Benign unilateral diaphragmatic dysfunction or paralysis (BUDDP) is not associated with known malignancy and may be idiopathic or due to previous trauma. BUDDP is generally thought to be of little clinical significance. Previous studies have been of limited scope, and have not included sleep studies. We assessed the physiologic and polysomnographic findings in 6 patients with BUDDP.
Six patients with suspected BUDDP and an elevated hemi-diaphragm on chest X-ray were identified and studied with chest fluoroscopy and sniff maneuver to quantify diaphragmatic movement (grade1=decreased movement, grade 2 = no movement, grade 3 = paradoxical movement). Additional studies included pulmonary function testing (PFTs), PI max, PE max and overnight polysomnography.
Mean age of our patients was 63 years (range 39-73 years). Four patients were male, 3 patients had previous chest surgery. 3 patients were assessed as grade 1, 2 grade 2 and 1 grade 3. PFTs revealed mild restriction with mean TLC 78% predicted (70-96%) and 4 patients had superimposed obstruction (FV1/FVC < 75%). PI max and PE max were within normal limits (86% and 116% predicted). Mean obstructive apnea index was 7(0-30), mean RDI was 30 (2-97). Mean RDI during NREM and REM-sleep were 27(1-91) vs. 45 (5-76) (p=0.18). All patients demonstrated nocturnal desaturation. Mean lowest saturation during sleep was 80 %( 66-87%). Mean lowest saturation was 84 %( 70-94%) during NREM sleep and 69 %( 51-81%) during REM sleep. (p=0.0017). Severity of BUDDP was significantly correlated with FEV1, PI max and desaturation during REM sleep.
During the wake state patients with BUDDP may be able to compensate for the unilateral loss of diaphragmatic function. However, during REM sleep, when the accessory respiratory muscles are inhibited, resultant hypoxemia can occur.
Patients with BUDDP have mild restrictive lung disease and REM associated desaturation which correlates with the degree of diaphragmatic dysfunction. The resultant desaturation may be severe enough to require oxygen supplementation.
Norman Wolkove, None.