patients in the intervention arm.

Thoracic esophageal perforations: a decade of experience

BACKGROUND Perforation of the thoracic esophagus is a formidable challenge. Treatment and outcome are largely determined by the time to presentation. We reviewed our experience with esophageal perforations to determine the overall mortality and whether the time to presentation should influence management strategy. METHODS A retrospective chart review was performed on all patients treated for perforation of the thoracic esophagus from 1990 to 2001. There were 26 patients (14 men and 12 women; median age, 62 years; range, 36 to 89 years). Fourteen patients presented within 24 hours (early), and 12 patients presented after 24 hours (delayed). Nine of the 12 patients in the delayed group presented after 72 hours. The causes of the perforations were as follows: instrumentation (19 patients), Boerhaaves syndrome (2 patients), intraoperative injury (1 patient), and other (4 patients). In the early group, 3 patients were treated conservatively, 10 patients underwent primary repair, and 1 patient required esophagectomy for carcinoma. In the delayed group, 3 patients were treated conservatively, 6 underwent successful repair of the perforation, 1 had a T-tube placement through the perforation and eventually required an esophagectomy, and 2 had an esophagectomy as primary surgical treatment. RESULTS Hospital mortality was 3.8% (1 of 26) and morbidity was 38% (10 of 26). Persistent leaks occurred in 3 patients, 2 after primary repair and 1 after T-tube drainage. All patients selected for conservative management successfully healed their perforation. CONCLUSIONS Primary repair can be carried out in most cases of thoracic esophageal perforation regardless of time to presentation, with a low mortality rate. A small but carefully selected group of patients may be treated successfully without operation. Esophagectomy should be reserved for patients with carcinoma or extensive necrosis of the esophagus.

End-of-life decision-making in the hospital: current practice and future prospects.

Chart review of patients who died in the hospital was used to describe the pattern of end-of-life decision-making and care for hospitalized dying patients and to propose a structured process of assessing the suitability of patients for palliative care. The setting was a large urban academic medical center, and the sample comprised 200 of 205 consecutive adult deaths during the first 4 months of 1996. The main outcome measures were identification of the patient as dying, do-not-resuscitate (DNR) orders, and comfort care plans. Charts of 72% of the patients had evidence that they were considered dying. DNR orders were in place for 77% of all the patients, and 46% had comfort care plans. Presence of a health care proxy was significantly associated with DNR orders and comfort care plans (P < 0.001). On average, comfort care plans were put in place 15 days after admission, as compared with an overall mean length of stay of 17 days. Substantial proportions of patients with comfort care plans continued to receive antibiotics (41%) and blood draws (30%). Only 13% of the patients on mechanical ventilation and 19% of those on artificial nutrition and hydration underwent withdrawal of these interventions prior to death. These findings suggest opportunities and challenges for improving practice patterns for hospitalized dying patients. We recommend several measurable objectives for evaluating end-of-life decision-making and care and propose the development of a goals of care assessment tool to guide appropriate transitions from life-sustaining treatment to comfort care and plan palliative services.

Obesity and underweight are associated with an increased risk of death after lung transplantation.

RATIONALE Obesity is considered a relative contraindication to lung transplantation, based on studies that have not accounted for key confounders. Little is known about the risk of death for underweight candidates after transplantation. OBJECTIVES To examine the associations of pretransplant obesity and underweight with the risk of death after lung transplantation. METHODS We examined 5,978 adults with cystic fibrosis, chronic obstructive pulmonary disease, and diffuse parenchymal lung disease who underwent lung transplantation in the United States between 1995 and 2003. We used Cox models and generalized additive models to examine the association between pretransplant body mass index and the risk of death after lung transplantation with adjustment for donor and recipient factors. MEASUREMENTS AND MAIN RESULTS The median follow-up time was 4.2 years. Compared with normal weight recipients, the multivariable-adjusted rates of death were 15% higher for underweight recipients (95% confidence interval, 3 to 28%), 15% higher for overweight recipients (95% confidence interval, 6 to 26%), and 22% higher for obese recipients (95% confidence interval, 8 to 39%). These relationships persisted when stratified by diagnosis. The multivariable-adjusted population attributable fraction was 12% at 1 year and 8% at 5 years. CONCLUSIONS Both obesity and underweight are independent risk factors for death after lung transplantation, contributing to up to 12% of deaths in the first year after transplantation. Primary care providers and pulmonologists should promote a healthy weight for patients with lung disease long before transplantation is considered.

Extracorporeal membrane oxygenation as a bridge to lung transplantation and recovery

OBJECTIVE Respiratory failure develops in many patients on lung transplant waiting lists before a suitable donor organ becomes available. Extracorporeal membrane oxygenation may be used to bridge such patients to recovery or lung transplantation. METHODS This is a review of a single-institutions experience with placing patients on extracorporeal membrane oxygenation with the intention of bridging them to lung transplantation. End points included successful bridging, duration of extracorporeal membrane oxygenation support, extubation, weaning from extracorporeal membrane oxygenation, overall survival, and extracorporeal membrane oxygenation-related complications. During an approximate 5-year period, acute respiratory failure developed in 18 patients (median age, 34 years) on the institutions lung transplant waiting list (8 hypoxemic, 9 hypercarbic, and 1 combined) who were placed on extracorporeal membrane oxygenation (13 venovenous and 5 venoarterial). RESULTS All patients achieved appropriate extracorporeal membrane oxygenation blood flow rates (median, 4.05 L/min) and good gas exchange (median, on extracorporeal membrane oxygenation partial pressure of arterial carbon dioxide 43 mm Hg and partial pressure of arterial oxygen 196 mm Hg). Thirteen patients (72%) were successfully bridged: 10 to transplant and 3 returned to baseline function. Eleven patients (61%) survived beyond 3 months, including the 10 (56%) who underwent transplantation and are still alive. The median duration of extracorporeal membrane oxygenation support for patients who underwent transplantation was 6 days (3.5-31 days) versus 13.5 days (11-19 days) for those who did not undergo transplantation (P = .45). Six patients (33%) were extubated on extracorporeal membrane oxygenation, 4 of whom underwent transplantation. Four patients (22%) who were too unstable for conventional interhospital transfer were transported on extracorporeal membrane oxygenation to Columbia University Medical Center. This subgroup had a 75% bridge to transplant or recovery rate and 100% survival in transplanted patients. CONCLUSIONS Extracorporeal membrane oxygenation is a safe and effective means of bridging well-selected patients with refractory respiratory failure to lung transplantation or return to their baseline condition.

Use of bicaval dual-lumen catheter for adult venovenous extracorporeal membrane oxygenation

BACKGROUND Extracorporeal membrane oxygenation (ECMO) provides supplementary oxygenation and carbon dioxide removal for selected patients on mechanical ventilatory support. Venovenous ECMO is traditionally established by dual cannulation of the internal jugular and femoral veins. We report our institutional experience using single-site, dual-lumen cannula for venovenous ECMO as an alternative to the 2-catheter approach. This approach minimizes recirculation and avoids use of the femoral site, which confers potential advantages. METHODS This is a retrospective review of a single institutions experience with a new bicaval dual lumen ECMO cannula. During a 19-month period, 27 consecutive patients were placed on ECMO using this catheter inserted through the right internal jugular vein. RESULTS Single-site venovenous ECMO support was uneventfully initiated in 26 of the 27 patients (median age, 42 years; interquartile range, 31 to 58 years) and achieved full flows and adequate gas exchange. Median ventilator days before ECMO was 1 day (interquartile range, 0.25 to 3.5 days). The median duration of ECMO support was 9 days (interquartile range, 5.5 to 11.5 days). Decannulation was achieved in 70% of the patients and extubation in 59%. Two were bridged to lung transplantation and are still alive. The overall survival and hospital discharge rate was 56%. There was no device failure or in-cannula thrombosis. One superior vena cava injury occurred, and one cannula required repositioning. CONCLUSIONS Single-site venovenous ECMO has advantages compared with traditional venovenous ECMO. Using image guidance, the cannula can reliably be used in prolonged venovenous ECMO cases.

Pilot Study of Extracorporeal Carbon Dioxide Removal to Facilitate Extubation and Ambulation in Exacerbations of Chronic Obstructive Pulmonary Disease

RATIONALE Acute exacerbations of chronic obstructive pulmonary disease (COPD) requiring invasive mechanical ventilation (IMV) are associated with significant morbidity and mortality. Extracorporeal carbon dioxide removal (ECCO₂R) may facilitate extubation and ambulation in these patients and potentially improve outcomes. OBJECTIVES We assessed the feasibility of achieving early extubation and ambulation in subjects requiring IMV for exacerbations of COPD using single-site ECCO₂R. METHODS Five subjects with exacerbations of COPD with uncompensated hypercapnia requiring IMV were enrolled in this single-center, prospective, feasibility trial using a protocol of ECCO₂R, extubation, and physical rehabilitation. The primary endpoint was extubation within 72 hours of starting ECCO₂R. MEASUREMENTS AND MAIN RESULTS Mean preintubation pH and PaCO₂ were 7.23 ± 0.05 and 81.6 ± 15.9 mm Hg, respectively. All subjects met the primary endpoint (median duration, 4 h; range, 1.5-21.5 h). Mean duration of extracorporeal support was 193.0 ± 76.5 hours. Mean time to ambulation after extracorporeal initiation was 29.4 ± 12.6 hours. Mean maximal ambulation on extracorporeal support was 302 feet (range, 70-600). Four subjects were discharged home, and one underwent planned lung transplantation. Two minor bleeding complications occurred. There were no complications from mobilization on extracorporeal support. CONCLUSIONS ECCO₂R facilitates early extubation and ambulation in exacerbations of COPD requiring IMV and has the potential to serve as a new paradigm for the management of a select group of patients. Rigorous clinical trials are needed to corroborate these results and to investigate the effect on long-term outcomes and cost effectiveness over conventional management.

Insertion of bicaval dual lumen extracorporeal membrane oxygenation catheter with image guidance.

Correct placement of the Avalon Elite Bicaval Dual Lumen catheter (Avalon Laboratories, LLC, CA) for single-site venovenous extracorporeal membrane oxygenation (VV ECMO) is safe using image guidance. Using this technique, 26 of 27 patients (96%) had uneventful placement of the cannula in the right internal jugular vein. One patient had a superior vena cava injury during serial dilation, and another patient required cannula repositioning for improved flows. We recommend using both fluoroscopy and transesophageal echocardiogram (TEE) for training purposes or during initial use of the Avalon Elite. As proficiency improves, TEE at the bedside provides an excellent standard of care. Double-lumen ECMO catheters can be effectively placed under image guidance with minimal need for repositioning.

High Lung Allocation Score Is Associated With Increased Morbidity and Mortality Following Transplantation

BACKGROUND The lung allocation score (LAS) was initiated in May 2005 to allocate lungs based on medical urgency and posttransplant survival. The purpose of this study was to determine if there is an association between an elevated LAS at the time of transplantation and increased postoperative morbidity and mortality. METHODS The United Network for Organ Sharing provided de-identified patient-level data. Analysis included lung transplant recipients aged >or= 12 years who received transplants between April 5, 2006, and December 31, 2007 (n = 3,836). Recipients were stratified into three groups: LAS < 50 (n = 3,161, 83.87%), LAS 50 to 75 (n = 411, 10.9%), and LAS >or= 75 (n = 197, 5.23%), referred to as low LAS (LLAS), intermediate LAS (ILAS), and high LAS (HLAS), respectively. The primary outcome was posttransplant graft survival at 1 year. Secondary outcomes included length of stay and in-hospital complications. RESULTS HLAS recipients had significantly worse actuarial survival at 90 days and 1 year compared with LLAS recipients. When transplant recipients were stratified by disease etiology, a trend of decreased survival with elevated LAS was observed across all major causes of lung transplant. HLAS recipients were more likely to require dialysis or to have infections compared with LLAS recipients (P < .001). In addition, length of stay was higher in the HLAS group when compared with the LLAS group (P < .001). CONCLUSIONS HLAS is associated with decreased survival and increased complications during the transplant hospitalization. Whereas the LAS has improved organ allocation through decreased waiting list deaths and waiting list times, lower survival and higher morbidity among HLAS recipients suggests that continued review of LAS scoring is needed to ensure optimal long-term transplant survival.