Stanley J. Dudrick

Artificial Nutritional Support in Patients with Gastrointestinal Fistulas

Abstract. Gastrointestinal (GI) fistulas allow abnormal diversions of GI contents, digestive juices, water, electrolytes, and nutrients from one hollow viscus to another or to the skin, potentially precipitating a wide variety of pathophysiologic effects. Mortality rates have decreased significantly during the past few decades from as high as 40% to 65% to 5.3% to 21.3% largely as a result of advances in intensive care, nutritional support, antimicrobial therapy, wound care, and operative techniques. The primary causes of death secondary to enterocutaneous fistulas have been, and continue to be, malnutrition, electrolyte imbalances, and sepsis, especially in high-output fistulas, which continue to have a mortality rate of about 35%. Priorities in the management of GI fistulas include restoration of blood volume and correction of fluid, electrolyte, and acid-base imbalances; control of infection and sepsis with appropriate antibiotics and drainage of abscesses; initiation of GI tract rest including secretory inhibition and nasogastric suction; control and collection of fistula drainage with protection of the surrounding skin; and provision of optimal nutrition by total parenteral nutrition (TPN) or enteral nutrition (EN) (or both). The role of nutrition support in the management of enterocutaneous fistulas as either TPN or EN is primarily one of supportive care to prevent malnutrition, thereby obviating further deterioration of an already debilitated patient. It has been shown in several studies that TPN has substantially improved the prognosis of GI fistula patients by increasing the rate of spontaneous closure and improving the nutritional status of patients requiring repeat operations. Moreover, other studies have shown that nutritional support decreases or modifies the composition of the GI tract secretions and is thus considered to have a primary therapeutic role in the management of fistula patients. Finally, if a fistula has not closed within 30 to 40 days, or if it is unlikely to close because of a variety of collateral or compounding pathophysiologic conditions, consideration must be given to operative resection of the fistula while continuing to maintain the previous nutritional and metabolic support. The morbidity and mortality rates in such unfortunate patients remain high despite the many recent advances in surgical and metabolic technology.

Ten years experience with intravenous hyperalimentation and inflammatory bowel disease.

A retrospective analysis was conducted on 74 patients with inflammatory bowel disease who were treated with intravenous hyperalimentation at the Hospital of the University of Pennsylvania between the years 1967–1976. Intravenous hyperalimentation can ameliorate the inevitable protein-calorie malnutrition present in patients with inflammatory bowel disease. Combined with complete bowel rest, intravenous hyperalimentation can effectively function as the primary treatment or as an adjunct to the surgical management of the complications of inflammatory bowel disease. Intravenous hyperalimentation can be safely administered to these severely ill patients, almost certainly improving survival rates in the patients treated.

Early developments and clinical applications of total parenteral nutrition

BACKGROUNDnThis article recounts the conditions and status of surgical nutrition support in the 1960s and the antecedent basic and clinical investigational work leading to the development of a practical and efficacious method of adequate nourishment entirely by vein in Beagle puppies; describes the subsequent clinical application of the knowledge, techniques, and technology to the first successful long-term total parenteral nutrition (TPN) support of critically ill pediatric and adult patients; and admonishes nutritionists of all backgrounds that some need for parenteral nutrition will likely always exist and that it is incumbent upon everyone to continue endeavors to advance the germinal methodology to perfection.nnnMETHODSnThe relevant indications, limitations, hindrances, motivational factors, and studies regarding the development of TPN are reviewed, and the fundamental investigational work culminating in the first successful growth and development of Beagle puppies and a human infant fed entirely by vein are described firsthand. The details of the orderly and logical scientific development of the principles and components of the techniques in animals, infants, and adults are related.nnnRESULTSnKnowledge, techniques, and technologic constituents of the first successful long-term TPN system were developed in the basic biochemical and animal laboratories initially in 6 puppies and subsequently adapted clinically for the efficacious long-term i.v. support of 6 critically ill surgical adult patients and a newborn infant before its widespread clinical application.nnnCONCLUSIONSnLong-term TPN was inaugurated successfully as a safe and effective i.v. feeding technique nearly 4 decades ago. However, basic and clinical investigations must continue to be encouraged, supported, and carried out in the quest to perfect the current rudimentary technology, methodology, and outcomes.

Tumor growth in experimental animals: nutritional manipulation and chemotherapeutic response in the rat.

The effects of nutritional manipulation on host body weight dynamics, tumor growth patterns and host-tumor responses to chemotherapy were studied in Spraque-Dawley rats with Walker-256 carcinosarcomas. Group I maintained throughout on a regular diet (RD) gained carcass weight steadily. Group II lost carcass weight while fed a protein-free diet (PFD) but rapidly gained weight after switching to RD on day 15. Mean tumor volume increased 105% in Group I from day 15 to 21, 218% in Group II and 77% in Group III (continued on PFD p < 0.05). From day 21 to day 33 tumor growth patterns were similar in Groups I and II, while mean tumor volume eventually plateaued in Group III. In Study B, Group II animals were given Methotrexate (MTX-20 mg/kg) two days and six days after switching from PFD to RD. The mean change in tumor volume in the MTX-treated rats was 1.31 ± 0.1 cm11 compared with 8.14 ± 0.1cm3(p < 0.001) in the saline-treated control rats. MTX did not significantly affect tumor growth patterns in Group III (PFD) rats. In Study A, protein-calorie malnutrition resulted in host carcass weight loss and tumor growth retardation while nutritional repletion restored host carcass weight and stimulated tumor growth. In Study B, MTX was maximally effective in tumor-bearing rats that were switched from PFD to RD demonstrating that nutritional manipulation can improve host nutritional status and increase tumor response to chemotherapy.

Gastrointestinal adaptation following small bowel bypass for obesity.

Small intestinal morphologic and biochemical changes were studied following jejuno-ileal bypass for obesity after body weight stabilization had occurred. Four patients underwent biopsy of in-continuity and bypassed jejunal and ileal segments of the small intestine 11 to 22 months after the bypass operation. Microscopically, marked mucosal villus hypertrophy of the in-continuity bowel was observed, especially in the ileum. Bypassed jejunal mucosa underwent atrophy compared with pre-bypass jejunum, whereas bypassed ileum appeared similar microscopically to pre-bypass ileum. The specific activities of mucosal disaccharidase enzymes (maltase, sucrase, lactase and trehalase) in units per mg protein remained similar to pre-bypass levels in segments of the in-continuity jejunum and the bypassed jejunum and ileum. On the other hand, elevated mucosal disaccharidase levels were measured in biopsy specimens of the in-continuity ileum. Total enzyme activity per unit length of intestine, however, was estimated to be elevated in both in-continuity jejunum and ileum secondary to mucosal villus hypertrophy. These data indicate that following small bowel bypass: (1) the in-continuity ileum undergoes greater biochemical and morphologic adaptation than the jejunum; and (2) intraluminal nutrients and chyme appear to be essential to maximal intestinal adaptation.

Intravenous hyperalimentation. Effect on delayed cutaneous hypersensitivity in cancer patients.

Effects of nutritional repletion with intravenous hyperalimentation (IVH) on sequential skin test reactivity were evaluated in 160 malnourished cancer patients undergoing chemotherapy (76 patients), surgery (49 patients), radiation therapy (20 patients) and supportive care (15 patients). In the chemotherapy group, 45 patients had negative reactions initially, and 25 patients (55%) had at least one skin test convert to positive in an average period of 19 days of IVH. In the surgery group, 23 patients (46%) were initially positive and remained positive, 13 patients (24%) converted from negative to positive, and 13 patients (30%) remained negative or converted to negative. Postoperative complications occurred in 25% of positive reactors, compared with 69% (p < 0.01) of negative reactors. In the radiation therapy group, the skin tests of six patients (30%) remained positive, three patients (15%) converted from negative to positive and the skin tests of nine patients (45%) remained negative. In the supportive care group, the skin tests of 73% of the patients either remained positive or converted to positive with IVH within an average period of 11 days of treatment. Nutritional therapy with IVH was associated with restored skin test reactivity in 51% of malnourished cancer patients undergoing oncologic therapy. Radiation therapy was generally immunosuppressive despite adequate nutritional repletion. In surgical patients, positive skin test reactivity correlated directly with a favorable response to operative therapy.

Effects of protein depletion and repletion on cell-mediated immunity in experimental animals.

Protein-calorie malnutrition leads to depression of host cell-mediated immunity. Nutritional repletion initially results in rapid weight gain followed by a more gradual return of immunocompetence. Administration of a synthetic amino acid diet to normal animals did not preserve body weight or cell-mediated immunity any better than did a high carbohydrate, protein-free diet. Administration of a synthetic amino acid diet to malnourished animals maintained body weight, but did not restore immunocompetence. Proper nutritional repletion should provide both adequate protein and nonprotein calories if a return of immunocompetence is to be anticipated.

The efficacy of x-rays after chest tube removal

BACKGROUNDnThe insertion and subsequent removal of chest tubes are frequently performed procedures. We hypothesize that routine chest radiographs obtained after chest tube removal to confirm the absence of any post-procedure complications have little impact on clinical management.nnnMATERIALS AND METHODSnA 5-year retrospective study of 73 patients with tube thoracotomies was performed in a level II trauma centers intensive care unit. Patients were identified from billing records for chest tube placement. Medical records and official chest x-ray film reports, both before and after removal, were reviewed, and demographic data were collected.nnnRESULTSnOf the 73 patients examined, only 8 had postprocedure reports that differed from the preprocedure reports. Two of these 8 patients required reinsertion of a chest tube to treat the recurrence of a significant pneumothorax. However, the decision to reinsert the chest tube was based on the patients clinical appearance rather than on the x-ray findings.nnnCONCLUSIONnChest radiography following the removal of chest tubes should not be a routinely performed procedure, but should preferably be based on the good clinical judgement and discrimination of the surgeon.

Routine chest radiographs following central venous recatheterization over a wire are not justified.

BACKGROUNDnSubclavian vein central venous catheterization and the subsequent exchange of subclavian catheters over a guidewire are frequently performed procedures. We hypothesized that the policy of obtaining a routine postprocedure chest radiograph to confirm appropriate catheter placement and to rule out complications after exchanging central venous catheters over a wire was no longer justifiable.nnnMETHODSnA retrospective study of 295 patients with Swan-Ganz catheters (SGC) was performed between July 1, 1994 and June 30, 1996. One hundred fourteen of these SGCs were exchanged over a guidewire for a central venous catheter (CVC). Postexchange chest radiograph and associated radiologists report, as well as age, gender, and duration of catheter placement were all recorded. Since July 1996, this study has been extended prospectively.nnnRESULTSnOf the 380 documented over-a-wire exchanges, none has resulted in a complication, including catheter malposition.nnnCONCLUSIONnWe conclude from these data that a routine chest radiograph following the replacement of a CVC over a guidewire is not necessary when good clinical judgment and discrimination are used in a monitored setting.

Decreased use of computed tomography with a modified clinical scoring system in diagnosis of pediatric acute appendicitis.

HYPOTHESISnUse of a modified clinical grading score improves accuracy in diagnosing acute appendicitis in the pediatric population while decreasing the use of computed tomography (CT).nnnDESIGNnRetrospective medical records review after approval by the institutional review board. We determined the Alvarado score for each patient and correlated it with the pathological findings and imaging studies to evaluate the efficacy of CT and its attendant radiation exposure.nnnSETTINGnCommunity teaching hospital.nnnPATIENTSnSixty-one patients, aged 3 to 16 years, admitted with suspected acute appendicitis.nnnMAIN OUTCOME MEASURESnSensitivity, specificity, and accuracy of the modified Alvarado scoring system.nnnRESULTSnThe standard Alvarado score for acute appendicitis had a sensitivity of 92% and a specificity of 82%, with an accuracy of 92%. In the modified Alvarado scoring system, CT findings were substituted for Alvarado scores in the ranges of 5 or 6, 5 to 7, 5 to 8, and 5 to 9. The modification resulted in the greatest accuracy (98%) in diagnosing appendicitis in patients with scores in the range of 5 to 7. This modification theoretically would have decreased the use of CT by about 27% in this group of retrospectively studied patients. Furthermore, in patients with Alvarado scores of 1 to 4, another diagnosis should be considered; in patients with scores of 5 to 7, CT should be performed; and, in patients with scores of 8 to 10, an appendectomy should be performed promptly without further studies.nnnCONCLUSIONSnThe modified Alvarado score is useful as an aid in diagnosing acute appendicitis in the pediatric population. This scoring system eliminates unnecessary use of CT and the attendant potential cancer-inducing radiation in the pediatric population.