Chest
Volume 95, Issue 2, February 1989, Pages 338-343
Journal home page for Chest

Transmural Pressure Measurements: Importance in the Assessment of Pulmonary Hypertension in Obstructive Sleep Apneas

https://doi.org/10.1378/chest.95.2.338Get rights and content

Seven patients with OSAS were studied during nocturnal sleep in order to assess the trend of PAP throughout apneas and to identify factors possibly associated with such a trend. All patients underwent a polysomnography including the monitoring of PAP and esophageal pressure. While intravascular PAP decreased during apneas and increased at the resumption of breathing, transmural PAP values (ie, corrected for intrathoracic pressure swings) showed a trend toward a progressive increase throughout apneas and toward a decrease once ventilation had been resumed. The measurement of transmural values allowed a reliable assessment of PAP changes occurring during apneas, and different degrees of such changes shown by different patients may be related to a host of factors relevant to wakefulness and sleep, including individual responsivity to hypoxic stimulus.

(Chest 1989; 95:338-42)

Ppl=pleural pressure; AI = apnea index; AT=apnea time; TST = total sleep time: Ps = systolic intravascular value; Pd = diastolic intravascular value; Pstm = transmural systolic pressure; Pdtm = transmural diastolic pressure

Section snippets

PATIENTS AND METHODS

Seven patients, three men and four women, affected by OSAS, previously diagnosed by means of nocturnal polysomnography, were studied; they showed normal or mildly altered blood gas tensions during wakefulness, normal spirometric values, and a variable degree of weight excess (Table 1). All patients gave informed consent to the following studies.

A Swan-Ganz catheter was introduced into the pulmonary artery through an antecubital or femoral vein and connected to a pressure transducer; mean PAP

RESULTS

All patients were shown to be affected by severe OSAS, as demonstrated by a high frequency of apneas (AI = 89.9 ± 15.2 SD) of variable duration (26 ± 9.6 s), which accounted for a high AT/TST percentage (65.3 ±15.6 percent). Only NREM sleep was recorded. The selected apneas were characterized by comparable duration (26.9 ±8.3 s), resulting in marked falls in SaO2 (lowest SaO2, 77.3 ±4.2 percent; SaO2 fall, 12.1 ±4.5 percent) (Table 2).

Periodic oscillations corresponding to the apneaventilation

DISCUSSION

Evaluation of pulmonary hemodynamics during sleep-induced obstructive apneas clearly demonstrated that these events were associated with a progressive increase in PAP. Although this phenomenon had already been hypothesized,5, 6, 7 a reliable account of its actual relationship with mechanical and chemical variables throughout the apnea has never been reported, since all previous investigations have had major limitations. In fact, the only investigation1 dealing with hemodynamic follow-up in the

ACKNOWLEDGMENTS

the authors are indebted to Professor Carlo Giuntini and Professor Mario Morpurgo for their helpful advice.

REFERENCES (15)

  • GroverRF et al.

    Pulmonary hypertension: individual and species variability relative to vascular reactivity (Editorial).

    Am Heart J

    (1963)
  • LonsdorferJ et al.

    Aspects hemodynamiques et respiratoires du syndrome pickwickien.

    Bull Physiopath Resp

    (1972)
  • CoccagnaG et al.

    Continuous recording of the pulmonary and systolic arterial pressure during sleep in syndromes of hypersomnia with periodic breathing.

    Bull Physiopath Resp

    (1972)
  • TilkianAG et al.

    Hemodynamics in sleep-induced apnea.

    Studies during wakefulness and sleep. Ann Intern Med

    (1976)
  • SchroederJS et al.

    Hemodynamic studies in sleep apnea.

    Sleep apnea syndromes.

    (1978)
  • ShepardJW Jr

    Gas exchange and hemodynamics during sleep.

    Med Clin NA

    (1985)
  • PodszusT et al.

    Nocturnal hemodynamics in patients with sleep apnea.

    Eur J Respir Dis

    (1986)
There are more references available in the full text version of this article.

Cited by (51)

  • Current understanding of the role of sleep-disordered breathing in pediatric pulmonary hypertension

    2023, Progress in Pediatric Cardiology
    Citation Excerpt :

    post-apneic arousals with increasing sympathetic system activation [9,10]. Respiratory effort against a closed upper airway leads to more negative pleural pressure and increased transmural pressure or RV afterload [51]. There is an initial decrease in RV output during the apneic period due to a decrease in heart rate and stroke volume.

  • Mon sommeil, mon coeur, mes vaisseaux

    2022, Revue des Maladies Respiratoires Actualites
  • The association between sleep-related breathing disorders and pre-capillary pulmonary hypertension: A chicken and egg question

    2021, Respiratory Medicine and Research
    Citation Excerpt :

    OSA diagnosis is based on a combination of a polysomnographic criteria (Apnea-Hypopnea Index ≥ 5 (AHI)) and clinical criteria such as excessive daytime drowsiness and nocturnal snoring. In the 1980s, early studies identified cyclic changes in pulmonary artery pressure (PAP) related to OSA with elevated PAP values, immediately following the end of the obstructive event [10]. However, whether OSA is responsible for a persistent increase in mPAP independent of associated comorbidities, particularly lung diseases, remains a controversial issue.

  • Sleep disordered breathing in adults living with a Fontan circulation and CPAP titration protocol

    2020, International Journal of Cardiology
    Citation Excerpt :

    Indeed, peripheral venous pressure measured at the end of an obstructive respiratory event showed a 2 mmHg rise in comparison to baseline awake measurements. This may reflect the time delay necessary for hypoxic pulmonary vasoconstriction to manifest [27,28]. Our study was limited by its small sample size.

  • Cardiovascular, neurological, and inflammatory complications of obesity hypoventilation syndrome

    2020, Obesity Hypoventilation Syndrome: From Physiologic Principles to Clinical Practice
  • Pulmonary Hypertension and Thrombembolism—Long-Term Management and Chronic Oral Anticoagulation

    2017, Physician Assistant Clinics
    Citation Excerpt :

    The survival rate at 5 years is 36% in patients with COPD and an mPAP greater than or equal to 25 mm Hg51,52 and in 40% of patients with left lateral decubitus PH. Sleep-disordered breathing is common in patients with PH. Central sleep apnea and Cheyne-Stokes respirations are more common in the younger population with PH and right-sided heart failure, whereas obstructive sleep apnea (OSA) is frequently found in older, obese male patients with PH.53 There is a high incidence of increased mPAP in OSA, and treatment of OSA can improve the mPAP.54,55 Evidence suggests that in patients with OSA, the presence of obesity, daytime hypoxia and hypercapnia, abnormal pulmonary function testing, and nocturnal oxygen desaturation strongly correlates with PH.53

View all citing articles on Scopus

Manuscript received February 25; revision accepted June 8.

View full text