Effect of postoperative nutrition on muscle high energy phosphates

Cysteinyl-leukotriene generation as a biomarker for survival in the critically ill

OBJECTIVE

To evaluate the capacity of cysteinyl-leukotriene generation in the progression of critical illness compared with that in healthy volunteers and to clarify interrelationships between the rate of leukotriene generation, severity of the disease, and clinical outcome.

DESIGN

Prospective, observational study.

SETTING

Surgical intensive care unit (ICU) in a German university hospital.

PATIENTS

We studied 14 ICU patients (nine men, five women; aged 42-82 yrs) suffering from systemic inflammatory response syndrome, sepsis, or sepsis syndrome, with a calculated sepsis severity score of 17.7+/-4.2 and a Simplified Acute Physiology score of 17.6+/-3.0. In addition, five healthy volunteers (three men, two women; aged 34-38 yrs) were included in the study.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Blood samples were obtained every second day from septic patients until discharge from the ICU or death. Leukotriene C4 (LTC4) synthesizing capacity was assessed in isolated and stimulated leukocytes (Ca-ionophore) by using combined reversed-phase, high-pressure liquid chromatography and radioimmunoassay methods. Initially, all patients synthesized less LTC4 than the healthy subjects. In patients who did not survive, the low LTC4 generation persisted throughout the observation period, whereas in surviving patients, its formation was normalized during convalescence. In surviving patients, LTC4 concentrations correlated with sepsis severity score.

CONCLUSIONS

LTC4 generation is impaired in sepsis and may serve as a biomarker for survival in the critical ill.

Experimental study of efficacy and optimal dose of intraoperative glucose in rabbits under general anesthesia

This experimental study was designed to investigate the efficacy of glucose loading during surgery. Rabbits, fasted overnight, received 20 ml·kg^-1·h^-1 fluid infusion containing glucose at various concentration (0,0.5, 1.0, 1.5, 2.0% w/v) for 3 h intraoperatively. Plasma glucose level increased after the beginning of operation, but the increase was slight in groups given 0.2 g·kg^-1·h^-1 or lower doses of glucose. Glucose at higher doses caused marked hyperglycemia. These higher doses also promoted urinary glucose excretion, and in the group given the maximum glucose dose (0.4 g·kg^-1·h^-1), this parameter was significantly elevated compared with findings in the 0.2 g·kg^-1·h^-1 group (P<0.05), whereas it showed no significant difference among groups given 0-0.2g·kg^-1·h^-1. The liver glycogen content in animals that received no glucose was significantly lower than that of the 0.2 g·kg^-1·h^-1 group (P <0.01). However, there was no correlation between glycogen level and glucose dose among groups receiving glucose. These results suggest that intraoperative glucose supplementation is effective in preventing glycogen depletion, and indicate that, to avoid glucose overloading, the optimal dose is 0.1-0.2 g·kg^-1·h^-1.

Postoperative fatigue

Uncomplicated major surgery is followed by a pronounced increased feeling of fatigue extending throughout the first month in about one-third of patients. Postoperative fatigue correlates with the degree of surgical trauma but is not related to duration of general anesthesia and surgery or to preoperative nutritional status, age, or sex. Fatigue also correlates with postoperative deterioration in nutritional parameters and impaired adaptability of heart rate during exercise. Furthermore, a postoperative decrease in muscle force and endurance is related to postoperative fatigue, whereas psychological factors are of minor importance. These findings suggest postoperative fatigue to be mediated by the endocrine-metabolic response to surgery, impaired nutritional intake, or immobilization, but the relative role of these factors remains to be established. Until then, therapeutic measures against the development of postoperative fatigue should aim at reducing the surgical stress response, effective treatment of pain to facilitate mobilization, and exercise to increase postoperative nutritional intake.

Elective abdominal surgery depresses muscle protein synthesis and increases subjective fatigue: effects lasting more than 30 days

Ten patients without metabolic disease undergoing elective cholecystectomy were studied before surgery and on days 3, 10, 20 and 30 after operation. Percutaneous muscle biopsies were taken and protein synthesis was determined from the total concentration and size distribution of ribosomes. The subjective feeling of fatigue was estimated using a visual analogue scale. The nitrogen balance was calculated at 20 days following surgery. The mean (s.e.m.) total concentration of ribosomes per milligram of DNA decreased by 27.5(6.6) per cent (P less than 0.01), 44.5(6.5) per cent (P less than 0.001), 48.3(8.9) per cent (P less than 0.001) and 45.0(8.2) per cent (P less than 0.01) on days 3, 10, 20 and 30, respectively. By 30 days after surgery no sign of restoration of normality was seen. The relative proportion of polyribosomes had decreased by 20.4(6.4) per cent (P less than 0.05) on the third postoperative day and by 20.4(3.9) per cent (P less than 0.01) on the tenth postoperative day and was restored to the preoperative level by day 20. The subjective fatigue score increased after operation and five of nine patients had not regained their preoperative scores 30 days after surgery. The daily nitrogen balance was negative for 5 days. The cumulated nitrogen losses were not restored until after 18 days following surgery. Elective abdominal surgery caused a sustained depression of protein synthesis for over 30 days, a longer period than previously presumed. These results show that long-term follow-up is required when the effect of different postoperative nutritional regimens are to be evaluated.

Skeletal muscle enzyme activities and metabolic substrates during exercise in patients with postoperative fatigue

Subjective fatigue was quantified before and 20 days after uncomplicated elective abdominal surgery in 12 patients and compared with changes in heart rate, enzyme activities and skeletal muscle substrates before and after bicycle exercise for 10 min at 65 per cent of patients' preoperative maximum work capacity. Fatigue increased from a mean(s.e.m.) preoperative level of 2.5(0.5) arbitrary units to 4.6(0.5) on postoperative day 20 (P less than 0.01). Body-weight, triceps skinfold thickness and arm circumference decreased postoperatively (P less than 0.02). Postoperative values of muscle enzyme activities indicative of oxidative phosphorylation capacity (citrate synthase and 3-OH-acyl coenzyme A dehydrogenase) were lower than preoperative values (P less than 0.05). Lactate dehydrogenase was unaltered and resting values of muscle glycogen and adenosine triphosphate were higher after operation (P less than 0.05). In response to exercise, heart rate, muscle glucose, glucose-6-phosphate and lactate increased (P less than 0.05), while muscle glycogen and creatine phosphate decreased (P less than 0.05). Increase in postoperative fatigue correlated with the increase in heart rate (P less than 0.05), while no significant correlations were found between fatigue and muscle parameters. Our results suggest that lack of exercise and malnutrition may be of importance in the decrease in work capacity and in fatigue after operation.

The effect of intravenous nutrition on muscle mass and exercise capacity in perioperative patients

This study was undertaken to compare the efficacy of four different types of perioperative intravenous nutritional support. Fifty-five patients undergoing routine major surgery were studied. They were prospectively assigned to one of four study groups. Group 1 received formal total parenteral nutrition (90 g amino acids, 3,000 calories as glucose, per day); Group 2, 100 g glucose per day; Group 3, 90 g amino acids per day; and Group 4, peripheral parenteral nutrition (90 g amino acids plus 1,600 calories, 60 percent as fat per day). Group 1 was maintained on therapy for 3 weeks and the other groups for 8 days. Nitrogen balance, maintenance of body cell mass, serum albumin levels, and maintenance of exercise capacity were measured. Patients receiving peripheral parenteral nutrition maintained their nutritional parameters, as did those receiving total parenteral nutrition. These infusions were both markedly superior to those receiving glucose alone or those receiving amino acids alone. Nitrogen balance was not correlated with maintenance of function, but maintenance of body cell mass was correlated with maintenance of exercise capacity (r = 0.66, p less than or equal to 0.01). We conclude that perioperative peripheral parenteral nutrition, in contradistinction to hypocaloric infusions of glucose or amino acids, is capable of maintaining postoperative muscle mass and function close to preoperative levels after major surgery, and in situations of relatively mild surgical stress, approaches the efficacy of total parenteral nutrition in this regard. A significant correlation exists between changes in body cell mass determined from isotope dilution and changes in the exercise capacity of large muscle masses.

Muscle high energy phosphates in chronic peripheral vascular disease

There is little information available concerning the alterations in skeletal muscle energy metabolism which occur in response to chronic arterial occlusive disease. In addition, the effect of arterial reconstruction on skeletal muscle energy metabolism in patients with peripheral vascular disease has not been defined. Needle biopsies were obtained from the quadriceps femoris muscle of 7 patients with aortoiliac disease and 15 patients with femoropopliteal disease and from the gastrocnemius muscle of 9 patients with femoropopliteal disease. Muscle samples were analyzed for ATP, ADP, AMP, phosphocreatine, creatine, and lactate. Eleven patients were rebiopsied after vascular reconstruction. Patients with rest pain had decreased total adenine nucleotides, energy charge potential, and ATP/ADP ratios as compared to those of controls. ATP levels were significantly decreased in muscle samples obtained distal to the arterial occlusion (i.e., quadriceps/aortoiliac, gastrocnemius/femoropopliteal) in patients with rest pain (compared with controls). ATP levels did not differ significantly from those of controls in muscle samples obtained from patients with claudication. However, energy charge potential was significantly decreased in all patients with claudication regardless of biopsy site and location of arterial occlusive disease. Normalization of muscle energy metabolism was not demonstrated following arterial reconstruction. We conclude that resting skeletal muscle energy metabolism is abnormal in patients with chronic arterial insufficiency and that progression of disease toward more severe ischemia is associated with more marked derangement. Whether the possible beneficial effects of revascularization on muscle energy metabolism are masked by the concurrent effect of injury in the early postoperative period remains to be clarified.

Patterns of fuel utilization during parenteral nutrition

Utilization of fuel in clinical conditions has become an important area of interest to the clinician. Injury and sepsis cause predictable changes in the metabolism of fuel, favoring a shift toward the oxidation of fat. Similar considerations apply to the tumor-bearing host.

Automated microanalysis of adenosine phosphates, phosphocreatine, creatine, and lactate in muscle

An automated enzymatic procedure suitable for determination of ATP, ADP, AMP, phosphocreatine, creatine, and lactate in needle biopsies of human skeletal muscle (ca. 30 mg dry wt) using a fast centrifugal analyzer (Multistat III, Instrumentation Laboratory Inc.) is presented. Coefficients of variation ranged from 0.7 to 4.2% for multiple determinations of ATP, ADP, phosphocreatine, and creatine; from 6 to 24% for lactate; and from 9 to 20% for AMP. The procedure should be usable, with appropriate modification, with other tissues and with other fast centrifugal analyzers. Muscle samples are collected into liquid freon, lyophilized, and extracted with 600 microliter of 0.65 M perchloric acid. Neutralized supernatants can be stored for up to 3 years at -80 degrees C with no significant deterioration. The procedure takes much less time than similar manual procedures and gives better reproducibility, particularly for ADP and AMP.

Parenteral nourishment of patients undergoing surgical or traumatic stress

Severe surgical or other traumatic stress initiates an integrated central nervous system and metabolic response characterized by catabolism which selectively preserves vital organs, drawing on peripheral tissue proteins for required amino acids. When oral intake is prohibited adequate intravenous nutritional support hastens convalescence and may be life-saving. Intravenous nutrients routinely consist of amino acids for replacement of lost protein, a nonprotein calorie source--usually glucose, and vitamins and minerals. Lipid, infrequently used in routine surgery as part of the calorie source, supplies essential fatty acids and prevents side effects resulting with large amounts of intravenous glucose. Lipid has other benefits. Stress-induced hormones stimulate lipid catabolism. When lipid is used for part of the calorie requirement in intravenous feedings, the plasma insulin level is reduced and peripheral amino acids become available for synthesis of critically needed visceral proteins. Recent work has shown that the branched chain amino acids carnitine and some species of lipid added to intravenous nutrient formulations postoperatively affect the nitrogen retention and may hasten convalescence. Further work should be directed at understanding the unique biochemical changes occurring after injury, devising objective assay procedures to measure the severity of the response and improving intravenous formulations for the acutely ill surgical patient.

Relative value of glucose and amino acids in preserving exercise capacity in the postoperative period

The value of crystalline amino acids compared with glucose in maintaining functional muscle mass (maximum exercise capacity) in the perioperative period was studied. Twelve surgical patients received 100 g of glucose (Group 1) for 7 to 10 days perioperatively, and 12 (Group 2) received 90 g of crystalline amino acids for a similar period. Maximum exercise capacity, nitrogen balance, and serum albumin were studied. The use of amino acids instead of glucose spared nitrogen. Net nitrogen loss was 64.7 +/- 6.7 g in Group 1 compared with 34.7 +/- 4 g in Group 2 (p less than or equal to 0.001). Exercise capacity decreased 13.8 +/- 4.5 percent in Group 1 and 13.3 +/- 2.9 percent in group 2. The serum albumin level decreased by 0.30 +/- 0.2 g/100 ml in Group 1 compared with 0.34 +/- 0.15 g/100 ml in Group 2. These differences were not significant. Changes in serum albumin were correlated with changes in exercise capacity (r = 0.7, p less than or equal to 0.002), but neither was significantly correlated with nitrogen loss. We concluded that the use of amino acids instead of glucose during moderate periods of semi-starvation associated with moderate trauma will not influence loss of exercise capacity significantly, although some nitrogen will be spared; patients undergoing moderately severe surgical procedures accompanied by moderate periods of semistarvation will lose approximately 14 percent of their exercise capacity; and loss of exercise capacity is not correlated with loss of nitrogen under these conditions but is loosely correlated with changes in serum albumin levels.

Effect of injury, sepsis, and parenteral nutrition on high-energy phosphates in human liver and muscle

This study examined the effect of varying degrees of resting hypermetabolism and total parenteral nutrition on muscle and hepatic high-energy phosphates. Twelve severely injured patients, five critically ill patients with normal blood pressure, and six severely ill patients on 1 wk of total parenteral nutrition were investigated, and the results were compared with those in 14 normal controls. High-energy phosphates were not significantly changed in liver and muscle after severe injury; lactate and pyruvate levels in both tissues were increased; glycogen levels in the liver were decreased. In critical illness, muscle and hepatic adenosine triphosphate as well as adenosine diphosphate were decreased significantly; energy charge potential dropped; adenosine monophosphate, lactate, and the ratio of lactate to pyruvate were increased. Liver glycogen, but not muscle glycogen, dropped remarkably. The correlation coefficient between hepatic and muscle adenosine triphosphate was 0.61. In patients on 1 wk of total parenteral nutrition, hepatic and muscle high-energy phosphates were not significantly changed before or during total parenteral nutrition. Alterations in the adenosine triphosphate-adenosine diphosphate-adenosine monophosphate system in liver and muscle suggest a low-energy charge in severe injury and critical illness. This would indicate a decreased capacity for biosynthetic reactions and production of storage compounds. The changes of high-energy phosphates in liver are always parallel to changes in muscle.

An assessment of nutritional depletion following major colonic surgery

This study was undertaken to determine the changes in basic nutritional indices associated with major colonic surgery accompanied by periods of semi-starvation. Changes in weight, serum albumin, nitrogen balance, and maximum exercise capacity were studied. Weight loss was 5.5 +/- 1 per cent, serum albumin decreased 0.20 +/- 0.15 gm per cent. Nitrogen loss was 5.9 +/- 0.9 gm per day and maximum exercise capacity decreased by 13.5 +/- 1.8 per cent. Nitrogen balance improved when amino acids were substituted for glucose as the maintenance regimen, but no corresponding improvement in exercise performance could be demonstrated. It is concluded that major colonic surgery associated with moderate periods of semi-starvation is associated with an average nitrogen loss of 5.9 +/- 0.9 gm per day and a 13.5 +/- 1.8 per cent loss in maximum exercise capacity or effective muscle mass.

Metabolic effects of four intravenous nutritional regimens in patients undergoing elective surgery II.—Muscle amino acids and energy-rich phosphates

Muscle amino acids and energy-rich phosphates have been determined in 28 patients before and after resection of a carcinoma of colon or rectum. Before operation the patients received a synthetic diet (Vivasorb for four days and postoperatively four different intravenous regimens with different amounts and proportions of amino acids were given for six days, the energy intake being the same for all groups. When compared with age-matched healthy controls the patients showed only slight increases in phenylalanine and isoleucine concentration in muscle and plasma with elevated plasma glutamate during the four days prior to the operation. Vivasorb treatment increased the concentration of alanine, glycine and methionine in both muscle and plasma while increases of threonine and histidine were seen only in muscle. Decreased concentrations of valine were found in muscle and plasma, while lysine and leucine decreased only in plasma. As an effect of operation, but independent of the nutritional regimen, muscle asparagine increased and muscle glutamine and glutamate decreased in all groups. The unique pattern of amino acid changes in postoperative trauma was confirmed in the present investigation but few differences in amino acid concentrations could be related to the various nutritional intakes. Alterations in the individual amino acid concentrations were not influenced by the intake of amino acids and seemed to have little relationship to the composition of any solution infused. Prior to operation there were low levels of ATP in muscle possibly due to immobilisation and chronic semistarvation but no changes in the energy rich phosphates could be attributed to trauma or nutrition. The content of muscle glycogen increased as a result of the Vivasorb supply indicating that the preoperative carbohydrate administration promotes muscle glycogen synthesis and postoperatively muscle glycogen was reduced significantly indicating enhanced glycogenolysis in the postoperative state. This finding emphasizes the importance of providing the patients with ample amount of glucose before and after surgery.