Pulmonary embolization complicating total intravenous alimentation

Thrombosis associated with ventriculoatrial shunts

Ventriculoatrial shunts are the most common second-line procedure for cases in which ventriculoperitoneal shunts are unsuitable. Shunting-associated thrombosis is a potentially life-threatening complication after ventriculoatrial shunt insertion. The overall prevalence of this complication is still controversial because of substantial differences in the numbers found in studies using clinical data and in those analyzing postmortem findings. The etiology of thrombosis may be multifactorial, including shunt catheter itself, contents of cerebrospinal fluid, shunt infection, and genetic disorder. The clinical presentation can vary widely, ranging from asymptomatic to a life-threatening condition. Timely recognition of thromboembolic lesions is critical for treatment. However, early diagnosis and management is still challenging because of a relatively long asymptomatic latency and lack of clear guideline recommendations. The purpose of this review is to provide an overview of ventriculoatrial shunt thrombosis, especially to focus on its etiopathogenesis, diagnosis, treatment, and prevention.

Parenteral nutrition for hospitalized infants: 20th-century advances in venous access

OBJECTIVE

To review the literature related to venous access for parenteral infant feeding.

DATA SOURCES

Sources included medical, nursing, and nutrition literature from 1900 to 1994.

STUDY SELECTION

One hundred ten studies were reviewed. Studies were selected based on historical significance and contribution to current practice.

DATA EXTRACTION

Data relating to the development of parenteral nutrients or evolution of parenteral techniques were extracted.

DATA SYNTHESIS

The central venous catheter was a significant development in meeting the nutritional needs of hospitalized infants.

CONCLUSION

Delivery of parenteral nutrition through percutaneous, peripherally inserted central venous catheters provides the least trauma and greatest benefit.

Pulmonary thromboembolism and unexpected death in infancy

Review of the Department of Histopathology autopsy files over a 30 year period from 1962 to 1991 revealed only three cases in which unexpected death occurred in infants under 1 year of age due to massive pulmonary thromboemboli. Predisposing factors included necrotizing enterocolitis with gut perforation and sepsis, a ventriculoatrial shunt and idiopathic arterial calcification. Diagnosis of the latter autosomal recessive condition was only made at autopsy. These cases demonstrate that pulmonary thromboembolism is a possible, although exceedingly rare, cause of sudden infant death, that some predisposing factors are unique to infancy and that the source of the pulmonary thromboembolus may be difficult to determine at autopsy. Massive pulmonary thromboembolism in infancy may point to the presence of other significant, clinically-unsuspected, disorders.

Cor pulmonale as a complication of ventriculo-atrial shunts reviewed

The authors present the case of a nine-year-old patient with spina bifida and hydrocephalus treated with a ventriculo-atrial shunt who developed fatal pulmonary hypertension 5 1/2 years after his last valve revision; he had been well and active up to one month before his death. Details of the dramatic cardiovascular findings are given. The problems of treatment, once symptoms occur, and the difficulty of pre-symptomatic detection are discussed.

Pulmonary embolism in burned children

There are occasional reports in the literature concerning the incidence of pulmonary embolism in the postburn population, but reports of burned children are especially rare. The clinical diagnosis of pulmonary embolism is particularly difficult in these populations due to the postburn pulmonary complications of pneumonia, bronchopneumonia, respiratory distress syndrome, and changes incurred through inhalation injury. A retrospective review of all patient deaths occurring at this institution during the past 22 years was performed in order to document the incidence of pulmonary embolism in burned children. Of the 6589 patients admitted during this time, 178 patients died (2.7%) and three (1.7%) deaths were attributable to pulmonary embolism. Two other deaths (1.1%) were associated with deep vein thrombosis. The incidence of pulmonary embolism can then be calculated at 46 per 100,000 admissions in this population of burned children. Burned patients always pose an increased risk for the development of pulmonary embolism. These patients are traumatized, require multiple venous and/or arterial cannulations, undergo multiple surgical procedures, are immobile for prolonged periods, prone to infectious processes and fluid and electrolyte imbalances. Despite all these risk factors, the incidence of pulmonary embolism is less than 2 per cent of all deaths in this postburn paediatric population.

Thrombus associated with central venous catheters in infants and children

From 1978 to 1987, 350 infants and children had silicone central catheters placed for long-term venous access. Real time echocardiography showed a catheter tip thrombus in 16 patients, including 12 premature infants and four children. Catheters had been in place for eight to 560 days. Thirteen patients were receiving total parenteral nutrition (TPN) at the time thrombus was identified, and one patient had received TPN 2 weeks previously. Indications for echocardiography included sepsis (7), respiratory insufficiency (6), evaluation of heart disease (3), and catheter malfunction (1); several patients had multiple indications. Treatment was individualized and included atriotomy (2), systemic heparin and thrombolytic agents with or without catheter removal (8), catheter removal only (3), and observation (3). Four of eight patients treated with thrombolysis had complete clot lysis and four had partial dissolution. Two patients managed expectantly had resolution of the thrombus. None of the patients suffered further complications or died as a result of the thrombus, but ten of the 16 died 1 to 12 weeks later from their underlying disease. Forty-seven asymptomatic patients were studied by echocardiography to assess the incidence of unsuspected right atrial thrombus. Their catheters had been in place for a mean of 200 days and only 11 had been used for TPN. None of these patients had identifiable thrombus at the catheter tip. The incidence of catheter tip thrombus, which is higher than previously suspected, is related to prematurity, TPN, and continuous catheter use, but not duration of catheterization. The incidence is low in asymptomatic patients. Treatment regimen must be individualized and this series reflects a trend toward more conservative management.

Urokinase therapy for a catheter-related right atrial thrombus and pulmonary embolism in a 2-month-old infant

Thrombolytic therapy seems to be effective in clearing catheter-related thrombi, allowing subsequent reuse of the Broviac catheter. We have confirmed the previously theoretical risk that thrombolytic therapy in such cases may create pulmonary emboli, but such therapy (in our very limited experience) dissolves the clot extremely quickly. This latter observation may mean that thrombolytic therapy is particularly useful for pulmonary emboli in infants and young children.

Streptokinase dissolution of a right atrial thrombus

A critically ill 20-month-old white male with severe bronchopulmonary dysplasia, cor pulmonale, and intolerance to enteral feeds, required a left percutaneous subclavian Broviac catheter. Echocardiogram showed a right atrial thrombus, resolution of which was demonstrated after infusion of streptokinase through the Broviac catheter for 16 hours. The catheter remained in place, functioning well, for a further 4 months. The patient suffered no bleeding complications, and was spared the prohibitive risk of right atrial thrombectomy. This use of streptokinase has not previously been reported.

Fatal pulmonary embolism following removal of a central venous catheter

A 1-year-old child developed fatal septic pulmonary embolism upon removal of a central intravenous catheter. Histologically identical material was found in the pulmonary arteries and in the inferior vena cava at the catheter tip site. The pathophysiology of pulmonary embolism occurring during childhood is reviewed.

Thromboembolic complications with silicone elastomer subclavian catheters

Central venous thrombosis is a well-recognized complication of plastic catheters used during parenteral nutrition and occurs in up to 33% of cases if examined venographically. Silicone elastomer catheters, in addition to their favorable handling properties, are less thrombogenic than plastic varieties and are now increasingly used for parenteral nutrition. However, their use does not prevent the possibility of catheter-related thrombosis as this study demonstrates. In a consecutive series of 118 silicone elastomer subclavian catheters, 83% of which were used for parenteral nutrition, two instances of clinically apparent catheter-related thrombosis occurred and one of these was complicated by major pulmonary embolism. Catheter malplacement, catheter infection, and coagulation abnormalities were absent. Both catheters were used for parenteral nutrition and were in place for 20 and 28 days, respectively. Twenty-eight consecutive silastic catheters used for parenteral nutrition were studied, prior to removal, by simultaneous bilateral ascending phlebography. One clinically inapparent nonocclusive, catheter-related thrombus was detected which detached during catheter removal. This study suggests an incidence of symptomatic and asymptomatic silastic catheter-related thrombosis to be around 4%. Silicone catheters therefore may reduce but cannot abolish catheter-related thrombosis. Furthermore, when present, catheter-related thrombosis may be a source of major pulmonary thromboembolism.