Delmar J. Gillespie

Prevention of Infection in Critically Ill Patients by Selective Decontamination of the Digestive Tract

OBJECTIVE To determine whether selective decontamination of the digestive tract using oral and nonabsorbable antimicrobial agents and parenteral cefotaxime prevents infection in critically ill patients. DESIGN Randomized, controlled trial without blinding. SETTING Surgical trauma and medical intensive care units in a tertiary referral hospital. PATIENTS One hundred fifty patients admitted to surgical trauma and medical intensive care units during a 3-year interval, whose condition suggested a prolonged stay (greater than 3 days). INTERVENTION Patients were randomly allocated to an experimental group (n = 75) that received cefotaxime, 1 g intravenously every 8 hours for the first 3 days only, and oral, nonabsorbable antibiotics (gentamicin, polymyxin, and nystatin by oral paste and oral liquid) for the entire stay in the intensive care unit. Control patients (n = 75) received usual care. MEASUREMENTS The number of infections, total hospital days, and deaths, as well as the number of days in intensive care unit, were recorded. RESULTS Control patients experienced more infections (36 compared with 12, P = 0.04), including bacteremias (14 compared with 4, P = 0.05) and pulmonary infections (14 compared with 4, P = 0.03). Although total hospital days, days in intensive care, and the overall death rate all were lower in the treatment group, these differences were not statistically significant. Clinically important complications of selective decontamination of the digestive tract were not encountered. CONCLUSIONS Selective decontamination of the digestive tract decreases subsequent infection rates, especially by gram-negative bacilli, in selected patients during long-term stays in the intensive care unit.

Primary Mediastinal Neoplasms (Other Than Thymoma)

Primary mediastinal neoplasms encompass a long list of histologically diverse lesions that can arise from a wide variety of mediastinal structures. Recent advances in diagnostic techniques have considerably enhanced the evaluation of the mediastinum with use of noninvasive or minimally invasive procedures. In adults, most primary mediastinal neoplasms can be classified in one of four categories: thymus-derived neoplasms, neurogenic tumors, lymphomas, or germ cell neoplasms. In children, neurogenic tumors (especially neuroblastomas) and lymphomas are most frequently encountered. Because of the presence of many vital structures in the confined thoracic cavity, even benign mediastinal neoplasms can cause severe symptoms from the mass effect and therefore warrant a carefully planned management strategy. With modern therapeutic and surgical interventions, associated morbidity and mortality can often be substantially decreased.

Intraoperative Ultrasonographically Guided Biopsy in Testicular Sarcoidosis: A Case Report

We present a case of sarcoidosis with involvement of a solitary testis that was discovered incidentally on an ultrasonogram of the scrotum. This appears to be case 8 of sarcoidosis with genitourinary involvement limited to the testis. We believe it is the second report of intraoperative ultrasonography used to locate and perform a biopsy of impalpable testicular lesions. We consider this technique to be useful in instances of solitary gonads or in cases of bilateral lesions.

Ventilation-perfusion distribution after aortic valve replacement

In eight patients, the ventilation-perfusion (VA/Q) relationships after uncomplicated aortic valve replacement were studied by the multiple inert gas technique. Postoperatively, all patients had a right-to-left intra-pulmonary shunt (Qsp/Qt) (range 2.4% to 14.4%) and abnormal distribution of VA/Q patterns to varying degrees. No single mechanism was identified that defined gas exchange in all patients. In three patients, moving from the supine to the right lateral decubitus position resulted in improved oxygenation which occurred because of better matching of VA/Q, not because of a decrease in Qsp/Qt. (Crit Care Med 1990; 18:136)

Solitary Pulmonary Metastasis Presenting 20 Years After Primary Resection of Wilms Tumor

Wilms tumor is the most common renal malignancy of childhood. Relapse occurs most often within 4 years of initial diagnosis, and the most common site of metastasis is the lung. We describe a 22-year-old man who presented with hemoptysis and a solitary pulmonary lesion 20 years after primary resection of Wilms tumor. Computed tomography of the chest showed an indeterminate pulmonary mass of heterogeneous attenuation with no other intrathoracic abnormalities. Surgical resection revealed a solitary pulmonary metastasis from Wilms tumor. Further evaluation yielded no evidence of extrathoracic metastases. This case shows that late relapse in the form of a solitary pulmonary mass can occur in patients with Wilms tumor.

Effect of ventilation by high-frequency oscillation on lung and chest wall mechanics in the dog

High-frequency oscillation (HFO) has been shown to be effective in maintaining gas exchange, but the effects of high-frequency, small-volume ventilation on the mechanical properties of the respiratory system are unknown. A volume displacement plethysmograph was used to study lung volumes and static pressure-volume (PV) curves during HFO in pentobarbital-anesthetized dogs. During long-term studies, adequate gas exchange was maintained with a stroke volume of 2.5 ml/kg and frequencies between 15 and 30 Hz. The effect of 5–7 hours of HFO on lung and chest wall mechanics was studied in 8 dogs. In another 8 dogs the relationship of volume history and respiratory muscle tone to occlusion airway pressure and lung volume during short-term HFO was investigated. With prolonged HFO, a small but significant decrease in total lung capacity occurred by 5 hours and the static respiratory system PV curve shifted slightly to the right. These changes were reversed by muscle paralysis and may be explained by a change in respiratory muscle tone. Static lung compliance and the hysteresis ratio (an index of tissue properties) remained unchanged. The relationship of occlusion airway pressure and lung volume during short-term HFO was dependent on the lung volume history and was influenced by respiratory muscle tone only at low airway pressures. These findings suggest that during prolonged HFO a small increase in chest wall stiffness may result. However, occlusion airway pressure and lung volume at the onset of HFO are mainly dependent on the volume history of the lung.