Salt Toxicity: A Systematic Review and Case Reports.

INTRODUCTION: Salt toxicity is a rare form of hypernatremia that typically occurs after a single massive ingestion of salt over a short period of time (minutes/hours). It is a dangerous imbalance capable of causing significant neurological injury; quick recognition of salt toxicity is crucial to allow treatment before permanent brain injury occurs. The purpose of this review is to assist emergency nurses in gaining knowledge on the causes, pathophysiology, symptoms, and treatment of salt toxicity. METHODS: A systematic search for case reports of hypernatremia due to salt toxicity was conducted in the PubMed and Scopus electronic databases. The search terms used were salt, sodium, hypernatremia, toxicity, poisoning, case reports, case series, and cases. The following were the inclusion criteria: publication dates between January 1, 2000, and September 30, 2019; evidence of an acute large oral or gastric tube ingestion of salt over a short period of time (minutes/hours); admission for treatment within hours of the event; laboratory verification of hypernatremia; and full-text article available electronically in English. The following were the exclusion criteria: an unclear history, high salt consumption over a period of days, high sodium intake via the intravenous route, and breast feeding. RESULTS: Only 15 cases met the inclusion criteria for the review. Patients described in the case reports ranged in age from 5 days to 73 years. Forty percent of the patients were children less than 15 years old. Of the 14 cases with known outcomes, 50% were fatal. The most frequent causes of salt toxicity were salt water emetics, intentional administration of large quantities of salt to a child by a caregiver, and suicide attempts. Among the other causes were unintentional salt overload in infant formula, an exorcism ritual, and a college prank. DISCUSSION: Findings from this review of 15 case reports in which a large salt load was ingested over a short period of time suggest that salt toxicity is a rare condition associated with high mortality. In addition, salt toxicity can occur in patients of all ages for a variety of reasons; the most frequently identified reasons in this review were use of salt water as an emetic and child abuse by the intentional administration of a high salt load by a caregiver. For patients whose massive exposure to salt is recent (such as minutes to hours), rapidly reducing the serum sodium concentration may prevent irreversible neurological injury.

A review of published case reports of inadvertent pulmonary placement of nasogastric tubes in children.

PROBLEM: Little is known about the incidence of inadvertent pulmonary placement of nasogastric tubes during blind insertions in children. PURPOSE: The purpose of this paper was to conduct a review of published case reports over the past two decades. METHODS: An OVID Medline search was conducted of articles published from 1993 through 2012. RESULTS: Fifteen published case reports were located; four patients died as a result of their malpositioned tubes. The auscultatory bedside method failed to detect the malpositioned tubes in all seven cases in which it was used. CONCLUSIONS: The incidence of inadvertent pulmonary placement of nasogastric tubes is relatively low but can lead to serious and even lethal results in children. The auscultatory method to predict tube location is unreliable.

Intrapulmonary Feeding Tube Placements While Using an Electromagnetic Placement Device: A Review (2019-2021).

BACKGROUND: Intrapulmonary placements of feeding tubes inserted with use of an electromagnetic placement device (EMPD) continue to occur. OBJECTIVE: To describe circumstances and outcomes associated with intrapulmonary feeding tube placements during use of an EMPD. METHODS: A retrospective review of reports to the US Food and Drug Administration's Manufacturer and User Facility Device Experience (MAUDE) database of intrapulmonary feeding tube placements during use of an EMPD from 2019 through 2021. Complications, outcomes, operator training, interference from anatomical variations and medical devices, and the use and accuracy of radiographs in identifying pulmonary placements were recorded. RESULTS: Sixty-two cases of intrapulmonary tube placement were identified; 10 were associated with a fatal outcome. Pneumothorax occurred in 35 cases and feedings were delivered into the lung in 11 cases. User error was cited in 6 cases and was implicit in most others. Little information was provided about operator training. Four intrapulmonary placements were associated with anatomical variations and 1 with a left ventricular assist device. Radiographic follow-up was described in 28 cases and correctly identified 23 of the intrapulmonary placements. CONCLUSIONS: User error was a significant factor, which highlights the need for empirical data to clarify the amount of training needed to safely credential EMPD operators. Clearer information is needed about anatomical variations that may contraindicate use of an EMPD, as well as medical devices that may interfere with an EMPD. Use of follow-up radiographs, interpreted by qualified personnel, is supported to increase the probability of identifying intrapulmonary tube placements.

CE: Monitoring Adult Patients for Intolerance to Gastric Tube Feedings.

ABSTRACT: Gastric tube feeding is a common and valuable intervention for patients in a variety of care settings. While tube feeding can save the lives of patients for whom oral feeding isn't possible, intolerance to tube feeding is a potential complication. This article discusses risk factors for feeding intolerance; the assessment of signs and symptoms of feeding intolerance; the various means of assessing gastric emptying, including the practice of monitoring gastric residual volume (GRV); the controversy surrounding GRV monitoring in assessing feeding tolerance; and the special considerations for monitoring feeding tolerance in acutely and critically ill adults with coronavirus disease 2019. The author, a nurse researcher with extensive experience in the area of enteral feeding, briefly summarizes recommendations and guidelines for enteral feeding published by national and international health care organizations between 2015 and 2020, and offers her perspective on best nursing practices for monitoring food tolerance in adults.

Effectiveness of an aspiration risk-reduction protocol.

BACKGROUND: Aspiration of gastric contents is a serious problem in critically ill, mechanically ventilated patients receiving tube feedings. OBJECTIVES: The purpose of this study was to evaluate the effectiveness of a three-pronged intervention to reduce aspiration risk in a group of critically ill, mechanically ventilated patients receiving tube feedings. METHODS: A two-group quasi-experimental design was used to compare outcomes of a usual care group (December 2002-September 2004) with those of an Aspiration Risk-Reduction Protocol (ARRP) group (January 2007-April 2008). The incidence of aspiration and pneumonia was compared between the usual care group (n = 329) and the ARRP group (n = 145). The ARRP had three components: maintaining head-of-bed elevation at 30 degrees or higher, unless contraindicated; inserting feeding tubes into distal small bowel, when indicated; and using an algorithmic approach for high gastric residual volumes. RESULTS: Two of the three ARRP components were implemented successfully. Almost 90% of the ARRP group had mean head-of-bed elevations of 30 degrees or higher as compared to 38% in the usual care group. Almost three fourths of the ARRP group had feeding tubes placed in the small bowel as compared with less than 50% in the usual care group. Only three patients met the criteria for the high gastric residual volume algorithm. Aspiration was much lower in the ARRP group than that in the usual care group (39% vs. 88%, respectively). Similarly, pneumonia was much lower in the ARRP group than that in the usual care group (19% vs. 48%, respectively). DISCUSSION: Findings from this study suggest that a combination of a head-of-bed position elevated to at least 30 degrees and use of a small-bowel feeding site can reduce the incidence of aspiration and aspiration-related pneumonia dramatically in critically ill, tube-fed patients.

A review of guidelines to distinguish between gastric and pulmonary placement of nasogastric tubes.

The purpose of this review was to (1) identify areas of agreement and disagreement in guidelines/recommendations to distinguish between gastric and pulmonary placement of nasogastric tube and (2) summarize factors that affect choices made by clinicians regarding which method(s) to use in specific situations. Systematic searches were conducted in the PubMed, Scopus, and CINAHL Plus databases using a combination of keywords and data-specific subject headings. Searches were limited to guidelines/recommendations from national level specialty groups and governmental sources published in the English language between January 1, 2015 and September 20, 2018. Fourteen guidelines that described methods to distinguish between gastric and pulmonary placement of nasogastric tubes were identified from a variety of geographic locations. Tube placement testing methods included in the review were: radiography, respiratory distress, aspirate appearance, aspirate pH, auscultation, carbon dioxide detection and enteral access devices. All fourteen guidelines agreed that radiography is the most accurate testing method. Of the nonradiographic methods, pH testing was most favored; least favored was auscultation.

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.

Preventing aspiration in older adults with dysphagia.

Dysphagia, the impairment of any part of the swallowing process, increases the risk of aspiration. Dysphagia and aspiration are associated with the development of aspiration pneumonia. While some changes in swallowing may be a natural result of aging, dysphagia is especially prevalent among older adults with neurologic impairment or dementia, leading to an increased risk of aspiration and aspiration pneumonia. This article discusses best practices for assessment and prevention of aspiration among older adults who are being hand-fed or fed by tube. To view an accompanying online video, go to http://links.lww.com/A226.

Incidence of Sinusitis Associated With Endotracheal and Nasogastric Tubes: NIS Database.

BACKGROUND: Endotracheal and nasogastric tubes are recognized risk factors for nosocomial sinusitis. The extent to which these tubes affect the overall incidence of nosocomial sinusitis in acute care hospitals is unknown. OBJECTIVE: To use data for 2008 through 2013 from the Nationwide Inpatient Sample database to compare the incidence of sinusitis in patients with nasogastric tubes with that in patients with an endotracheal tube alone or with both an endotracheal tube and a nasogastric tube. METHODS: Patients' data with any of the following International Classification of Disease, Ninth Revision, Clinical Modification codes were abstracted from the database: (1) 96.6, enteral infusion of concentrated nutritional substances; (2) 96.07, insertion of other (naso-)gastric tube; or (3) 96.04, insertion of an endotracheal tube. Sinusitis was defined by the appropriate codes. Weighted and unweighted frequencies and weighted percentages were calculated, categorical comparisons were made by χ2 test, and logistic regression was used to examine odds of sinusitis development by tube type. RESULTS: Of 1 141 632 included cases, most (68.57%) had an endotracheal tube only, 23.02% had a nasogastric tube only, and 8.41% had both types of tubes. Sinusitis was present in 0.15% of the sample. Compared with patients with only a nasogastric tube, the risk for sinusitis was 41% greater in patients with an endotracheal tube and 200% greater in patients with both tubes. CONCLUSION: Despite the low incidence of sinusitis, a significant association exists between sinusitis and the presence of an endotracheal tube, especially when a nasogastric tube is also present.

Update on Effectiveness of an Electromagnetic Feeding Tube-Placement Device in Detecting Respiratory Placements.

BACKGROUND: Radiography is the accepted gold standard for testing feeding tube placement; however, an electromagnetic tube-placement device (ETPD) is sometimes used in lieu of radiography for this purpose. High success rates have been reported when the device was used by well-trained individuals. However, authors previously described 20 cases that occurred between 2007 and 2012 in which clinicians voluntarily reported inability to detect inadvertent tube insertions in the respiratory tract while using an ETPD. OBJECTIVE: To describe case reports to the US Food and Drug Administration's Manufacturer and User Facility Device Experience (MAUDE) database between 2013 and 2015 regarding inadvertent respiratory placement of feeding tubes by operators using an ETPD. METHODS: The MAUDE database was searched for cases dated from January 1, 2013, through December 31, 2015, along with selected brand names. A total of 34 cases (25 after removal of duplicates) were located in which a feeding tube was inserted into the respiratory tract during insertions assisted by an ETPD. RESULTS: Sites of the malpositioned tubes included the right lung (n = 13), left lung (n = 6), unspecified lung (n = 4), and bronchus (n = 2). A pneumothorax occurred in 17 of the 25 misplacements; feedings were administered in 6 cases. CONCLUSIONS: Many case reports involved clinicians failing to recognize tube misplacements in the respiratory tract while using an ETPD. These reports provide evidence that not all clinicians can use the device effectively to detect malpositioned tubes. Thus, one must continue to question the wisdom of eliminating radiographic confirmation of tube position before starting feedings.

Administering Polyethylene Glycol Electrolyte Solution Via a Nasogastric Tube: Pulmonary Complications.

BACKGROUND: Patients sometimes require insertion of a nasogastric tube for the administration of a large volume of a polyethylene glycol electrolyte solution. If the tube is malpositioned, the risk for direct instillation of the solution into the lung increases. The risk for aspiration also increases if the infusion rate exceeds gastrointestinal tolerance. PURPOSE: To review published cases of patients' experiencing adverse pulmonary events after administration of polyethylene glycol electrolyte solution via a nasogastric tube and to offer suggestions to prevent these outcomes. METHODS: A search of the literature from 1993 through 2014 was performed by using the PubMed, MEDLINE, Cumulative Index to Nursing and Allied Health Literature, and Scopus databases. RESULTS: In the 12 case reports located, none of the patients had radiographs to verify tube location before infusion of polyethylene glycol electrolyte solution. After symptoms developed in 3 children (ages 8-11 years), radiographs showed their tubes incorrectly positioned in the bronchus, lung, or esophagus; ports of a fourth child's tube were in the oropharynx. The remaining 8 patients (ages 5-86 years) never had radiographs to determine tube placement. Pulmonary complications from the infusions of polyethylene glycol electrolyte solution contributed to the death of 5 of the patients. CONCLUSION: Relatively simple maneuvers to reduce the likelihood of adverse pulmonary events following the administration of large volumes of polyethylene glycol electrolyte solution via a nasogastric tube are well worth the cost and effort to protect patients from potential serious injury.

Testing Placement of Gastric Feeding Tubes in Infants.

BACKGROUND: Inadvertent positioning of a nasogastric tube in the lung can cause serious complications, so identifying methods to detect improperly inserted tubes is imperative. OBJECTIVES: To compare the sensitivity, specificity, and negative and positive predictive values of 4 pH cut points (< 4.0, < 4.5, < 5.0, and < 5.5) in differentiating gastric and tracheal aspirates under various treatment conditions and to explore the utility of a pepsin assay for distinguishing between gastric and tracheal aspirates. METHODS: Gastric and tracheal aspirates were collected from critically ill infants undergoing mechanical ventilation who had nasogastric or orogastric feeding tubes. Aspirates were tested with colorimetric pH indicators and a rapid pepsin assay. Information about treatment conditions was obtained from medical records. RESULTS: Two hundred twelve gastric aspirates and 60 tracheal aspirates were collected from 212 patients. Sensitivity was highest and specificity was lowest at the gastric aspirate pH cut point of less than 5.5. Positive predictive values were 100% at all pH cut points less than 5.0. Negative predictive values were higher at the pH cut point of less than 5.0 than at cut points less than 4.5. A higher percentage of pepsin-positive readings was found in gastric aspirates (88.3%) than in tracheal aspirates (5.4%). CONCLUSION: For a desired positive predictive value of 100%, a pH cut point of less than 5.0 provides the best negative predictive values, regardless of gastric acid inhibitor administration and feeding status. The pepsin assay is promising as an additional marker to distinguish gastric from tracheal aspirates.

Effect of pH Test-Strip Characteristics on Accuracy of Readings.

BACKGROUND: Little is known about characteristics of colorimetric pH test strips that are most likely to be associated with accurate interpretations in clinical situations. OBJECTIVES: To compare the accuracy of 4 pH test strips with varying characteristics (ie, multiple vs single colorimetric squares per calibration, and differing calibration units [1.0 vs 0.5]). METHODS: A convenience sample of 100 upper-level nursing students with normal color vision was recruited to evaluate the accuracy of the test strips. Six buffer solutions (pH range, 3.0 to 6.0) were used during the testing procedure. Each of the 100 participants performed 20 pH tests in random order, providing a total of 2000 readings. The sensitivity and specificity of each test strip was computed. In addition, the degree to which the test strips under- or overestimated the pH values was analyzed using descriptive statistics. RESULTS: Our criterion for correct readings was an exact match with the pH buffer solution being evaluated. Although none of the test strips evaluated in our study was 100% accurate at all of the measured pH values, those with multiple squares per pH calibration were clearly superior overall to those with a single test square. CONCLUSIONS: Test strips with multiple squares per calibration were associated with greater overall accuracy than test strips with a single square per calibration. However, because variable degrees of error were observed in all of the test strips, use of a pH meter is recommended when precise readings are crucial.

Preventing respiratory complications of tube feedings: evidence-based practice.

The most dreaded complication of tube feedings is tracheobronchial aspiration of gastric contents. Strong evidence indicates that most critically ill tube-fed patients receiving mechanical ventilation aspirate gastric contents at least once during their early days of tube feeding. Those who aspirate frequently are about 4 times more likely to have pneumonia develop than are those who aspirate infrequently. Although a patient's illness might not be modifiable, some risk factors for aspiration can be controlled; among these are malpositioned feeding tubes, improper feeding site, large gastric volume, and supine position. A review of current research-based information to support modification of these risk factors is provided.

Strategies to prevent aspiration-related pneumonia in tube-fed patients.

It is improbable that aspiration and aspiration-pneumonia can be entirely prevented, but application of one or more of the strategies described in this article probably can reduce these potentially life threatening conditions. Fortunately, many of these strategies are relatively easy and inexpensive to incorporate into routine care.

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.