Contralateral Pneumonectomy Research Articles

Living-donor lobar lung transplantation.

Living-donor lobar lung transplantation (LDLLT) has become an important life-saving option for patients with severe respiratory disorders, since it was developed by a group in the University of Southern California in 1993 and introduced in Japan in 1998 in order to address the current severe shortage of brain-dead donor organs. Although LDLLT candidates were basically limited to critically ill patients who would require hospitalization, the long-term use of steroids, and/or mechanical respiratory support prior to transplantation, LDLLT provided good post-transplant outcomes, comparable to brain-dead donor lung transplantation in the early and late phases. In Kyoto University, the 5- and 10-year survival rates after LDLLT were reported to be 79.0% and 64.6%, respectively. LDLLT should be performed under appropriate circumstances, considering the inherent risk to the living donor. In our transplant program, all living donors returned to their previous social lives without any major complications, and living-donor surgery was associated with a morbidity rate of <15%. Both functional and anatomical size matching were preoperatively performed between the living-donor lobar grafts and recipients. Precise size matching before surgery could provide a favorable pulmonary function and exercise capacity after LDLLT. Various transplant procedures have recently been developed in LDLLT in order to deal with the issue of graft size mismatching in recipients, and favorable post-transplant outcomes have been observed. Native upper lobe-sparing and/or right-to-left inverted transplantation have been performed for undersized grafts, while single-lobe transplantation has been employed with or without contralateral pneumonectomy and/or delayed chest closure for oversized grafts.

Primary Tumor Control in Stereotactic Ablative Radiation Therapy for Large (≥ 5 cm) Non-Small Cell Lung Cancer: Does It Last?

<h3>Purpose/Objective(s)</h3> While prospective trials have established stereotactic body radiation therapy (SBRT) as standard of care for inoperable early-stage non-small cell lung cancer (NSCLC), these studies excluded patients with tumors larger than 5 cm. Since these patients have few treatment options and conservative management is associated with significant morbidity, many clinicians utilize SBRT if dosimetric constraints can be met. The purpose of this study is to determine the rate of primary tumor failure (PTF) after SBRT for NSCLC with primaries ≥ 5cm. <h3>Materials/Methods</h3> We performed a retrospective review of all patients with NSCLC and large primary tumors (≥ 5 cm in maximum dimension) treated at our institution using SBRT from 2010 – 2018. Patients with nodal or distant disease were included, but only evaluated for toxicity and PTF. Treatment failures were captured by review of imaging, pathology, and clinical notes. PTF was defined as disease recurrence in or at the margin of the primary tumor volume (PTV) and was measured from end of SBRT to PTF. Patients without PTF were censored at last follow up or death. The Kaplan-Meier method was used to estimate event-time probabilities for PTF. Predictors of PTF were analyzed using log rank tests between groups and a parsimonious multivariate Cox multivariate model. <h3>Results</h3> A total of 145 patients were identified. Median age was 78 years (Interquartile rage [IQR] 72 -84). Evidence of regional disease was present in 5 (3%) patients and metastatic disease in 14 (10%). Median tumor diameter was 5.75 cm (IQR 5.25 – 6.43) and tumor volume was 37.9 cm³ (IQR 25.4 – 53.6). The most common SBRT regimen was 48 Gy in 4 fractions (68 patients). Median BED10 was 105.6 (IQR 105.6-151.2). With a median follow up of 21 months (IQR 9 – 32), PTF at 1, 2, and 3 years was 10.6% (95% Confidence Interval [CI] 5.1 – 16.1), 17.0% (95% CI 9.9 – 24.1), and 22.0% (95% CI 13.4 – 30.6). On univariate analysis, factors associated with PTF included lobe involved (<i>P</i> = 0.01), maximum tumor diameter > 5.75 cm (<i>P</i> < 0.01), four-fraction SBRT (<i>P</i> = 0.01), and BED10 ≤ 105.6 (<i>P</i> = 0.03). On multivariate analysis, tumor diameter > 5.75cm (HR 3.28, 95% CI 1.44 – 7.46) and four-fraction SBRT (HR 3.20, 95% CI 1.38 – 7.41) remained significant. In patients with node negative and non-metastatic disease, 2-year disease free survival and overall survival were 62.1% (95% CI 51.6 – 70.8) and 49.3% (95% CI 41.5 – 59.9). Acute toxicity was absent in 106 (73%) patients and no patients experienced grade 3 or higher acute toxicity. Maximum late toxicity was Grade 1-2 in 96 (66%) patients (predominantly asymptomatic radiation pneumonitis) and Grade 3 or higher in five (3%) patients including one patient with a contralateral pneumonectomy who experienced fatal radiation pneumonitis. <h3>Conclusion</h3> SBRT for medically inoperable NSCLC ≥ 5cm results in acceptable tumor control and toxicity, although the rate of PTF increases with longer follow up. PTF appears to be higher in patients with tumors > 5.75 cm in diameter and those receiving 48 Gy in 4 fractions.

Outcome of lung transplantation in cystic fibrosis patients with severe asymmetric chest cavities

ObjectiveA small but relevant proportion of patients with cystic fibrosis develop severely asymmetric chest cavities during the course of their disease. For these patients, the best surgical approach for lung transplantation (LTx) and optimal size matching strategies are controversial. MethodsAll cystic fibrosis patients with asymmetric chest cavities who underwent LTx at the Medical University of Vienna between 2003 and 2017 were identified (n = 13). Patients were grouped according to different surgical strategies: unilateral full-size and contralateral lobar transplantation (n = 4), standard double LTx after mobilization/repositioning of the mediastinum (n = 3), oversized single LTx followed by pneumonectomy on the smaller contralateral side (n = 4), and single LTx after a remote contralateral pneumonectomy (n = 2). ResultsCompared with cystic fibrosis patients with symmetric chests (n = 276, control group), the perioperative management of patients with asymmetric chests was often more complicated. Consequently, 90-day mortality was heightened (23.1% vs 6.5%). Despite this, long-term survival was good with a 5-year survival rate of 69% compared with 78%. Of note, outcome seemed superior for patients who surgery was undertaken with a bilateral compared with a unilateral approach. ConclusionsSeverely asymmetric chest cavities present challenges in regard to the surgical strategy, size matching, and postoperative management. However, in carefully selected patients, LTx provides an adequate long-term outcome.

Combined Single Lung and Liver Transplantation in a Cystic Fibrosis Patient With Previous Contralateral Pneumonectomy: A Case Report

Combined lung-liver transplantation is a rare life-saving procedure to treat concomitant end-stage lung and liver failure. In this report, we describe the first published case of single lung and liver transplantation in a cystic fibrosis patient who had previously undergone a pneumonectomy for the treatment of an infected and destroyed right lung. We detail the lung first, sequential transplant procedure and surgical difficulties due to mediastinal shift. Emergent intraoperative renal replacement therapy was carried out before liver transplantation to overcome pulmonary edema in the transplanted lung. After fluid balance equilibration, liver transplantation was performed in good conditions. The patient is currently alive with no signs of rejection 8 years after the procedure.

Thoracoscopic partial lung resection following pneumonectomy: a report of three cases

BackgroundThe prognosis of patients who undergo unilateral pneumonectomy and subsequently develop a contralateral pulmonary tumor can be improved by tumor resection. Thus, surgery is a treatment option if the patient’s pulmonary function and performance status are satisfactory. To date, there have been only few cases reporting thoracoscopic lung resection for pulmonary tumor after contralateral pneumonectomy because of the difficulty in respiratory management during surgery. Thoracoscopic surgery requires the maintenance of the operative field to allow the lung to collapse, and in partial lung resection we need to identify tumor localization. The identification of a tumor lesion just inferior to the pleura is easy; however, the identification of a tumor lesion in the deep parts is difficult. The tumor in the deep part of the lung segments can be easily located if the tumor-affected lobe is allowed to completely collapse. Therefore, ventilation technique should be modified according to the tumor localization.Case presentationHere, we report three cases of thoracoscopic partial lung resections for pulmonary tumors that developed after contralateral pneumonectomy. Intermittent manual ventilation using a tracheal tube was performed in two cases with a lesion just inferior of the pleura. The tumors in both patients were resected using automatic suturing devices while arresting manual ventilation. The affected lobe was allowed to collapse using a bronchial blocker in one of the cases with a lesion in the deep part. Furthermore, she had contralateral pneumothorax with bullae on the right upper and lower lobes of the lung. The tumor in the deep part of the lung segment and ruptured bullae were easily located and resected using automatic suturing devices. The hemodynamic status of the patients was stable, and the intra- and postoperative courses were uneventful.ConclusionsOur cases demonstrate that thoracoscopic lung resection after contralateral pneumonectomy can be performed if intermittent manual ventilation is utilized when the tumor is located just inferior to the pleura and if selective double ventilation using an intrabronchial blocker is utilized when the tumor is located in the deep part.

Airway Management of the Right Anterior Segmentectomy through Uniportal video-assisted thoracoscopic surgery (VATS) after left pneumonectomy by an adapted double-lumen endobronchial tube (DLT): a case report

BackgroundLung resection after previous contralateral pneumonectomy is rare. We present a case of right anterior segmentectomy despite previous left pneumonectomy, demanding special airway management strategy.Case presentationA 48-year-old woman who had left pneumonectomy 2 years ago was scheduled to have the right anterior segmentectomy through uniportal video-assisted thoracoscopy (VATS). A 32-French (Fr) left-sided double-lumen endobronchial tube (DLT) was chosen and adapted. The DLT was intubated into the bronchus intermedius. And the upper lobe can be isolated from the ventilation in the middle and lower lobes when the bronchial cuff’s inflated. The perioperative period was uneventful and the pathological diagnosis was adenocarcinoma.ConclusionLung cancer radical resection was discouraged after previous contralateral pneumonectomy partly due to the challenging ventilation and isolation. With this new DLT adapting and intubation technique showed in this case, the challenging ventilation and isolation that deter the implementation of the operation mentioned above could be solved.

Thoracoscopic wedge resection in single-lung patients.

The thoracoscopic approach has become a standard procedure in the field of lung resections. However, its advantage in single-lung patients has not yet been well studied. We describe a series of successful thoracoscopic wedge resections in patients presenting with lung cancer after contralateral pneumonectomy. Eight patients, with a previous pneumonectomy (5 right and 3 left) for lung cancer, underwent resection for a suspicious neoplasm on the remaining lung. All lesions were detected in the asymptomatic phase during regular follow-up after pneumonectomy based on repeated computer tomography (CT). Only single peripheral lesions less than 2 cm were eligible for wedge resection were eligible for surgery. Video-assisted thoracoscopic, margin-free tumor wedge resections, were performed during apnea windows with the lung in a deflated position. All patients were treated by a wedge resections smaller than a single segment. Only one patient needed a mini-thoracotomy conversion to accomplish a safe margin-free resection. Median total surgical operative time was 37 minutes. There were no postoperative deaths, while morbidity was 12.5%. Thoracoscopic surgery represents a feasible surgical option in selected patients after contralateral pneumonectomy, with careful preoperative assessment and using short apnea windows in good collaboration with anesthesiologists. Histological definition, made possible by the surgical-procedure, gives patients the possibility to eventually undergo further targeted therapies. Randomized prospective trials are necessary to assess the best management of peripheral small lung nodules in single-lung patients, in particular to define which patients can benefit from a surgical approach.

Anaesthetic approach to VATS in a patient with one lung

SummarySpontaneous pneumothorax after a contralateral pneumonectomy is a potentially fatal condition. It can be treated with pleurodesis via video‐assisted thoracoscopic surgery. However, achieving sufficient lung deflation to perform this whilst maintaining good oxygenation in a patient with a single lung is challenging. We describe the anaesthetic management of a 47 year‐old male who underwent left‐sided video‐assisted thoracoscopic pleurodesis for a life‐threatening pneumothorax with a previous right pneumonectomy. We used total intravenous anaesthesia for induction and maintenance of anaesthesia with intermittent apnoeic ventilation. Both adequate surgical field visualisation and oxygenation were achieved. He had an uneventful postoperative course.

Intraoperative veno-venous extracorporeal lung support in thoracic surgery: a single-centre experience.

Intraoperative extracorporeal lung support (ECLS) during thoracic surgical procedures is a modern concept that is gaining increasing acceptance. So far, cardiopulmonary bypass (CPB), veno-arterial extracorporeal membrane oxygenation (v-a-ECMO) or pumpless arterio-venous interventional lung assist (iLA) were utilized for intraoperative support. Only a few case reports have described the use of veno-venous ECMO for intraoperative ECLS. Here, we report our experience with intraoperative ECLS using different veno-venous low-flow and high-flow settings adapted to the individual patient requirements. Between April 2014 and April 2015, 9 patients underwent pulmonary resections under ECLS. In 6 patients, a twin-port double-lumen cannula was inserted percutaneously into the right femoral vein for low-flow ECLS. In 3 patients, high-flow ECLS was achieved either by femoro-atrial (n = 1) or femoro-jugular cannulation. Indications for ECLS were severely impaired lung function (n = 3), previous pulmonary resections including contralateral pneumonectomy (n = 4), previous single-lung transplantation (sLTX) (n = 1) and extended carinal pneumonectomy (n = 1). Procedures included segmentectomy (n = 3), extended lobectomy with bronchial and vascular anastomoses (n = 1), VATS lobectomy (n = 2), extended left-sided carinal pneumonectomy (n = 1) as well as extended metastasectomy (n = 2). Low-flow ECLS allowed for apnoea up to 45 min in patients with previous pneumonectomy (n = 3) and facilitated protective single-lung ventilation in patients (n = 3) with severely impaired pulmonary function. During trans-sternal carinal pneumonectomy (n = 1), high-flow ECLS achieved by femoro-atrial cannulation allowed for apnoea for 40 min, avoiding cross-field ventilation. In 2 patients requiring extended metastasectomy after previous lobectomy of the contralateral lower lobe (n = 1) or pulmonary metastases in the graft after sLTX for end-stage fibrosis (n = 1), high-flow ECLS by percutaneous femoro-jugular cannulation allowed for extensive metastasectomy under optimal atelectasis of the lung. For intraoperative ECLS, different modes may be applied depending on the intended procedures and required mechanical ventilation. In our experience, different settings of veno-venous ECLS provide sufficient partial or complete lung support, avoiding possible complications associated with other forms of extracorporeal support such as CPB or v-a-ECMO.

Non-intubated video-assisted thoracic surgery management of secondary spontaneous pneumothorax.

Secondary spontaneous pneumothorax (SSP) is serious entity, usually due to underlying disease, mainly chronic obstructive pulmonary disease (COPD). Its morbidity and mortality is high due to the pulmonary compromised status of these patients, and the recurrence rate is almost 50%, increasing mortality with each episode. For persistent or recurrent SSP, surgery under general anesthesia (GA) and mechanical ventilation (MV) with lung isolation is the gold standard, but ventilator-induced damages and dependency, and postoperative pulmonary complications are frequent. In the last two decades, several groups have reported successful results with non-intubated video-assisted thoracic surgery (NI-VATS) with thoracic epidural anesthesia (TEA) and/or local anesthesia under spontaneous breathing. Main benefits reported are operative time, operation room time and hospital stay reduction, and postoperative respiratory complications decrease when comparing to GA, thus encouraging for further research in these moderate to high risk patients many times rejected for the standard regimen. There are also reports of special situations with satisfactory results, as in contralateral pneumonectomy and lung transplantation. The aim of this review is to collect, analyze and discuss all the available evidence, and seek for future lines of investigation.

Is it safe and worthwhile to perform pulmonary resection after contralateral pneumonectomy?

A best evidence topic was written according to a structured protocol. The question addressed was whether pulmonary resection is safe and worthwhile in patients who have undergone previous pneumonectomy. A total of 141 studies were identified using the reported search, of which 8 represented the best evidence to answer the clinical question. Studies on multiple lung cancers with patients undergoing subsequent pulmonary resection after previous pneumonectomy, without outcome data specifically for this group of patients and case reports, were not included in this analysis. The authors, date, journal, country, study type, population, outcomes and key results are tabulated. All studies were retrospective. In total, 102 patients underwent pulmonary resection after contralateral pneumonectomy, of which 96 had sublobar resections and 6 had lobectomies. Postoperative complications, reported in four of the eight studies, ranged from 21 to 44% (mean from four studies 36.8%). Four of the eight studies reported no mortality after pulmonary resection following pneumonectomy, whereas the other four reported mortality rates from 6.7 to 43%. For patients undergoing sublobar resections, the postoperative mortality was 6.2% (6/96), while for those submitted to lobectomy, mortality was 33.3% (2/6). Five-year survival rates ranged from 14% for metastatic disease to 50% for metachronous lung cancer. Due to the infrequent situation of a patient being considered for a pulmonary resection after contralateral pneumonectomy, this analysis was based on a limited number of patients from eight reports. Nevertheless, analysis of the data suggests that pulmonary resection for metastatic or metachronous disease can be performed with acceptable morbidity and low mortality in appropriately selected patients who have previously undergone a pneumonectomy. Sublobar resection is the treatment of choice whenever possible, for which long-term results are rewarding especially for patients with metachronous lung cancer.

Pulmonary Resection for Metachronous Lung Cancer Following Contralateral Pneumonectomy

Patients who undergo pneumonectomy for lung cancer are at risk of recurrent disease and metachronous tumours in the remaining lung. Establishing a diagnosis can be difficult as biopsy may induce a pneumothorax, whilst resection is limited by remaining lung function. However, pneumonectomy should not be a contraindication to further lung resection. We report two cases of lung cancer resection in the residual lung 6 and 11 years following pneumonectomy respectively. A limited resection can be safely performed for a new pulmonary parenchymal lesion on a background of a previous pneumonectomy.

High-frequency jet ventilation during video-assisted thoracoscopic surgery in a patient with previous contralateral pneumonectomy

A case of high-frequency jet ventilation (HFJV) during video-assisted thoracoscopic surgery (VATS) in a patient with previous contralateral pneumonectomy is presented. A 77-year-old man with a right pneumothorax was scheduled for bullectomy by VATS. He had undergone left pneumonectomy due to lung cancer 6 years earlier. Anesthesia was induced and maintained with propofol and fentanyl. The patient was intubated with a normal, single-lumen endotracheal tube (ETT). HFJV was applied through the ETT during the VATS procedure. Although PaCO2 gradually increased from 51.9 mmHg to 80.0 mmHg, appropriate surgical conditions were provided, PaO2 was well preserved, and blood pressure and heart rate were stable throughout the VATS procedure.

Anesthetic experience in patient for single lung transplantation with previous contralateral pneumonectomy -A case report-

A 48-year-old woman with cystic fibrosis and a previous left pneumonectomy had surgery planned for single lung transplantation under general anesthesia. Due to progressive dyspnea and recurrent respiratory infection, she could not maintain her normal daily life without lung transplantation. The anesthetic management and surgical procedure was expected to be difficult because of the left mediastinal shift and an asymmetric thorax after the left pneumonectomy, but the single lung transplantation was successfully done under cardiopulmonary bypass.

193 Lung cancer resection can be performed safely following previous contralateral pneumonectomy

193 Lung cancer resection can be performed safely following previous contralateral pneumonectomy

Le pneumothorax tuberculeux (PT) : à propos de 29 cas

Background: Hypercapnic coma is a rare differential diagnosis in the unconscious patient. One underlying mechanism may be hypoventilation due to spontaneous pneumothorax. Although hypercapnia is not a typical finding in spontaneous pneumothorax in patients with otherwise healthy lungs, under certain circumstances, hypercapnia may readily develop. Objectives: We report a rare case of profound hypercapnic coma due to spontaneous pneumothorax after contralateral pneumonectomy. In addition, we review other causes of hypercapnic coma and its outcome and discuss the relationship between arterial carbon dioxide partial pressure and level of consciousness. Case Report: An 85-year-old man without evidence of trauma or intoxication presented unconscious to our Emergency Department. The physical examination and X-ray study revealed a left-sided spontaneous pneumothorax. A right-sided pneumonectomy 25 years earlier had promoted the development of profound hypercapnic coma. After insertion of a thoracic drain, the coma rapidly resolved without any neurological deficit. Conclusions: Although severe hypercapnia is usually due to decompensation of chronic lung disease, pneumothorax potentially may cause hypercapnic coma. Review of the literature suggests that there is no close correlation between arterial pCO2 (partial pressure of CO2) levels and the degree of impairment of consciousness; however, levels exceeding 80 mm Hg are likely associated with significantly impaired consciousness. Hypercapnic coma usually resolves without neurological deficit as arterial pCO2 tensions decline.

Living-donor, single-lobe lung transplantation and simultaneous contralateral pneumonectomy in a child

An 8-year-old girl became ventilator-dependent due to severe bronchiolitis obliterans/interstitial pneumonia caused by cord-blood cell transplantation for neuroblastoma. Her mother's right lower lobe was twice as large as her right chest cavity. She successfully underwent living-donor, right, single-lobe lung transplantation and simultaneous left pneumonectomy under conditions of cardiopulmonary bypass. At 18 months after transplantation, the patient returned to school life and is currently able to carry out daily activities without supplemental oxygen.

Successful pediatric single-lung transplantation with previous contralateral pneumonectomy, using controlled “donation after cardiac death” lung, for congenital pulmonary vein stenosis

From the Department of Cardiothoracic Surgery and Transplantation, Pediatric Respiratory Medicine, Freeman Hospital, Newcastle upon Tyne, United Kingdom. Disclosures: None. Received for publication Dec 31, 2008; revisions received April 25, 2009; accepted for publication June 4, 2009; available ahead of print Aug 26, 2009. Address for reprints: Amit Pawale, MRCS, Department of Cardiothoracic Surgery, Freeman Hospital, Newcastle upon Tyne NE7 7DN, United Kingdom (E-mail: amitpawale@doctors.org.uk). J Thorac Cardiovasc Surg 2010;139:e125-6 0022-5223/$36.00 Copyright 2010 by The American Association for Thoracic Surgery doi:10.1016/j.jtcvs.2009.06.006

Single-lung transplantation in patients with previous contralateral pneumonectomy: technical aspects and results

Single-lung transplantation (SLTX) in patients with previous contralateral pneumonectomy (PN) is a rarely observed situation. Intrathoracic anatomical changes caused by mediastinal shift may complicate the surgical procedure. We collected observations from different transplantation centres to analyse the technical aspects and results. Between July 1990 and September 2008, 14 patients (seven women and seven men) with previous PN underwent SLTX for end-stage pulmonary failure. Patients were categorised in three groups according to lung disease: cystic fibrosis bronchiectasis (group 1; n=4), non-cystic fibrosis bronchiectasis (group 2; n=6) and bronchioloalveolar carcinoma (group 3; n=4). We reviewed patients' characteristics according to mediastinal shift, thoracic approach, bypass cannula procedure, perioperative difficulties and immediate and long-term results. Median age was 19.5, 33.5 and 52.5 years in groups 1, 2 and 3, respectively; there were nine left and five right cases of SLTX. Surgery was performed by sternotomy (n=4), anterolateral thoracotomy (n=4), clamshell (n=4) or posterolateral thoracotomy (n=2). Cannulas for bypass were inserted into femoral (n=7) or central vessels (n=5) or both (n=2). Mediastinal shift did not complicate surgical procedure but rendered cannulation more difficult with ensuing cardiopulmonary bypass dysfunction (n=3) and early bronchial complications (n=2). In-hospital mortality rate was 29% (4 out of 14 patients), including two deaths due to perioperative difficulties linked to mediastinal shift. Median global survival was 108 months. Median survival was higher in group 2 (108 months vs 1 month in the other groups) and in case of PN during childhood (n=6, median survival 108 months corresponding to one death). SLTX after PN is associated with high perioperative morbidity and mortality due to mediastinal shift. Best results are observed in patients undergoing PN for non-cystic fibrosis bronchiectasis and during childhood. Anatomical changes induced by PN must be anticipated to adapt the thoracic approach and cardiopulmonary bypass access.

Hypercapnic Coma Due to Spontaneous Pneumothorax: Case Report and Review of the Literature

Background: Hypercapnic coma is a rare differential diagnosis in the unconscious patient. One underlying mechanism may be hypoventilation due to spontaneous pneumothorax. Although hypercapnia is not a typical finding in spontaneous pneumothorax in patients with otherwise healthy lungs, under certain circumstances, hypercapnia may readily develop. Objectives: We report a rare case of profound hypercapnic coma due to spontaneous pneumothorax after contralateral pneumonectomy. In addition, we review other causes of hypercapnic coma and its outcome and discuss the relationship between arterial carbon dioxide partial pressure and level of consciousness. Case Report: An 85-year-old man without evidence of trauma or intoxication presented unconscious to our Emergency Department. The physical examination and X-ray study revealed a left-sided spontaneous pneumothorax. A right-sided pneumonectomy 25 years earlier had promoted the development of profound hypercapnic coma. After insertion of a thoracic drain, the coma rapidly resolved without any neurological deficit. Conclusions: Although severe hypercapnia is usually due to decompensation of chronic lung disease, pneumothorax potentially may cause hypercapnic coma. Review of the literature suggests that there is no close correlation between arterial pCO 2 (partial pressure of CO 2) levels and the degree of impairment of consciousness; however, levels exceeding 80 mm Hg are likely associated with significantly impaired consciousness. Hypercapnic coma usually resolves without neurological deficit as arterial pCO 2 tensions decline.