The following definitions were used to classify breathing patterns and arousals: apnea was defined as the absence of airflow for more than 10 seconds. In central apnea, respiratory effort was absent, whereas in obstructive apnea, respiratory efforts continued. Hy-popnea was defined as a reduction the amplitude of respiratory movement for more than 10 seconds to less than 50 percent of the maximum thoracoabdominal amplitude during the breathing cycle. Paradoxic respirations were defined as out of phase chest and abdominal wall movement as indicated by inductance plethysmography. An arousal was defined as an awakening from sleep for >5 seconds as shown by alpha activity on the EEG, EMG activation, and eye movements which occurred simultaneously. The apnea hypopnea index is the number of apneas and hypopneas per hour of total sleep time.
In the group 1 patients, since rocking beds maintained “respiratory effort,” their apneic or hypopneic episodes were documented as loss of airflow (as indicated by absence of CO, measured at the nose and mouth). These episodes most closely resembled obstructive episodes (Fig 3). Even though the rocking beds generate constant respiratory efforts, hypopnea is seen as a reduced displacement of abdomen and ribcage similar to hypopnea in a routine study as described previously. All group 1 patients were evaluated first on CPAP then on nasal ventilation. buy levaquin online
The group 2 patients thought to require ventilatory assistance were first tried on nasal CPAP and on nasal ventilation if CPAP was insufficient.
The protocol was approved by the Ethics Committee at our institution and a written informed consent was obtained from each patient.
Figure3. Polysomnogram demonstrating KMC, KKC (C3/A2), KKC (02/A1), KOC (T4/T3), KCC, SaO2, heart rate (IIK), airflow (CO,) with patient in RKM sleep on a rocking bed. Regular large breaths depicted are generated by the rocking bed with smaller breaths in between patient effort. Despite this, there is no substantial airflow detected and a significant drop in oxygen saturation. The tiny (X)2 deflections and the lack of rilnage abdominal paradox suggests that the upper airway is not totally occluded (obstructive hypopnea).