The most effective treatments for sleep central, mixed and certain cases of obstructive sleep apnea are devices that deliver slightly pressurized air to keep the throat open during the night.
In order to determine the appropriate amount of air pressure, the patient usually needs to be monitored in a sleep laboratory. Although this may require only one night, patients may need to be retested if they do not experience improved daytime alertness. These days\’ portable-home-sleep study machines are available.
CPAP usually is administered at bedtime through a nasal or facial mask held in place by Velcro straps around the patient’s head. The mask is connected by a tube to a small air compressor about the size of a shoe box.
The CPAP machine sends air under pressure through the tube into the mask, where it imparts positive pressure to the upper airways. This essentially splints the upper airway open and keeps it from collapsing. Mask fitting is an essential element of a patient’s success with positive airway pressure therapy since it affects compliance and effectiveness of treatment.
Higher pressures can result in air leak and patient discomfort. Demands on mask stability increase as pressure increases. Higher pressures may also require tighter head gear to maintain an adequate seal contributing to the discomfort.
All these devices, particularly the mask, often produce anxiety and discomfort. Starting out with low pressure to get used to the mask may help. Patients may actually experience less sleep or sleep of a different quality in the beginning.
Perhaps the biggest problem with CPAP therapy is noncompliance. Frequently, patients use the machine for only a few hours a night or a few days a week.
Patents feel very shy to carry these boxes around while visiting friends home or while traveling.
Sneezing, nasal discharge and dryness sometimes result in noncompliance, but CPAP failure may also be caused by perceived discomfort, claustrophobia and panic attacks.
Nearly half of complaints are related to the mask. Many can be alleviated with a well-chosen mask that is comfortable and reduces leakage as much as possible.
Few patients get allergic reaction on the face from using the mask.
Mixed Sleep Apnea-Cause of CPAP failure
If the patient has obstructive components in the upper airway-Nose, Nasopharynx, and Throat, this should be cleared by surgery-using Laser, Coblator or Harmonic scalpel.
If the obstructive element is the nasal cavity, using chin strapping closes the mouth and makes the patient more obstructive.
The surgery to cure a deviated nasal septum, reduction of the nasal turbinates, removal of nasal polyps, adenoid, tonsil, reducing the base of tongue, removing part of soft palate, and uvula, all will help to a large extent.
Even if the central component of mixed apnea persists, at least patients can comfortable sleep on CPAP.
If surgery in mixed sleep apnea is undertaken, either Laser or Coblator, the anesthetist should be well informed, as always they are, about the difficulties in the recovery period till the start using CPAP. It is better to keep the patient in ICU with ventilator facility, if needed, in first 24 hrs.
Complex sleep apnea
Central sleep apnea may emerge during titration of CPAP in patients previously diagnosed with obstructive sleep apnea. This syndrome, termed complex sleep apnea, has become a controversial topic in the sleep literature and has been raised as a possible type of difficult-to-treat obstructive sleep apnea. As many as 6.5% of patients with obstructive sleep apnea may develop emergent or persistent central sleep apnea with CPAP treatment. CPAP emergent central sleep apnea is generally transitory and is eliminated after 8 weeks of CPAP therapy. Persistent CPAP-related central sleep apnea has been observed in approximately 1.5% of treated patients. Similarly, complex sleep apnea can occur following a Tracheostomy for obstructive sleep apnea. Central apneas have been found initially after a Tracheostomy, but after an extended period, central sleep apnea decreased on repeat PSG.
Depression and sleep apnea
Approximately one in five people who suffer from depression also suffer from sleep apnea, and people with sleep apnea are five times more likely to become depressed. Existing depression may also be worsened by sleep apnea. While it is not clear whether the apnea causes the depression or vice-versa, studies show that by treating sleep apnea symptoms, depression may be alleviated in some people.
