Bilevel vs ICU Ventilators Providing Noninvasive Ventilation: Effect of System Leaks A COPD Lung Model Comparison

Background: Noninvasive positive-pressure ventilation (NPPV) modes are currently available on bilevel and ICU ventilators. However, little data comparing the performance of the NPPV modes on these ventilators are available. Methods: In an experimental bench study, the ability of nine ICU ventilators to function in the presence of leaks was compared with a bilevel ventilator using the IngMar ASL5000 lung simulator (IngMar Medical; Pittsburgh, PA) set at a compliance of 60 mL/cm H(2)O, an inspiratory resistance of 10 cm H(2)O/L/s, an expiratory resistance of 20 cm H(2)O/L/s, and a respiratory rate of 15 breaths/min. All of the ventilators were set at 12 cm H(2)O pressure support and 5 cm H(2)O positive end-expiratory pressure. The data were collected at baseline and at three customized leaks. Main results: At baseline, all of the ventilators were able to deliver adequate tidal volumes, to maintain airway pressure, and to synchronize with the simulator, without missed efforts or auto-triggering. As the leak was increased, all of the ventilators (except the Vision [Respironics; Murrysville, PA] and Servo I [Maquet; Solna, Sweden]) needed adjustment of sensitivity or cycling criteria to maintain adequate ventilation, and some transitioned to backup ventilation. Significant differences in triggering and cycling were observed between the Servo I and the Vision ventilators. Conclusions: The Vision and Servo I were the only ventilators that required no adjustments as they adapted to increasing leaks. There were differences in performance between these two ventilators, although the clinical significance of these differences is unclear. Clinicians should be aware that in the presence of leaks, most ICU ventilators require adjustments to maintain an adequate tidal volume. (CHEST 2009; 136:448-456)

Ranolazine Exerts Potent Effects on Atrial Electrical Properties and Abbreviates Atrial Fibrillation Duration in the Intact Porcine Heart

Introduction: In vitro studies and ambulatory ECG recordings from the MERLIN TIMI-36 clinical trial suggest that the novel antianginal agent ranolazine may have the potential to suppress atrial arrhythmias. However, there are no reports of effects of ranolazine on atrial electrophysiologic properties in large intact animals. Methods and Results: In 12 closed-chest anesthetized pigs, effects of intravenous ranolazine (similar to 9 mu M plasma concentration) on multisite atrial effective refractory period (ERP), conduction time (CT), and duration and inducibility of atrial fibrillation (AF) initiated by intrapericardial acetylcholine were investigated. Ranolazine increased ERP by a median of 45 ms (interquartile range 29-50 ms; P < 0.05, n = 6) in right and left atria compared to control at pacing cycle length (PCL) of 400 ms. However, ERP increased by only 28 (24-34) ms in right ventricle (P < 0.01, n = 6). Ranolazine increased atrial CT from 89 (71-109) ms to 98 (86-121) ms (P = 0.04, n = 6) at PCL of 400 ms. Ranolazine decreased AF duration from 894 (811-1220) seconds to 621 (549-761) seconds (P = 0.03, n = 6). AF was reinducible in 1 of 6 animals after termination with ranolazine compared with all 6 animals during control period (P = 0.07). Dominant frequency (DF) of AF was reduced by ranolazine in left atrium from 11.7 (10.7-20.5) Hz to 7.6 (2.9-8.8) Hz (P = 0.02, n = 6). Conclusions: Ranolazine, at therapeutic doses, increased atrial ERP to greater extent than ventricular ERP and prolonged atrial CT in a frequency-dependent manner in the porcine heart. AF duration and DF were also reduced by ranolazine. Potential role of ranolazine in AF management merits further investigation. (J Cardiovasc Electrophysiol, Vol. 20, pp. 796-802, July 2009).

Pulmonary involvement in pleural tuberculosis: How often does it mean disease activity?

Objective: To evaluate in chest X-rays and high-resolution computed tomographies of patients with pleural tuberculosis, the incidence of parenchymal and mediastinal lung lesions suggestive of active disease. Methods: Prospective study (2008-2009) evaluating the radiographic and tomographic abnormalities of 88 HIV-negative patients with pleural tuberculosis (unilateral effusion). The images were reviewed by 3 independent specialists, and the observed changes were classified according to previously established criteria: presence or absence of signs suggestive of disease activity, and nonspecific findings. Results: Abnormal changes were observed in chest X-rays of 22 (25%) patients and in the computed tomography of 55 (63%). Images compatible with active pulmonary tuberculosis were detected by radiography in 9 (10%) patients and by tomography in 38 (43%). Only 4 (4.5%) patients had tomography images suggestive of residual disease. Conclusion: The present study demonstrates that pulmonary involvement is quite common in pleural tuberculosis. This finding is mainly observed in high-resolution computed tomography and has important epidemiological implications, since patients with pleural tuberculosis are significant sources of infection and disease dissemination. (C) 2011 Elsevier Ltd. All rights reserved.

Twenty seven-year experience with sternal cleft repair

Congenital sternal cleft is a rare disease, and primary repair in the neonatal period is its best management. In 1998 we presented three surgical techniques for sternal cleft correction, but since 1999 we have elected one of them as our procedure of choice. Our latest results are now presented. It is a review of 15 patients operated from October 1979 to December 2007. Surgical repair consisted of 3 sliding chondrotomies, 10 reconstructions basec on a `posterior sternal wall`, 1 reconstruction combined to Ravitch operation for pectus excavatum and 1 associated with total repair of Cantrell`s pentalogy. Data concerning epidemiological features, surgical reconstruction, aesthetic results, postoperative major complications, mortality and hospital stay, were collected from hospital charts. Follow-up ranged from 4 months to 27 years. All patients submitted to surgical, correction had a good aesthetic and functional result. Neither postoperative mortality nor major complication was observed. Two patients had subcutaneous fluid collection that prolonged the drainage duration. The mean hospital stay was 6 days. In conclusion, reconstructing sterna. cleft with a `posterior periosteal flap from sternal bars and chondral graft` is an effective option with good aesthetic and long-term functional results. (C) 2008 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.

Improvements in the 6-Min Walk Test and Spirometry Following Thoracentesis for Symptomatic Pleural Effusions

Background: Impairment in pulmonary capacity due to pleural effusion compromises daily activity. Removal of fluid improves symptoms, but the impact, especially on exercise capacity, has not been determined. Methods: Twenty-five patients with unilateral pleural effusion documented by chest radiograph were included. The 6-min walk test, Borg modified dyspnea score, FVC, and FEV, were analyzed before and 48 h after the removal of large pleural effusions. Results: The mean fluid removed was 1,564 +/- 695 mL. After the procedure, values of FVC, FEV and 6-min walk distance increased (P<.001), whereas dyspnea decreased (P<.001). Statistical correlations (P<.001) between 6-min walk distance and FVC (r=0.725) and between 6-min walk distance and FEV, (r=0.661) were observed. Correlations also were observed between the deltas (prethoracentesis X postthoracentesis) of the 6-min walk test and the percentage of FVC (r=0.450) and of FEV, (r=0.472) divided by the volume of fluid removed (P<.05). Conclusion: In addition to the improvement in lung function after thoracentesis, the benefits of fluid removal are more evident in situations of exertion, allowing better readaptation of patients to routine activities. CHEST 2011; 139(6):1424-1429

Elevated left and reduced right orbitomedial prefrontal fractional anisotropy in adults with bipolar disorder revealed by tract-based spatial statistics

Context Diffusion tensor imaging (DTI) studies in adults with bipolar disorder (BD) indicate altered white matter (WM) in the orbitomedial prefrontal cortex (OMPFC), potentially underlying abnormal prefrontal corticolimbic connectivity and mood dysregulatioin in BD. Objective: To use tract-based spatial statistics (TBSS) to examine VVM skeleton (ie, the most compact whole-brain WM) in subjects with BD vs healthy control subjects. Design: Cross-sectional, case-control, whole-brain DTI using TBSS. Setting: University research institute. Participants: Fifty-six individuals, 31 having a DSM-IV diagnosis of BD type 1 (mean age, 35.9 years [age range, 24-52 years]) and 25 controls (mean age, 29.5 years [age range, 19-52 years]). Main Outcome Measures: Fractional anisotropy (FA) longitudinal and radial diffusivities in subjects with BD vs controls (covarying for age) and their relationships with clinical and demographic variables. Results: Subjects with BD vs controls had significantly greater FA (t > 3.0, P <=.05 corrected) in the left uncinate fasciculus (reduced radial diffusivity distally and increased longitudinal diffusivity centrally), left optic radiation (increased longitudinal diffusivity), and right anterothalamic radiation (no significant diffusivity change). Subjects with BD vs controls had significantly reduced FA (t > 3.0, P <=.05 corrected) in the right uncinate fasciculus (greater radial diffusivity). Among subjects with BD, significant negative correlations (P <.01) were found between age and FA in bilateral uncinate fasciculi and in the right anterothalamic radiation, as well as between medication load and FA in the left optic radiation. Decreased FA (P <.01) was observed in the left optic radiation and in the right anterothalamic radiation among subjects with BD taking vs those not taking mood stabilizers, as well as in the left optic radiation among depressed vs remitted subjects with BD. Subjects having BD with vs without lifetime alcohol or other drug abuse had significantly decreased FA in the left uncinate fasciculus. Conclusions: To our knowledge, this is the first study to use TBSS to examine WM in subjects with BD. Subjects with BD vs controls showed greater WM FA in the left OMPFC that diminished with age and with alcohol or other drug abuse, as well as reduced WM FA in the right OMPFC. Mood stabilizers and depressed episode reduced WM FA in left-sided sensory visual processing regions among subjects with BD. Abnormal right vs left asymmetry in FA in OMPFC WM among subjects with BD, likely reflecting increased proportions of left-sided longitudinally aligned and right-sided obliquely aligned myelinated fibers, may represent a biologic mechanism for mood dysregulation in BD.

Urogenital tuberculosis in a patient with AIDS: an unusual presentation

Background A 38-year-old man with AIDS presented to hospital with a 3-month history of fevers, bilateral lumbar pain, dysuria and increased urinary frequency. Six years earlier he had received 6 months` treatment for pulmonary tuberculosis. At presentation, he was on antiretroviral therapy with a combination of efavirenz, stavudine and lamivudine. Investigations Physical examination, evaluation of HIV viral load, CD4 count, measurement of serum hemoglobin concentration, white blood cell count, urinalysis, urine culture for usual pathogens, direct smear and urine culture for Mycobacterium tuberculosis, chest radiography, abdominal CT, measurement of serum creatinine concentration and estimated creatinine clearance. Diagnosis Urogenital tuberculosis. Management The patient`s symptoms and radiological abnormalities persisted despite antibiotic therapy for presumed bacterial infection. After urine culture had confirmed M. tuberculosis infection, he was administered pharmacological treatment comprising isoniazid, rifampin, pyrazinamide and ethambutol for 2 months, with isoniazid and rifampin given for a further 7 months. His symptoms improved within a few days of initiating treatment. Six months after treatment started, CT revealed a nonfunctioning right kidney and a functional left kidney with areas of scarring. The patient refused right nephrectomy, and completed his pharmacological treatment. No evidence of disease recurrence was observed during 2 years of follow-up.

Technical modifications in stabilisers and in bar removal in the Nuss procedure

Pectus excavatum is a congenital deformity that can require surgical treatment. Since Nuss proposed a correction technique, several modifications have been proposed in order to achieve more safety and efficiency in the placement and removal of both bars. Our objective is to describe the technique of placing and removing the bars by proposing three technical modifications: two in bar placement and one in the bar removal. We describe two cases where Nuss bars were placed and one case where the bar was removed as per the technical modification proposed herein. According to the original technique, bar stabilisers. were placed close to the lateral bar edges. We propose a more medial position in order to reduce bar displacement. New stabilisers were designed with central grooves in the posterior surface, which allow better sliding. The technical modification suitable for bar removal was the use of a protective film around the bars to protect the surrounding tissues from the sharp edges, and thereby minimise the risk of injuries. All the proposed modifications were performed without any additional surgical risk or perioperative complication. These three technical modifications can be easily and safety performed, and seem to reduce the risk of bleeding with no additional perioperative complications. (C) 2009 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.

Is Full Postpleurodesis Lung Expansion a Determinant of a Successful Outcome After Talc Pleurodesis?

Study objectives: To analyze and compare radiologic lung expansion after tale pleurodesis performed either by videothoracoscopy or chest tube and correlate it with clinical outcome. Secondary end points evaluated were its follows: clinical efficacy; quality of life; safety; and survival. Methods: Prospective randomized study that included 60 patients (45 women, 15 men; mean age, 55.2 years) with recurrent malignant pleural effusion between January, 2005 and January 2008. They were randomized into the following two groups: video-assisted thoracic surgery (VATS) talc poudrage; and tale slurry (TS) administered through a chest tube. Lung expansion was evaluated through chest CT scans obtained 0, 1, 3 and 6 months after pleurodesis. Complications, drainage time, hospital stay,and quality of life (Medical Outcomes Study 36-item short form and World Health Organization quality-of-life questionnaires) were also analyzed. Results: There were no significant differences in preprocedure clinical and pathologic variables between groups. The immediate total (ie, > 90%) lung expansion was observed in 27 patients (45%) and wits more frequent in the VATS group (60% vs 30%, respectively; p = 0.027). During follow-up, 71% of the patients showed unaltered or improved lung expansion and 9 patients (15%) needed new pleural procedures (VATS group, 5 recurrences; TS group, 4 recurrences; p = 0.999). No differences, were found between groups regarding quality of life, complications, drainage time, hospital stay, and survival. Immediate lung expansion (lid not correlate with radiologic recurrence, clinical recurrence, or complications (p = 0.60, 0.15, and 0.20, respectively). Conclusion: Immediate partial lung expansion was a frequent finding and was more frequent after TS. Nonetheless, no correlation between immediate lung expansion and clinical outcome was found in this study. (CHEST 2009; 136:361-368)

Placental transmogrification of the lung presenting as giant bullae with soft-fatty components

A 44-year-old man presented with progressive dyspnea and a previous pneumothorax. Chest CT scan showed a mediastinal shift due to giant bullae containing soft tissue and fatty components in the left lower lung Lobe, and a right upper lung lobe partially collapsed. The pulmonary function tests revealed forced vital capacity (FVC) 53% (of the predicted) and forced vital capacity in 1 s (FEV1) 52%. Then, resection of the lower lobe was performed with intention to prevent other pneumothoraxes and to revert the upper lobe collapse. The pathological examination showed a placental. transmogrification of the lung (PTL). One month after the surgery, the patient was asymptomatic, the pulmonary function tests normalized and the upper lobe was well expanded. In conclusion, we described the first CT finding of soft tissue and fatty components within the PTL-related bullae, and the PTL should be considered in the differential diagnosis of pulmonary lesions with soft-fatty and air components. (c) 2007 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.

Hemangioma of the Rib

An asymptomatic 48-year-old woman presented to our hospital with a tumor of the rib incidentally diagnosed on a chest roentgenogram. The patient was investigated and underwent tumor resection of the chest wall. The pathologic study revealed that it was cavernous hemangioma. This tumor of the bone is a distinctly uncommon benign vascular tumor, generally occurring in the spine or skull. Hemangiomas involving the rib are even more rare, with only 22 cases described in the literature. However, we suggest that this tumor of the rib should be considered in the differential diagnosis, principally in asymptomatic patients. (Ann Thorac Surg 2011;91:595-6) (C) 2011 by The Society of Thoracic Surgeons

Right adolescent idiopathic thoracic curve (Lenke 1 A and B): does cost of instrumentation and implant density improve radiographic and cosmetic parameters?

In adolescent idiopathic scoliosis (AIS) there has been a shift towards increasing the number of implants and pedicle screws, which has not been proven to improve cosmetic correction. To evaluate if increasing cost of instrumentation correlates with cosmetic correction using clinical photographs. 58 Lenke 1A and B cases from a multicenter AIS database with at least 3 months follow-up of clinical photographs were used for analysis. Cosmetic parameters on PA and forward bending photographs included angular measurements of trunk shift, shoulder balance, rib hump, and ratio measurements of waist line asymmetry. Pre-op and follow-up X-rays were measured for coronal and sagittal deformity parameters. Cost density was calculated by dividing the total cost of instrumentation by the number of vertebrae being fused. Linear regression and spearman`s correlation were used to correlate cost density to X-ray and photo outcomes. Three independent observers verified radiographic and cosmetic parameters for inter/interobserver variability analysis. Average pre-op Cobb angle and instrumented correction were 54A degrees (SD 12.5) and 59% (SD 25) respectively. The average number of vertebrae fused was 10 (SD 1.9). The total cost of spinal instrumentation ranged from $6,769 to $21,274 (Mean $12,662, SD $3,858). There was a weak positive and statistically significant correlation between Cobb angle correction and cost density (r = 0.33, p = 0.01), and no correlation between Cobb angle correction of the uninstrumented lumbar spine and cost density (r = 0.15, p = 0.26). There was no significant correlation between all sagittal X-ray measurements or any of the photo parameters and cost density. There was good to excellent inter/intraobserver variability of all photographic parameters based on the intraclass correlation coefficient (ICC 0.74-0.98). Our method used to measure cosmesis had good to excellent inter/intraobserver variability, and may be an effective tool to objectively assess cosmesis from photographs. Since increasing cost density only improves mildly the Cobb angle correction of the main thoracic curve and not the correction of the uninstrumented spine or any of the cosmetic parameters, one should consider the cost of increasing implant density in Lenke 1A and B curves. In the area of rationalization of health care expenses, this study demonstrates that increasing the number of implants does not improve any relevant cosmetic or radiographic outcomes.

The Ideal Timing for Experimental Cleft Lip Creation

Cleft lip and palate (CLP) is the most common congenital defect of the face. Many animal models have been utilized to study embryogenesis and pathogenesis of CLP, including the development of secondary anomalies and consequent deformities. However, the ideal gestational age for surgical creation of lip or palate defects in rat models has never been determined. The aim of the present study is to improve the experimental model utilizing rat fetuses, defining the most appropriate timing for creation of the lip defect model. The study was composed of three groups of fetuses undergoing surgical creation of a lip defect at the left side of the superior lip at 17.5, 18.5, and 19.5 days of gestation. Fetuses were harvested at 21.5 days of gestation (term = 22 days) and underwent macroscopic and microscopic analyses. We found that the most appropriate moment for lip defect creation was at 19.5 days, given the presence of lip depression at the site of the defect and asymmetry and retraction associated with interruption of the lip and complete reepithelialization of the borders of the defect.

Quality control of blood irradiation with a teletherapy unit: damage to stored red blood cells after cobalt-60 gamma irradiation

BACKGROUND: Previous publications have documented the damage caused to red blood cells (RBCs) irradiated with X-rays produced by a linear accelerator and with gamma rays derived from a Cs-137 source. The biologic effects on RBCs of gamma rays from a Co-60 source, however, have not been characterized. STUDY DESIGN AND METHODS: This study investigated the effect of 3000 and 4000 cGy on the in vitro properties of RBCs preserved with preservative solution and irradiated with a cobalt teletherapy unit. A thermal device equipped with a data acquisition system was used to maintain and monitor the blood temperature during irradiation. The device was rotated at 2 r.p.m. in the irradiation beam by means of an automated system. The spatial distribution of the absorbed dose over the irradiated volume was obtained with phantom and thermoluminescent dosimeters (TLDs). Levels of Hb, K+, and Cl- were assessed by spectrophotometric techniques over a period of 45 days. The change in the topology of the RBC membrane was investigated by flow cytometry. RESULTS: Irradiation caused significant changes in the extracellular levels of K+ and Hb and in the organizational structure of the phospholipid bilayer of the RBC membrane. Blood temperature ranged from 2 to 4 degrees C during irradiation. Rotation at 2 r.p.m. distributed the dose homogeneously (92%-104%) and did not damage the RBCs. CONCLUSIONS: The method used to store the blood bags during irradiation guaranteed that all damage caused to the cells was exclusively due to the action of radiation at the doses applied. It was demonstrated that prolonged storage of Co-60-irradiated RBCs results in loss of membrane phospholipids asymmetry, exposing phosphatidylserine (PS) on the cells` surface with a time and dose dependence, which can reduce the in vivo recovery of these cells. A time- and dose-dependence effect on the extracellular K+ and plasma-free Hb levels was also observed. The magnitude of all these effects, however, seems not to be clinically important and can support the storage of irradiated RBC units for at last 28 days.

Experimental model for study of anorectal sphincter musculature by manometry and computerized tomography in piglets

There seems to be controversy on the anorectal sphincter presentation and anatomical division, as well as on its functional representation. Evaluation of the anorectal sphincter musculature has been achieved through several methods, including anorectal manometry and computerized tomography, but to date there is no experimental model allowing a detailed manometric study of this muscle complex. In this work, we have developed such a model, which should enable the manometric and radiographic study of the anatomical features and functional mechanisms of sphincteric injuries, as well as the assessment of drug effects on the anorectal musculature upon incontinence and constipation. Twenty-two piglets (aged 25-30 days, weighing 5-7 kg) were studied by anorectal manometry (rectoanal inhibitory reflex and vector volume) and computerized tomography (anorectal angle and anal canal length). The data obtained for the rectoanal inhibitory reflex, represented here as the average and standard deviation, were the following: relaxation duration = 14.75 +/- 3.62 s, sphincter basal pressure = 41.58 +/- 8.20 mmHg, relaxation index = 87.26 +/- 11.52%, speed of relaxation = 5.90 +/- 2.10 mm/s, and speed of relaxation recovery = 4.03 +/- 1.78 mm/s. As for the vector volume, results were as follows: vector volume = 2692.32 +/- 1298.12 mmHg(2) cm, sphincter length = 11.82 +/- 2.74 mm, high pressure zone length = 5.09 +/- 1.34 mm, maximum pressure = 61.50 +/- 20.58 mmHg, and asymmetry index = 43.50 +/- 10.03%. Radiographic evaluation led to the following results: anal canal length = 9.61 +/- 2.14 mm and anorectal angle = 137.91 +/- 7.75 degrees. The experimental model designed here allows both anorectal manometry and computerized tomography to be carried out in the same way it is performed in human beings, as long as animal sedation is strictly controlled.