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NCT Number: NCT05817864

Diagnostic Accuracy of Capnography in Nasogastric Tube Placement

A prospective observational diagnostic study will be conducted to assess the sensitivity and specificity of using capnography in detecting the correct placement of nasogastric tubes using the reference standards of radiography and measurement of aspirates for pH value.

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Key information

Conditions

Capnography Diagnostic Accuracy Nasogastric Tube

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

The Chinese University of Hong Kong

Hong Kong, Hong Kong SAR, China

Location status: Recruiting

Location contact

Janita Pak Chun Chau, PhD

CONTACT

[email protected]

+852 3943 6226

About this study

A prospective observational diagnostic study will be conducted. Patients ≥ 18-year-old and requiring the insertion of an nasogastric tube will be recruited using a convenience sampling method from general medical and geriatric wards, intensive care units (ICUs), accident and emergency departments (AEDs), and subacute/rehabilitation/infirmary wards in 21 acute or subacute/convalescent/extended care hospitals. End-tidal carbon dioxide (ETCO2) detection by sidestream capnography, which indicates airway intubation of an nasogastric tube when a capnogram waveform or an ETCO2 level > 10 mmHg, will serve as the index test. The reference standards will be the pH value of gastric content aspiration (pH ≤ 5.5 indicates gastric placement) and X-ray performed after the index test. Each participant will be included only once. Sensitivity, specificity, positive predictive value, and negative predictive value, and the area under the receiver operating characteristic curve of capnography will be calculated to assess the diagnostic performance of capnography. The variability in diagnostic accuracy in participants with different characteristics will be compared. The time spent and the cost of the index test and the reference test will be compared.

This study will provide evidence on the diagnostic accuracy of capnography in verifying nasogastric tube placement and inform the update of clinical practice guidelines and stakeholders' decisions regarding the adoption of ETCO2 detection as a routine method for verifying nasogastric tube placement.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • 18 years old or above;
  • Admitted to the general medical and geriatric wards, ICUs, or subacute/rehabilitation/infirmary wards in subacute/convalescent/extended care hospitals or visiting AEDs in acute hospitals;
  • Requiring the insertion of an nasogastric tube into the stomach for assessment, nutritional support and medication administration during the study period.

Exclusion criteria

  • Participants receiving life-saving intervention at the time of recruitment.

Treatment and study plan

Capnography

Diagnostic Test

Index test: Capnography, which monitors ETCO2, the percentage concentration, or partial pressure of CO2 at the end of exhalation, will serve as the index test. It will be performed by connecting the end of the nasogastric tube with the sensor of the bedside sidestream capnography device. Placement within the airway is defined as detecting a capnogram waveform or an ETCO2 level > 10 mmHg.

Reference standard: This study will use radiography (chest/abdominal X-ray) as the reference standard for determining the correct placement of nasogastric tubes. Radiology will be performed as soon as possible and interpreted by a physician. A repeat radiography will be performed if necessary. We will also use pH-Fix-4.5-10 to determine the pH value, and its accuracy is +/- 0.2 pH with minimum increments of 0.5. A pH of 5.5 or below indicates gastric placement.

Primary outcomes

  1. Sensitivity of Capnography

    Time frame: Through study completion, an average of 2 year

    True Positive / (True Positive + False Negative) × 100%

  2. Specificity of Capnography

    Time frame: Through study completion, an average of 2 year

    True Negative / (True Negative + False Positive) × 100%

  3. Positive Predictive Value of Capnography

    Time frame: Through study completion, an average of 2 year

    True Positive / (True Positive + False Positive) × 100%

  4. Negative Predictive Value of Capnography

    Time frame: Through study completion, an average of 2 year

    True Negative / (True Negative + False Negative) × 100%

  5. Overall diagnostic performance of Capnography

    Time frame: Through study completion, an average of 2 year

    Measured by the area under the receiver operating characteristic curve (AUROC). The test accuracy level is considered high when the AUROC value is ≥ 0.9.

Secondary outcomes

  1. Difference in the time spent of index test and reference test

    Time frame: Through study completion, an average of 2 year

    Compare the time spent of index test (i.e., capnography) and reference test (i.e., radiography)

  2. Difference in the cost of index test and reference test

    Time frame: Through study completion, an average of 2 year

    Compare the cost of index test (i.e., capnography) and reference test (i.e., radiography)

Study contacts

Contact information is provided by the study sponsor or research team.

Janita Pak Chun Chau, PhD

CONTACT

[email protected]

+852 3943 6226

Suzanne Hoi Shan Lo, PhD

CONTACT

[email protected]

+852 3943 4485

Sponsors and collaborators

Lead sponsor

Chinese University of Hong Kong

Other

Collaborators

  • Hospital Authority, Hong Kong

Registry information

Official study title

Diagnostic Accuracy of Using Capnography in Verification of Nasogastric Tube Placement in Hospital Settings

Important dates

Study start
2023
Primary completion
2025
Study completion
2025
First posted
Apr 18, 2023
Registry last updated
Sep 5, 2024

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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