Neuromuscular blockers in early acute respiratory distress syndrome

BACKGROUND

In patients undergoing mechanical ventilation for the acute respiratory distress syndrome (ARDS), neuromuscular blocking agents may improve oxygenation and decrease ventilator-induced lung injury but may also cause muscle weakness. We evaluated clinical outcomes after 2 days of therapy with neuromuscular blocking agents in patients with early, severe ARDS.

METHODS

In this multicenter, double-blind trial, 340 patients presenting to the intensive care unit (ICU) with an onset of severe ARDS within the previous 48 hours were randomly assigned to receive, for 48 hours, either cisatracurium besylate (178 patients) or placebo (162 patients). Severe ARDS was defined as a ratio of the partial pressure of arterial oxygen (PaO2) to the fraction of inspired oxygen (FIO2) of less than 150, with a positive end-expiratory pressure of 5 cm or more of water and a tidal volume of 6 to 8 ml per kilogram of predicted body weight. The primary outcome was the proportion of patients who died either before hospital discharge or within 90 days after study enrollment (i.e., the 90-day in-hospital mortality rate), adjusted for predefined covariates and baseline differences between groups with the use of a Cox model.

RESULTS

The hazard ratio for death at 90 days in the cisatracurium group, as compared with the placebo group, was 0.68 (95% confidence interval [CI], 0.48 to 0.98; P=0.04), after adjustment for both the baseline PaO2:FIO2 and plateau pressure and the Simplified Acute Physiology II score. The crude 90-day mortality was 31.6% (95% CI, 25.2 to 38.8) in the cisatracurium group and 40.7% (95% CI, 33.5 to 48.4) in the placebo group (P=0.08). Mortality at 28 days was 23.7% (95% CI, 18.1 to 30.5) with cisatracurium and 33.3% (95% CI, 26.5 to 40.9) with placebo (P=0.05). The rate of ICU-acquired paresis did not differ significantly between the two groups.

CONCLUSIONS

In patients with severe ARDS, early administration of a neuromuscular blocking agent improved the adjusted 90-day survival and increased the time off the ventilator without increasing muscle weakness. (Funded by Assistance Publique-Hôpitaux de Marseille and the Programme Hospitalier de Recherche Clinique Régional 2004-26 of the French Ministry of Health; ClinicalTrials.gov number, NCT00299650.)

Nasal CPAP or intubation at birth for very preterm infants

BACKGROUND

Bronchopulmonary dysplasia is associated with ventilation and oxygen treatment. This randomized trial investigated whether nasal continuous positive airway pressure (CPAP), rather than intubation and ventilation, shortly after birth would reduce the rate of death or bronchopulmonary dysplasia in very preterm infants.

METHODS

We randomly assigned 610 infants who were born at 25-to-28-weeks' gestation to CPAP or intubation and ventilation at 5 minutes after birth. We assessed outcomes at 28 days of age, at 36 weeks' gestational age, and before discharge.

RESULTS

At 36 weeks' gestational age, 33.9% of 307 infants who were assigned to receive CPAP had died or had bronchopulmonary dysplasia, as compared with 38.9% of 303 infants who were assigned to receive intubation (odds ratio favoring CPAP, 0.80; 95% confidence interval [CI], 0.58 to 1.12; P=0.19). At 28 days, there was a lower risk of death or need for oxygen therapy in the CPAP group than in the intubation group (odds ratio, 0.63; 95% CI, 0.46 to 0.88; P=0.006). There was little difference in overall mortality. In the CPAP group, 46% of infants were intubated during the first 5 days, and the use of surfactant was halved. The incidence of pneumothorax was 9% in the CPAP group, as compared with 3% in the intubation group (P<0.001). There were no other serious adverse events. The CPAP group had fewer days of ventilation.

CONCLUSIONS

In infants born at 25-to-28-weeks' gestation, early nasal CPAP did not significantly reduce the rate of death or bronchopulmonary dysplasia, as compared with intubation. Even though the CPAP group had more incidences of pneumothorax, fewer infants received oxygen at 28 days, and they had fewer days of ventilation. (Australian New Zealand Clinical Trials Registry number, 12606000258550.).

Effect of cerium on drug metabolizing activity in rat liver

Objectives

To meta-analyze complication rate in computed tomography (CT)-guided transthoracic lung biopsy and associated risk factors.

Methods

Four databases were searched from 1/2000 to 8/2015 for studies reporting complications in CT-guided lung biopsy. Overall and major complication rates were pooled and compared between core biopsy and fine needle aspiration (FNA) using the random-effects model. Risk factors for complications in core biopsy and FNA were identified in meta-regression analysis.

Results

For core biopsy, 32 articles (8,133 procedures) were included and for FNA, 17 (4,620 procedures). Pooled overall complication rates for core biopsy and FNA were 38.8 % (95 % CI: 34.3–43.5 %) and 24.0 % (95 % CI: 18.2–30.8 %), respectively. Major complication rates were 5.7 % (95 % CI: 4.4–7.4 %) and 4.4 % (95 % CI: 2.7–7.0 %), respectively. Overall complication rate was higher for core biopsy compared to FNA (p < 0.001). For FNA, larger needle diameter was a risk factor for overall complications, and increased traversed lung parenchyma and smaller lesion size were risk factors for major complications. For core biopsy, no significant risk factors were identified.

Conclusions

In CT-guided lung biopsy, minor complications were common and occurred more often in core biopsy than FNA. Major complication rate was low. For FNA, smaller nodule diameter, larger needle diameter and increased traversed lung parenchyma were risk factors for complications.

Key Points

• Minor complications are common in CT-guided lung biopsy

• Major complication rate is low in CT-guided lung biopsy

• CT-guided lung biopsy complications occur more often in core biopsy than FNA

• Major complication rate is similar in core biopsy and FNA

• Risk factors for FNA are larger needle diameter, smaller lesion size

Electronic supplementary material

The online version of this article (doi:10.1007/s00330-016-4357-8) contains supplementary material, which is available to authorized users.

Complications of central venous catheters: internal jugular versus subclavian access--a systematic review

OBJECTIVE

To test whether complications happen more often with the internal jugular or the subclavian central venous approach.

DATA SOURCE

Systematic search (MEDLINE, Cochrane Library, EMBASE, bibliographies) up to June 30, 2000, with no language restriction.

STUDY SELECTION

Reports on prospective comparisons of internal jugular vs. subclavian catheter insertion, with dichotomous data on complications.

DATA EXTRACTION

No valid randomized trials were found. Seventeen prospective comparative trials with data on 2,085 jugular and 2,428 subclavian catheters were analyzed. Meta-analyses were performed with relative risk (RR) and 95% confidence interval (CI), using fixed and random effects models.

DATA SYNTHESIS

In six trials (2,010 catheters), there were significantly more arterial punctures with jugular catheters compared with subclavian (3.0% vs. 0.5%, RR 4.70 [95% CI, 2.05-10.77]). In six trials (1,299 catheters), there were significantly less malpositions with the jugular access (5.3% vs. 9.3%, RR 0.66 [0.44-0.99]). In three trials (707 catheters), the incidence of bloodstream infection was 8.6% with the jugular access and 4.0% with the subclavian access (RR 2.24 [0.62-8.09]). In ten trials (3,420 catheters), the incidence of hemato- or pneumothorax was 1.3% vs. 1.5% (RR 0.76 [0.43--1.33]). In four trials (899), the incidence of vessel occlusion was 0% vs. 1.2% (RR 0.29 [0.07-1.33]).

CONCLUSIONS

There are more arterial punctures but less catheter malpositions with the internal jugular compared with the subclavian access. There is no evidence of any difference in the incidence of hemato- or pneumothorax and vessel occlusion. Data on bloodstream infection are scarce. These data are from nonrandomized studies; selection bias cannot be ruled out. In terms of risk, the data most likely represent a best case scenario. For rational decision-making, randomized trials are needed.

Blunt thoracic trauma. Analysis of 515 patients

A retrospective analysis of 515 cases of blunt chest trauma is presented. The overall thoracic morbidity rate was 36% and mortality rate was 15.5%. Atelectasis was the most common complication. Severe chest trauma can be present in the absence of rib or other thoracic bony fractures. Emergency thoracotomies for resuscitation of the patient with blunt chest trauma with absent vital signs proved unsuccessful in 39 of 39 patients. A high index of suspicion for blunt chest injury occurring in blunt trauma, coupled with an aggressive diagnostic and therapeutic approach, remains the cornerstone of treatment to minimize the morbidity and mortality of such injuries.

Risk Factors of Pneumothorax and Bleeding

BACKGROUND

The results of studies identifying the risk factors for pneumothorax and bleeding in CT-guided coaxial lung needle biopsies were inconsistent and some were even contradictory. All reported series were small with patient populations averaging about 200.

STUDY OBJECTIVES

To determine the risk factors for pneumothorax and bleeding after CT-guided coaxial cutting needle biopsy of lung lesions.

DESIGN

Retrospective analysis.

METHODS

We reviewed 660 biopsy procedures. The risk factors for pneumothorax and bleeding were determined by multivariate analysis of variables related to patient demographics, lung lesions, biopsy procedures, and the individual radiologist.

RESULTS

The main complications were pneumothorax (23%; 155 of 660 procedures), chest tube insertion (1%; 9 of 660 procedures), and hemoptysis (4%; 26 of 660 procedures), with no patient mortality. The highest pneumothorax rate correlated with a lesion size of </= 2 cm, a lesion depth of 0.1 to 2 cm, and less experienced radiologists. The highest bleeding risk correlated with a lesion size </= 2 cm, a lesion depth of >/= 2.1 cm, and the absence of pleural effusion.

CONCLUSIONS

The risk factors for highest pneumothorax rate are lesion size </= 2 cm, a subpleural lesion depth of 0.1 to 2.0 cm, and a less experienced radiologist. The risk factors for highest bleeding rate are lesion size </= 2 cm, lesion depth >/= 2.1 cm, and lung lesions not associated with a pleural effusion.

Major complications after radio-frequency thermal ablation of hepatic tumors: spectrum of imaging findings

Although radio-frequency (RF) ablation has been accepted as a promising and safe technique for treatment of unresectable hepatic tumors, investigation of its complications has been limited. According to the multicenter (1,139 patients in 11 institutions) survey data of the Korean Study Group of Radiofrequency Ablation, a spectrum of complications occurred after RF ablation of hepatic tumors. The prevalence of major complications was 2.43%. The most common complications were hepatic abscess (0.66%), peritoneal hemorrhage (0.46%), biloma (0.20%), ground pad burn (0.20%), pneumothorax (0.20%), and vasovagal reflex (0.13%). Other complications were biliary stricture, diaphragmatic injury, gastric ulcer, hemothorax, hepatic failure, hepatic infarction, renal infarction, sepsis, and transient ischemic attack. One procedure-related death (0.09%) occurred (due to peritoneal hemorrhage). Three important strategies for decreasing the rate of complications are prevention, early detection, and proper management. A physician who performs RF ablation of hepatic malignancies should be aware of the broad spectrum of major complications so that these strategies can be used.

Risk of pneumothorax in CT-guided transthoracic needle aspiration biopsy of the lung

PURPOSE

To determine risk factors for pneumothorax and chest tube placement associated with computed tomography (CT)-guided transthoracic needle aspiration biopsy (TNAB) of the lung.

METHODS

One hundred twenty-one consecutive CT-guided TNAB procedures were performed in 117 patients. Patient age, sex, number of needle passes and pleural planes traversed, lesion size, distance of lesion from the pleura, and results of pulmonary function tests were analyzed as single and multiple dependent variables for pneumothorax and chest tube placement.

RESULTS

Pneumothorax occurred in 54 of 121 procedures (44.6%); a chest tube was required in 18 cases (14.9%). Increased lesion depth was the most significant predictor of pneumothorax (P = .002). Smaller lesion size also correlated with increased risk of pneumothorax (P = .04). Among patients with pneumothorax, a significantly higher frequency of chest tube placement was seen in those with severe obstructive lung disease, as measured by percentage of predicted FEV1 (forced expiratory volume in 1 second) (51% in patients requiring a chest tube vs 81% in those not requiring a chest tube, P = .006) and FEV1/FVC (forced vital capacity) (x100) (45% vs 66%, P = .001).

CONCLUSION

Increased lesion depth and smaller lesion size correlated strongly with the development of pneumothorax. Once pneumothorax occurred, chest tube placement related to the severity of the patient's obstructive lung disease.

Lung cysts, spontaneous pneumothorax, and genetic associations in 89 families with Birt-Hogg-Dubé syndrome

RATIONALE

Birt-Hogg-Dubé syndrome (BHDS) is an autosomal, dominantly inherited genodermatosis that predisposes to fibrofolliculomas, kidney neoplasms, lung cysts, and spontaneous pneumothorax.

OBJECTIVES

We evaluated 198 patients from 89 families with BHDS to characterize the risk factors for pneumothorax and genotype-pulmonary associations.

METHODS

Helical computed tomography scans of the chest were used to screen for pulmonary abnormalities. BHD mutation data were used for genotype-pulmonary associations. We examined the relationship of pneumothorax with categorical parameters (sex, smoking history, and lung cysts) and continuous parameters (number of cysts, lung cyst volume, and largest cyst diameter and volume). Logistic regression analyses were used to identify the risk factors associated with pneumothorax.

MEASUREMENTS AND MAIN RESULTS

Twenty-four percent (48/198) of patients with BHDS had a history of pneumothorax. The presence of lung cysts was significantly associated with pneumothorax (p = 0.006). Total lung cyst volume, largest cyst diameter and volume, and every parameter related to the number of lung cysts were significantly associated (p < 0.0001) with pneumothorax. A logistic regression analysis showed that only the total number of cysts in the right parenchymal lower lobe and the total number of cysts located on the pleural surface in the right middle lobe were needed to classify a patient as to whether or not he or she was likely to have a pneumothorax. Exon location of the BHD mutation was associated with the numbers of cysts (p = 0.0002).

CONCLUSIONS

This study indicates that patients with BHDS have a significant association between lung cysts and spontaneous pneumothorax.

Epidemiology of pneumothorax in England

BACKGROUND

Little is known of the epidemiology of pneumothorax. Routinely available data on pneumothorax in England are described.

METHODS

Patients consulting in primary care with a diagnosis of pneumothorax in each year from 1991 to 1995 inclusive were identified from the General Practice Research Database (GPRD). Emergency hospital admissions for pneumothorax were identified for the years 1991-4 from the Hospital Episode Statistics (HES) data. Mortality data for England & Wales were obtained for 1950-97. Analyses of pneumothorax rates by age and sex were performed for all data sources. Seasonal and geographical analyses were carried out for the HES data.

RESULTS

The overall person consulting rate for pneumothorax (primary and secondary combined) in the GPRD was 24. 0/100 000 each year for men and 9.8/100 000 each year for women. Hospital admissions for pneumothorax as a primary diagnosis occurred at an overall incidence of 16.7/100 000 per year and 5.8/100 000 per year for men and women, respectively. Mortality rates were 1. 26/million per year for men and 0.62/million per year for women. The age distribution in both men and women showed a biphasic distribution for both GP consultations and hospital admissions. Deaths showed a single peak with highest rates in the elderly. There was an urban-rural trend observed for hospital admissions in the older age group (55+ years) with admission rates in the conurbations significantly higher than in the rural areas. Analysis for trends in mortality data for 1950-97 showed a striking increase in the death rate for pneumothorax in those aged 55+ years between 1960 and 1990, with a steep decline in the 1990s. Mortality in the younger age group (15-34 years) remained low and constant.

CONCLUSION

There is evidence of two epidemiologically distinct forms of spontaneous pneumothorax in England. The explanation for the rise and fall in mortality for secondary pneumothorax is obscure.

COVID-19 and pneumothorax: a multicentre retrospective case series

INTRODUCTION

Pneumothorax and pneumomediastinum have both been noted to complicate cases of coronavirus disease 2019 (COVID-19) requiring hospital admission. We report the largest case series yet described of patients with both these pathologies (including nonventilated patients).

METHODS

Cases were collected retrospectively from UK hospitals with inclusion criteria limited to a diagnosis of COVID-19 and the presence of either pneumothorax or pneumomediastinum. Patients included in the study presented between March and June 2020. Details obtained from the medical record included demographics, radiology, laboratory investigations, clinical management and survival.

RESULTS

71 patients from 16 centres were included in the study, of whom 60 had pneumothoraces (six with pneumomediastinum in addition) and 11 had pneumomediastinum alone. Two of these patients had two distinct episodes of pneumothorax, occurring bilaterally in sequential fashion, bringing the total number of pneumothoraces included to 62. Clinical scenarios included patients who had presented to hospital with pneumothorax, patients who had developed pneumothorax or pneumomediastinum during their inpatient admission with COVID-19 and patients who developed their complication while intubated and ventilated, either with or without concurrent extracorporeal membrane oxygenation. Survival at 28 days was not significantly different following pneumothorax (63.1±6.5%) or isolated pneumomediastinum (53.0±18.7%; p=0.854). The incidence of pneumothorax was higher in males. 28-day survival was not different between the sexes (males 62.5±7.7% versus females 68.4±10.7%; p=0.619). Patients aged ≥70 years had a significantly lower 28-day survival than younger individuals (≥70 years 41.7±13.5% survival versus <70 years 70.9±6.8% survival; p=0.018 log-rank).

CONCLUSION

These cases suggest that pneumothorax is a complication of COVID-19. Pneumothorax does not seem to be an independent marker of poor prognosis and we encourage continuation of active treatment where clinically possible.

Randomized study of high-frequency oscillatory ventilation in infants with severe respiratory distress syndrome. HiFO Study Group

We conducted a multicenter, prospective, noncrossover, randomized study to determine whether high-frequency oscillatory ventilation (HFOV) would decrease the development or progression of air leak syndrome in infants with severe respiratory distress syndrome. Air leak syndrome was defined as pulmonary interstitial emphysema or gross air leak such as pneumothorax. Infants were eligible for study entry if they were less than 48 hours of age and had severe respiratory distress syndrome, defined by peak inspiratory pressure or the presence of air leak syndrome. Infants who weighed > or = 0.5 kg at birth were randomly assigned to receive either conventional ventilation (CV) or HFOV. HFOV was provided by a ventilator that operated at 15 Hz, with a 1:2 inspiratory/expiratory ratio and no background tidal breaths. Severity of pulmonary interstitial emphysema was scored independently by two neonatologists unaware of the infants' ventilatory group. Gross air leak severity was scored according to the number of chest tubes required and duration of air leak. Eighty-six infants received HFOV; 90 received CV. During the first 24 hours of the study, patients in the HFOV group received significantly higher mean airway pressure and lower inspired oxygen concentration, had significantly lower arterial carbon dioxide tension, and had a higher ratio of arterial to alveolar oxygen tension. When the HFOV and CV groups were compared with control for birth weight strata, study site, and inborn versus outborn status, HFOV significantly reduced the development of air leak syndrome in those patients who entered the study without the syndrome. We conclude that HFOV, when the strategy employed in this study is used, provides effective ventilation, improves oxygenation, and significantly reduces the development of air leak syndrome in infants with severe respiratory distress syndrome.

Recurrence of primary spontaneous pneumothorax

BACKGROUND

Primary spontaneous pneumothorax (PSP) is a common clinical problem and its incidence is thought to be increasing. The risk of recurrence is high and various studies quote rates of 20-60%. Factors which may or may not predispose to recurrence have not yet been established.

METHODS

In a study period of four years 291 cases with a diagnosis of pneumothorax were reviewed; 153 patients with PSP were included in the study. Their risk of recurrence was analysed with particular reference to the following variables: age, sex, height and body mass index (BMI) of the patient, the initial size of pneumothorax, the smoking status of the patient, and the primary form of treatment employed. Univariate analysis was carried out by chi 2 testing and multivariate analysis was calculated by a logistic regression model.

RESULTS

A retrospective study of 275 episodes of PSP in 153 patients over a four year period confirmed a high incidence of recurrence (54.2%). PSP was twice as common in men as in women, though women were significantly more likely to develop a recurrence (chi 2 = 7.58, df = 1, p < 0.01). Male height was the second most important factor, and smoking cessation the only other variable which significantly influenced the risk of recurrence.

CONCLUSIONS

Analysis of several potential risk factors revealed that recurrence was not related to the BMI of the patient, the initial treatment of the pneumothorax, nor to its size. Recurrence was more common in taller men and in women. Smoking cessation appeared to reduce the risk of recurrence. These findings are discussed in the context of the possible aetiology of spontaneous pneumothorax, recurrences, and the management thereof.

Patient and surgical factors influencing air leak after lung volume reduction surgery: lessons learned from the National Emphysema Treatment Trial

BACKGROUND

Although staple line buttressing is advocated to reduce air leak after lung volume reduction surgery (LVRS), its effectiveness is unknown. We sought to identify risk factors for air leak and its duration and to estimate its medical consequences for selecting optimal perioperative technique(s), such as buttressing technique, to preempt or treat post-LVRS air leak.

METHODS

Detailed air leak data were available for 552 of 580 patients receiving bilateral stapled LVRS in the National Emphysema Treatment Trial. Risk factors for prevalence and duration of air leak were identified by logistic and hazard function analyses. Medical consequences were estimated in propensity-matched pairs with and without air leak.

RESULTS

Within 30 days of LVRS, 90% of patients developed air leak (median duration = 7 days). Its occurrence was more common and duration prolonged in patients with lower diffusing capacity (p = 0.06), upper lobe disease (p = 0.04), and important pleural adhesions (p = 0.007). Duration was also protracted in Caucasians (p < 0.0001), patients using inhaled steroids (p = 0.004), and those with lower 1-second forced expiratory volume (p = 0.0003). Surgical approach, buttressing, stapler brand, and intraoperative adjunctive procedures were not associated with fewer or less prolonged air leaks (p >/= 0.2). Postoperative complications occurred more often in matched patients experiencing air leak (57% vs 30%, p = 0.0004), and postoperative stay was longer (11.8 +/- 6.5 days vs 7.6 +/- 4.4 days, p = 0.0005).

CONCLUSIONS

Air leak accompanies LVRS in 90% of patients, is often prolonged, and is associated with a more complicated and protracted hospital course. Its occurrence and duration are associated with characteristics of patients and their disease, not with a specific surgical technique.

Predictors and treatment of persistent air leaks

BACKGROUND

Air leaks prolong hospital stay.

METHODS

A prospective algorithm was applied to patients. If patients were ready for discharge but still had an air leak, a Heimlich valve was placed and they were discharged. If the leak was still present after 2 weeks, the tube was clamped for a day and removed.

RESULTS

There were 669 patients. Factors that predicted a persistent air leak were FEV1% of less than 79% (p = 0.006), history of steroid use (p = 0.002), male gender (p = 0.05), and having a lobectomy (p = 0.01). Types of air leaks on day 1 that eventually required a Heimlich valve were expiratory leaks (p = 0.02), leaks that were an expiratory 4 or more (p < 0.0001), and the presence of a pneumothorax concomitant with an air leak (p < 0.0001). Thirty-three patients were placed on a Heimlich valve, and 6 patients had a pneumothorax or subcutaneous emphysema develop; all patients had an expiratory 5 leak or larger (p < 0.0001). Thirty-three patients went home on a valve. Seventeen patients had leaks that resolved by 1 week, 6 by 2 weeks, and the remaining 9 had their tubes removed without problems.

CONCLUSIONS

Steroid use, male gender, a large leak, a leak with a pneumothorax, and having a lobectomy are all risk factors for a persistent leak. Discharge on a Heimlich valve is safe and effective for patients with a persistent leak unless the leak is an expiratory 5 or more. Once home on a valve, most air leaks will seal in 2 weeks; if not, chest tubes can be safely removed regardless of the size of the leak or the presence of a pneumothorax.

Safety and efficacy of video-assisted thoracic surgical techniques for the treatment of spontaneous pneumothorax

Video-assisted thoracic surgery has been widely used in the treatment of spontaneous pneumothorax despite a paucity of data regarding the relative safety and long-term efficacy for this procedure. We reviewed 113 consecutive patients (68 male and 45 female patients, aged 15 to 92 years, mean 35.1) who underwent 121 video-assisted thoracic surgical procedures during 119 hospitalizations from 1991 through 1993. Recurrent ipsilateral pneumothorax was the most frequent indication for surgery and occurred in 77 patients (65%). The most common method of management was stapling of an identified bleb in the lung, which was undertaken in 105 (87%) patients. No operative deaths occurred. Complications included an air leak lasting longer than 5 days in 10 (8%) patients, two of whom required second procedures for definitive management. No episodes of postoperative bleeding or empyema occurred. The postoperative stay ranged from 1 day to 39 days (median 3 days, average 4.3 days) and 99 patients (84%) were discharged within 5 days. Mean follow-up was 13.1 months and ranged from 1 to 34 months. Eleven patients (10%) were lost to follow-up. Ipsilateral pneumothorax recurred after five of 121 procedures (4.1%). Twelve perioperative parameters (age, gender, race, smoking history, site of pneumothorax, severity of pneumothorax, operative indications, number of blebs, site of blebs, bleb ablation, method of pleurodesis, and prolonged postoperative air leak) were entered into univariate and multivariate analysis to identify significant independent predictors of recurrence. The only independent predictor of recurrence was the failure to identify and ablate a bleb at operation, which resulted in a 23% recurrence rate versus a 1.8% rate in those with ablated blebs (p < 0.001). These data suggest that video-assisted thoracic surgery is a viable alternative to thoracotomy for the treatment of recurrent spontaneous pneumothorax. It results in a short hospital stay, low morbidity, high patient acceptance, and a low rate of recurrence.

Outcome of tunneled hemodialysis catheters placed by radiologists

PURPOSE

To compare the outcomes of hemodialysis catheters placed by interventional radiologists with those placed by surgeons.

MATERIALS AND METHODS

The outcomes were retrospectively analyzed of 237 hemodialysis catheters placed in 140 patients by a radiology service from January 1991 through December 1992. Follow-up data were available for 222 catheters (94%). Catheter secondary patency and freedom from infection were analyzed statistically and by means of life-table analysis.

RESULTS

Pneumothorax occurred after the placement of six catheters (2.5%); in two patients, a chest tube was required for decompression. Other short-term complications included air embolism with no clinical sequelae (two procedures) and prolonged oozing from the tunnel (two procedures). Long-term complications included infection and catheter failure. Infection occurred in 26 patients (18%) with 32 catheters (14%) and resulted in removal of 25 catheters. Ninety-three catheters (42%) failed, and 63 catheters (28%) were removed because of failure.

CONCLUSION

Hemodialysis catheters placed by radiologists do not have a higher rate of complications or failure than catheters placed by surgeons.

Pneumothorax, Pleural Effusion, and Chest Tube Placement after Radiofrequency Ablation of Lung Tumors: Incidence and Risk Factors

PURPOSE

To retrospectively evaluate the incidence of and risk factors for pneumothorax, pleural effusion, and chest tube placement for pneumothorax after radiofrequency (RF) ablation of lung tumors.

MATERIALS AND METHODS

Institutional review board approval was obtained, with waiver of informed consent. This retrospective study comprised 224 ablation sessions for 392 tumors in 142 patients (92 men, 50 women; mean age, 64.0 years). Multiple variables were analyzed by using the Student t test or the Mann-Whitney U test for numerical values and by using the chi(2) test or the Fisher exact test for categorical values in order to assess risk factors for pneumothorax, pleural effusion, and chest tube placement for pneumothorax.

RESULTS

The incidence of pneumothorax, pleural effusion, and chest tube placement for pneumothorax was 52% (117 of 224 sessions), 19% (42 of 224 sessions), and 21% (24 of 117 sessions), respectively. For pneumothorax, risk factors included male sex (P = .030), no history of pulmonary surgery (P < .001), a greater number of tumors ablated (P < .001), involvement of the middle or lower lobe (P = .008), and increased length of the aerated lung traversed by the electrode (P = .014). For pleural effusion, risk factors included the use of a cluster electrode (P = .008), decreased distance to the nearest pleura (P = .040), and decreased length of the aerated lung traversed by the electrode (P = .019). For chest tube placement for pneumothorax, risk factors included no history of pulmonary surgery (P = .002), the use of a cluster electrode (P < .001), and involvement of the upper lobe (P < .001).

CONCLUSION

Pneumothorax and pleural effusion can occur after RF ablation in patients with lung tumors, and chest tube placement for pneumothorax is sometimes required.

Radiofrequency ablation for the treatment of non-small cell lung cancer in marginal surgical candidates

OBJECTIVE

Treatment options for patients with non-small cell lung cancer who are not surgical candidates or who refuse operation are limited. Radiofrequency ablation represents a potential less invasive option for these patients. Our initial experience with radiofrequency ablation for peripheral, primary non-small cell lung cancer is reported.

METHODS

We treated 21 tumors in 18 patients. Median age was 75 (range 58-86) years. Cancer stages were I (n = 9), II (n = 2), III (n = 3), and IV (n = 4). Patients with stage IV disease included 3 with recurrence after previous lobectomies and 1 with a synchronous liver metastasis also treated with radiofrequency ablation. Median tumor diameter was 2.8 cm (range 1.2-4.5 cm). Radiofrequency ablation was delivered by minithoracotomy in 2 cases and by a computed tomography-guided percutaneous approach in 16 patients. Computed tomographic and positron emission tomographic scans were used to evaluate recurrence and radiographic response in ablated nodules.

RESULTS

One postoperative death occurred from pneumonia after open radiofrequency ablation. Median hospital stay was 2.5 days. A chest tube or pigtail catheter was required in 7 patients (38.9%) for procedure-related pneumothoraces. At a median follow-up of 14 months, 15 patients (83.3%) were alive. Local progression occurred in 8 nodules (38.1%). Mean and median progression-free intervals were 16.8 and 18 months, respectively. For stage I cancers, mean progression-free interval was 17.6 months. Median progression-free interval was not reached.

CONCLUSION

This study demonstrates the feasibility of radiofrequency ablation for small, peripheral non-small cell lung cancer tumors. Local control is comparable to, if not better than, that provided by radiotherapy. Radiofrequency ablation should continue to be evaluated by thoracic surgeons as a noninvasive therapy for the high-risk patient with non-small cell lung cancer.

Telomerase mutations in smokers with severe emphysema

Mutations in the essential telomerase genes TERT and TR cause familial pulmonary fibrosis; however, in telomerase-null mice, short telomeres predispose to emphysema after chronic cigarette smoke exposure. Here, we tested whether telomerase mutations are a risk factor for human emphysema by examining their frequency in smokers with chronic obstructive pulmonary disease (COPD). Across two independent cohorts, we found 3 of 292 severe COPD cases carried deleterious mutations in TERT (1%). This prevalence is comparable to the frequency of alpha-1 antitrypsin deficiency documented in this population. The TERT mutations compromised telomerase catalytic activity, and mutation carriers had short telomeres. Telomerase mutation carriers with emphysema were predominantly female and had an increased incidence of pneumothorax. In families, emphysema showed an autosomal dominant inheritance pattern, along with pulmonary fibrosis and other telomere syndrome features, but manifested only in smokers. Our findings identify germline mutations in telomerase as a Mendelian risk factor for COPD susceptibility that clusters in autosomal dominant families with telomere-mediated disease including pulmonary fibrosis.

Risk factors for morbidity in mechanically ventilated patients with acute severe asthma

Acute severe asthma is associated with significant morbidity and mortality. We retrospectively quantified hypotension, pulmonary barotrauma, and cardiac arrhythmias in all patients with severe asthma admitted to the intensive care unit (ICU) and prospectively evaluated the predictive value of a measurement of dynamic hyperinflation (DHI) in those patients who required mechanical ventilation. In the first study, 88 ICU admissions for severe asthma over 5 yr (73 patients, 40 +/- 18 yr, 36 men, 37 women) were evaluated. Fifty-one admissions were mechanically ventilated, 29 were not, and 8 previously ventilated patients remained briefly intubated but were not ventilated in the ICU. Hypotension (18/88, 20%), pulmonary barotrauma (12/88, 14%), and arrhythmias (9/88, 10%) were entirely confined to patients who had been mechanically ventilated. There were no significant differences in ventilatory parameters, airway pressures, or blood gases between mechanically ventilated patients with and without complications. Two patients with previous severe hypoxic cerebral damage died from this complication after ICU discharge. In the second study, the end-inspiratory lung volume (VEI) (1) was compared with standard ventilatory parameters in 22 patients. There were no ICU deaths, but high incidences of pulmonary barotrauma (27%) and hypotension (41%) were found. Both minute ventilation (VE and VEI) were significantly higher in patients who developed complications (VE 13.7 +/- 3.0 versus 11.2 +/- 2.5 L/min, VEI 26.1 +/- 4.7 versus 20.0 +/- 7.4 ml/kg, p less than 0.05) but only VEI had a threshold value significantly predictive of complications. For VEI less than 1.4 L, 0/5 (0%) patients had complications; for VEI greater than or equal to 1.4 L, 11/17 (65%) had complications (p = 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)

Pulmonary barotrauma in mechanical ventilation. Patterns and risk factors

The incidence of mediastinal emphysema (ME) and pneumothorax (PTX) was analyzed to determine the roentgenographic patterns and risk factors for the development of barotrauma in a population of mechanically ventilated patients. The roentgenograms of 139 intubated patients admitted to our medical intensive care unit over a ten-month period were evaluated for the presence of ME and PTX. Barotrauma was diagnosed in 34 of these patients, and ME was the initial manifestation in 24 patients. Of these patients with initial ME, ten subsequently developed PTX, a positive predictive value of 42 percent. The adult respiratory distress syndrome (ARDS) patient population was at highest risk for barotrauma, with an intermediate risk seen in those admitted with COPD or pneumonia. Values of peak inspiratory pressure, positive end-expiratory pressure level, respiratory rate, tidal volume, and minute ventilation were significantly elevated in patients who developed barotrauma as compared with patients who did not develop barotrauma. However, these elevations in part reflect the high incidence of barotrauma in the ARDS population, a patient group in which all of the above parameters were elevated.

Relationship between ventilatory settings and barotrauma in the acute respiratory distress syndrome

OBJECTIVE

High pressures or volumes may increase the risk of barotrauma in the acute respiratory distress syndrome (ARDS).

METHODS

The first part of the study analyzed data from a prospective trial of two ventilation strategies in 116 patients with ARDS retrospectively, and ventilatory pressures and volumes were compared in patients with or without pneumothorax. The second part consisted of a literature analysis of prospective trials (14 clinical studies, 2270 patients) describing incidence and risk factors for barotrauma in ARDS patients, and mean values of ventilatory parameters were plotted against incidence of barotrauma.

RESULTS

In our clinical trial comparing two tidal volumes, 15 patients (12.3%) developed pneumothorax. There was no significant difference in any pressure or volume between these patients and the rest of the population, including end-inspiratory plateau pressure (P(plat)), driving pressure (P(plat)-PEEP), respiratory rate and compliance. Multiple trauma was more frequent among patients with pneumothorax (27%) than in those without (7%). Duration of mechanical ventilation tended to be longer with pneumothorax. In the literature review, the incidence of barotrauma varied between 0% and 49%, and correlated strongly with P(plat), with a high incidence above 35 cmH(2)O, and with compliance, with a high incidence below 30 ml/cmH(2)O.

CONCLUSION

Clinical studies maintaining P(plat) lower than 35 cmH(2)O found no apparent relationship between ventilatory parameters and pneumothorax. Analysis of the literature suggests a correlation when patients receive mechanical ventilation with P(plat) levels exceeding 35 cmH(2)O.