Enteral feeding intolerance: an indicator of sepsis-associated mortality in burned children

Nomogram to predict feeding intolerance in critically ill children

Feed intolerance (FI) is significantly associated with poor prognosis in critically ill patients. This study aimed to understand the characteristics of children with FI and identify the factors predicting FI in critically ill children. This retrospective cohort study was conducted between January 2017 and June 2022 in the Pediatric Intensive Care Unit of a specialized children's hospital. Eighteen factors, including age, body mass index for age z-score (BAZ) < -2, paediatric index of mortality (PIM)3 score, Glasgow coma scale score, mechanical ventilation (MV), enteral nutrition delay, vasoactive drugs, sedatives, sepsis, heart disease, neurological disease, hypokalemia, arterial PH < 7.35, arterial partial pressure of oxygen (PaO2), blood glucose, hemoglobin, total protein, and albumin, were retrieved to predict FI. The outcome was FI during PICU stay. During the study period, a total of 854 children were included, of which 215 children developed FI. Six predictors of FI were selected: PIM3 score, MV, sepsis, hypokalemia, albumin, and PaO2. Multivariate logistic regression analysis showed that higher PIM3 score, MV, sepsis, hypokalemia, and lower PaO2 were independent risk factors for FI, whereas higher albumin was an independent protective factor for FI. The C-index of the predictive nomogram of 0.943 was confirmed at internal validation to be 0.940, indicating a good predictive value of the model. Decision curve analysis shows good clinical applicability of the nomogram in predicting FI.    Conclusion: The nomogram was verified to have a good prediction performance based on discrimination, calibration, and clinical decision analysis. What is Known: • Research has demonstrated that gastrointestinal (GI) dysfunction is not only a fundamental element of Multiple Organ Dysfunction Syndrome (MODS), but also the initiator of MODS. • Previous study has demonstrated a significant association between FI and poor prognosis in critically ill patients. What is New: • We excluded patients with primary gastrointestinal tract disease from our study, and we observed an incidence of FI of 25.2% in the Pediatric Intensive Care Unit (PICU). • Our study revealed that PIM3 score, MV, sepsis, hypokalemia, albumin, and PaO2 are significant predictors of FI.

Introduction: The Multidisciplinary Team Approach to Burn Care

Since the first burn units were established following World War II, great advances in understanding and treating burn shock, smoke inhalation injury, pneumonia, and invasive burn wound infections, and in achieving early burn-wound closure, have greatly decreased postburn morbidity and mortality. These advances were the result of closely integrated multidisciplinary teams of clinicians and researchers. The team approach to burns is a model for success in the care of any challenging clinical problem.

Sepsis in Burns-Lessons Learnt from Developments in the Management of Septic Shock

After surviving the acute phase of resuscitation, septic shock is the cause of death in the majority of burn patients. Therefore, the management of septic shock is a cornerstone in modern burn care. Whereas sepsis therapy in general has undergone remarkable developments in the past decade, the management of septic shock in burn patients still has a long way to go. Instead, the differences of burn patients with septic shock versus general patients have been emphasized and thus, burn patients were excluded in every sepsis study which are the basis for modern sepsis therapy. However, due to the lack of evidence in burn patients, the standards of procedure for general sepsis therapy have been adopted in burn care. This review identifies the differences of burn patients with sepsis versus other septic patients and summarizes the scientific basis for modern sepsis therapy in general ICU patients and burn patients. Consequently, the results in general sepsis research should be transferred to burn care, which means the implementation of effective screening, early resuscitation, and efficient antimicrobial treatment. Therefore, on the basis of past developments and in the light of the current update of the Surviving Sepsis Campaign guidelines, this review introduces the "Burn SOFA score" and the "3 H's of burn sepsis" as a screening tool for early sepsis recognition in burn patients.

Sepsis Definitions in Burns

Background: Sepsis is the leading cause of death in burns. Despite its importance, sepsis lacks a proper definition. An established definition will lead to early and accurate diagnosis, prompt treatment, and a reduced mortality rate. The aim of this work is to discuss current definitions and to look ahead at novel definitions with clinical implications. Method: A review of the current understanding of sepsis definitions in burns. Results: Adaptation of sepsis definitions in the general population and specific burn definitions have gotten better but still need improvements and, potentially, incorporation of molecular, laboratory, patient-specific, and clinical factors. This work includes the history, evolution, and predictive value of current definitions of sepsis in burns. A review of current and future markers of sepsis and potentially useful definitions are presented. Conclusions: Sepsis definitions have evolved over the last decades and will continue to do so. We believe the best definition in burn patients is the Sepsis-3 that was developed originally for critically ill patients. However, there are several studies investigating more specific definitions with better sensitivity and specificity.

Comparison of non-burn-specific systemic inflammatory response syndrome criteria and burn-specific American Burn Association systemic inflammatory response syndrome criteria in paediatric burned patients

AIM

We aim to investigate the diagnostic value of newly defined criteria for the systemic inflammatory response syndrome (SIRS) for paediatric burn patients by the American Burn Association (ABA) by comparing the non-burn-specific SIRS criteria for children.

METHODS

A total of 147 paediatric burn patients were included in this study. Patients diagnosed with sepsis were included in the sepsis group. Clinical parameters were obtained from the electronic medical records at the time of preliminary sepsis diagnosis. Both the non-burn-specific SIRS criteria and the burn-specific ABA SIRS criteria were applied to both the sepsis group and the non-sepsis group.

RESULTS

Of 147 patients, 50 had sepsis according to the non-burn-specific sepsis criteria. When the 50-patient sepsis group was compared to the 97-patient non-sepsis group, the sepsis group had a significantly higher duration of hospitalisation, burn percentage, burn state and abbreviated burn scoring index (ABSI) (P < 0.05). The specificity of the two scales was 29.9% for the non-burn-specific SIRS and 74.2% for the burn-specific ABA SIRS. The sensitivity for the burn-specific ABA SIRS was calculated as 58%, the sensitivity for the non-burn-specific SIRS was 100%. While positive predictive value was calculated as 42.4% for the non-burn-specific SIRS, this value was found as 53.7% for the burn-specific ABA SIRS criteria. The correlation coefficient between the non-burn-specific SIRS and the burn-specific ABA SIRS was 0.378 (P < 0.001).

CONCLUSIONS

Our study underlines the need for widespread use of more specific and sensitive burn-specific clinical criteria to early diagnosis of infection in burn patients to prevent unnecessary antibiotic usage.

Outcomes in Burn-Injured Patients Who Develop Sepsis

This study examines health outcomes in burn patients with sepsis. We hypothesized that burn patients with sepsis would have an increased odds risk for in-hospital death and longer intensive care unit (ICU) stays. This was a retrospective cohort of consecutive patients admitted to the burn ICU with total BSA (TBSA) ≥10% and/or inhalation injury between January 2008 and March 2015. Overall 407 burn patients were included; the case-rate for sepsis was 39.1% (n = 159); 20.1% (n = 82) patients were septic and 18.9% (n = 77) patients experienced septic shock. Patients with septic shock had the highest mortality rate (13.31% no sepsis vs 3.7% sepsis vs 49.4% septic shock, P < .01). Median 28-day ICU-free days was higher in patients without sepsis (23 days [Interquartile range (IQR) 14-27] no sepsis vs 0 days [IQR 0-10] sepsis vs 0 days [IQR 0-0] septic shock, P < .01). Sepsis (with or without shock) increased odds of in-hospital death (odds ratio 7.04, 95% confidence interval 1.93-25.7) in reference to the no sepsis group. With each incremental Sequential Organ Failure Assessment (SOFA) score or 10% TBSA increase, the odds risk for in-hospital death increased by 56 and 75%, respectively. Our study characterized outcomes in patients with sepsis after severe burn injury. The odds risk for in-hospital death was greater in patients with sepsis, increasing burn severity according to TBSA and SOFA score.

Measuring gastric residual volumes in critically ill burn patients - A systematic review

PURPOSE

Measuring gastric residual volumes (GRV) is common in intensive care units (ICU) in patients receiving enteral nutrition (EN) and are a common source of feeding interruptions. Interruptions in EN yield adverse outcomes and are an area of improvement in burn care. The objectives of this study are to summarize the literature's ICU GRV practices and offer practical suggestions to GRV management in the burn patient.

METHODS

PubMed, SCOPUS, and OvidSP Medline were systematically reviewed using the keywords: burns; thermal injury; gastric residual volume; enteral feeding; tube feeding; enteral nutrition; gastric intolerance; ICU; critical illness. Reviews, case reports, and consensus and opinion papers were excluded.

RESULTS

26 articles were identified. Six burn-specific studies were identified. GRV practices vary widely and are a common cause of EN interruption. Elevated GRVs do not equate to gastrointestinal intolerance and do not always reflect aspiration risk.

CONCLUSIONS

We advocate a GRV threshold of 500mL should be used to optimize the benefits of EN in burn ICUs. A single incident of elevated GRVs should not mandate immediate EN rate reduction or cessation but should prompt a thoughtful examination of secondary causes of gastrointestinal intolerance. Randomized controlled trials are needed to define the ideal GRV threshold and re-evaluate its role in burn care.

Comparison of Automated Methods Versus the American Burn Association Sepsis Definition to Identify Sepsis and Sepsis With Organ Dysfunction/Septic Shock in Burn-Injured Adults

To develop an algorithm to identify sepsis and sepsis with organ dysfunction/septic shock in burn-injured patients incorporating criteria from the American Burn Association sepsis definition that possesses good test characteristics compared with International Classification of Diseases, Ninth Revision-Clinical Modification (ICD-9) codes and an algorithm previously validated in nonburn-injured septic patients (Martin et al method). This was a retrospective cohort study of consecutive patients admitted to the burn intensive care unit between January 2008 and March 2015. Of the 4761 admitted, 8.6% (n = 407) met inclusion criteria, of which the case rate for sepsis was 34.2% (n = 139; n = 48 sepsis; n = 91 sepsis with organ dysfunction/septic shock). For sepsis identification, the novel algorithm had an accuracy of 86.0% (95% CI: 82.2-89.2%), sensitivity of 66.9% (95% CI: 59.1-74.7%), and specificity of 95.9% (95% CI: 93.5-98.3%). The novel algorithm had better discrimination (0.81, 95% CI: 0.77-0.86) than the ICD-9 method (0.77, 95% CI: 0.73-0.81), although this was not significant (P = .08). For sepsis with organ dysfunction/septic shock, the novel algorithm plus vasopressors (0.67, 95% CI: 0.63-0.72) and the ICD-9 method (0.63, 95% CI: 0.58-0.68) performed equivocal (P = 0.15) but the Martin method (0.76, 95% CI: 0.71-0.81) had superior discrimination than other methods (P < .01). The novel algorithm is an accurate and simple tool to identify sepsis in the burn cohort with good sensitivity and specificity and equivocal discriminative ability to ICD-9 coding. The Martin method had superior discriminative ability for identifying sepsis with organ dysfunction/septic shock in burn-injured patients than either the novel algorithm plus vasopressors or ICD-9 coding.

Permissive Underfeeding of the Critically Ill Patient

The rise in the popularity of nutrition support in the 1970s was associated with the concept of "hyperalimentation." This concept was based on the early findings that increased metabolic rates were observed in various disease states such as trauma, sepsis, and burns. The aim was to feed 40% to 100% above the basal metabolic rate to avoid weight loss associated with critical illness. Since that time, several observations have indicated that permissive underfeeding may be beneficial because: (a) the metabolic rate is not markedly increased in most patients with critical illness except burns; (b) weight gain during nutrition support in critical illness is not caused by a gain in nitrogen but fat; (c) energy intake as glucose in excess of needs causes increased carbon dioxide production and a fatty liver; (d) hyperglycemia increases the risk of infective complications; and (e) a controlled trial of preoperative nutrition in which patients received 1000 kcal above the metabolic rate increased infectious complications.

Effect of Feeding-Tube Properties on Residual Volume Measurements in Tube-Fed Patients

BACKGROUND

The effect of feeding tube size and port configuration on the ability to measure gastric residual volume (GRV) is poorly understood. In addition, there is confusion about the need to measure GRVs during feedings into the small bowel. This study sought to (1) compare the volume of gastric contents obtained from small-diameter feeding tubes and large-diameter sump tubes concurrently positioned in the stomach and (2) describe the distribution of GRVs during small-bowel feedings.

METHODS

For the first objective, GRV measurements were made from 10-Fr tubes (n = 645) and 14-Fr or 18-Fr sump tubes (n = 645) concurrently present in 62 critically ill patients. Sixty-milliliter syringes were used to measure GRVs from the 10-Fr tubes; the fluid was returned to the stomach and measurements were repeated from the large-diameter sump tubes. To address the second research objective, 890 GRV measurements were made from 14-Fr or 18-Fr gastric sump tubes (not connected to suction) in 75 critically ill patients who were receiving small-bowel feedings.

RESULTS

When GRVs were >50 mL, a linear regression equation indicated that volumes obtained from the large-diameter sump tubes were about 1.5 times greater than those obtained from the small-diameter tubes concurrently present in the stomach, p < .001. Gastric volumes > or =100 mL were found in 11.6% of the 890 measurements made in patients receiving small-bowel feedings; volumes > or =150 mL were found in 5.4% of the measurements.

CONCLUSIONS

The findings suggest that GRVs obtained from large-diameter sump tubes are about 1.5 times greater than those obtained from 10-Fr tubes. Large GRVs occur in at least 5% of patients receiving postpyloric feedings.

Burn intensive care

As a result of continuous development in the treatment of burns, the LD50 (the burn size lethal to 50% of the population) for thermal injuries has risen from 42% total body surface area (TBSA) during the 1940s and 1950s to more than 90% TBSA for young thermally injured patients. This vast improvement in survival is due to simultaneous developments in critical care, advancements in resuscitation, control of infection through early excision, and pharmacologic support of the hypermetabolic response to burns. This article reviews these recent advances and how they influence modern intensive care of burns.

Severe burn injury, burn shock, and smoke inhalation injury in small animals. Part 2: diagnosis, therapy, complications, and prognosis

OBJECTIVE

To review the evaluation and treatment of patients suffering from severe burn injury (SBI), burn shock, and smoke inhalation injury. Potential complications and prognosis associated with SBI are also discussed.

DIAGNOSIS

Diagnosis of burn injury and burn shock is based on patient history and clinical presentation. Superficial burn wounds may not be readily apparent for the first 48 h whereas more severe wounds will be evident at presentation. Patients are diagnosed with local or SBI by estimating total body surface area involved using the 'Rule of Nines' or the Lund-Browder chart adapted from the human literature.

THERAPY

Patients suffering from SBI require immediate and aggressive fluid therapy. Burn wounds require prompt cooling to prevent progressive tissue damage. Due to significant pain associated with burn wounds and therapeutic procedures, multimodal analgesia is recommended. Daily wound management including hydrotherapy, topical medications, and early wound excision and grafting is necessary with SBI.

COMPLICATIONS

There are numerous complications associated with SBI. The most common complications include infections, hypothermia, intra-abdominal hypertension, and abdominal compartment syndrome.

PROGNOSIS

The prognosis of SBI in domestic animals is unknown. Based on information derived from human literature, patients with SBI and concomitant smoke inhalation likely have a worse prognosis than those with SBI or smoke inhalation alone.

Impact of disease severity on gastric residual volume in critical patients

AIM: To investigate whether illness severity has an impact on gastric residual volume (GRV) in medical critically ill patients.

METHODS: Medical intensive care unit (ICU) patients requiring nasogastric feeding were enrolled. Sequential Organ Failure Assessment (SOFA) score was assessed immediately preceding the start of the study. Acute Physiology and Chronic Health Evaluation (APACHE) II scores were recorded on the first, fourth, seventh, and fourteenth day of the study period. GRV was measured every 4 h during enteral feeding. The relationship between mean daily GRV and SOFA scores and the correlation between mean daily GRV and mean APACHE II score of all patients were evaluated and compared.

RESULTS: Of the 61 patients, 43 patients were survivors and 18 patients were non-survivors. The mean daily GRV increased as SOFA scores increased (P < 0.001, analysis of variance). Mean APACHE II scores of all patients correlated with mean daily GRV (P = 0.011, Pearson correlation) during the study period. Patients with decreasing GRV in the first 2 d had better survival than patients without decreasing GRV (P = 0.017, log rank test).

CONCLUSION: GRV is higher in more severely ill medical ICU patients. Patients with decreasing GRV had lower ICU mortality than patients without decreasing GRV.

Gastric Residual Volume and Aspiration in Critically Ill Patients Receiving Gastric Feedings

Background The helpfulness of bedside assessment of gastric residual volume in the prediction of aspiration has been questioned, as has the volume that signals increased risk of aspiration.

Objective To describe the association between gastric residual volumes and aspiration of gastric contents.

Methods In a prospective study of 206 critically ill patients receiving gastric tube feedings for 3 consecutive days, gastric residual volumes were measured with 60-mL syringes every 4 hours. Measured volumes were categorized into 3 overlapping groups: at least 150 mL, at least 200 mL, and at least 250 mL. Patients were categorized as frequent aspirators if 40% or more of their tracheal secretions were positive for pepsin and as infrequent aspirators if less than 40% of their secretions were positive for pepsin. Gastric residual volumes were compared between the 2 aspiration groups.

Results Approximately 39% of the 206 patients had 1 or more gastric residual volumes of at least 150 mL, 27% had 1 or more volumes of at least 200 mL, and 17% had 1 or more volumes of at least 250 mL. Large-bore tubes identified most of the high volumes. Eighty-nine patients were frequent aspirators. Volumes less than 150 mL were common in both aspiration groups. However, the frequent aspirators had a significantly greater frequency of 2 or more volumes of at least 200 mL and 1 or more volumes of at least 250 mL.

Conclusions No consistent relationship was found between aspiration and gastric residual volumes. Although aspiration occurs without high gastric residual volumes, it occurs significantly more often when volumes are high.

Resting energy expenditure in severely burned children: Analysis of agreement between indirect calorimetry and prediction equations using the Bland–Altman method

INTRODUCTION

Knowledge of a child's resting energy expenditure (REE) is essential in optimizing nutritional support for severely burned children. The provision of adequate nutritional support is vital in order to avoid the consequences of malnutrition or overfeeding. Nutritional requirements for severely burned children are often based on equations for estimates of REE. The accuracy of the predictive equations of REE has been questioned and many authors have advocated the measurement of REE. This study tests the hypothesis that estimates of REE vary significantly from measured REE (MREE) in a population of severely burned children, and are not accurate for determining nutritional requirements.

METHODS

In 91 severely burned children aged between 3 and 18 years, REE was measured by indirect calorimetry (MREE) at the height of the hypermetabolic response and compared with predicted equations (PREE) from the Food and Agriculture/World Health Organization/United Nations University (FAO/WHO/UNU), Schofield-HW and Harris-Benedict. Agreement between indirect calorimetry and predicted equations was assessed following the Bland-Altman method.

RESULTS

In the entire cohort group, predicted REE from all three equations were significantly lower compared to MREE (p<0.05). There was poor agreement between the MREE and predicted using all three equations. The Schofield-HW equation showed the lowest mean MREE-PREE difference: 635+/-526 kcal/day (limits of agreement -608 and 1878 kcal/day; 95% confidence interval for the bias 525-745 kcal/day). Additionally, all three equations under predicted REE and were not significantly different from one another (p=0.98).

CONCLUSIONS

Until more accurate predicted equations are developed, we recommend indirect calorimetry measurements for determining resting energy expenditure in severely burned children.

Poor validity of residual volumes as a marker for risk of aspiration in critically ill patients

BACKGROUND AND AIMS

Elevated residual volumes (RV), considered a marker for the risk of aspiration, are used to regulate the delivery of enteral tube feeding. We designed this prospective study to validate such use.

METHODS

Critically ill patients undergoing mechanical ventilation in the medical, coronary, or surgical intensive care units in a university-based tertiary care hospital, placed on intragastric enteral tube feeding through nasogastric or percutaneous endoscopic gastrostomy tubes, were included in this study. Patients were fed Probalance (Nestle USA) to provide 25 kcal/kg per day (to which 10 yellow microscopic beads and 4.5 mL of blue food coloring per 1,500 mL was added). Patients were randomized to one of two groups based on management of RV: cessation of enteral tube feeding for RV >400 mL in study patients or for RV >200 mL in controls. Acute Physiology and Chronic Health Evaluation (APACHE) III, bowel function score, and aspiration risk score were determined. Bedside evaluations were done every 4 hrs for 3 days to measure RV, to detect blue food coloring, to check patient position, and to collect secretions from the trachea and oropharynx. Aspiration/regurgitation events were defined by the detection of yellow color in tracheal/oropharyngeal samples by fluorometry. Analysis was done by analysis of variance, Spearman's correlation, Student's t-test, Tukey's method, and Cochran-Armitage test.

RESULTS

Forty patients (mean age, 44.6 yrs; range, 18-88 yrs; 70% male; mean APACHE III score, 40.9 [range, 12-85]) were evaluated (21 on nasogastric, 19 on percutaneous endoscopic gastrostomy feeds) and entered into the study. Based on 1,118 samples (531 oral, 587 tracheal), the mean frequency of regurgitation per patient was 31.3% (range, 0% to 94%), with a mean RV for all regurgitation events of 35.1 mL (range, 0-700 mL). The mean frequency of aspiration per patient was 22.1% (range, 0% to 94%), with a mean RV for all aspiration events of 30.6 mL (range, 0-700 mL). The median RV for both regurgitation and aspiration events was 5 mL. Over a wide range of RV, increasing from 0 mL to >400 mL, the frequency of regurgitation and aspiration did not change appreciably. Aspiration risk and bowel function scores did not correlate with the incidence of aspiration or regurgitation. Blue food coloring was detected on only three of the 1,118 (0.27%) samples. RV was < or =50 mL on 84.1% and >400 mL on 1.4% of bedside evaluations. Sensitivities for detecting aspiration per designated RV were as follows: 400 mL = 1.5%; 300 mL = 2.3%; 200 mL = 3.0%; and 150 mL = 4.5%. Low RV did not assure the absence of events, because the frequency of aspiration was 23.0% when RV was <150 mL. Raising the designated RV for cessation of enteral tube feeding from 200 mL to 400 mL did not increase the risk, because the frequency of aspiration was no different between controls (21.6%) and study patients (22.6%). The frequency of regurgitation was significantly less for patients with percutaneous endoscopic gastrostomy tubes compared with those with nasogastric tubes (20.3% vs. 40.7%, respectively; p = .046). There was no correlation between the incidence of pneumonia and the frequency of regurgitation or aspiration.

CONCLUSIONS

Blue food coloring should not be used as a clinical monitor. Converting nasogastric tubes to percutaneous endoscopic gastrostomy tubes may be a successful strategy to reduce the risk of aspiration. No appropriate designated RV level to identify aspiration could be derived as a result of poor sensitivity over a wide range of RV. Study results do not support the conventional use of RV as a marker for the risk of aspiration.

Support of the metabolic response to burn injury

Severe burn causes metabolic disturbances that can last for a year after injury; persistent and profound catabolism hampers rehabilitative efforts and delays the meaningful return of individuals to society. The simplest, effective anabolic strategies for severe burn injuries are: early excision and grafting of the wound; prompt treatment of sepsis; maintenance of environmental temperature at 30-32 degrees C; continuous feeding of a high carbohydrate, high protein diet, preferably by the enteral route; and early institution of vigorous and aerobic resistive exercise programmes. To further keep erosion of lean body mass to a minimum, administration of anabolic agents, recombinant human growth hormone, insulin, oxandrolone, or anticatabolic drugs such as propranolol are alternative approaches. Exogenous continuous low-dose insulin infusion, beta blockade with propranolol, and use of the synthetic testosterone analogue oxandrolone are the most cost effective and least toxic pharmacological treatments to date.

Feeding Intolerance as a Result of Small-Intestine Intussusception in a Child With Major Burns

Feeding intolerance is common in critically ill children. We present an unusual case of jejunojejunal intussusception causing feeding intolerance in a child with major burns. An 18-month-old female was admitted to the intensive care unit after sustaining a 65% TBSA burn. Following a decompressive laparotomy for abdominal compartment syndrome, nasojejunal feeds were started immediately after surgery, which she did not tolerate. A plain abdominal radiograph revealed a collection of intraluminal air and an abdominal CT revealed a proximal jejunojejunal intussusception. The patient underwent laparotomy and an uncomplicated reduction of the small-bowel intussusception (SBI). Successful enteral feedings were commenced on hospital day 24, and the patient was discharged to home after approximately a 4.5-month hospitalization. The major learning point is that SBI can cause feeding intolerance in the child with major burns. Despite the low incidence of SBI in critically ill children, arriving at a timely diagnosis is essential because the consequences of a missed or delayed diagnosis include intestinal ischemia, necrosis, or perforation. Because SBI defies diagnosis by techniques traditionally used to diagnose intussusception involving the colon, clinical suspicion for intussusception is needed to facilitate the urgent diagnosis and correction of feeding intolerance caused by mechanical obstruction.

Clinical use of gastric residual volumes as a monitor for patients on enteral tube feeding

BACKGROUND

The use of gastric residual volumes (GRVs) as a clinical monitor for patients receiving enteral tube feeding (ETF) is based on presumptions that are not physiologically sound and practice that is poorly standardized.

METHODS

This systematic review of the medical literature summarizes results from studies that evaluate the practice, interpretation, and impact on patient outcome from use of GRV.

RESULTS

Little data exist to support a correlation of GRV with gastric emptying, volume of gastric contents, or changes in the infusion of ETF. GRVs do not correlate to regurgitation or aspiration, and their use cannot be relied on to protect patients against aspiration pneumonia. Although recent reports suggest that elevated GRVs correlate to "intolerance" of ETF, use as a marker of impending clinical deterioration is limited by the fact that the timing of increases in GRV is unpredictable and high GRVs do not correlate independently to adverse outcome. The practice of GRV may in fact impede delivery of ETF by promoting inappropriate cessation and reducing potential infusion time.

CONCLUSIONS

Modifying interpretation and the response by healthcare providers to GRV data are needed to preserve any clinical use for this practice.

Enteral feeding in patients with major burn injury: the use of nasojejunal feeding after the failure of nasogastric feeding

Patients with major burn injury have increased protein and energy requirements and early feeding is an established part of their management. The optimal method of feeding is unknown. Nasogastric feeding is often unsuccessful and total parenteral nutrition has a number of potential disadvantages. Post pyloric feeding is an alternative means of providing enteral nutrition. We report our experience of enteral feeding of patients with significant burn injury. Nasogastric feeding was successful in only 7 of 17 patients (41%). The commonest reason that nasogastric feeding failed was gastric stasis. All patients who failed nasogastric feeding were commenced on nasojejunal feeding and a further two patients were fed by this route initially. Ten of these 12 patients (83%) were successfully fed nasojejunally. No major adverse events attributable to nasojejunal feeding were identified, a nasojejunal tube was successfully placed in all but 1 patient and the tubes were well tolerated. We conclude that nasojejunal tube feeding should be considered in all patients with significant burn injury who cannot tolerate nasogastric tube feeding.

Energy expenditure and caloric balance after burn: increased feeding leads to fat rather than lean mass accretion

OBJECTIVE

Resting energy expenditure (REE) is commonly measured in critical illness to determine caloric "demands" and thus nutritive needs.

SUMMARY BACKGROUND DATA

The purpose of this study was to 1) determine whether REE is associated with clinical outcomes and 2) determine whether an optimal caloric delivery rate based on REE exists to offset erosion of lean mass after burn.

METHODS

From 1995 to 2001, REE was measured by indirect calorimetry in 250 survivors of 10 to 99%TBSA burns. Caloric intake and REE were correlated with muscle protein catabolism, length of stay, ventilator dependence, sepsis, and mortality. From 1998 to 2000, 42 patients (>60%TBSA burns) received continuous enteral nutrition at a spectrum of caloric balance between 1.0x REE kcal/d -1.8x REE kcal/d. Serial body composition was measured by dual energy x-ray absorptiometry. Lean mass, fat mass, morbidity, and mortality were determined.

RESULTS

REE/predicted basal metabolic rate correlated directly with burn size, sepsis, ventilator dependence, and muscle protein catabolism (P <.05). Declining REE correlated with mortality (P <.05). 2) Erosion of lean body mass was not attenuated by increased caloric balance, however, fat mass increased with caloric supply (P <.05).

CONCLUSION

In surviving burned patients, caloric delivery beyond 1.2 x REE results in increased fat mass without changes in lean body mass. Declining energy expenditure appears to be a harbinger of mortality in severely burned patients.

Upper digestive intolerance during enteral nutrition in critically ill patients: frequency, risk factors, and complications

OBJECTIVE

To study the frequency of and risk factors for increased gastric aspirate volume (GAV) and upper digestive intolerance and their complications during enteral nutrition (EN) in critically ill patients.

DESIGN

Prospective observational study.

SETTING

Intensive care unit (ICU) in a general hospital.

PATIENTS

A total of 153 patients with nasogastric tube feeding.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Upper digestive intolerance was considered when GAV was between 150 and 500 mL at two consecutive measurements, when it was >500 mL, or when vomiting occurred. Forty-nine patients (32%; 95% confidence interval [CI], 25%-42%) presented increased GAV after a median EN duration of 2 days (range, 1-16 days), and 70 patients (46%; 95% CI, 38%-54%) presented upper digestive intolerance. Independent risk factors for high GAV were GAV >20 mL before the start of EN (odds ratio [OR], 2.16; 95% CI, 1.11-4.18; p =.02), GAV >100 mL during EN (OR, 1.49; 95% CI, 1.01-2.19; p <.05), sedation during EN (OR, 1.78; 95% CI, 1.17-2.71; p =.007), use of catecholamines during EN (OR, 1.81; 95% CI, 1.21-2.70; p =.004). Complications related to high GAV were a lower feed intake (15 +/- 7 vs. 19 +/- 8 kcal/kg/day; p =.0004) and vomiting (53% vs. 23%; p =.0002). Complications related to upper digestive intolerance were the development of pneumonia (43% vs. 24%; p =.01), a longer ICU stay (23 +/- 21 vs. 15 +/- 16 days; p =.007), and a higher ICU mortality (41% vs. 25%; p =.03), even after adjustment for Simplified Acute Physiology Score II (OR, 1.48; 95% CI, 1.04-2.10; p =.028).

CONCLUSION

In ICU patients receiving nasogastric tube feeding, high gastric aspirate volume was frequent, occurred early, and was more frequent in patients with sedation or catecholamines. High gastric aspirate volume was an early marker of upper digestive intolerance, which was associated with a higher incidence of nosocomial pneumonia, a longer ICU stay, and a higher ICU mortality.

Effectiveness and safety of a protocol for promotion of early intragastric feeding in critically ill children

OBJECTIVES: To investigate the feasibility, adequacy, and efficacy of early poststress intragastric feeding (EPIGF) in critically ill children. DESIGN: A prospective clinical study. SETTING: Pediatric intensive care unit in a tertiary care children's hospital. PATIENTS: Seventy-one consecutively enrolled critically ill children requiring prolonged mechanical ventilation. INTERVENTIONS: Full-strength intragastric tube feedings (Nutrison Pediatric, Standard) were initiated within 12 hrs of the study-entry event. Enteral feedings were advanced to a target volume of energy intake = 1/2, 1, 5/4, 6/4, and 6/4 of the predicted basal metabolic rate (PBMR) on days 1-5, respectively. MEASUREMENTS AND MAIN RESULTS: Nutritional status by the caloric intake, recommended dietary allowances, PBMR, predicted energy expenditure (PEE), anthropometry, and clinical indices were evaluated on days 1 and 5. Safety was assessed by the clinical course of disease, laboratory findings, and occurrence of complications. Success was determined by accomplishment of the PEE target. The early success rate was 94.4% and predicted late enteral feeding success accurately (p =.0001). Caloric intake approached PBMR the second day (43 +/- 1.7 kcal/kg/day vs. 43.2 +/- 1.1 kcal/kg/day) and PEE the fifth day (66.2 +/- 2.7 kcal/kg/day vs. 67.7 +/- 6.4 kcal/kg/day). Multivariate stepwise regression analysis showed that poor outcome and a high Therapeutic Intervention Scoring System score correlated with failure of EPIGF (p <.0001). Patients who succeeded EPIGF had significantly higher myocardial ejection (65% vs. 43%; p <.0001) or shortening fractions (34% vs. 20%; p =.0001) on day 1 than those who failed. Patients tolerated EPIGF well; 9.9% developed nosocomial pneumonia, 5.6% developed diarrhea, and 8.5% needed treatment with cisapride because of a delay of gastric emptying. The mortality rate (5.6%) was different between initial and final success and failure groups (p <.0001) and was lower than predicted by the admission severity scores (12% +/- 2%). CONCLUSIONS: This study showed that increases of caloric intake during the acute phase of a critical illness are well tolerated and may approach PBMR by the second day and PEE by the fourth day in critically ill children. Caloric intake lower than PBMR is associated with higher mortality and morbidity rates.

Determinants of skeletal muscle catabolism after severe burn

OBJECTIVE

To determine which patient factors affect the degree of catabolism after severe burn.

SUMMARY BACKGROUND DATA

Catabolism is associated with severe burn and leads to erosion of lean mass, impaired wound healing, and delayed rehabilitation.

METHODS

From 1996 to 1999, 151 stable-isotope protein kinetic studies were performed in 102 pediatric and 21 adult subjects burned over 20-99. 5% of their total body surface area (TBSA). Patient demographics, burn characteristics, and hospital course variables were correlated with the net balance of skeletal muscle protein synthesis and breakdown across the leg. Data were analyzed sequentially and cumulatively through univariate and cross-sectional multiple regression.

RESULTS

Increasing age, weight, and delay in definitive surgical treatment predict increased catabolism (P < .05). Body surface area burned increased catabolism until 40% TBSA was reached; catabolism did not consistently increase thereafter. Resting energy expenditure and sepsis were also strong predictors of net protein catabolism. Among factors that did not significantly correlate were burn type, pneumonia, wound contamination, and time after burn. From these results, the authors also infer that gross muscle mass correlates independently with protein wasting after burn.

CONCLUSIONS

Heavier, more muscular subjects, and subjects whose definitive surgical treatment is delayed are at the greatest risk for excess catabolism after burn. Sepsis and excessive hypermetabolism are also associated with protein catabolism.

Nutritional support in sepsis: still skeptical?

The immediate metabolic response to a septic challenge is probably adaptive, meaning that nutritional interference, mainly via the parenteral route, during this early phase of instability can do more harm than good. During the later phases, a gradual increase in enteral nutrition, at the expense of parenteral nutrition, combined with the administration of nutraceuticals such as glutamine and omega-3 fatty acids, can counteract wasting and modulate the complex inflammatory response and immunosuppression associated with sepsis. In these times of scarce resources, there is an urgent need to clearly document the efficacy of immuno/pharmaconutrients, individually and in combination, enterally or parenterally, before proposing them for routine management of septic patients in the intensive care unit.