Pedunculated colonic lipoma prolapsing through the anus.

Colorectal lipomas are the second most common benign tumors of the colon. These masses are typically incidental findings with over 94% being asymptomatic. Symptoms-classically abdominal pain, bleeding per rectum and alterations in bowel habits-may arise when lipomas become larger than 2 cm in size.

Correlation between alveolar recruitment/derecruitment and inflection points on the pressure-volume curve.

Objective: To determine whether individual alveolar recruitment/derecruitment (R/D) is correlated with the lower and upper inflections points on the inflation and deflation limb of the whole-lung pressure-volume (P-V) curve.

Design And Setting: Prospective experimental study in an animal research laboratory.

Subjects: Five anesthetized rats subjected to saline-lavage lung injury.

Absence of alveolar tears in rat lungs with significant alveolar instability.

Background: Lung injury associated with the acute respiratory distress syndrome can be exacerbated by improper mechanical ventilation creating a secondary injury known as ventilator-induced lung injury (VILI). We hypothesized that VILI could be caused in part by alveolar recruitment/derecruitment resulting in gross tearing of the alveolus.

Objectives: The exact mechanism of VILI has yet to be elucidated though multiple hypotheses have been proposed.

Effect of positive end-expiratory pressure and tidal volume on lung injury induced by alveolar instability.

Introduction: One potential mechanism of ventilator-induced lung injury (VILI) is due to shear stresses associated with alveolar instability (recruitment/derecruitment). It has been postulated that the optimal combination of tidal volume (Vt) and positive end-expiratory pressure (PEEP) stabilizes alveoli, thus diminishing recruitment/derecruitment and reducing VILI. In this study we directly visualized the effect of Vt and PEEP on alveolar mechanics and correlated alveolar stability with lung injury.

Isolated jejunal perforation after blunt thoracoabdominal trauma.

A case report of isolated jejunal perforation secondary to a relatively unique mechanism of blunt thoracoabdominal trauma is presented. A thorough and concise review of the multimodal approach that may be necessary to diagnose such a rare clinical problem is discussed.

Dynamic alveolar mechanics in four models of lung injury.

Objective: To determine whether pathological alterations in alveolar mechanics (i.e., the dynamic change in alveolar size and shape with ventilation) at a similar level of lung injury vary depending on the cause of injury.

Wood smoke inhalation causes alveolar instability in a dose-dependent fashion.

Background: Wood smoke inhalation causes severe ventilation and oxygenation abnormalities. We hypothesized that smoke inhalation would cause lung injury by 2 mechanisms: (1) direct tissue injury by the toxic chemicals in the smoke and (2) a mechanical shear-stress injury caused by alveolar instability (ie, alveolar recruitment/derecruitment). We further postulated that alveolar instability would increase with the size of the cumulative smoke dose.

Pulmonary impedance and alveolar instability during injurious ventilation in rats.

The mechanical derangements in the acutely injured lung have long been ascribed, in large part, to altered mechanical function at the alveolar level. This has not been directly demonstrated, however, so we investigated the issue in a rat model of overinflation injury. After thoracotomy, rats were mechanically ventilated with either 1) high tidal volume (Vt) or 2) low Vt with periodic deep inflations (DIs).