Publications by authors named "Sigurd Aarrestad"

9 Publications

  • Page 1 of 1

Measuring diaphragm movement and respiratory frequency using a novel ultrasound device in healthy volunteers.

J Ultrasound 2021 Mar 6;24(1):15-22. Epub 2019 Nov 6.

Department of Pulmonary Medicine, Oslo University Hospital, Kirkeveien 166, 0450, Oslo, Norway.

Purpose: To evaluate the ability of a novel ultrasound (US) device, DiaMon, to monitor diaphragm movement via its proxy liver movement, and compare it with the respired flow measured with a flowmeter, in awake and healthy volunteers. We wanted to (1) establish the optimal anatomical position for attaching the DiaMon device to the abdominal wall, and (2) evaluate the accuracy of continuous monitoring of respiratory frequency.

Methods: Thirty healthy subjects were recruited. The DiaMon probe was applied subcostally in four different positions with the subjects in five different postures. The subjects breathed tidal volumes into a spirometer for 30-60 s with the DiaMon recording simultaneously.

Results: The device detected a readable signal in 83-100% of the position/posture-combinations. The technical correlation between the two signals was highest in the anterior axillary-supine position (mean ± SD: 0.95 ± 0.03), followed by paramidline-supine (0.90 ± 0.09) and midclavicular-supine (0.89 ± 0.12). The frequency measurements yielded a mean difference of 0.03 (95% limits of agreement - 0.11, 0.16) breaths per minute in the anterior axillary-supine position.

Conclusion: The DiaMon device is able to detect liver movement in most subjects, and it measures breathing frequency accurately.
View Article and Find Full Text PDF

Download full-text PDF

Source Listing
March 2021

Diagnostic accuracy of simple tools in monitoring patients with chronic hypoventilation treated with non-invasive ventilation; a prospective cross-sectional study.

Respir Med 2018 11 26;144:30-35. Epub 2018 Sep 26.

Division of Pulmonary Diseases, Geneva University Hospitals, Switzerland.

Objectives: To evaluate the sensitivity and specificity of a screening test panel for nocturnal hypoventilation (NH) and other sleep related respiratory events during monitoring of patients with chronic hypercapnic respiratory failure (CRF) treated with NIV.

Methods: We performed a prospective study at Oslo University Hospital. Eligible for inclusion were consecutive adults with CRF due to neuromuscular diseases or chest wall disorders treated with NIV scheduled for a follow-up visit. All patients underwent the screening test panel (clinical evaluation, daytime arterial blood gas (ABG), nocturnal pulse oximetry (SpO) and data from ventilator software) and the reference tests; sleep polygraphy and nocturnal transcutaneous CO.

Results: Of 67 patients included, NH was confirmed in 23-50 according to the 3 definitions used for NH, apnea-hypopnea index (AHI) ≥ 10 was confirmed in 16 and patient-ventilator asynchrony (PVA) ≥ 10% of total recording time in 14. Sensitivity of the combined screening test panel for NH was 87% (95% confidence interval 66-97), 84% (66-95) and 80% (66-90), for abnormal AHI 91% (59-100) and for PVA 71% (42-92). Sensitivity for NH of SpO was 48% (27-69), 39% (22-58) and 38% (24-53) and of daytime ABG 74% (52-90), 74% (55-88) and 68% (53-80). Sensitivity and specificity of AHI for AHI ≥ 10 was 93% (68-100) and 92% (81-98) respectively.

Discussion: In patients treated with long term NIV, screening test panel, nocturnal SpO and daytime ABG all failed to accurately detect NH, underlining the importance of nocturnal monitoring of CO. AHI accurately identified obstructive events and can be used to modify NIV settings.

Trial Registration: N° NCT01845233.
View Article and Find Full Text PDF

Download full-text PDF

Source Listing
November 2018

Sleep related respiratory events during non-invasive ventilation of patients with chronic hypoventilation.

Respir Med 2017 Nov 2;132:210-216. Epub 2017 Nov 2.

Division of Pulmonary Diseases, Geneva University Hospitals, Switzerland, Rue Gabrielle-Perret-Gentil 4, 1205 Geneva, Switzerland. Electronic address:

Background: Non-invasive ventilation (NIV) is increasingly used in the treatment of patients with chronic hypercapnic respiratory failure (CRF). Residual sleep related respiratory events under NIV such as obstructive or central apnea/hypopnea (AH), or patient-ventilator asynchrony (PVA), may compromise treatment efficacy and/or comfort.

Aims Of Study: 1/to quantify the frequency and describe the types of both AH and PVA in a large group of stable patients with CRF during night-time NIV; 2/to analyze the influence of these events on overnight pulse oximetry and transcutaneous CO and 3/to assess interrater agreement in identifying and quantifying AH and PVA.

Methods: We quantified AH and PVA by performing sleep polygraphy in 67 patients during elective follow-up visits. Traces were scored by two trained physicians.

Results: Residual AH were frequent: 34% of the patients had an AH Index >5/hour, with obstructive hypopnea being the most frequent event. In addition, 21% of the patients had PVA >10% of total recording time. No correlation was found between respiratory events and overnight hypercapnia. The intraclass correlation coefficients for scoring AHI and time with PVA were 0.97 (0.94-0.98) and 0.85 (0.75-0.91) respectively.

Conclusions: Residual respiratory events are common in patients treated with long term NIV for chronic hypercapnic respiratory failure and can be scored with a very high interobserver agreement. However, these events were not associated with persistent nocturnal hypercapnia; thus, their clinical relevance has yet to be clarified. CLINICALTRIALS.GOV REGISTRATION N°: NCT01845233.
View Article and Find Full Text PDF

Download full-text PDF

Source Listing
November 2017

Health and social conditions in Norwegian polio survivors: A 20-year follow-up study.

J Rehabil Med 2016 Oct;48(8):688-695

, Sunnaas Rehabilitation Hospital, Bjørnemyrveien 11, NO-1450 Nesoddtangen, Norway.

Objective: To explore the physical and social situation of the Norwegian polio population in 2014, and to compare the status of this population in 2014 with the results of a similar survey carried out 20 years previously, in 1994.

Design: The study was based on a questionnaire covering demographics, polio history, and current medical, psychological and social conditions.

Subjects: The questionnaire was prepared in cooperation with the National Society of Polio Survivors and others with known polio (n = 1,968). A total of 1,408 persons responded (72%), mean age 70 years (range 28-98 years).

Results: The most frequent health problems reported were muscle and joint pain, cold intolerance and insomnia. New muscle weakness and loss of muscle volume were reported more frequently in 2014 than in the 1994 study. The use of orthopaedic aids, assistive devices, ventilators and other respiratory aids had increased significantly, but 83% reported that they still had no home care or nursing services support. The 2014 polio population reported only minor subjective worsening of health and well-being compared with the 1994 cohort.

Conclusion: The present study indicates that the elderly polio population are experiencing new muscle weakness and increasing health problems, but that the deterioration occurs slowly and with fewer consequences for the subjective experience of general health and well-being, indicating that the patients are adapting to their life situation. However, subgroups of the elderly polio population are in need of special care.
View Article and Find Full Text PDF

Download full-text PDF

Source Listing
October 2016

Validity of transcutaneous PCO2 in monitoring chronic hypoventilation treated with non-invasive ventilation.

Respir Med 2016 Mar 27;112:112-8. Epub 2016 Jan 27.

Department of Pulmonary Medicine, Oslo University Hospital, Ullevål, Oslo, Norway; University of Oslo, Oslo, Norway.

Background: Non-invasive ventilation (NIV) is an efficient treatment for patients with chronic hypercapnic respiratory failure (CRF), but requires regular monitoring to detect both diurnal and nocturnal residual hypercapnia. The present study was designed to determine 1) whether transcutaneous PCO2 (PtcCO2) is a valid tool for monitoring PaCO2 in this group of patients, and 2) if overnight instrumental drift of the PtcCO2 sensor is clinically significant.

Methods: Sixty-seven patients with CRF on long term NIV were included. Arterial blood gases (ABG) were sampled from the radial artery during PtcCO2 measurement. PtcCO2 was recorded 2 min after ABG sampling. Instrumental drift was tested by measuring a gas of known CO2 concentration after auto-calibration of the sensor in the evening, and on the following morning.

Findings: PaCO2 values ranged from 3.97 kPa to 9.0 kPa. Thirty-six (53%) patients were hypercapnic. Correlation between PaCO2 and PtcCO2 was highly significant (r(2) = 0.9, p < 0.0001), Bias (d) and SD of bias (s) were 0.23 kPa and 0.28 kPa respectively, with a minor underestimation of PaCO2. Limits of agreement (d ± 2s) were; -0.32; 0.79 kPa. None of the paired values of PaCO2/PtcCO2 had a difference exceeding 1 kPa. The mean drift of PtcCO2 was 0.14 ± 0.54 kPa/8 h (p = 0.04; 95% CI: 0.01-0.27).

Interpretation: With the device tested, in stable patients under NIV-treatment for CRF, PtcCO2 accurately reflects PaCO2. PtcCO2 can be used to monitor CO2 overnight during NIV without any clinically significant drift. TRIAL REGISTRATION N°: NCT01845233.
View Article and Find Full Text PDF

Download full-text PDF

Source Listing
March 2016

[Obstructive sleep apnea].

Tidsskr Nor Laegeforen 2015 Nov 17;135(21):1954-6. Epub 2015 Nov 17.

Avdeling for nevrologi og klinisk nevrofysiologi St. Olavs hospital og Institutt for nevromedisin Det medisinske fakultet Norges teknisk-naturvitenskapelige universitet.

View Article and Find Full Text PDF

Download full-text PDF

Source Listing
November 2015

[Termination of mechanical ventilation in amyotrophic lateral sclerosis].

Tidsskr Nor Laegeforen 2009 Mar;129(7):628-31

Nevrologisk avdeling Ullevål universitetssykehus 0407 Oslo.

Background: Mechanical ventilation may relieve symptoms and prolong life for patients with amyotrophic lateral sclerosis, but may also prolong suffering. More knowledge is needed on ethical, legal and medical aspects upon termination.

Material And Methods: Two cases are discussed in light of relevant laws and literature, as well as the authors' own research and clinical experience.

Results: A patient who had first declined life-sustaining treatment eventually chose to undergo tracheostomy. He later approached a locked-in state and wanted to terminate the treatment. Another patient reported poor quality of life and wanted to die, but declined to make a statement on refusal of resuscitation in case of an emergency. He was later resuscitated from CO2 narcosis and received non-invasive ventilation. He repeated that he wanted to die, but did not decide to terminate the ventilator until he was offered palliative treatment. Both patients received morphin and anxiolytics, and died shortly after the ventilator was withdrawn.

Interpretation: Mechanical ventilation can be terminated in line with good medical and ethical standards, and will then usually be legal. Patients have a legal right to refuse life-sustaining treatment, but not everybody want to make decisions regarding their own death. Fear of conducting euthanasia may prolong the patient's death process and prevent adequate palliative treatment.
View Article and Find Full Text PDF

Download full-text PDF

Source Listing
March 2009