Use of Parenteral Nutrition in Patients Receiving Isolated Kidney or Simultaneous Pancreas/Kidney Transplantation
From the * Division of Pharmacy Practice, School
of Pharmacy, and the Correspondence: Gordon S. Sacks, PharmD, 777 Highland Avenue, University of Wisconsin–Madison, Madison, WI 53705. Electronic mail may be sent to gssacks{at}pharmacy.wisc.edu. Background: There is little information available on the use of parenteral nutrition (PN) in patients after a kidney (KID) or simultaneous pancreas-kidney (SPK) transplantation. This study examined the indications and use of PN in these patients. Methods: Retrospective study of 25 patients (12M/13F; mean age: 51 ± 11 years old) receiving PN after KID or SPK transplantation. Patients were divided in 2 groups according to the number of PN days (group A = <7 days and group B = >7 days). Results: Overall mortality was 16% (group A: 0/7; group B: 4/18). Postoperative ileus (n = 7), intestinal fistula (n = 5), and nausea/vomiting (n = 4) were the most common indications for PN. Functional disorders accounted for 56% (14/25) of the indications for PN. Factors differentiating group A (7/25; median = 5 [4–6] days) from group B (18/25; median =9 [7–31] days) included a significantly higher preoperative serum albumin, SPK transplantation for the first time, and diagnosis of ileus as the indication for PN initiation. Conclusions: Functional disorders of the digestive tract are the primary reason for initiation of PN in isolated KID and SPK transplantation patients. Well-nourished patients undergoing their first SPK transplantation who develop postoperative ileus usually do not need nutrition intervention.
The early ( Parenteral nutrition (PN) is often administered at our institution due to the high number of isolated KID and SPK transplants performed, as well as the overall poor nutrition status of the patients. Postoperative gastrointestinal dysfunction is common and includes gastroparesis, prolonged ileus, intestinal fistulae, nausea, and vomiting. These problems frequently occur in association with surgical complications, delayed graft function, and organ rejection.5,6 As a result, PN is used to support both isolated KID and SPK transplantation patients unable to be fed enterally. Currently, little information exists on the use of PN in patients receiving an isolated KID or SPK transplantation. This study defines the use and indications for PN during the early and late postoperative course following KID/SPK transplantation.
This project was approved by the University of Wisconsin–Madison, Health Sciences Minimal Risk Institutional Review Board (IRB). The IRB approved a waiver of documentation for informed consent to use/disclose protected patient health information as it was viewed impractical to obtain a signed authorization from all of the patients for use of such information obtained by a retrospective review of their medical records. We retrospectively reviewed the charts of adult KID and SPK transplant patients who received PN during 2004–2005 at the University of Wisconsin Hospital and Clinics, Madison, WI. Data collection included the following nutrition parameters: body mass index (BMI), nutrition status according to preoperative percentage of weight loss, ideal body weight (IBW, using the Hamwi formula),7 percentage of IBW (%IBW = current weight x 100/IBW), indication for PN, days of PN, and preoperative and postoperative serum albumin, prealbumin, and C-reactive protein (CRP) concentrations. Malnutrition was defined as a reported involuntary weight loss >10% of usual body weight within 6 months and preoperative serum albumin concentrations <3.9 g/dL.8 Patients were divided into 2 groups according to the number of PN days: Group A received  7 days and group B received >7 days. A combination of chronic or
recurrent gastrointestinal symptoms not explained by structural or biochemical
abnormalities was classified as functional gastrointestinal disorders
(FGIDs).9 As such,
nausea/vomiting and gastroparesis (ie, dysmotility-like dyspepsia) are
examples of FGIDs, whereas ileus is considered a symptom of FGIDs. Other
clinical variables collected were length of hospital stay (LOS) and mortality
rate. Dichotomous data were compared using the  2 test.
Student's t-test was used to compare continuous data. Continuous data
are presented as mean ± SD, including the range when appropriate. A
p value < .05 was considered statistically significant.
Between April 2004 and May 2005, the University of Wisconsin–Madison Transplant Service performed 361 isolated KID and 87 SPK transplantations. During this period, 25 patients (5.6%) received PN. No patient undergoing an isolated KID received PN on initial hospitalization and only 8% (7/87) of patients undergoing their first SPK transplantation received PN. The remaining 18 of 25 patients received PN after readmission for postoperative complications related to SPK (n = 10) or isolated KID (n = 8). Etiologic factors responsible for isolated KID transplantation included longstanding diabetes mellitus (n = 4), KID failure of unknown origin (n = 2), lithium-induced KID disease (n = 1), and medullary sponge KID disease (n = 1). The demographic data of these patients is shown in Table I.
Figure 1 shows the most common indications for PN: postoperative ileus (n = 7), intestinal fistula (n = 5), and nausea/vomiting (n = 4). Other indications included gastroparesis (n = 3), gastrointestinal obstruction (n = 2), severe pancreatitis (n = 2), perforated viscus (n = 1), and prolonged nil per os (NPO) status >7 days (n = 1). FGIDs (ie, ileus, gastroparesis, and nausea/vomiting) accounted for 56% (14/25) of PN indications. Indications according to post-transplant period are displayed in Table II, with postoperative ileus the most common indicator for PN after initial SPK transplantation.
Nutrition Parameters
Eleven of 25 (44%) patients were considered malnourished according to preoperative serum albumin concentrations (eg, <3.9 g/dL) and weight loss (eg, >10% over the previous 6 months). There were more malnourished patients in group B, although this did not reach statistical significance (p = .07). The overall mortality rate was 16% (4/25) and this was significantly higher in malnourished patients (4/11; 36.4% vs 0/13; 0%; p = .03). Postoperative prealbumin and CRP concentrations were similar between the 2 groups. There was a trend for increased LOS and mortality in patients receiving >7 days of PN (Table III).
Malnutrition is a common condition in candidates awaiting KID and SPK transplantation. Nutrition status is often compromised in renal failure due to chronic uremia, causing alterations in protein, carbohydrate, and lipid metabolism.10 Additional contributing catabolic factors include acidemia, resistance to anabolic hormones, and removal of nutrients via the dialysate.11 Nearly 50% of our patients receiving postoperative PN met criteria for pretransplant malnutrition. Preoperative serum albumin concentrations and percent weight loss were the criteria used in this study to define a malnourished state. Plasma albumin concentrations have been shown to correlate well with body protein stores, and most studies evaluating the nutrition status of patients awaiting KID and SPK transplantation used this plasma protein and traditional anthropometric measurements.12 Clinical practice guidelines published by a nutrition work group for the National Kidney Foundation Dialysis Outcome Quality Initiative (K/DOQI) recommend that serum albumin be measured monthly for monitoring the nutrition status of maintenance dialysis patients.13 Because no single measure provides a complete evaluation of malnutrition, the K/DOQI guidelines recommend a combination of complementary parameters, including a predialysis serum albumin, percent of usual body weight, percent standard body weight, subjective global assessment, dietary interviews, and diaries. Malnutrition may persist in the postoperative transplantation phase, as well. One group of investigators estimated that approximately 15% of patients were malnourished up to 180 months after KID transplantation.14 These malnourished transplant patients had a BMI <21 kg/m2 and displayed significantly lower concentrations of total protein, albumin, and hemoglobin compared with normally nourished patients. Practice guidelines published by the American Society for Parenteral and Enteral Nutrition (A.S.P.E.N.) recommend that PN not be prescribed for a short course, particularly if enteral feeding can be provided or it is expected that an oral diet will be resumed within 4–6 days. These conclusions follow the examination of many studies evaluating the use of PN in which the majority of patients were able to consume an oral diet within 6–8 days. It was unlikely that patients benefited from such short PN administration. Even with malnutrition, a few days of PN is unlikely to yield substantial benefit.15 Inappropriate PN only increases the likelihood of complications in patients, with little expected gain. For example, our recent data documented that metabolic complications with PN arose from transcription and administration errors associated with the PN process.16 Several studies support reducing inappropriate use of PN. Trujillo et al17 found that of the 209 PN formulations initiated over a 4-month period, 31 (15%) were not indicated according to A.S.P.E.N. guidelines. PN was inappropriately used more often in general surgical or burn/trauma patients than in medical patients (78% vs 48%, p = .001). Maurer et al18 reported similar findings in a prospective study conducted in a large teaching hospital. Using A.S.P.E.N. and American Gastroenterological Association guidelines, 105 of 469 (22%) patient-days of PN were deemed inappropriate, with more than half of the surgical or trauma patients (10 of 19) receiving "avoidable" PN. PN was categorized as "avoidable" when the gastrointestinal tract was intact but there was a prolonged delay (>4 days) in gaining access when the patient underwent a laparotomy and no enteral feeding access (ie, jejunostomy) was obtained at surgery.18 None of these studies included the solid-organ-transplant population. PN is rarely indicated after isolated renal transplantation,12 but debate exists about the benefits of PN after SPK transplantation. Some authors advocate routine use of PN after SPK transplantation according to the high incidence of preoperative malnutrition and postoperative complications that may preclude use of the gastrointestinal tract among recipients.19 Others argue that hyperglycemia, which is common during PN, may increase morbidity and mortality as observed in critically ill patients20 and may interfere with the graft recovery during the post-transplant period. In our study, only patients undergoing initial SPK transplantation received PN during the early postoperative period (ie, within 7 days of initial surgery), with postoperative ileus and gastroparesis the usual indications during the early post-transplant phase. After initial SPK transplantation, ileus accounted for almost 60% of the indications for PN. However, most of these patients received PN for <7 days, with a median of 5 days. These patients were generally well nourished, and their ileus improved quite rapidly. Using current A.S.P.E.N. guidelines, these transplant patients received inappropriate PN for functional disorders because PN was stopped within 7 days. More appropriate selection could produce cost savings and potentially reduce inherent complications associated with IV nutrition support. In the study by Trujillo et al,17 avoidable patient charges for inappropriate PN amounted to $49,665 over a 4-month period. Significant savings could be realized by not administering PN after initial SPK according to the rapid recovery of the gastrointestinal tract and the usual need for just a short course of PN. Intestinal obstruction, perforation, and fistula were the most common indications for PN in patients during the late post-transplant phase. This tended to be a more malnourished patient population admitted with postoperative complications, which required PN for >7 days and had a hospital length of stay just under 1 month. PN was clearly indicated as a method to support these patients who could not be fed via the gastrointestinal tract. To our knowledge, these observations have not been previously reported in the transplantation population. Functional disorders within the gastrointestinal tract occur during the early postoperative period after isolated KID or SPK transplants. However, these functional disorders resolve quickly in most patients so that routine PN should not be prescribed for the mere diagnosis of ileus. PN is clearly indicated for patients with severe complications during initial admission or for those who are severely malnourished or readmitted with postoperative complications. We do not recommend routinely instituting PN in patients undergoing their initial KID or initial SPK transplantation. Received for publication May 23, 2006. Accepted for publication September 6, 2006.
Journal of Parenteral and Enteral Nutrition, Vol. 31, No. 1,
8-11 (2007)
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METHODS
RESULTS