Accuracy of Nasal Cannula Pressure Recordings for Assessment of Ventilation during Sleep

Thurnheer, Robert; Xie, Xiaobin; Bloch, Konrad E.

doi:10.1164/ajrccm.164.10.2102104

Cited by 122 publications

(101 citation statements)

References 15 publications

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“…Recordings were visually analyzed by review of the raw data on a computer video screen. An episode of apnoea or hypopnoea was defined as a decrease in the sum signal of the respiratory inductive plethysmograph to %50% of baseline for more than 10 s. We have previously shown that the apnoea/hypopnoea-index (AHI), calculated as the number of apnoeas/hypopnoeas per hour, determined by this technique agrees closely with facemask pneumotachography (19). Central apnoea was differentiated from obstructive apnoea/hypopnoea by the absence of chest-wall motion during the event (20).…”

Section: Measurementsmentioning

confidence: 75%

Effect of transsphenoidal surgery on sleep apnoea in acromegaly

Sze

Schmid²,

Bloch³

et al. 2007

eur j endocrinol

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Objective: Sleep apnoea syndrome (SAS) is common in acromegaly and both diseases are independently associated with hypertension and insulin resistance contributing to increased morbidity and mortality. Pituitary surgery remains the principal treatment modality in acromegaly. The aim of this study was to assess the prevalence and risk factors of SAS in acromegaly and to analyze the effect of transsphenoidal adenomectomy on SAS and cardiovascular risk factors. Subjects and methods: Thirteen consecutive patients (seven women and six men, aged 25-77 years) with newly diagnosed acromegaly were prospectively studied. Biochemical assessment (IGF-I, GH, acid labile subunit, fasting blood glucose (FBG), insulin), overnight respiratory polygraphy, and an Epworth Sleepiness scale score (ESS) were obtained before and 12 weeks after surgery. SAS was defined by an ESS R10 and R5 apnoeas/hypopnoeas (central or obstructive) per hour. Results: Six of the thirteen (46%) patients had SAS. Risk factors were male gender (83.3 vs 14.3% without SAS) and long disease duration until diagnosis of acromegaly (10.2G3.2 vs 4.6G3.6 years, meanGS.D.). Ten patients had a homeostasis assessment model score R4 indicating insulin resistance and one had diabetes mellitus requiring insulin. Seven patients had hypertension (R140/90 mmHg). Postoperatively, GH and IGF-I levels decreased, but only five patients were cured. However, SAS resolved in all patients irrespective of whether acromegaly was cured or not. FBG (5.5G1.2 vs 4.8G0.4 mmol/l) and systolic blood pressure (150.8G18.5 vs 130.8G17.5 mmHg) decreased in all SAS patients. Conclusion: We found a high prevalence of SAS in acromegaly patients, in particular, in men and those with long duration of disease. Importantly, a marked reduction of GH excess by transsphenoidal adenomectomy may cure SAS and improve insulin resistance and hypertension.European Journal of Endocrinology 156 321-329

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Section: Measurementsmentioning

confidence: 75%

Effect of transsphenoidal surgery on sleep apnoea in acromegaly

Sze

Schmid²,

Bloch³

et al. 2007

eur j endocrinol

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“…Receiver operating characteristic (ROC) curves were used to test the diagnostic accuracy of impedance signal analysis for the detection of sleep apnea syndrome at various AHI cutoffs. 14 Statistical significance was assumed at a value of PϽ0.05. All analyses were performed by use of a commercially available statistical package (SPSS for Windows 9.0).…”

Section: Discussionmentioning

confidence: 99%

Diagnosis of Sleep-Related Breathing Disorders by Visual Analysis of Transthoracic Impedance Signals in Pacemakers

et al. 2004

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Background-Minute ventilation sensors of cardiac pacemakers measure ventilation by means of transthoracic impedance changes between the pacemaker case and the electrode tip. We investigated whether this technique might detect sleep-related breathing disorders. Methods and Results-In 22 patients, analog waveforms of the transthoracic impedance signal measured by the pacemaker minute ventilation sensor over the course of a night were visualized, scored for apnea/hypopnea events, and compared with simultaneous polysomnography. Analysis of transthoracic impedance signals correctly identified the presence or absence of moderate to severe sleep apnea (apnea/hypopnea index, AHI Ͼ20 h Ϫ1 ) in all patients (receiver operating characteristics, ROCϭ1.0). The ROC for AHI scores of Ն5 h Ϫ1 and Ն10 h Ϫ1 showed an area under the curve of 0.95, PϽ0.005, and 0.97, PϽ0.0001, respectively. Accuracy over time assessed by comparing events per 5-minute epochs was high (Cronbach ␣ reliability coefficient, 0.85; intraclass correlation, 0.73). Event-by-event comparison within Ϯ15 seconds revealed agreement in 81% (, 0.77; PϽ0.001). Conclusions-Detection of apnea/hypopnea events by pacemaker minute ventilation sensors is feasible and accurate compared with laboratory polysomnography. This technique might be useful to screen and monitor sleep-related breathing disorders in pacemaker patients.

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“…They have been widely used in sleep studies and have been shown to be reliable and sensitive for detection of apnoea and hypopnea (Thurnheer, Xie, & Bloch, 2001). Nasal pressure measures of respiration have been shown to be comparable with facemask pneumotachography, which is the gold standard quantitative measurement for respiration in sleep (Thurnheer et al, 2001). They have also been shown to be more sensitive than thermocouples or thermistors to subtle changes in airflow and airway resistance, indicating the potential of pressure measurements for use in cough strength testing 1 .…”

Section: Cough Pressuresmentioning

confidence: 99%