Cerebral blood flow autoregulation in ischemic heart failure.

Patients with ischemic heart failure (iHF) have a high risk of neurological complications such as cognitive impairment and stroke. We hypothesized that iHF patients have a higher incidence of impaired dynamic cerebral autoregulation (dCA). Adult patients with iHF and healthy volunteers were included. Cerebral blood flow velocity (CBFV, transcranial Doppler, middle cerebral artery), end-tidal CO2 (capnography), and arterial blood pressure (Finometer) were continuously recorded supine for 5 min at rest. Autoregulation index (ARI) was estimated from the CBFV step response derived by transfer function analysis using standard template curves. Fifty-two iHF patients and 54 age-, gender-, and BP-matched healthy volunteers were studied. Echocardiogram ejection fraction was 40 (20-45) % in iHF group. iHF patients compared with control subjects had reduced end-tidal CO2 (34.1 ± 3.7 vs. 38.3 ± 4.0 mmHg, P < 0.001) and lower ARI values (5.1 ± 1.6 vs. 5.9 ± 1.0, P = 0.012). ARI <4, suggestive of impaired CA, was more common in iHF patients (28.8 vs. 7.4%, P = 0.004). These results confirm that iHF patients are more likely to have impaired dCA compared with age-matched controls. The relationship between impaired dCA and neurological complications in iHF patients deserves further investigation.

São Paulo lung transplantation waiting list: patient characteristics and predictors of death.

INTRODUCTION: Nowadays, lung transplantation (LTx) allocation in Brazil is based mainly on waiting time. There is a need to evaluate the equity of the current lung allocation system. OBJECTIVES: We sought to (1) determine the characteristics of registered patients on the waiting list and (2) identify predictors of death on the list. MATERIALS AND METHODS: We analyzed the medical records as well as clinical and laboratory data of 164 patients registered on the waiting list from 2001 to June 2008. Predictors of mortality were obtained using Cox proportional hazards analysis. RESULTS: Patients who were registered on the waiting list showed a mean age of 36.1 +/- 15.0 vs. 42.2 +/- 15.7 years, considering those who did versus did not, die on the list, respectively (P = .054). Emphysema was the most prevalent underlying disease among the patients who did not die on the list (28.8%); its prevalence was low among the patients who died on the list (6.5%; P = .009). The following variables correlated with the probability of death on the waiting list: emphysema or bronchiectasis diagnosis (hazard ratio [HR] = 0.15; P = .002); activated partial thromboplastin time > 30 seconds (HR = 3.28; P = .002); serum albumin > 3.5 g/dL (HR = 0.41; P = .033); and hemoglobin saturation > 85% (HR = 0.44; P = .031). CONCLUSIONS: Some variables seemed to predict death on the LTx waiting list; these characteristics should be used to improve the LTx allocation criteria in Brazil.

Bronchial complications following lung transplantation.

INTRODUCTION: Bronchial complications owing to the airway anastomosis in lung transplantation are important causes of morbidity and mortality. They occur in up to 27% of cases as defined by stenosis, necrosis, and dehiscence. Treatment depends on the type of complication. OBJECTIVE: To report our experience to treat this complication. METHODS: Between 2000 and 2007, we performed 71 lung transplants of which 36 were bilateral. The total number of anastomoses was 107:52 to the right and 55 to the left. The telescoping technique was initially used (14 initial unilateral transplants), and after October, 2003 it was changed to an end-to-end anastomosis (57 transplants and 93 anastomoses). RESULTS: Eight patients developed bronchial complications including two that were bilateral. There were 4 stenosis, 3 dehiscences, and 3 necrosis complications (9.4%). The complication rate for telescoping anastomosis was 21.4%, and for the end-to-end technique, 7.5%. The treatment of the stenosis used metallic or plastic self-expandable stents. Two bronchial dehiscences resulted in case of bronchopleural fistulae, empyema, and death; the other patient experienced spontaneous resolution. Concerning bronchial necrosis, 1 patient developed fistulization to the pulmonary artery and massive hemoptysis, and the other with bilateral necrosis, a spontaneous resolution. CONCLUSION: Our bronchial anastomosis complication rate was comparable with that in other reports. The rate for the telescoping technique was greater compared with the end-to-end technique. The treatment of bronchial stenosis with a self-expandable prosthesis showed good results.

Bilateral lung transplantation in asymmetric thorax: case reports.

Suppurative lung diseases, such as cystic fibrosis and bronchiectasis, when diffuse and associated with important functional loss, can be treated with bilateral lung transplantation with good results. These diseases are frequently associated with previous lung resections presenting an asymmetric thorax, thus making lung extraction difficult and generating disproportion between the graft and the pleural cavity. To treat this condition, pneumonectomy and single lung transplantation is a feasible option; however, there are associated comorbidities and an invariable need for extracorporeal circulation. Described herein are 2 patients with an asymmetric thorax, treated with bilateral transplantation and lung volume reduction with lobectomy.

Cerebral hemodynamics with intra-aortic balloon pump: business as usual?

OBJECTIVE: Intra-aortic balloon pump (IABP) is commonly used as mechanical support after cardiac surgery or cardiac shock. Although its benefits for cardiac function have been well documented, its effects on cerebral circulation are still controversial. We hypothesized that transfer function analysis (TFA) and continuous estimates of dynamic cerebral autoregulation (CA) provide consistent results in the assessment of cerebral autoregulation in patients with IABP. APPROACH: Continuous recordings of blood pressure (BP, intra-arterial line), end-tidal CO2, heart rate and cerebral blood flow velocity (CBFV, transcranial Doppler) were obtained (i) 5 min with IABP ratio 1:3, (ii) 5 min, starting 1 min with the IABP-ON, and continuing for another 4 min without pump assistance (IABP-OFF). Autoregulation index (ARI) was estimated from the CBFV response to a step change in BP derived by TFA and as a function of time using an autoregressive moving-average model during removal of the device (ARI t ). Critical closing pressure and resistance area-product were also obtained. MAIN RESULTS: ARI with IABP-ON (4.3 ± 1.2) were not different from corresponding values at IABP-OFF (4.7 ± 1.4, p = 0.42). Removal of the balloon had no effect on ARI t , CBFV, BP, cerebral critical closing pressure or resistance area-product. SIGNIFICANCE: IABP does not disturb cerebral hemodynamics. TFA and continuous estimates of dynamic CA can be used to assess cerebral hemodynamics in patients with IABP. These findings have important implications for the design of studies of critically ill patients requiring the use of different invasive support devices.

Upregulation of collagen messenger RNA expression occurs immediately after lung damage.

BACKGROUND: Mortality of ARDS still exceeds 50%. Though pulmonary fibrosis is a marker of severe prognosis in the evolution of ARDS, its onset is not yet established. Cardiopulmonary bypass (CPB), usually utilized in patients with a previously normal lung, can cause ARDS and often causes alveolar damage, the earliest lesion observed in ARDS, thus providing a unique opportunity to study the molecular mechanisms of fibrogenesis. OBJECTIVE: To measure immediately after CPB, at the onset of alveolar damage, the expression of messenger RNAs (mRNAs) for collagen type I. METHODS: Pre-CPB and post-CPB lung biopsy specimens were obtained from patients submitted to myocardial revascularization for coronary artery disease. Alveolar damage was characterized by comparison between before and after specimens and quantified by point counting of polymorphonuclear cells (PMN). Type I collagen mRNAs were quantified by scanning densitometry of Northern blot autoradiographs, corrected for RNA loading by 18S ribosomal RNA hybridization. RESULTS: Alveolar damage was characterized by lung interstitial edema and by polymorphonuclear cell infiltration after CPB (PMN pre-CPB 0.010+/-0.004xPMN post-CPB 0.052+/-0.022; n=7; p=0.0017, t test). Type I collagen mRNA increased 91.1+/-68.2% (Ln pre-CPBxLn post-CPB; n=15; p<0.00001, t test) immediately after CPB (mean CPB time, 108.8+/-37.2 min). CONCLUSION: Fibrogenesis, as measured at the molecular level, is a very early event following diffuse alveolar damage, attributable mainly to resident fibroblast activation.

Effects of bronchial transection and reanastomosis on mucociliary system.

STUDY OBJECTIVES: The mechanisms involved in the impairment of mucociliary function after lung transplantation are not completely understood. The purpose of the present study was to isolate the effects of unilateral bronchial transection and reanastomosis in a rat model. DESIGN: In situ bronchial mucociliary transport (MCT) was determined proximal and distal to the bronchial anastomosis, as well as in the right bronchus, in 48 rats classified into six groups: intact rats, and rats at 1 day, 2 days, 7 days, 15 days, and 30 days after bronchial transection and reanastomosis of the left main stem bronchus. In vitro mucus transportability and mucus contact angle were studied in another group of eight rats after 1 week of surgery. RESULTS: Distal to the anastomosis site, left bronchus in situ MCT (mean +/- SD) was 0.26 +/- 0.19 mm/min for the intact group, and 0.11 +/- 0.13 mm/min, 0.07 +/- 0.04 mm/min, 0.03 +/- 0.04 mm/min, 0.07 +/- 0.12 mm/min, and 0.05 +/- 0.06 mm/min for 1 day, 2 days, 7 days, 15 days, and 30 days after surgery, respectively (all significantly reduced, p < 0.05). No intergroup differences were found proximal to the anastomosis (p = 0.30). When comparing the left and right bronchi, differences were detected in both distal (p < 0.0001) and proximal sides (p = 0.0001). No significant differences in mucus transportability in vitro were found (p = 0.15). Mucus contact angle of the left bronchus (52.8 +/- 20.5 degrees ) was significantly greater than that of the mucus from the right bronchus (34.4 +/- 12.9 degrees; p < 0.05). CONCLUSIONS: We conclude that bronchial transection and reanastomosis lead to a marked impairment of MCT in distal airways, which can in part be explained by alterations in the surface properties of mucus.

Hepatic and pulmonary biopsy by mini-thoracotomy and transdiaphragmatic access.

Frequently, immunodeficient patients have more than one organ or system affected by opportunistic infection or neoplasia, requiring quick and precise diagnostic investigation. In some situations, different invasive diagnostic procedures may be necessary. Open lung biopsy is sometimes necessary to clarify the pulmonary diagnosis. Laparoscopy may be useful to clarify liver or other peritoneal diseases. Some specific patients might require both procedures. In this way it is proposed that the surgeon, through a microthoracotomy used for the pulmonary biopsy, has access to the diaphragm. A small phrenotomy is performed and then a liver needle biopsy under direct vision. The described technique of simultaneous open lung and hepatic biopsy permits better handling of the needle and hemostasis of the hepatic lesion at the puncture site. This method has been used since 1994 on 16 HIV-positive patients, all having clinical and laboratory manifestations of lung disease associated with liver disease of unknown etiology. No complications related to the method were observed. It is significant that different etiologies for the lung and liver disease were found in 50% of the cases. We conclude that the presented technique is simple, useful, and safe.

Thoracoscopy in children and adolescents.

STUDY OBJECTIVES: Present the feature characteristics of the use and findings of thoracoscopy in children and adolescents. DESIGN: From February 1983 to February 1996, 77 thoracoscopic procedures were done on patients ranging in ages from 5 months to 18 years (mean, 9.8 years). Two-thirds (66.2%) were male. They were divided into three groups (1, 2, and 3) based on age (up to 2, from 2 to 8, and older than 8 years), predominance of certain diseases in these ages, and the size of the instruments utilized. They were operated on using general anesthesia with Carlens' mediastinoscope routinely used in 64 (83%) and videothoracoscopy in 13 (17%). The chief indication for therapeutic thoracoscopy was treatment of empyema, while for diagnostic thoracoscopy it was pleural biopsy and diagnosis of pleural effusions. RESULTS: In group 1, thoracoscopy was solely for the treatment of pleural disorders. In group 2, it was for the treatment of pleuropulmonary diseases. Group 3 behaved almost like adults, with broad diagnostic and therapeutic indications for thoracoscopic procedure. CONCLUSIONS: Thoracoscopy, which is a useful diagnostic and therapeutic procedure, has secured an important place in pediatric surgical practice.

Human pulmonary dirofilariasis: analysis of 24 cases from São Paulo, Brazil.

STUDY OBJECTIVE: To present the clinical, radiologic, and pathologic aspects of 24 cases of human pulmonary dirofilariasis (HPD) from São Paulo, Brazil. DESIGN: Retrospective study of 24 patients with a confirmed diagnosis of HPD over a 14-year period (from February 1982 to June 1996). SETTING: Thoracic Surgery and Pulmonary Division, University of São Paulo and Hospital Albert Einstein, São Paulo, Brazil. RESULTS: Seventeen patients were male (70.1%) and seven were female (29.9%). Their mean age was 51.4 years. Fifty-four percent of the patients were asymptomatic and 75% had a well-circumscribed noncalcified peripheral subpleural pulmonary nodule on the chest radiograph and thoracic CT scan, located preferentially in the lower lobes. The diagnosis was made after thoracotomy and wedge resections in 16 patients, by videothoracoscopy in six, after a pleural biopsy in one, and after necropsy in one. The pathologic examination of all the nodules revealed a central zone of necrosis, surrounded by a narrow granulomatous zone and peripherally by fibrous tissue. Pulmonary vessels exhibit varying degrees of endarteritis. In all cases, a dead worm, usually necrotic and fragmented, was found. CONCLUSIONS: A subpleural, noncalcified pulmonary nodule in the appropriate clinical and epidemiologic setting should alert the clinician, radiologist, or pathologist to the possibility of Dirofilaria. HPD should be considered in the differential diagnosis of pulmonary nodules.