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

Abstract

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.

Accuracy of the combined method (auscultation and pH measurement) and ultrasonography for confirmation of gastric tube placement: a study protocol for a prospective study

“…While a typical pH test strip costs less than 25 cents, a single chest or abdominal radiography may cost from $100 to several hundred US dollars. 9 According to the NHS, the routine use of radiography to confirm NGT positioning is not recommended except for patients at high risk of tube displacement, such as newborns or patients in a critical condition. 10 Ultrasonography is another diagnostic method currently used in the clinical practice to confirm NGT placement.…”

“…Among the other non-radiographic methods used, the measurement of pH is the first line test and the most sensitive. According to a recent review of international guidelines, 9 epigastric auscultation is the least desirable method, with pH measurement recommended by the UK National Patient Safety Agency (NPSA) 10 and American Association of Critical-Care Nurses. 7…”

“…The gastric pH is acid, with values varying from 1 to 5.5. 9 Values equal to or higher than 6 are indicators of gut or respiratory aspiration, with the latter being more alkaline. 7 Accordingly, values that are lower than 6 indicate gastric positioning and exclude the possible displacement of the tube to the lungs.…”

Análise da concordância da ausculta epigástrica e mensuração do pH na confirmação do posicionamento de sonda nasoenteral

“…A Associação Americana de Enfermeiros de Cuidados Críticos (em inglês, American Association of Critical Care Nurses -AACN) (2016) orienta a confirmação radiográfica de qualquer sonda nasoenteral recém inserida às cegas, à beira leito, antes da administração da NE ou de medicamentos. Na Europa e Austrália, o exame de raios X é realizado somente nos casos em que não for possível obter o aspirado, quando o resultado da medição do pH for inconclusivo ou quando o paciente apresentar elevado risco de aspiração(METHENY et al, 2019). No entanto, o exame necessita ser interpretado por profissional especializado em radiologia porque há relatos, na literatura, de eventos adversos respiratórios, ocasionados por falhas na interpretação do exame pelo profissional médico.…”

“…O exame deve mostrar todo o trajeto da sonda no UKOUMUNNE, 2011) e expor o paciente ao risco de pneumonia aspirativa se a sonda estiver inserida nos pulmões (NATIONAL HEALTH SERVICE, 2019).O resultado também pode ser alterado em pacientes em uso de medicamentos supressores de ácidos (TURGAY; KHORSHID, 2010). A utilização de fármacos antagonistas do receptor H2 (como ranitidina e cimetidina, por exemplo) pode elevar o pH gástrico, dificultando a determinação do local exato da extremidade distal da sonda (COLAÇO; NACIMENTO, 2014).Também foi verificado que, nesse hospital, todas as sondas Dobbhoff® são medidas para inserção no intestino, independentemente do paciente, e que o método clínico, utilizado para confirmar a posição da sonda, é a ausculta epigástrica seguida do exame de raios X, considerado o método de primeira linha na confirmação do posicionamento de sondas nasoenterais(METHENY et al, 2019).…”