Journal of Parenteral and Enteral Nutrition

Derangements of posttraumatic glucose metabolism have long been recognized, with observed changes implicating abnormal action of insulin on target tissues. Insulin is important as well in fat metabolism, and "resistance" to insulin's effects on lipid metabolism after injury has been demonstrated. Although fat-derived fuels are the body's major energy source during starvation and after injury, most studies of posttraumatic insulin "resistance" have focused on carbohydrate metabolism. This study investigated adipose tissue response to insulin in vitro in rats subjected to starvation and/or trauma. Relationships between various parameters, including adipocyte size and weight, plasma glucose, insulin, and glycerol, and basal and insulin-suppressed lipolytic rates, were also studied. Results observed include a decrease in adipocyte size and an increase in basal lipolysis in both starved and traumatized rats, with both decreased sensitivity (T > S) and responsiveness (S > T) to insulin. These results support the concept that adipocytes of injured animals retain the ability to respond to insulin but lipolytic rates at maximal suppression are still quite high as compared to fed controls. Only minor differences were observed between starved animals and those with starvation and superimposed trauma. (Journal of Parenteral and Enteral Nutrition 11:513-520, 1987)

The metabolic effects and immune responses of different levels of fish oil in enteral formulas for postburn nutritional support were studied. Thirty-seven burned guinea pigs with previously placed gastrostomy feeding tubes were given diets containing 5, 15, 30, or 50% of nonprotein calories as fish oil. These diets were isonitrogenous, isocaloric, and contained identical amounts of vitamins and minerals. After 14 days of enteral feeding, there were no significant differences in resting metabolic expenditure, serum transferrin, and albumin levels. Weight loss was significantly greater in groups receiving 30 and 50% of fish oil compared to groups which received 5 and 15% of fish oil. Carcass weights and liver weights of animals in the two groups that received diets with higher lipid content were also significantly lower. Cell-mediated immunity, macrophage bactericidal indices, and opsonic indices were not different among the groups. This study confirms that diets containing lower levels of lipids are more effective for enteral nutritional support than those containing higher levels. In contrast to linoleic acid rich lipid sources, higher levels of fish oil did not show adverse effects on immunity possibly because it contained high concentrations of ω3 fatty acids which are not precursors of immunosuppressive prostaglandin E₂. (Journal of Parenteral and Enteral Nutrition 11:521-528, 1987)

Nutrient intake patterns were analyzed in 23 patients with gut failure who were receiving home parenteral nutrition (HPN). All patients had stable weights without changes in intravenous calories or protein for 3 consecutive months. Our objectives were to assess oral intake of calories, carbohydrates, fat, and protein, to examine relationships between oral nutrient intakes and disease categories, and to compare oral and intravenous intakes to calculated resting energy expenditure (REE). Two patterns of oral nutrient intake were identified among the patients. Patients with short bowel syndrome, regardless of the underlying disease, consumed calories by mouth that clearly exceeded calculated resting energy expenditure (short bowel, non-Crohn's, 170% of REE; short bowel, Crohn's, 200 of REE); however, calories approximating the REE had to be given via HPN, suggesting that efficiency of absorption was at a very low level. Patients with diffuse gut diseases (radiation enteritis or pseudo-obstruction syndromes) had very low intakes of oral nutrients. The distribution of oral calories among carbohydrate, protein, and fat did not differ among the disease categories. (Journal of Parenteral and Enteral Nutrition 11:529-532, 1987)

A previous study indicated increased urea production and low nitrogen (N) retention on a free amino acid elemental formula (FAA; Vivonex-HN). The limitations of this earlier study were: irregular nitrogen absorption in the malabsorption patients, high nitrogen intake, and failure to match FAA to control formula (hydrolyzed casein; CAS; Criticare-HN) with respect to kcal/nitrogen. A more critical test of FAA quality was sought in the current study. Four healthy males received the minimal daily nitrogen requirements (0.6 g protein/kg) from either FAA or CAS in a 10-day balance study; a second balance on the alternate formula followed. Maintenance energy, minerals, and vitamins were supplied in each period. The results indicated a higher apparent nitrogen absorption (p < 0.05) from FAA relative to CAS in the first 5 days of the balance, although these differences were no longer present in the remaining 5 days of the period. Urinary total nitrogen increased on FAA, most of which could be accounted for by urea nitrogen; urinary creatinine nitrogen, ammonia nitrogen, and uric acid nitrogen were nearly identical between formulas. The unmeasured fraction of urinary nitrogen was markedly diminished on FAA while the urea nitrogen to total nitrogen ratio was significantly increased (p < 0.05) compared to CAS. During the initial 5 days of study nitrogen balance was lower on FAA than on CAS and this difference became significant during the last 5 days of the period (X ± SD for FAA = -0.42 ± 0.59 g/D vs CAS = 0.98 ± 0.30 g/day, p < 0.001). Hyperglycinemia was consistently present during FAA infusion. Hence the low biologic value of FAA and associated metabolic effects persist under stringent study conditions. (Journal of Parenteral and Enteral Nutrition 11:533-539, 1987)

Hepatic dysfunction is a frequent complication of total parenteral nutrition (TPN), indicated by derangement of standard liver function tests. However, such changes are variable and nonspecific, and represent hepatic injury rather than changes in hepatic function. Antipyrine (Phenazone) clearance is a sensitive indicator of hepatic microsomal enzyme activity and provides a more specific indication of hepatic function. This was used to investigate the effect of different TPN regimens. Patients receiving a postoperative 2000 kcal TPN regimen providing all nonprotein calories as dextrose (n = 16) showed a 34% reduction of mean antipyrine clearance after 7 days of TPN compared to controls (n = 13, p < 0.05). This effect was seen also in patients receiving a 1600 kcal dextrose-based regimen (n = 8). In patients receiving a 2000 kcal TPN regimen in which 500 kcal were provided as lipid (n = 10), mean antipyrine clearance was not significantly different from that of the control group. This study indicates the sensitivity of hepatic microsomal oxidative function, an important route of drug metabolism, to different TPN regimens. (Journal of Parenteral and Enteral Nutrition 11:540-543, 1987)

The relation between nasoenteric formula caloric infusion rate and the serum bilirubin level was examined in 15 healthy subjects. The study protocol spanned 3 days and included fasting studies on day 1, continuous maintenance nasogasteric feeding of a formula diet on day 2, and continuous feeding at a rate twice the maintenance level on day 3. Blood studies were performed in the early morning of each day. Fifteen subjects underwent the fasting measurements and the maintenance infusion, while 11 underwent all 3 days of the protocol. With the maintenance infusion serum bilirubin fell from the fasting value of (X ± SD) 0.77 ± 0.53 to 0.63 ± 0.49 mg/dl for a reduction of 18% (p < 0.05). For the subgroup of 11 subjects receiving two levels of formula infusion, fasting and maintenance serum bilirubin levels were 0.81 ± 0.57 and 0.65 ± 0.47 mg/dl, respectively, (p < 0.05). With the twice maintenance infusion the plasma bilirubin decreased further to 0.46 ± 0.29 mg/dl, a decrement of 43% relative to fasting (p < 0.01). No other significant changes were detected during the protocol in the standard blood chemical and hematologic studies. Thus, the serum level of bilirubin is inversely related to the formula caloric infusion rate during continuous nasoenteric feeding. (Journal of Parenteral and Enteral Nutrition 11:544-546, 1987)

Muscular activity is a fundamental determinant of muscle mass. Transcutaneous muscle stimulation (TMS) may reverse muscle atrophy and lean mass loss in immobile patients by "artificial exercise." Four paraplegic patients with upper motor neuron lesions entered The Ohio State University Clinical Research Center for a 21-day metabolic balance study. After 6 days of baseline monitoring, each underwent isometric tetanic contractions (15 sec on; 45 sec off) of all major lower extremity muscle groups with TMS for 10 hr daily. Cross-sectional areas of muscle plus bone were calculated with CAT scan planimetry at 7 levels in both lower extremities before and after the TMS period. Three patients completed the metabolic balance study. TMS produced significant growth of innervated thigh and calf muscles in all paraplegic patients. Little growth occurred where bone and tendon predominate. No significant changes in nitrogen balance (urine and stool excretion), potassium balance (urine excretion only), or phosphate balance (urine excretion only) could be demonstrated. Two possible explanations are (1) that the patients may have been underfed and (2) that perhaps due to an increase in metabolic rate owing to the stimulation, lean tissue in other locations may have been mobilized to meet leg muscle demands. Future studies will incorporate metabolic monitoring of oxygen consumption and CO₂ production during the experiment. (Journal of Parenteral and Enteral Nutrition 11:547-551, 1987)

To determine whether muscular contractions obtained by electrical stimulation in immobilized patients are able to reduce muscle catabolism, we studied 10 patients (65-79 yr old) hospitalized in the intensive care unit for postoperative ventilatory failure or cerebral infarction. Artificial nutrition was the same for each patient during the 9-day study period. Two periods of 4 days were defined and randomized for each patient, separated by one day. During the muscular stimulation (MS) period, intermittent electrical stimulation of the muscles of the legs (external electrodes), were performed daily during 2 X 30 mn. During the other period, muscular stimulations were not performed.

Urinary excretion of nitrogen (micro-Kjeldhal digestion and Nessler procedure), creatinine (Jaffe reaction), and 3-methyl histidine (3-MH) (gas phase chromatography) was measured every day.

^a t-test for paired data.

We conclude that a significant decrease in 3-MH and creatinine excretion is observed during the MS period. In intensive care unit patients, muscle protein breakdown may be influenced by intermittent muscular electrical stimulation. (Journal of Parenteral and Enteral Nutrition 11:552-555, 1987)

Acute renal failure in the surgical patient is accompanied by a state of hypermetabolism and increased catabolism. Nutritional therapy is therefore directed at the preservation of body cell mass and protein synthesis for repair of wounds and damaged renal tubuli and for maintenance of host defense mechanisms. We examined the effect of two levels of protein intake (18.4 ± 1.4 and 30.8 ± 2.4 mg N/100 g BW/ day) and three different amino acid formulations (Freamine III, Nephramine, and a made-up mixture of Nephramine + Freamine HBC)† on renal function following mercurv chloride-induced acute renal failure in the rat. All animals suffered severe renal failure manifested by increased plasma urea and creatinine levels, decreased creatinine clearance, and increased fractional excretion of sodium. On day 4 of acute renal failure, rats receiving low dose amino acids had better-preserved renal function than those receiving high dose amino acids. However, the type of solution infused did not affect recovery of renal function. (Journal of Parenteral and Enteral Nutrition 11:556-559, 1987)

Posttraumatic lung failure is often associated with alterations in lung surfactant composition and function. Our previous studies with total parenteral nutrition (TPN) have shown the effect of fat supply on phospholipid composition in pulmonary surfactant. Consequently, we attempted to determine whether fat supply would also improve the functional properties of the lung and surfactant. After polytrauma consisting of laparotomy, hypovolemia, and a single femur fracture, the animals were fed only parenterally for 14 days. Two groups of rats were infused via the jugular vein with isocaloric (260 kcal/kg/day) and isonitrogenous (5.62 gN/kg/day) regimens. The nonprotein calories were given either as glucose alone or 30% of calories as fat. Lung function was assessed by measurement of static lung compliance and total lung capacity. Surfactant isolated from lavage fluid was evaluated by means of a Wilhelmy balance. In agreement with our previous studies, in which we obtained a higher level of saturated lecithin in the fat groups, we found significantly (p < 0.05) increased compliance (2.93 ± 0.54 ml/cm H₂O/kg BW) in the fat group compared to the carbohydrate group (2.02 ± 0.36 ml/cm H ₂O/kg BW). Furthermore, a significantly (p < 0.05) elevated total lung capacity was noted in the fat group (32.60 ± 3.90 us 26.00 ± 1.45 ml/kg BW). The relatively improved surface tension properties as expressed by stability index (S = 0.89 ± 0.24 vs 0.66 ± 0.22) and minimum surface tension (γ min = 18.5 ± 5.01 vs 20.75 ± 2.81) is a characteristic change, and was seen in the fat group. From these data, we conclude that it is possible to influence surfactant composition and to improve lung function properties with a lipid emulsion. Such an emulsion may prove useful in preventing posttraumatic lung complications. (Journal of Parenteral and Enteral Nutrition 11:560-565, 1987)

Totally implantable vascular access catheters with injection ports (IP) have been used for total parenteral nutrition (TPN). It is well known that thrombosis may cause occlusion of catheters. Recently we have experienced occlusion of the vascular access chambers in TPN-patients because of precipitation from the solutions.

Three different IPs were tested in vitro: Port-A-Cath (PAC), Vascular-Access-Port (VAP), and Implantofix (IMP). Each received a daily infusion of a 2.5-liter solution consisting of fat emulsion, amino acids, glucose, and additives from a "3-liter bag." After infusions, the IPs were washed with three different rinsing methods, one including 45% v/v alcohol. After 70 days the ports were opened and examined for precipitation. Ports washed with alcohol showed no signs of precipitation, while four of six ports which were washed with conventional rinsing methods had precipitates. (Journal of Parenteral and Enteral Nutrition 11:566-568, 1987)

Ammonia is a toxic molecule that is the principal by-product of amino acid metabolism. Although the transport of ammonia in a nontoxic form protects the brain against high circulating levels, the interorgan transport of this molecule and the orchestration between tissues that has evolved is related primarily to the fact that the nitrogen molecule is an essential molecule for the maintenance of the body's nutrition economy and overall metabolic homeostasis. Efficient handling and disposal of ammonia requires a cooperative effort between tissues in order to maintain nitrogen homeostasis. The liver is the central organ of ammonia metabolism, but other organs also play a key role in the interorgan exchange of this molecule. Alterations in ammonia metabolism occur during critical illness. These changes are adaptive and are designed to maintain metabolic homeostasis. Interorgan cooperation in ammonia metabolism is necessary to insure the proper integration of the metabolic processes which contribute to and are essential for survival during critical illness. An understanding of these processes improves our knowledge of metabolic regulation and will lead to a rational approach to the nutritional and metabolic support provided to critically ill patients. (Journal of Parenteral and Enteral Nutrition 11:569-579, 1987)

Venopulmonary fistula occurred in a 13-year-old girl, 2 weeks after insertion of a silicone parenteral nutrition catheter. "TPN pneumonia" evolved to life-threatening respiratory failure. Complete resolution of the respiratory insufficiency followed removal of the catheter. (Journal of Parenteral and Enteral Nutrition 11:580-582, 1987)

Necrotizing fasciitis of the abdominal wall is a rare clinical entity. The following case study is the first report of necrotizing fasciitis as a complication of percutaneous endoscopic gastrostomy. (Journal of Parenteral and Enteral Nutrition 11:583-585, 1987)

D-Lactic acid can accumulate in blood in some patients with intestinal failure, leading to a clinical syndrome of severe acidosis and encephalopathy. The possible impact of parenteral nutrition on its clinical course has not been established. One patient with a severe short-bowel syndrome supported by long-term parenteral nutrition who suffered repeated episodes of ataxia and disorientation associated with elevated serum levels of D-lactate was studied. Results demonstrated no impact of glucose- vs lipid-based parenteral nutrition formulations on total acid production or serum D-lactic acid levels, increased serum D-lactate levels during administration of neomycin, but prompt resolution of both acidosis and clinical symptoms with discontinuation of oral intake. This study confirms the findings of other investigators that D-lactic acidosis may be a significant, heretofore unappreciated complication in patients with severe short-bowel syndrome, and that prompt resolution may be effected with abrupt discontinuation of oral intake. Furthermore, the present study suggests neither a detrimental nor a beneficial effect of parenteral nutrition on this syndrome. (Journal of Parenteral and Enteral Nutrition 11:586-589, 1987)

Total parenteral nutrition lines are commonly tunneled subcutaneously to decrease rates of sepsis. The history of line tunneling is discussed briefly, noting that to date a surgical approach, a detachable hub catheter or more recently a tunneling rod and 'peel away' introducer have been necessary for this form of central venous access. These systems have problems associated with cost, catheter type and insertion technique.

A simple technique for insertion of tunneled total parenteral nutrition catheters is described. The device used consists of a polyurethane catheter with a fixed-hub. The applications of this approach are discussed. (Journal of Parenteral and Enteral Nutrition 11:590-593, 1987)

Nine substances (Pancrease, Viokase, pork pancreatin, bromelain, papain, cranberry juice, Coca-Cola, chymotrypsin, and distilled water) were tested every half-hour for 4 hr using 900 mm of water pressure to determine their effectiveness in declogging small-bore feeding tubes. At the end of 4 hr the tubes were irrigated with air using a 50-cc syringe. None of the substances tested were effective within 4 hr. Three substances allowed for successful syringe irrigation at the end of 4 hr. They were: chymotrypsin, papain, and distilled water. (Journal of Parenteral and Enteral Nutrition 11:594-597, 1987)