Nutritional support in the critical care setting (Part 1)

Nutrition and Nutritional Support in Critically Ill Patients

The use of intravenous nutritional support has increased dramatically in the last 20 years. Although it is not without controversy, administration of nutritional support is common practice in hospitalized patients including critically ill patients. Malnutrition continues to be reported in a significant number of hospitalized patients. The incidence of malnutrition in critically ill patients may be even higher than that reported in hospitalized patients overall. The consequences of malnutrition in a critically ill patient may be severe. Nutritional assessment and nutritional support can present special challenges to the intensivist. Techniques of nutritional assessment in critically ill patients are evaluated. Guidelines for the determination of the nutritional needs of these patients are outlined. Methods of delivery of nutritional support in critically ill patients are reviewed. Complications of nutritional support are discussed.

Why critically ill patients are protein deprived

Critical illness dramatically increases muscle proteolysis and more than doubles the dietary protein requirement. Yet surprisingly, most critically ill patients receive less than half the recommended amount of protein during their stay in a modern intensive care unit. What could explain the wide gap between the recommendations in clinical care guidelines and actual clinical practice? We suggest that an important aspect of the problem is the failure of guidelines to explain the pathophysiology of protein-energy malnutrition and the ways critical illness modifies protein metabolism. The difficulty created by the lack of a framework for reasoning about appropriate protein provision in critical illness is compounded by the many ambiguous and often contradictory ways the word malnutrition is used in the critical care literature. Failing to elucidate these matters, the recommendations for protein provision in the guidelines are incoherent, unconvincing, and easy to ignore.

Nutrition support in a surgical patient

Nutrition has very important role to play during health and disease state in human beings. Neonates and younger children are more prone to develop nutritional deficiencies. They have very critical reserves and are rapidly growing. Any surgical insult leads to multiple nutritional problems. Careful planning of nutritional management in a surgical patient is mandatory. Nutritional support should start from the day when the child develops the surgical condition to withstand stress of disease and surgical procedure. In the postoperative period nutritional support should start as early as possible. Start with small amount and build up gradually till the normal enteral nutrition (EN) is tolerated. When EN is not tolerated parenteral nutrition (PN) should be considered. Parenteral nutrition on short term basis is very important to tide over the crisis due to postoperative complications. Parenteral nutrition on long term basis is required in short bowel syndrome resulting from resection of large part of the gut. During PN, enteral nutrition should be continued in small amounts in order to maintain the integrity of mucosal lining of the gut. Enteral nutrition is more physiological and can provide adequate amount of immunonutrients, minerals and vitamins.

Complications of laparoscopy-aided gastrostomies in pediatric practice

PURPOSE

The aim of this report is to establish the frequency and type of complications of laparoscopy-aided gastrostomy in pediatric practice and to identify patients at risk for postoperative complications.

METHOD

This is a follow-up study of 98 children with nutritional problems including inability to swallow, inadequate calorie intake in neurologically impaired children, patients with cystic fibrosis, malignancies, neurometabolic diseases, and cardiac malformations. Laparoscopy-aided gastrostomy was attempted in all patients. These patients have undergone follow-up at our outpatient clinic. Postoperative complications and problems with the gastrostomy device were registered. The postoperative complications were divided into minor problems and major or life-threatening complications.

RESULTS

There was no perioperative mortality. No life-threatening complication developed, whereas minor problems were common, necessitating medical attention postoperatively. Patients with congenital heart disease, chronic respiratory failure, and metabolic diseases experienced the highest frequency of postoperative complications.

CONCLUSIONS

The surgical placement of an enteral access device in children should be considered a major surgical procedure, demanding medical attention for 1 to 2 months postoperatively. The rate and severity of complications with the method described are tolerable considering the severity of the underlying diseases.

Modifying perfusion, nutrition, and stress to promote wound healing in patients with acute wounds

Tissue injury is common among patients in acute care settings. The subsequent response to injury, wound healing, follows an intricate but well-defined sequence that, under normal conditions, proceeds to satisfactory repair. However, because of the complexity of the healing response, several factors can intervene to impair normal healing. As a better understanding of how diverse factors influence healing is gained, the use of interventions that modulate these factors becomes possible and potentially beneficial. This article reviews knowledge of perfusion, nutrition, and stress as they relate to healing in patients experiencing acute wounds. Therapeutic implications based on current research are discussed.

Percutaneous endoscopic gastrostomy in paediatric practice: complications and outcome

PURPOSE

The aim of this study was to establish the morbidity and mortality of percutaneous endoscopic gastrostomy (PEG) in a tertiary referral paediatric practice and to identify risk factors for developing complications after a PEG.

METHODS

The medical records of all patients who had a percutaneous endoscopic gastrostomy attempted over a 5-year period (1990 to 1995) were reviewed.

RESULTS

One hundred thirty percutaneous gastrostomies were placed in 120 paediatric patients. Indications for insertion were inability to swallow (n = 74, of which, 52 were neurologically impaired), inadequate calorie intake (n = 30), special feeding requirements (n = 12), continuous enteral feeding in short gut (n = 2), and malabsorption (n = 2). All the children had complex medical problems, and 80% of the patients were rated as "high risk" for general anaesthesia (> or = ASA grade 3). Major complications developed in 21 children (17.5%) and minor complications in 27 (22.5%). Of the 17 children in whom gastroesophageal reflux (GOR) became symptomatic, 10 required a Nissen fundoplication. Nine of these 10 children were neurologically impaired (19% of the neurologically impaired children). One postrenal transplant patient on immunosuppression died 54 days after the procedure of intraabdominal sepsis. Thirty-one patients required secondary surgical procedures.

CONCLUSIONS

PEG is associated with significant morbidity. Neurologically impaired children are at risk of acquiring symptomatic GOR, but the risk does not warrant routine fundoplication. Major complications are common and need urgent surgical consultation with many requiring secondary surgical procedures. PEG in paediatric patients should be considered a major surgical undertaking.

Neonatal nutritional requirements and formula composition: a review

Adequate neonatal nutrition is essential for appropriate growth and avoidance of complications associated with deficiencies. Neonatal nutritional requirements vary with metabolic states, degree of prematurity, and diseases affecting the gastrointestinal, pulmonary, and cardiac systems. Differences exist between formula brands for protein, fat, and carbohydrate sources. Differences also exist between formulas designed for preterm and full-term infants, as well as infants with special nutritional needs. Optimal nutrition should be a consistent goal for each infant, whether in a healthy newborn nursery, intensive-care unit, or home care setting. Nurses must be aware of the possibilities available to address the special needs of infants.

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.

Nutrition of critically ill people

There has been an increasing awareness over the past few years of malnourishment in hospital patients (Horwood 1990, Wallace 1993). Critically ill patients are a particularly vulnerable group as their physical problems can mean depleted energy reserves and an increase in energy consumption. The aim here is to consider ways in which malnutrition can be avoided in critically ill people. Different methods to provide patients with adequate nutrition, and the associated complications, are also discussed. To give critically ill patients the best possible chance of survival, intensive care staff need to be aware of recent developments in clinical nutrition. A multidisciplinary approach to nutrition is essential to achieve the best possible outcome for patients in intensive care units (ICUs).

Utilization patterns of total parenteral nutrition in a university hospital. A methodological approach

To study the utilization of total parenteral nutrition, using methodology recommended by the World Health Organization, classification of components in accordance with the anatomical therapeutic chemical classification and defined daily dose system is necessary. Anatomical therapeutic chemical indices are available but defined daily dose values have not been established yet. In this article, a methodology to study both the total utilization of total parenteral nutrition, the utilization of individual substances and the composition of total parenteral nutrition is presented. To validate the proposed methodology, the utilization of total parenteral nutrition in a teaching hospital is studied, based on pharmacy computer data. The total utilization of total parenteral nutrition in the hospital in 1990 is 1.4 defined daily doses/100 bed-days. The composition of total parenteral nutrition varied greatly between the clusters. In this study we showed that utilization of total parenteral nutrition can be measured with the proposed methodology, using a defined daily dose for total parenteral nutrition in concurrence with a defined daily dose for the individual components.