Detection of aspiration in enterally fed patients: a requiem for bedside monitors of aspiration

Association of enteral feeds in critically ill bronchiolitis patients supported by high-flow nasal cannula with adverse events and outcomes

To study association of enteral feeds in bronchiolitis patients supported by different levels of high flow nasal cannula (HFNC) with adverse events, nutritional goals, and clinical outcomes. Bronchiolitis patients ≤ 24 months of age treated with < 1 L/kg/min, 1-2 L/kg/min and > 2 L/kg/min of HFNC between January 2014 and December 2021 were studied retrospectively at a tertiary care children's hospital. Adverse events (aspiration pneumonia, emesis, and respiratory support escalation), nutritional goals (initiation of enteral feeds, achievement of nutritional goal volume and goal calories, percentage weight change during hospital stay) and clinical outcomes (HFNC duration, oxygen supplementation duration after HFNC, length of hospital stay following HFNC support, total length of hospital stay and follow-up for 1 month after hospital discharge) were compared between fed and non-fed patients on HFNC. Six hundred thirty-six (489 fed and 147 not-fed) bronchiolitis patients on HFNC studied. 260 patients, 317 patients and 59 patients were supported by < 1 L/kg/min, 1-2 L/kg/min and > 2 L/kg/min of HFNC, respectively. Enterally fed patients had significantly less adverse events (OR = 0.14, 95% CI 0.083 - 0.23, p < 0.001), significantly better nutritional goals: earlier initiation of enteral feeds by 65% in time (mean ratio = 0.35, 95% CI 0.28 - 0.43, p < 0.001), earlier achievement of goal volume and goal calorie needs by 14% in time (mean ratio = 0.86, 95% CI 0.78 to 0.96, p = 0.005) and significantly better clinical outcomes: shorter HFNC duration by 29.75 h (95% CI 20.19 -39.31, p < 0.001), shorter oxygen supplementation duration after HFNC by 12.14 h (95% CI 6.70 -17.59, p < 0.001), shorter length of hospital stay after HFNC support by 21.35 h (95% CI 14.71-27.98, p < 0.001) and shorter total length of hospital stay by 51.10 h (95% CI 38.65 -63.55, p < 0.001), as compared to non-fed patients, after adjusting for age, weight, prematurity, comorbidities, admission time, admission bronchiolitis score, admission respiratory rate, and HFNC levels. The number of revisits and readmissions at 7 and 30 days after hospital discharge were not significantly different (p > 0.05) between the fed and non-fed groups.    Conclusion: Enteral feeding of bronchiolitis patients supported by different levels of HFNC is associated with less adverse events and better nutrition goals and clinical outcomes. What is Known: •There is general apprehension to feed critically ill bronchiolitis patients supported by high flow nasal cannula. What is New: •Our study reveals that enteral feeding of critically ill bronchiolitis patients supported by different levels of high flow nasal cannula is associated with minimal adverse events, better nutritional goals and improved clinical outcomes as compared to non-fed patients.

Complications during Fiberoptic Endoscopic Evaluation of Swallowing (FEES) in 5680 examinations

OBJECTIVE

To evaluate retrospectively the incidence of complications during Fiberoptic Endoscopic Evaluation of Swallowing (FEES) in 5680 examinations.

PATIENTS AND METHODS

5680 patients were evaluated at the Department of Otorhinolaryngology, Audiology and Phoniatrics of Pisa University Hospital between January 2014 and December 2018, involving both inpatients and outpatients. Most common comorbidities included neurological pathologies such as stroke (11.8%), neurodegenerative diseases (28.9%) and a history of previous head and neck surgery (24.6%). The evaluation was conducted by clinicians with experience in swallowing for a minimum of 10 years with the assistance of one or more speech language pathologists.

RESULTS

In all patients studied the endoscope insertion was tolerated and it was possible to visualize the pharyngo-laryngeal structures. Most patients reported discomfort In a minority of patients, complications were recorded, such as anterior epistaxis, posterior epistaxis, vasovagal crises and laryngospasm. Laryngospasm was recorded in patients affected by Amyotrophic Lateral Sclerosis (ALS). Multivariate binary logistic regression showed that discomfort, chronic gastrointestinal diseases, neurodegenerative diseases and brain tumors were risk factors associated with minor complications.

CONCLUSIONS

FEES proved to be easy to perform, well tolerated by the patients and cost-effective. It can be performed at the patient's bedside and it is characterized by low rate of complications. As a matter of fact, normally only discomfort, gagging and/or vomit are reported. Only rarely complications occur, such as anterior or posterior epistaxis episodes or vasovagal crises, but these are still easily managed. Exceptionally, more severe complications are reported: adverse drug reactions to substances such as blue dye (methylene blue) and local anesthetics (not used in our protocol), and laryngospasm.

Assessment of the effect of colored beverage on gastric returns after gastric tube replacement to enhance placement verification

BACKGROUND

Verification of appropriate placement of newly replaced gastrostomy tubes is essential prior to use to avoid potentially serious adverse events.

PROBLEM

A lack of standardized guidance regarding effective and practical means to verify placement exists. Aspiration or drainage of gastric-like contents is one mean suggested to help determine placement, yet when returns are minimal, this becomes challenging.

MATERIALS, METHOD, INTERVENTION

Oral ingestion or the instillation of a colored beverage prior to tube replacement was used in a midwestern healthcare clinical setting to enhance returns in both volume and color via the newly replaced gastrostomy tube. A retrospective review of this practice was conducted, which included 176 gastric tube replacements over 4 years.

RESULTS

A significant increase in volume of returns via the newly replaced tube was noted (P < .001) and a strong correlation of color to the ingested or consumed beverage was found with 95% of returns reflecting color tinting of the beverage or in many cases, strong color change to that of the beverage color.

CONCLUSION

Presented is a simple, cost-effective method that has shown to be clinically useful in assessing placement of newly replaced gastrostomy tubes that may be useful in other practices and settings.

Comparison of continuous versus intermittent enteral nutrition in critically ill patients (COINN): study protocol for a randomized comparative effectiveness trial

Background

Enteral nutrition is part of the treatment of critically ill patients. Administration of enteral nutrition may be associated with signs of intolerance, such as high gastric residual volumes, diarrhea, and vomiting. Clinical trials regarding the effects of the mode of administration of enteral nutrition on the occurrence of these complications have yielded conflicting results. This trial aims to investigate whether the mode of administration of enteral nutrition affects the time to reach nutritional targets, intolerance, and complications.

Methods

COINN is a randomized, monocentric study for critically ill adult patients receiving enteral nutrition. Patients will be randomly assigned to two groups receiving (1) continuous or (2) intermittent administration of enteral nutrition. Enhancement of enteral nutrition will depend on signs of tolerance, mainly the gastric residual volume. The primary outcome will be the time to reach the energetic target. Secondary outcomes will be the time to reach the protein target, tolerance, complications, hospital and ICU lengths of stay, and 28-day mortality.

Discussion

This trial aims to evaluate whether the mode of application of enteral nutrition affects the time to reach nutritional targets, signs of intolerance, and complications.

Trial registration

ClinicalTrials.gov NCT03573453. Registered on 29 June 2018

Nutritional aspects of care

Malnutrition in the oral and maxillofacial surgery surgical patient can have critical implications in the overall well-being and prognosis of the long-term, hospitalized, ill patient. The OMS should be capable of assessing the patient's nutritional status and nutritional requirements and developing appropriate recommendations for proper nutritional management. Knowledge of the various modalities of nutritional support should be readily available to the OMS practitioner.

Use of methylene blue spectrophotometry to detect subclinical aspiration in enterally fed intubated pediatric patients

OBJECTIVE

Enteral feeding is widely used in ventilated patients admitted to pediatric intensive care units. Although studies in adult patients have shown that the site of feeding (stomach vs. small intestine) may be associated with aspiration pneumonia, there are no such reports in critically ill pediatric patients. We hypothesized that in intubated pediatric patients, there was no difference in the frequency of aspiration between nasogastric and postpyloric enteral feeding.

DESIGN

Randomized, prospective clinical study.

SETTING

Single pediatric intensive care unit of a tertiary care children's hospital.

PATIENTS

Forty-four intubated patients (< or = 18 yrs old).

INTERVENTIONS

Intubated patients were randomized to receive either nasogastric (n = 27) or postpyloric (n = 17) enteral feeding. Feeding tube placement by the bedside nurse was confirmed by abdominal radiograph. Methylene blue was added at a standard dilution to an age-appropriate formula. Tracheal secretions were suctioned every 8 hrs, tested for blue color by observation, and analyzed via spectrophotometry. Patients were followed until feeds were stopped for anticipated extubation. Aspiration pneumonia was defined using criteria of the Centers of Disease Control and Prevention (CDC).

MEASUREMENTS AND MAIN RESULTS

Methylene blue was detected in two patients in the postpyloric group by spectrophotometry. None of the patients met the CDC criteria for aspiration. There was no difference in the frequency of aspiration between the two groups (p < .07). The time until beginning feedings in the postpyloric group was greater than that for the nasogastric group (18-24 hrs vs. 6 hrs, p < .05). The postpyloric group required more abdominal radiographs compared with the nasogastric group (three radiographs vs. one, p < .05).

CONCLUSIONS

Use of nasogastric feeding shortens the time needed to reach nutritional goals and reduces the number of radiographic studies. Nasogastric feeding demonstrates no increase in aspiration compared with postpyloric feeding in intubated pediatric patients.

Assessment of the prevalence of microaspiration by gastric pepsin in the airway of ventilated children

AIM

Mechanically ventilated patients are at risk for aspiration of gastric contents. The aim of this observational study was to determine the prevalence of micro-aspiration in children with cuffed and uncuffed endotracheal (ET) tubes and with tracheostomies and to assess the effect of feeding status on aspiration. Micro-aspiration was determined by measuring gastric pepsin in tracheal aspirates.

METHODS

We studied 27 children on ventilators in paediatric intensive care unit (PICU) and 10 children undergoing elective surgeries for various indications. Tracheal aspirates were collected from children on ventilatory support in the intensive care unit during medically indicated suctioning and from the group of children undergoing elective surgery in the operation room. Pepsin was detected by enzymatic assay.

RESULTS

Overall 70% of cases in PICU were positive for pepsin in at least one of the aspirates. Pepsin positivity was significantly lower in the cuffed group than in the uncuffed and tracheostomy groups. Tube feedings did not significantly influence the prevalence of pepsin positivity.

CONCLUSIONS

Measurement of gastric pepsin in tracheobronchial fluid is a sensitive tool to detect aspirations in mechanically ventilated children and to assess the efficacy of preventive measures in PICU settings.

Risk of aspiration in patients on enteral nutrition: frequency, relevance, relation to pneumonia, risk factors, and strategies for risk reduction

Upper digestive feeding intolerance, as evidenced by high gastric residual volume and vomiting, is the most common complication among hospitalized patients receiving enteral nutrition. These patients are at high risk of developing aspiration pneumonia, which in turn is associated with prolonged hospital stay and increased mortality. Most episodes of aspiration are small in volume and do not lead to pneumonia. The likelihood of pneumonia increases with multiple aspirations. Pneumonia is also more common in critically ill patients who have bacterial colonization of the oropharynx. Gastric residual volume is commonly used as a means to assess aspiration risk during tube feeding. However, recent studies have demonstrated that this measurement has limited sensitivity. The approach to minimizing the frequency of aspiration during tube feeding involves assessment of the patient's degree of risk and initiation of appropriate measures directed at risk reduction.

Fiberoptic endoscopic evaluation of swallowing (FEES) with and without blue-dyed food

The purpose of this prospective study was to determine if fiberoptic endoscopic evaluation of swallowing (FEES) maintains high intra- and interrater reliability in detecting pharyngeal dysphagia and aspiration without the addition of FD&C Blue No. 1 to food. Twenty consecutive adults referred for a swallow evaluation participated. Nine subjects received blue-dyed food and 11 subjects received regular nondyed food, i.e., yellow pudding and white skim milk. Four variables were rated: (1) the stage transition characterized by depth of bolus flow to at least the vallecula prior to the pharyngeal swallow; (2) evidence of bolus retention in the vallecula or pyriform sinuses after the pharyngeal swallow; (3) laryngeal penetration defined as material in the laryngeal vestibule but not passing below the level of the true vocal folds either before or after the pharyngeal swallow; and (4) tracheal aspiration defined as material below the level of the true vocal folds either before or after the pharyngeal swallow. Three speech-language pathologists experienced in interpreting FEES results independently and blindly reviewed the digitized videotape three times. Intrarater agreements for the four variables with blue-dyed and non-blue-dyed food trials were 100% and monochrome trials ranged from 95% to 100%. Average kappa values for interrater reliability ranged from moderate to excellent agreement (0.61-1.00) for all viewing conditions. Kappa values for blue-dyed trials versus monochrome trials were 0.83 and for non-blue-dyed trials versus monochrome trials were 0.88, indicative of excellent reliability under both viewing conditions. FEES maintains both high intra- and interrater reliability in detecting the critical features of pharyngeal dysphagia and aspiration using either blue-dyed or non-blue-dyed foods. The endoscopist, therefore, can be assured of reliable FEES results using regular, non-dyed food trials.

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.

The nasogastric feeding tube as a risk factor for aspiration and aspiration pneumonia

PURPOSE OF REVIEW

Aspiration is one of the most common complications in enterally fed patients. The source of aspiration is due to the accumulation of secretions in the pharynx of reflux gastric contents from the stomach into the pharynx. The true prevalence of aspiration is difficult to determine because of vague definitions, poor assessment methods, and varying levels of clinical recognition.

RECENT FINDINGS

There is evidence in the literature showing that the presence of a nasogastric feeding tube is associated with colonization and aspiration of pharyngeal secretions and gastric contents leading to a high incidence of Gram-negative pneumonia in patients on enteral nutrition. However, other aspects may be equally important and should also be considered when evaluating a patient suspected of having aspiration and aspiration pneumonia. The mechanisms responsible for aspiration in patients bearing a nasogastric feeding tube are (1). loss of anatomical integrity of the upper and lower esophageal sphincters, (2). increase in the frequency of transient lower esophageal sphincter relaxations, and (3). desensitization of the pharyngoglottal adduction reflex.

SUMMARY

Sometimes it is possible to differentiate whether the aspirate is gastric or pharyngeal. The kind of bacterial contamination is, however, more difficult to establish. Oral or dental disease, antibiotic therapy, systemic illness or malnutrition and reduction of salivary flow are responsible for colonization of Gram-negative bacteria in oral and pharyngeal flora in nasogastric-tube-fed patients. The use of a nasogastric feeding tube and the administration of food increase gastric pH and lead to colonization of gastric secretions. It has also been suggested that gastric bacteria could migrate upward along the tube and colonize the pharynx.