Validation of a Predictive Score for HAST

NCT03728595 | Completed

• 3 other identifiers: RM18/10907524790218/WS/0117
• Study Type: observational
• Target: 96
• Locations: 1 country
• Sites: 1

Brief Summary

Patients with chronic lung diseases travelling by plane often suffer with symptoms related to lower oxygen levels they are exposed to while flying. Therefore, patients with respiratory conditions are routinely assessed to establish if they need supplemental oxygen in flight. A hypoxic altitude simulation test (HAST) is often part of this assessment and consists in having patients breathe a oxygen/nitrogen blend with a lower oxygen concentration compared to normal room air, simulating in-flight conditions. Oxygen levels are measured before and after the test through a blood sample (from the earlobe or an artery in the wrist) and with a finger probe. In-flight oxygen is required if the oxygen level in the blood is lower than 6.6 kPa. HASTs are time consuming, costly, and require a dedicated hospital appointment. Using historical data, the Investigators developed scores based on capillary blood gas (blood sample from the earlobe), diagnosis and sex to predict the outcome of the HASTs. The Investigators validated the proposed scores in a separate historic cohort of patients and showed it had good concordance with the HASTs results. In this study, the Investigators want to confirm prospectively if the score, based on blood results (venous and/or earlobe), can predict the outcome of the HASTs and therefore reduce the number of tests performed, travel time for patients, and costs for the NHS. All patients, aged 18 or older, who are having a HAST for clinical purposes at the cardio-respiratory lab at Leeds Teaching Hospital NHS Trust will be invited to take part in the study. The Investigators will record diagnosis, results of HAST and previous spirometry from the medical notes, perform a spirometry if not done in the previous 12 months and collect a blood sample (one tube, 4 mls). With these data, the Investigators will calculate the score and assess its agreement with the outcome of the HAST. Each participant's involvement in the study will last for approximately 90-120 minutes, which is the normal duration of a HAST. The Investigators aim to include up to 280 subjects in the study.

Conditions

Chronic Respiratory Disease; Hypoxia, Altitude; COPD; ILD; Cystic Fibrosis

Keywords

gas exchange; in-flight hypoxia; hypoxic altitude simulation test; blood gas response

Outcome Measures

Primary Outcomes (1)

• ROC AUC for Model 1 (3*SaO2 - HCO3 - 4 if ILD - 4 if F -3 if COPD), and the relative sensitivity, specificity, positive and negative predictive value of the threshold identified for negative and positive HAST

  The score based on Model 1 will be computed for all subjects and ROC curve analyses will be used to assess predictive value. Sensitivity, specificity, PPV and NPV for criteria previously identified in a historic cohort will be assessed.

  Up to 36 months

Secondary Outcomes (2)

• ROC AUC for the simplified score (3*SpO2 - sHCO3 - 4 if ILD - 4 if F - 3 if COPD)

  Up to 36 months

• ROC AUC for Model 2, and Model 3 and for baseline pO2 and relative sensitivity, specificity, positive and negative predictive value of the previously identified thresholds.

  Up to 36 months

Other Outcomes (3)

• Negative and positive predictive value for the criteria chosen for the simplified score.

  Up to 36 months

• Identification of a new predictive model for the outcome of the HAST

  Up to 36 months

• Identification of a model to predict the flow-rate of oxygen required by patients who have a positive HAST.

  Up to 36 months

Study Arms (1)

Patients with lung disease having HAST

Patients with chronic respiratory diseases who had a hypoxic altitude simulation test (HAST) for clinical purposes will have for research purposes: * venepuncture * spirometry.

Diagnostic Test: Venepuncture; Diagnostic Test: Spirometry; Diagnostic Test: Hypoxic altitude simulation test (HAST)

Interventions

Venepuncture DIAGNOSTIC_TEST

A blood sample will be taken for serum bicarbonate

Patients with lung disease having HAST

Spirometry DIAGNOSTIC_TEST

All patients who have not had a spirometry in the 12 months prior to the HAST will undergo one on the day of the HAST.

Patients with lung disease having HAST

Hypoxic altitude simulation test (HAST) DIAGNOSTIC_TEST

HAST will be performed as per clinical team request. No changes to this intervention will be made for research purposes.

Patients with lung disease having HAST

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Outpatient attending for a HAST at Leeds Teaching Hospital NHS Trust.

You may qualify if:

• Age ≥18 years old (at the time of HAST)
• Clinically stable
• Hypoxic altitude simulation test, scheduled as part of the clinical care

You may not qualify if:

• Inability to provide informed consent
• Being part of a clinical trial, which would exclude patients who are taking part in other studies including observational studies.

Sponsors & Collaborators

• The Leeds Teaching Hospitals NHS Trust: lead

Study Sites (1)

St James's University Hospital, LTHT

Leeds, West Yorkshire, LS9 7TF, United Kingdom

Location

Related Publications (8)

• Aerospace Medical Association; Aviation Safety Committee; Civil Aviation Subcommittee. Cabin cruising altitudes for regular transport aircraft. Aviat Space Environ Med. 2008 Apr;79(4):433-9. doi: 10.3357/asem.2272.2008.

  PMID: 18457303 BACKGROUND

• Ahmedzai S, Balfour-Lynn IM, Bewick T, Buchdahl R, Coker RK, Cummin AR, Gradwell DP, Howard L, Innes JA, Johnson AO, Lim E, Lim WS, McKinlay KP, Partridge MR, Popplestone M, Pozniak A, Robson A, Shovlin CL, Shrikrishna D, Simonds A, Tait P, Thomas M; British Thoracic Society Standards of Care Committee. Managing passengers with stable respiratory disease planning air travel: British Thoracic Society recommendations. Thorax. 2011 Sep;66 Suppl 1:i1-30. doi: 10.1136/thoraxjnl-2011-200295. No abstract available.

  PMID: 21856702 BACKGROUND

• Lien D, Turner M. Recommendations for patients with chronic respiratory disease considering air travel: a statement from the Canadian Thoracic Society. Can Respir J. 1998 Mar-Apr;5(2):95-100. doi: 10.1155/1998/576501.

  PMID: 9707451 BACKGROUND

• Aerospace Medical Association Medical Guidelines Task Force. Medical Guidelines for Airline Travel, 2nd ed. Aviat Space Environ Med. 2003 May;74(5 Suppl):A1-19. No abstract available.

  PMID: 12817610 BACKGROUND

• Bradi AC, Faughnan ME, Stanbrook MB, Deschenes-Leek E, Chapman KR. Predicting the need for supplemental oxygen during airline flight in patients with chronic pulmonary disease: a comparison of predictive equations and altitude simulation. Can Respir J. 2009 Jul-Aug;16(4):119-24. doi: 10.1155/2009/371901.

  PMID: 19707606 BACKGROUND

• Peckham D, Watson A, Pollard K, Etherington C, Conway SP. Predictors of desaturation during formal hypoxic challenge in adult patients with cystic fibrosis. J Cyst Fibros. 2002 Dec;1(4):281-6. doi: 10.1016/s1569-1993(02)00100-5.

  PMID: 15463828 BACKGROUND

• Edvardsen A, Akero A, Christensen CC, Ryg M, Skjonsberg OH. Air travel and chronic obstructive pulmonary disease: a new algorithm for pre-flight evaluation. Thorax. 2012 Nov;67(11):964-9. doi: 10.1136/thoraxjnl-2012-201855. Epub 2012 Jul 5.

  PMID: 22767877 BACKGROUND

• Edvardsen E, Akero A, Skjonsberg OH, Skrede B. Pre-flight evaluation of adult patients with cystic fibrosis: a cross-sectional study. BMC Res Notes. 2017 Feb 6;10(1):84. doi: 10.1186/s13104-017-2386-2.

  PMID: 28166839 BACKGROUND

Biospecimen

Retention: SAMPLES WITHOUT DNA

The Investigator will collect a blood sample to be processed for serum bicarbonate. As processing a sample for serum bicarbonate is very susceptible to pre-analytical sources of error, samples will be analysed immediately after collection and then discarded.

MeSH Terms

Conditions

Altitude Sickness; Pulmonary Disease, Chronic Obstructive; Cystic Fibrosis

Interventions

Blood Specimen Collection; Spirometry

Condition Hierarchy (Ancestors)

Respiration Disorders; Respiratory Tract Diseases; Lung Diseases, Obstructive; Lung Diseases; Chronic Disease; Disease Attributes; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Pancreatic Diseases; Digestive System Diseases; Genetic Diseases, Inborn; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Infant, Newborn, Diseases

Intervention Hierarchy (Ancestors)

Specimen Handling; Clinical Laboratory Techniques; Diagnostic Techniques and Procedures; Diagnosis; Punctures; Surgical Procedures, Operative; Investigative Techniques; Respiratory Function Tests; Diagnostic Techniques, Respiratory System

Study Officials

• Giulia Spoletini

  Leeds Teaching Hospital NHS Trust

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: CASE ONLY
• Time Perspective: CROSS SECTIONAL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: October 31, 2018
• First Posted: November 2, 2018
• Study Start: October 29, 2018
• Primary Completion: March 31, 2020
• Study Completion: March 31, 2021
• Last Updated: April 6, 2022

Record last verified: 2022-04

Data Sharing

• IPD Sharing: Will not share

Locations

GB (1)