Diagnostic Accuracy of Capnography in Nasogastric Tube Placement

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

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.

Study Overview

• Status: Recruiting
• Conditions: Nasogastric Tube; Diagnostic Accuracy; Capnography
• Intervention / Treatment: Diagnostic test: Capnography

Detailed Description

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.

• Study Type: Observational
• Enrollment (Estimated): 390

Contacts and Locations

• Study Contact: Name: Janita Pak Chun Chau, PhD; Phone Number: +852 3943 6226; Email: janitachau@cuhk.edu.hk
• Study Contact Backup: Name: Suzanne Hoi Shan Lo, PhD; Phone Number: +852 3943 4485; Email: suzannelo@cuhk.edu.hk

Study Locations

• China
  • Hong Kong SAR
    • Hong Kong, Hong Kong SAR, China
      • Recruiting
      • The Chinese University of Hong Kong
      • Contact: Janita Pak Chun Chau, PhD; Phone Number: +852 3943 6226; Email: janitachau@cuhk.edu.hk

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

A convenience sampling method will be adopted in this study. The participants will be recruited from general medical and geriatric wards, ICUs, AEDs, and subacute/rehabilitation/infirmary wards in 21 acute or subacute/convalescent/extended care hospitals. Each participant will be included in the study once.

Description

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.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

Observational group; All participants included will be in one observational cohort.

Diagnostic test: Capnography; 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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Sensitivity of Capnography	True Positive / (True Positive + False Negative) × 100%	Through study completion, an average of 2 year
Specificity of Capnography	True Negative / (True Negative + False Positive) × 100%	Through study completion, an average of 2 year
Positive Predictive Value of Capnography	True Positive / (True Positive + False Positive) × 100%	Through study completion, an average of 2 year
Negative Predictive Value of Capnography	True Negative / (True Negative + False Negative) × 100%	Through study completion, an average of 2 year
Overall diagnostic performance of Capnography	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.	Through study completion, an average of 2 year

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Difference in the time spent of index test and reference test	Compare the time spent of index test (i.e., capnography) and reference test (i.e., radiography)	Through study completion, an average of 2 year
Difference in the cost of index test and reference test	Compare the cost of index test (i.e., capnography) and reference test (i.e., radiography)	Through study completion, an average of 2 year

Collaborators and Investigators

• Sponsor: Chinese University of Hong Kong
• Collaborators: Hospital Authority, Hong Kong

Publications and helpful links

General Publications

• Chau JP, Thompson DR, Fernandez R, Griffiths R, Lo HS. Methods for determining the correct nasogastric tube placement after insertion: a meta-analysis. JBI Libr Syst Rev. 2009;7(16):679-760. doi: 10.11124/01938924-200907160-00001.
• Chau JP, Lo SH, Thompson DR, Fernandez R, Griffiths R. Use of end-tidal carbon dioxide detection to determine correct placement of nasogastric tube: a meta-analysis. Int J Nurs Stud. 2011 Apr;48(4):513-21. doi: 10.1016/j.ijnurstu.2010.12.004. Epub 2011 Jan 7.
• Chau JPC, Liu X, Choi KC, Lo SHS, Lam SKY, Chan KM, Zhao J, Thompson DR. Diagnostic accuracy of end-tidal carbon dioxide detection in determining correct placement of nasogastric tube: An updated systematic review with meta-analysis. Int J Nurs Stud. 2021 Nov;123:104071. doi: 10.1016/j.ijnurstu.2021.104071. Epub 2021 Aug 24.

Study record dates

Study Major Dates

• Study Start (Actual): July 1, 2023
• Primary Completion (Estimated): June 1, 2025
• Study Completion (Estimated): December 1, 2025

Study Registration Dates

• First Submitted: March 23, 2023
• First Submitted That Met QC Criteria: April 5, 2023
• First Posted (Actual): April 18, 2023

Study Record Updates

• Last Update Posted (Estimated): September 5, 2024
• Last Update Submitted That Met QC Criteria: September 2, 2024
• Last Verified: September 1, 2024

More Information

Terms related to this study

• Keywords: Diagnostic accuracy; Capnography; Intubation, gastrointestinal
• Other Study ID Numbers: 2022073

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: The datasets generated during and/or analysed during the current study will be available from the principal investigator on reasonable request.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No