Study of sleep – Related breathing disorders in patients admitted to respiratory intensive care unit

ObjectivesThe purpose of this study was to assess the prevalence of SRBDs in acutely ill patients admitted to respiratory ICU.Patients and methodsThe study enrolled 72 patients admitted to respiratory ICU. All patients were subjected to full clinical examination, Epworth Sleepiness score, arterial blood gases analysis and clinical apnea score calculation. According to this latter, patients were divided into group I: without clinically suspected SRBDs and group II: with clinically suspected SRBDs. Patients in group II were subjected to polysomnography.ResultsGroup I included 21 patients while group II included 51 patients. The BMI, neck circumference and waist/hip ratio were significantly higher in group II. Hypertension was the commonest comorbidity in group II. Type II respiratory failure was the commonest cause of ICU admission in both groups of patients. The mortality rate was higher within the 28 days that followed ICU admission in group I compared to group II. This latter group had a higher mortality rate later on. All patients subjected to polysomnography suffered from OSAHS, 82% of them showed associated sleep hypoventilation (SHV) with significantly elevated bicarbonate level. More than half the patients with SHV fulfilled the criteria of obesity hypoventilation syndrome. The AHI showed a significant direct correlation with neck circumference, systolic blood pressure, snoring index and T85%; and a significant inverse correlation with PaO2, minimal saturation as well as average saturation.ConclusionIn ICU patients, SRBDs are common coexistent findings and every physician should systematically search for them. Type II respiratory failure is the main cause of ICU admission in patients with SRBDs. Quality of sleep in ICU is very disturbed. Most ICU patients with SRBDs have concomitant SHVS mostly due to OHS. Important comorbidities coexist in patients with SRBDs; both influence each other and should be identified and managed properly for the wellbeing of the patient. BiPAP therapy is the cardinal mode of ventilation used in patients with respiratory failure and SRBDs.