Sclerotherapy of a bleeding duodenal varix.

A case of successful treatment of a bleeding duodenal varix in a patient with portal hypertension and compensated cryptogenic cirrhosis (Child A) is reported. The 42-year-old man had a history of recurrent gastrointestinal hemorrhage over 14 years. In 1966 he underwent a portocaval shunt operation. Angiography in 1968 revealed a thrombosis of the shunt as well as of the splenic vein. Splenectomy was performed because of hypersplenism. In 1980 bleeding from esophageal varices occurred and was treated by sclerotherapy. Seven weeks after sclerotherapy massive bleeding from a duodenal varix occurred. Sclerotherapy of the duodenal varix via a flexible endoscope proved successful. Since then, during a follow-up period of 15 months, the patient has had no further bleeding episodes.

Pathologic features and mechanisms of hypoxemia in adult respiratory distress syndrome.

In 45 consecutive patients referred for severe hypoxemia (Pao2 less than 100 mm Hg on positive end-expiratory pressure of 5 cm H2O and fraction of inspired O2 of 1.0), physiologic studies of gas exchange were correlated with pathologic features from 36 open lung biopsies and 15 autopsies. Three distinct groups were defined. Group 1 included 11 patients with the most severe hypoxia (Pao2, 47 +/- 12 mm Hg), minimal Pao2 response to a 10 cm H2O increase in positive end-expiratory pressure (+2.0 +/- 4.0 mm Hg), and a fixed shunt at all fractions of inspired O2. Pathologic study showed edema, exudation, and hemorrhage to the point of consolidation. In group 2 were 13 patients who had less severe hypoxia (Pao2, 60 +/- 17 mm Hg) and a moderate Pao2 response to a 10 cm H2O increase in positive end-expiratory pressure (+15 +/- 8 mm Hg), but whose maximal response was slowly achieved (30 min to several hours). Pathologic examination showed extensive fibrosis. The 21 patients in group 3 had the least hypoxia (66 +/- 15 mm Hg), and had a rapid and marked improvement in Pao2 with a 10 cm H2O increase in positive end-expiratory pressure (+68 +/- 59 mm Hg). Pathologic features were similar to but less severe than those in group 1. Venous admixture increased with decreasing inspired concentrations of O2, indicating diffusion or ventilation-perfusion abnormalities in groups 2 and 3. Prognosis was best for group 3, with 10 of 21 long-term survivors. Two of 11 group 1 patients survived, but only after prolonged periods of extracorporeal membrane oxygenation. Despite biopsy evidence of extensive fibrosis, 3 of 13 in group 2 survived with moderate to good pulmonary function, including 1 survivor who had had extracorporeal membrane oxygenation. Such combined physiologic and pathologic studies are useful (1) for optimal respiratory care, (2) for prognosis, (3) for development of indications for extracorporeal membrane oxygenation, and (4) for better understanding of the pathophysiology of adult respiratory distress syndrome.

An analysis of potential physiological predictors of respiratory adequacy following cardiac surgery.

More than 50 potential physiological and clinical predictors of postoperative respiratory adequacy were examined in an attempt to identify those few variables which, singly or in combination, best predicted the outcome of the first trial of spontaneous respiration following cardiac surgery. This trial was initiated when patients seemed hemodynamically stable and relatively alert following surgery. Analysis of data from 124 patients identified the following useful predictors: forced vital capacity, total lung capacity, and maximal mid-expiratory flow rate from preoperative pulmonary function tests; resting cardiac index from preoperative cardiac catheterization; postoperative compliance and resistance measured by a computer-based monitoring system; postoperative vital capacity per kilogram, and maximum inspiratory force, measured at the bedside prior to the weaning trial. Stepwise linear discriminant analysis indicated that vital capacity per kilogram and maximum inspiratory force were the most useful predictors, the dividing line between successes and failures being represented by a vital capacity per kilogram of 15 ml. and a maximum inspiratory force of 28 cm. H2O. Mean values of successes were 18.3 +/- 7 ml. per kilogram and 30.7 +/- 9 cm. H2O and, for failures, 11.9 +/- 4 ml. per kilogram and 24.3 +/- 8.4 cm H2O. These physiological variables assess patient effort acting upon an abnormal pulmonary system. Measurements of passive pulmonary mechanics, cardiac function, and the measurement of arterial blood gases were suprisingly poor predictors.

Pathophysiology of adult respiratory distress syndrome.

We have studied 45 patients with adult respiratory distress syndrome (ARDS). Pathological studies were performed on 30 open lung biopsies and 15 autopsies. Concomitantly the physiologic characteristics of the hypoxemia in response to different inspired oxygen fraction (FIO2) and Positive End Expiratory Pressure (PEEP) were determined. These studies allowed categorization of ARDS into 3 groups. Group I had the most severe hypoxemia and a severe fixed shunt at all PEEP and FIO2. Pathologically, there was extensive acute edema, hemorrhage, and exudation to the point of consolidation. Group II had less severe hypoxemia which improved moderately but slowly in response to PEEP and shunt increased with decrease in FIO2 indicating diffusion disturbances or severe ventilation-perfusion abnormalities. Pathology showed severe fribrosis. Group III had least hypoxia which rapidly and markedly improved with PEEP. Shunt also increased with decrease in FIO2. Pathology showed acute changes similar to but less severe than group I. Prognosis was best for group III with 10 of 21 long term survivors (one after ECMO or extracorporeal membrane exygenation). In group I only 2 of 11 survived after prolonged periods of ECMO. In group II, 3 of 13 survived (one required ECMO) with satisfactory pulmonary function despite biopsy evidence of severe fibrosis during the acute illness. These pathological and physiologic studies are useful to better understand ARDS, to optimize respiratory care and for prognosis.

Effects of extracorporeal membrane oxygenation (ECMO) on pulmonary hemodynamics, gas exchange and prognose.

Hemodynamic and gas exchange studies on acute respiratory failure patients treated by extracorporeal membrane oxygenation led to the following conclusions: pulmonary circulation can be influenced to a large extent Lamy, et al. Effects of extracorporeal membrane oxygenation on pulmonary hemodynamics by changes in bypass cannulation mode and bypass flow rate. An increase in pulmonary flow is followed by an increase in mean pulmonary artery pressure, a drop in total pulmonary vascular resistance, and an increase in shunt fraction. Forced opening of previously shut down vascular area (possibly due to hypoxic vasoconstriction) is a potential explantation for these physiological changes. Increase in bypass flow rate leads to increase in total systemic flow (pulmonary and oxygenator), but does not change total CO2 production and possibly total O2 consumption. Mixed cannulation mode (venoarterial and venovenous) guarantees adequate oxygenation of all the organs. Oxygenation of the heart can be jeopardized by venoarterial bypass, although the use of an aortic root cannula may decrease this major risk. Extracorporeal membrane oxygenation reversed the disease process in some of the patients treated. The best criteria of reversibility seem to be an improvement in arterial PO2 decrease in shunt fraction across the lung, and decrease in total pulmonary vascular resistance. The most striking change of these parameters has been observed after 2 to 3 days on bypass.