Nutritional support in the critical care setting (Part 2)

The Use of Transpyloric Enteral Nutrition in the Critically Ill Child

To assess the use and complications of transpyloric enteral nutrition (TEN) in the critically ill child we evaluated prospectively all children who received TEN in a pediatric intensive care unit (PICU) of a tertiary university hospital. The type of nutrition used, its duration, medication administered, tolerance, gastrointestinal complications (vomiting, abdominal distension or excessive gastric residue, diarrhea, and pulmonary aspiration), nongastrointestinal complications, and mortality were assessed. A comparative analysis was made between the first 2 years of the study and the remaining period. Over a period of 4.5 years, 152 patients between the ages of 3 days and 17 years received TEN for a duration of 19 ± 32.3 days (range 1–240 days). Forty-one patients received TEN during the first 2 years; 100 patients received TEN in the postoperative period after cardiac surgery (66%). One hundred seventeen patients (77%) received sedation and 65 (43%) received muscle relaxants, presenting no extra complications. Twenty-four patients (15.8%) presented with gastrointestinal complications: abdominal distension and/or excessive gastric residue in 17 and diarrhea in 11. Gastrointestinal intolerance was associated with pulmonary infection ( p < 0.05), altered hepatic function ( p < 0.001), and hypokalemia or hypocalcemia ( p < 0.05). Diarrhea was more frequent in patients with shock ( p < 0.05), altered hepatic function ( p < 0.05), excessive gastric residue ( p < 0.001), and hypokalemia or hypocalcemia ( p < 0.05). In the second study period, the number of patients on TEN and the doses of sedatives, muscle relaxants, and vasoactives were higher ( p < 0.05), with no increase in the incidence of complications. TEN is a useful method of nutrition with few complications in the critically ill child.

Recommended and actual calorie intake of intensive care unit patients in a private tertiary care hospital in the Philippines

OBJECTIVES

This study compared the computed nutrient requirements of geriatric patients under critical care with their actual intake within the first 3 d after admission to the intensive care unit (ICU) and determined the percentage of patients who achieved adequate intake.

METHODS

Fifty-eight geriatric patients who were admitted to the ICU from September to December 2002 were prospectively enrolled. Recommended and actual calorie intakes per patient were recorded and mean amount of carbohydrate, protein, and fat consumed were calculated. Student's t test was used to compare actual with recommended nutrient intakes.

RESULTS

Actual in relation to recommended nutrient intake was inadequate (41.5% on day 1 to 71.7% on day 3 for calories and 21.1% on day 1 to 24.3% on day 3 for protein, P < 0.001). Carbohydrate intake was low (falling from 61.9% on day 1 to 39.8% on day 3, P < 0.001) and fat intake was also low (increasing from 29.4% to 37.9% on day 3, P < 0.001). The percentage of patients who achieved adequate intake was 51.2% on day 1 and increased to 73.2% on day 3.

CONCLUSIONS

The intake of geriatric patients in the ICU is low, with differences in actual and recommended intakes. Delivering what is recommended is still a goal to be realized in the ICU setting.

Transpyloric enteral nutrition reduces the complication rate and cost in the critically ill child

BACKGROUND

Studies in adults have shown that transpyloric enteral nutrition (TEN) is useful in certain patients who cannot tolerate oral or gastric feeding. This study was conducted to compare TEN with parenteral nutrition (PN) in critically ill pediatric patients.

METHODS

A retrospective descriptive study conducted in the pediatric intensive care unit of a tertiary pediatric referral center. All patients in the pediatric intensive care unit (PICU) receiving PN and/or TEN from January 1993 through December 1996 were included in the study.

RESULTS

Two hundred forty patients (14.6% of all patients admitted to the PICU) received PN and/or TEN (168 exclusively PN, 21 exclusively TEN, and 51 a combined regimen). The number of patients receiving PN and duration of PN declined significantly from 1993 (65 patients, 703 days) through 1996 (48 patients, 395 days). This was mirrored by the increase in the number of patients receiving TEN and duration of TEN. The incidence of complications (hyperglycemia, hypertriglyceridemia, and cholestasis) was higher in the PN group. There was no difference in the incidence of hospital-acquired infection or mortality between the two groups. The cost of TEN was lower than that of PN, with an estimated annual saving of $5,422.

CONCLUSIONS

Transpyloric enteral nutrition is a suitable method of nutritional support for critically ill pediatric patients. It has fewer complications and a lower cost than PN.

A 10-year survey of nutritional support in a surgical ICU: 1986-1995

Total parenteral nutrition (TPN) has long been considered the optimal nutrition technique in critically ill patients, but recently the use of enteral nutrition (EN) has increased. This study describes the evolution of the different nutritional support techniques in a surgical intensive care unit (ICU) in a university hospital, through (1) a global survey over 10 y assessing the evolution of the use of EN and TPN, and (2) a prospective study performed over 6 mo. Severity of illness and diagnostic categories were stable (n = 11,539 patients). From 1986 to 1990, the proportion of TPN administered increased from 10-25% of ICU days, decreasing to 10% thereafter. EN was used in about 5% of ICU days in 1986, and had increased to 30% of total ICU treatment days in 1995. The proportion of nutrients actually delivered to the patients was 75% with EN and 88% with TPN. Major changes in nutritional support have been observed since 1986. The frequency of nutritional support provided in general has increased to 40% of ICU treatment days. TPN has been largely overtaken by EN, with the risk of insufficient energy delivery, related to the difficulties of EN in the critically ill. These results reinforce the importance of continuous quality control by daily assessment of nutrient supply.

Acute respiratory distress syndrome

OBJECTIVE

To review the pathophysiology, epidemiology, and therapy of patients with acute respiratory distress syndrome (ARDS).

DATA SOURCES

Articles pertaining to the pathophysiology, epidemiology, and supportive therapy of ARDS were chosen from a computerized literature search. Recent review articles addressing the specifics of treatment in an intensive care unit are cited rather than restating these specific aspects.

DATA EXTRACTION

Primary literature was chosen in reference to the pathophysiology, epidemiology, and supportive therapy of ARDS. Both human and animal studies were included. Review articles were cited regarding areas of ARDS supportive therapy rather than citing the primary literature.

STUDY SELECTION

Only peer-reviewed primary literature sources were chosen to describe the specifics of pathophysiology and epidemiology. When human data were unavailable, animal studies were cited. Recent review articles were cited for specifics on supportive therapy.

DATA SYNTHESIS

Consensus regarding the definition of ARDS and the difficulties of performing large controlled trials in patients with ARDS has made development of new modalities problematic. Understanding the underlying pathophysiology and risk factors for mortality are key to supportive therapy. Although many pharmacologic agents are being tested in patients with ARDS, attention to the aspects of supportive therapy is the only method to decrease mortality.

CONCLUSION

The mortality of ARDS continues to be 70%. Pharmacists can play an active role in the supportive therapy of patients with ARDS, which is currently the only way to impact mortality.

Artificial nutrition support in intensive care units in Spain. Nutritional and Metabolic Working Group of the Spanish Society of Intensive Care Medicine and Coronary Units (SEMIUC)

OBJECTIVE

A multicenter survey to study the use of nutritional support in patients admitted to the ICU in Spain.

DESIGN

The survey was announced during the annual Spanish Society of Intensive Care Medicine and Coronary Units (SEMIUC) congress meeting.

SETTING

Questionnaires designed to determine current clinical practice concerning artificial nutrition were sent to the 27 ICU who accepted to participate.

PATIENTS AND PARTICIPANTS

In each center the 235-question form was filled out individually for each patient admitted to the ICU during the month of March, 1992.

INTERVENTIONS

To validate the study a preliminary pilot surveys were conducted to ensure that there was a correct interpretation of the questions. The replies were entered into a database for analysis.

RESULTS

A total of 1261 patients were studied; 33.9% received artificial nutrition (AN). The administration of AN was significantly higher in the medical group (44%), than in the surgical (37%) and the trauma group (19%). AN was significantly lower in patients admitted to private clinic than public institutions (26.7% versus 34.7%). Among the patients who received AN, enteral nutrition (EN) was administered to 59.7% of the patients, total parenteral nutrition (TPN) to 38.5%, and peripheral parenteral nutrition (PPN) to 18.2%. Medical patients received significantly more EN than surgical and trauma patients. Surgical patients received more PN than medical and trauma groups.

CONCLUSIONS

Nutritional support is a common practice in the treatment of ICU patients in our country. All information concerning its use is necessary to optimize it.

Gastric emptying following brain injury: effects of choice of sedation and intracranial pressure

OBJECTIVE

To compare the effects of opioid and non-opioid sedation on gastric emptying.

DESIGN

Prospective, randomized trial.

SETTING

University teaching hospital ICU.

PATIENTS

21 brain injured patients requiring sedation, mechanical ventilation and intracranial pressure (ICP) monitoring for > 24 h.

INTERVENTIONS

Patients were randomized to receive infusions of either morphine plus midazolam (M), or propofol (P). Gastric emptying was assessed by the paracetamol absorption technique and by residual volumes following a 200 ml test feed.

MEASUREMENTS AND RESULTS

Pre-sedation Glasgow Coma Score, mean ICP and the presence of bowel sounds were noted. Plasma concentrations of paracetamol were measured over 3 h following a 1 g gastric dose. There were no differences in median peak paracetamol concentration (M, 18.5 versus P, 20.8 mg/l), median time to peak concentration (M, 20 versus P, 25 min), median area under the concentration-time curve (AUC), or in the median residual volumes at 1 h (M, 14 versus P, 10.5 ml) and 2 h (M, 5 versus P, 3 ml). In patients with ICP > 20 mmHg, paracetamol concentrations were lower (p < 0.05), and AUC after 30 min was lower (165 mg.min/l versus 411 mg.min/l, p = 0.023). Mean ICP was correlated with AUC (Kendall rank p = 0.027). Gastric emptying did not correlate with initial Glasgow Coma Score or presence of bowel sounds.

CONCLUSIONS

Gastric emptying is not improved in patients with brain injury by avoiding morphine (1-8 mg/h) in the sedative regimen. Intracranial hypertension is associated with reduced gastric emptying.

Substituted judgment, best interests, and the need for best respect

Perhaps the most troublesome medical decisionmaking cases facing state courts concern serious healthcare decisions involving patients with severe or profound retardation. The courts who face this issue encounter a difficult dilemma. A decision to terminate a medical treatment of a dependent, vulnerable person requires considerable solicitude. Allowing a helpless person to die sooner than is medically possible directly conflicts with that person's most basic right – the right to live. However, continuing treatment in the face of terminal illness may not only prolong but also increase intense mental and physical suffering. Perpetuating near torture in the name of protecting a person's life may be equally worrisome.

Glucose response to abrupt initiation and discontinuation of total parenteral nutrition

Plasma glucose was studied during the initiation of total parenteral nutrition (TPN) and the discontinuation of TPN without a tapering schedule. Blood was sampled every 5 minutes for 2 hours after the start of TPN and 1 week later as TPN was discontinued. A total of 14 initiations and 14 discontinuations were studied in 18 patients. Severity of illness in patients ranged from stable condition postoperatively to multiple-system failure; six patients had diabetes mellitus. The TPN solution was a 3:1 admixture that provided a caloric intake equal to 1.2 times the resting energy expenditure, with 40% fat and 60% carbohydrate calories. An average of 1963 kcal was provided per day (340 g of glucose, 79 g of fat). During the initiation phase, the mean increase in plasma glucose was 60 mg/dL. The increase for diabetic patients was 79 +/- 14 mg/dL compared with 52 +/- 23 mg/dL for the nondiabetics. During the discontinuation phase, the mean plasma glucose decreased 40 +/- 20 mg/dL; two patients with high concentrations of regular insulin (50 and 100 units) showed an increase in plasma glucose when the TPN was stopped. Plasma glucose returned to the preinfusion baseline after discontinuation. During both initiation and discontinuation, plasma glucose showed little change after the first 60 minutes. No clinical symptoms of hypoglycemia were observed. In conclusion, TPN as a 3:1 admixture can be safely started as full nutrition support and stopped abruptly without a tapering schedule. Plasma glucose response is rapid, predictable, and mostly complete within 60 minutes.

Oesophageal obstruction during nasogastric feeding

Although complications of enteral feeding are usually minor, we report an unusual and serious case of oesophageal obstruction after feeding with osmolite, a commonly used polymeric enteral feeding preparation. The patient described underwent rigid oesophagoscopy to remove the feed which had solidified and blocked the entire oesophageal lumen. The procedure resulted in oesophageal perforation which needed surgical repair by thoracolaparotomy and was followed by a difficult postoperative course. In vitro tests showed that all commonly used feeds containing casein (osmolite, ensure, ensure plus, paediasure, fortison, and pulmocare) solidified at a pH of less than 5. Clinifeed (containing dried skim milk) and peptamen (containing peptides) remained liquid at a pH of less than 1. Solidified feed could be liquefied by the addition of pepsin or pancrex V (a pancreatic enzyme formulation). We conclude that solidification could occur in all feeds containing casein and that alternative feeds should be considered in patients with increased gastric acidity. In addition, pepsin or pancrex V could be used to liquefy solidified feed.

The effect of duodenojejunal alimentation on gastric pH and hormones in intensive care unit patients

We evaluated effects of duodenojejunal (DJ) feeding on gastric pH and selected gastrointestinal hormones in 13 randomly selected patients in an intensive care unit (ICU). To obtain baseline values for gastric pH, a nasogastric (NG) tube was placed in each patient and gastric pH was measured every 30 minutes for 2 hours. To obtain control values, a Dobbhoff tube was placed fluoroscopically and 0.45 percent saline solution (NaCl), 75 ml, was infused for 1 hour and gastric pH was measured again; the previously placed NG tube was left in position. Then, by randomization, either 0.45 percent NaCl (pH = 5) was continued (n = 6) or a high-nitrogen, isotonic, enteral feeding solution (Osmolite HN, pH = 6.4) (n = 7) was infused, both at 75 ml/h. Gastric pH was noted hourly for 96 hours; antacid (Maalox TC, 15-ml aliquots) was given by NG tube when the pH was 4 or less. After 96 hours, the infusion was stopped and gastric pH was noted for 4 additional hours. Before and during initial saline solution infusion; after 24, 48, 72, and 96 hours of continuous infusion; and 4 hours after stopping the infusion, peripheral venous blood was obtained for measurement of plasma gastric inhibitory polypeptide (GIP) and serum gastrin. Data were analyzed by ANOVA (RMD), Fishers' exact test, and the unpaired t-test. Groups did not differ demographically. Throughout the infusion, gastric pH tended to be higher with the enteral feeding solution than with saline solution, but this was significant only at 24 hours. Less antacid was required with the enteral feeding solution at 24 and 48 hours than with saline solution. Plasma GIP levels were significantly higher with the enteral feeding solution than with saline solution during most of the infusion. Serum gastrin levels did not differ between the groups. In this cohort, infusion of the enteral feeding solution tended to maintain a gastric pH of more than 4 and was associated with increased plasma GIP levels, which may inhibit gastric acid secretion. Early enteral feeding may benefit certain ICU patients.