Intolerance to enteral feeding in the brain-injured patient

Use of residual volume as a marker for enteral feeding intolerance: prospective blinded comparison with physical examination and radiographic findings

High gastric residual volumes (RVs) are a frequent cause for cessation of total enteral nutrition (TEN). This study was designed to determine the RV that indicates intolerance or inadequate gastric emptying and to compare the RV findings in a blinded fashion with those findings obtained on physical examination and radiography. Twenty healthy normal volunteers (HNV), 8 stable patients with gastrostomy tubes (GTP), and 10 critically ill patients (CIP) were evaluated prospectively for 8 hours while receiving TEN. No subjects were clearly intolerant (ie, vomiting, aspiration). Of the total RVs recorded, 13.1% were greater than or equal to 150 mL in the CIP group, whereas only 2.4% of the RVs were greater than or equal to 150 mL in the HNV group. None of the RVs in the GTP group were greater than or equal to 150 mL. Objective scores on physical examination failed to correlate with RV (p = .397), as did objective scores on radiography (p = .742). However, objective scores on physical examination were significantly related to scores on radiography (p = .016). Abnormal physical examination findings were found in 4 out of 11 patients (GTP + CIP) with RVs less than 100 mL and in 6 out of 7 with RVs greater than or equal to 100 mL. Abnormal radiographic results were found in 6 out of 11 patients with RVs less than 100 mL, in 7 out of 7 patients with RVs greater than or equal to 100 mL, and in 4 out of 20 HNVs. There was no difference in RVs obtained from the supine or right lateral decubitus positions.(ABSTRACT TRUNCATED AT 250 WORDS)

Equal aspiration rates from postpylorus and intragastric-placed small-bore nasoenteric feeding tubes: a randomized, prospective study

Postpylorus delivery of enteral feeding is perceived by many experts to be safer than intragastric delivery. To test this assumption, patients with similar Glasgow Coma Scores were given identical enteral formulas continuously via a 10-French nasoenteric tube, placed into the stomach or beyond the second portion of the duodenum. Observations were made for attainment of desired nutrition, bowel changes, and clinical signs of aspiration. Radiographs of the chest and abdomen were obtained every 3 days. If a tube migrated out of a chosen location, it was replaced. Thirty-three patients were studied. Seventeen patients were fed into the stomach and 16 patients were fed postpylorus. The mean duration of enteral feeding was 11.8 days for the gastric group and 10.9 days for the postpylorus group (p = NS). The time to deliver the desired kilocalories was 3.33 and 2.77 days (p = NS) for gastric and postpylorus-fed patients. Tubes displaced similarly in each group, gastric 0.647, postpylorus 0.750 per duration of feeding (p = NS). Chest radiographs met the criteria for aspiration pneumonia in 31.3% of gastric and 40% of postpylorus-fed patients (p = NS). Together, these data indicate that complications from enterally fed patients are equally common whether the distal port of the feeding tube is in the stomach or beyond the second portion of the duodenum.

Altered gastric emptying in the head-injured patient: relationship to feeding intolerance

Most patients with moderate to severe head injury initially do not tolerate enteral feedings postinjury. This intolerance is more prolonged than that found in patients suffering other types of trauma. The authors prospectively evaluated 12 patients with moderate to severe head injury (Glasgow Coma Scale score between 4 and 10) throughout their hospitalization for liquid gastric emptying as a possible mechanism for intolerance to enteral feeding. During Week 1, the majority of patients displayed a delay in gastric emptying. Patients also displayed an abnormal biphasic response (gastric emptying faster than normal during the early stage but prolonged later). By Week 2, many patients still had delayed and abnormal biphasic responses to gastric emptying. By Week 3, an improvement was observed with the majority of patients exhibiting rapid gastric emptying, but delays and abnormal biphasic responses were still seen. Patients who initially had rapid or normal gastric emptying tolerated full-strength full-rate feedings significantly earlier compared with those who experienced delayed gastric emptying (8.5 +/- 0.5 days vs. 13.7 +/- 3.2 days, p less than 0.001). All patients tolerated full-strength full-rate feedings by Day 16 postinjury (range 7 to 16 days) except the two patients who displayed delayed gastric emptying for prolonged periods of time (mean 25 days). This is the first study to longitudinally evaluate gastric emptying following head injury. The authors suggest that patients with moderate to severe head injury often experience alterations in gastric emptying which may affect their ability to tolerate enteral feedings.

Early enteral nutrition after brain injury by percutaneous endoscopic gastrojejunostomy

Twenty-seven patients in a series of 52 patients with severe brain injury (Glasgow Coma Scale score less than or equal to 8) underwent insertion of intestinal feeding tubes at the bedside. The technique required endoscopy with externalization of gastric and intestinal ports through the abdominal wall. Feedings were begun through the intestinal tube with Vital HN within 4 hours of its insertion with simultaneous gastric decompression via the gastric tube. Tubes were placed 2.3 (range 0-5) days after injury. Full caloric intake (3020 kcal/24 h) was achieved by 6.8 (range 2-8) days after injury to 4.2 (range 2-8) days after placement of the feeding tube. Only 1 patient failed to tolerate feedings immediately after tube insertion. Technical inability to insert the tubes occurred in 3 patients and the intestinal tube migrated into the stomach in 2 patients; diarrhea occurred in only 1 patient. With this technique, it was possible to deliver an average daily intake of 1.2 g/kg of protein in 8-day balance periods beginning at the time of tube insertion. These data included 3- to 4-day periods in which feedings were steadily increased. In 16 patients in whom nitrogen balance was measured for 8-day balance periods, average nitrogen balance was -5.7 (range -11.3 to +3.5) g/24 h. The reduction in nitrogen loss by this technique appears equal to or superior to either gastric feeding or TPN. This technique provides the ability to enterally feed a high proportion of brain-injured patients (except those in barbiturate coma) very early after injury using a bedside procedure.(ABSTRACT TRUNCATED AT 250 WORDS)

Brain injury and nutrition

This review has discussed the current status of metabolic alterations and demands, nutrient administration, and nutritional assessment of the head-injured patient. More work is necessary in all areas to further describe and ascertain the nutritional requirements of these patients. Future research in this area should involve specific nutrient requirement, modification of the acute-phase response, and possibly administration of growth factors.

[Energy metabolism and craniocerebral injury]

Severe head injury induces major hormonal, humoral and metabolic changes, characterized by increases in stress hormone secretion, lymphokines production, associated with high lipid and protein catabolism as well as changes in energy expenditure (EE). Numerous factors influence EE in head-injured patients, particularly anthropometric data, body temperature, nutritional support, level of consciousness, muscular tone and activity. Resting EE is usually increased following brain trauma; however, normal or decreased metabolic rates can be observed in curarized patients on mechanical ventilation or in patients receiving high doses of barbiturates.