Latent variable modeling and its implications for institutional review board review: variables that delay the reviewing process.

BACKGROUND: To investigate the factors related to approval after review by an Institutional Review Board (IRB), the structure equation model was used to analyze the latent variables 'investigators', 'vulnerability' and 'review process' for 221 proposals submitted to our IRB. METHODS: The vulnerability factor included vulnerable cases, and studies that involved drug tests and genetic analyses. The principal investigator (PI) factor included the license level of the PI and whether they belonged to our institution. The review factor included administration time, total review time, and revision frequency. The revision frequency and total review time influenced the efficiency of review. RESULTS: The latent variable of reviewing was the most important factor mediating the PIs and vulnerability to IRB review approval. The local PIs moderated with genetic study and revision frequency had an impact on the review process and mediated non-approval. CONCLUSIONS: Better guidance of the investigators and reviewers might improve the efficiency with which IRBs function.

[Project to attain the ideal caloric intake level in critical patients within a 72-hour period].

BACKGROUND & PROBLEMS: Early enteral nutrition and receiving more than 70% of the ideal caloric intake level has been shown to reduce patient infection rates, duration of hospital stays, and mortality. Only 40.6% of patients in our surgical intensive care unit were achieving the ideal caloric intake level. PURPOSE: This project was designed to raise the ratio of those achieving an ideal caloric intake level from 40.6% to 70%. RESOLUTIONS: Strategies included: (1) providing education related to nutrition, (2) establishing an enteral nutrition flowchart and popularizing and carrying out the enteral nutrition flowchart, (3) discussing together with doctors and nutritionists about feeding conditions, and (4) revising standard procedures for the NG feeding of critical patients. RESULTS: Seventy percent of patients in the surgical intensive care unit achieved their ideal caloric intake level after implementation of this intervention. CONCLUSIONS: This project used interdisciplinary cooperation to improve caloric intake among patients in the surgical intensive care unit. The intervention and results may be used as a reference by hospitals for improving patient caloric intake and hospital quality of care.

Malignant peripheral nerve sheath tumor of the chest wall associated with neurofibromatosis: a case report.

Primary chest wall tumors are relatively rare and represent approximately 5% of all thoracic neoplasms. Malignant peripheral nerve sheath tumor (MPNST) is highly aggressive and occurs in the second or third decade of patients with neurofibromatosis type 1 (NF-1). The estimated incidence of MPNST in patients with NF-1 is 2-5% (general population, 0.001%). This neoplasm usually affects the extremities and rarely the thoracic cavity. We present a case of MPNST of the chest wall in a patient with NF-1 who developed local recurrence 5 months after complete surgical resection and postoperative adjuvant radiotherapy.

Schwannomatosis of a single intercostal nerve: a case report.

Schwannomatosis is a rare form of neurofibromatosis and is characterized by more than one schwannoma without any sign of neurofibromatosis. We report a case of a 60-year-old male patient admitted with progressive chest discomfort who was found to have six encapsulated tumors along the seventh intercostal space with a maximum tumor size of 3x2x1 cm.

Ventilation-perfusion distribution and shunt fraction during one-lung ventilation: effect of different inhaled oxygen levels.

Ventilation with higher fraction of inspired oxygen (F(I)O2) is one of the commonly-chosen strategies executed for treatment of hypoxemia during one lung ventilation (OLV) for thoracic surgery. In this study, we investigated the effect of F(I)O2 on pulmonary ventilation-perfusion (VA/Q) distribution during OLV. Six pigs, weighing 27 to 34 kg, were selected for this study. Following by a steady-state period, randomized administrations of F(I)O2 with 0.4, 0.6 and 1.0 were performed for 30 minutes at the right lateral decubitus position during OLV, while hemodynamic data and lung mechanics were simultaneously monitored. The VA/Q distributions of the lung(s) were assessed by the multiple inert gas elimination technique (MIGET). PaO2 at F(I)O2 of 100% was significantly reduced in OLV compared with two-lung ventilation (TLV) (522 +/- 104 vs. 653 +/- 21 mmHg; P < 0.001) at right lateral decubitus position. MIGET algorithms demonstrated a wider VA/Q distribution during OLV at F(I)O2 of 40%, as compared with distribution during TLV at F(I)O2 of 100%, but a bimodal perfusion distribution shifted to lower VA/Q component during OLV at F(I)O2 of 100%. There was an increase of pulmonary shunting in OLV, as compared with TLV at F(I)O2 of 100% (1.94 +/- 2.2% vs. 9.5 +/- 9.7%; P < 0.01). In addition, OLV caused a significant increase in the dispersion of perfusion at F(I)O2 of 100% (0.62 +/- 0.20 vs. 0.44 +/- 0.23; P < 0.01), but ventilation showed no denoting changes (1.06 +/- 0.20 vs. 0.98 +/- 0.35; P > 0.01). During OLV with right lateral decubitus position, there were no significant changes in the pulmonary shunt, the dispersion of perfusion and ventilation at different F(I)O2. OLV resulted in an increase in pulmonary shunting and heterogeneity compared with TLV. Furthermore, the PaO2 decreased during OLV regardless of the postural changes. At different F(I)O2, there were no significant changes in the pulmonary shunt, the dispersion of perfusion and ventilation during OLV with right lateral decubitus posture.

Ventilation and perfusion distribution during altered PEEP in the left lung in the left lateral decubitus posture with unchanged tidal volume in dogs.

Previous studies in anesthetized humans positioned in the left lateral decubitus (LLD) posture have shown that unilateral positive end-expiratory pressure (PEEP) to the dependent lung produce a more even ventilation distribution and improves gas exchange. Unilateral PEEP to the dependent lung may offer special advantages during LLD surgery by reducing the alveolar-to-arterial oxygen pressure difference {(A-a)PO2 or venous admixture} in patients with thoracic trauma or unilateral lung injury. We measured the effects of unilateral PEEP on regional distribution of blood flow (Q) and ventilation (V(A)) using fluorescent microspheres in pentobarbital anesthetized and air ventilation dogs in left lateral decubitus posture with synchronous lung inflation. Tidal volume to left and right lung is maintained constant to permit the effect on gas exchange to be examined. The addition of unilateral PEEP to the left lung increased its FRC with no change in left-right blood flow distribution or venous admixture. The overall lung V(A)/Q distribution remained relatively constant with increasing unilateral PEEP. Bilateral PEEP disproportionately increased FRC in the right lung but again produced no significant changes in venous admixture or V(A)/Q distribution. We conclude that the reduced dependent lung blood flow observed without PEEP occurs secondary to a reduction in lung volume. When tidal volume is maintained, unilateral PEEP increases dependent lung volume with little effect of perfusion distribution maintaining gas exchange.

Redistribution of blood flow and lung volume between lungs in lateral decubitus postures during unilateral atelectasis and PEEP.

The effect of left lung atelectasis on the regional distribution of blood flow (Q), ventilation (V(A)) and gas exchange on the right lung ventilated with 100% O2 was studied in anesthetized dogs in the lateral decubitus posture. Q and V(A) were measured in 1.7 ml lung volume pieces using injected and aerosolized fluorescent microspheres, respectively. Hypoxic pulmonary vasoconstriction (HPV) in the atelectatic lung shifted flow to the ventilated lung. The increased flow in the ventilated lung ensured adequate gas exchange, compensating for the hypoxemia due to shunt contributed by the atelectatic lung. Left lung atelectasis caused a compensatory increase in the ventilated lung FRC that was smaller in the right (RLD) than left (LLD) lateral posture, the effect of lung compression by the atelectatic lung and mediastinal contents in the RLD posture. The O2 deficit measured by (A-a)DO2 increased with left lung atelectasis and was exacerbated in the LLD posture by 10 cm H2O PEEP, a result of increased shunt caused by a shift in Q from the ventilated to the atelectatic lung. The PEEP-induced O2 deficit was eliminated with inversion to the RLD posture.

Spontaneous pneumothorax after steroid treatment in a patient with bronchiolitis obliterans organizing pneumonia.

Bronchiolitis obliterans organizing pneumonia (BOOP) is an uncommon pulmonary disorder which is a clinicopathologic syndrome. The typical symptoms include cough, fever and dyspnea. Corticosteroid therapy is effective. Death from progressive disease is infrequent. We report a case of BOOP in a 41-year-old male non-smoker, proved by pathologic findings. After steroid therapy (prednisolone 30 mg daily) for 10 days, he developed spontaneous pneumothorax of bilateral lung fields. Responses to steroid and chest tube thoracostomy were excellent. BOOP may be complicated with spontaneous pneumothorax which may adversely affect prognosis. BOOP should be included in the differential diagnosis of patients presenting with secondary spontaneous pneumothorax.

Glomus tumor of the trachea.

Glomus tumor of the trachea is extremely rare. There were approximately 15 reported cases before. Herein, we report another case of glomus tumor of the trachea in a 50-year-old woman presenting with cough and dyspnea for 8 years. She suffered from hemoptysis for 1 day before this admission. Bronchoscopy and CT scan showed a polypoid tumor protruding into the tracheal lumen and with extraluminal extension. The tumor was located at 9 cm below the vocal cord and 1.5 cm above the carina. It measured 2.5 x 2.5 x 2.0 cm and arose from the posterior wall of the trachea. Microscopically, the tumor consisted of a sheet of uniform cells surrounding the vascular spaces. Only few scattered tumor cells showed weak positive staining for muscle actin (HHF-35) by immunohistochemical stain. Ultrastructural study confirmed the presence of small amount of myofibrillar bundles with focal densities in some of the tumor cells. Other cells exhibited only rare or very sparse myofilaments. Characteristic feature of fine pinocytotic vesicles along the plasma membrance of the tumor cells was also noted.