Frequency and Correlates of the Saw-Tooth Pattern of Flow-Volume Curves in an Epidemiological Survey

Prediction of Minimal Pressure Support During Weaning From Mechanical Ventilation

“…This phenomenon is thought to bedue to the presence of redundant upper airway tissue and suggests similar upper airway abnormalities in our patients. 12 Upper airway damage, especially mucosal ulcers, but also upper airway edema, has been described as a complication of endotracheal intubation.P'!' The physiologic impact of such changes has not as yet been described, although it is possible that these changes are the source of the increase in inspiratory work.…”

Analysis of obstructive sleep apnea patients with “sawtooth sign” on the flow-volume curve

“…We did not exclude patients with FEV1/FVC< 0.70. Vincken et al proposed that flow oscillations are likely to originate either in the common airway proximal to the carina, or no further out than the lobar bronchi [12,29]. For this reason, the presence of COPD patients did not affect the results.…”

“…These differences are mainly a result of the presence of OSA, which is frequently associated with gross anatomic features, including obesity, that contribute to increased upper airway resistance and collapse [19]. Clinical studies suggested that the identification of flow oscillations in flow-volume curves should lead to investigation of the upper airway, as it might be an early indicator of ongoing disorders eventually leading to UAO [12]. The close follow-up of normal subjects and mild OSA patients having this sign may be helpful for the early detection and the disease progression of OSA.…”

“…Since the "sawtooth sign" is not specific for the OSA and has been reported in non-OSA patients, it reflects the heterogenicity of mechanisms in UAO in OSA during sleep [5,6,12]. OSA includes a heterogeneous group of patients, therefore, each OSA patient should be evaluated as a special patient.…”

Inspiratory Flow Volume Loops and the Diagnosis of Upper Airway Obstruction

“…Pulmonary Medicine • Volume 15, Number 5, September 2008 Inspiratory Flow Volume Loops and the Diagnosis of UAOa higher proportion of 13.4% was noted with forced inspiratory curves. Presence of flow oscillations likewise did not correlate with allergic rhinitis or OSA 106. …”