Follow-up data
Nine patients (13%) had available follow-up PSG data, ranging from one day to six weeks (mean 10 days) after the previous PSG. The most common indications for subsequent sleep studies were the presence of moderate to severe obstructive sleep apnea (89%) and periodic limb movements of sleep (33%) on previous sleep studies. Follow-up studies were performed after recommendations were implemented 6 weeks to three months from initial PSG (i.e., ear, nose, and throat referral with removal of causes of upper airway obstruction [adenotonsillectomy], CPAP and BiPAP initiation, administration of iron for periodic limb movements of sleep, neuroleptics for diaphragmatic flutter). There was statistically significant improvement in the apnea-hypopnea index, nadir saturation, and arousal index found on the follow-up PSG (Table 4). Two patients with familial dysautonomia had three follow-up studies during flare-ups without any specific intervention and were excluded from this assessment.