Reversal of Central Sleep Apnea Using Nasal CPAP Faiq G. Issa, M.B.Ch.B., Ph.D., Colin E. Sullivan, B.Sc. (Med), M.B.B.S., Ph.D. F.C.C.P.  CHEST  Volume 90, Issue 2, Pages 165-171 (August 1986) DOI: 10.1378/chest.90.2.165 Copyright © 1986 The American College of Chest Physicians Terms and Conditions

Figure 1 Polygraph record of repetitive central sleep apneas. Patient is in supine position. SaO2%, arterial oxyhemoglobin saturation (scale 100 to 75 percent); airflow, oronasal airflow; Pes, esophageal pressure (scale 0 to −25 cm H2O); EMGd, diaphragm electromyogram; time, time scale in seconds. Note the absence of airflow at the mouth/nose associated with absence of inspiratory efforts during the apnea evident by lack of swings in esophageal pressure and absence of phasic diaphragmatic inspiratory activity. CHEST 1986 90, 165-171DOI: (10.1378/chest.90.2.165) Copyright © 1986 The American College of Chest Physicians Terms and Conditions

Figure 2 Polygraph records demonstrating prevention of central sleep apnea by continuous positive airway pressure applied through the nose. Abbreviations as in Figure 1; Pn, nasal pressure (scale 0 to 15 cm H2O). Patient is in supine position. A, Note the presence of central apnea at nasal CPAP of 2.0 qm H2O. B, elevation of nasal CPAP to 6.6 cm H2O changes the apnea from a central to a mixed type. C, further increase of nasal CPAP to 10.0 cm H2O leads to a change in the apnea pattern from a mixed to an obstructive apnea. D, loud continuous snoring occurs when the nasal CPAP is elevated to 11.5 cm H2O. E, Finally, at nasal CPAP of 14.5 cm H2O, the patient breathes with an open airway. CHEST 1986 90, 165-171DOI: (10.1378/chest.90.2.165) Copyright © 1986 The American College of Chest Physicians Terms and Conditions

Figure 3 Polygraphic records demonstrating the effect of upper airway anesthesia on central sleep apnea. Both records are taken from one patient in the same night. Patient is in the supine position. Abbreviations as in Figure 1. A. This polygraph record represents the pattern of breathing observed within 50 minutes of local anesthesia of the upper airway. B. Repetitive obstructive and mixed apneas appeared 65 minutes after airway anesthesia. CHEST 1986 90, 165-171DOI: (10.1378/chest.90.2.165) Copyright © 1986 The American College of Chest Physicians Terms and Conditions

Figure 4 Polygraph record from patient 2. Abbreviations as in Figures 1 and 2; EOG, electrooculogram; EEG, two channels of electroencephalogram. The patient is in NREM sleep in the supine position. Central apnea is prevented by 8.0 cm H2O, and patient is breathing quietly. Arrow A, complete nasal occlusion. The first inspiratory effort results in inflection and plateau of nasal pressure, indicative of upper airway closure. This is followed by a central apnea of 10 second duration. Arrow B, release of nasal occlusion. CHEST 1986 90, 165-171DOI: (10.1378/chest.90.2.165) Copyright © 1986 The American College of Chest Physicians Terms and Conditions