Flow volume loop pattern in sitting and supine positions in obstructive sleep apnea

Episodes of obstructive sleep apnea depend on posture assumed during sleep, being more frequent in the supine position. Findings on supine flow volume loop [FVL] may therefore correlate better with obstructive apneic episodes than sitting FVL. In this study we investigated the FVL pattern in 27 obstructive sleep apnea [OSA] patients having upper airway obstruction in both sitting and supine positions compared to 20 control subjects. Diagnosis of OSA was based on full night polysonographic study. Spirometric measures were done in either group in sitting and supine positions in a random fashion. Sixteen patients with oropharyngeal airway obstruction underwent uvulopalatopharyngo plasty. Polysomnography and FVL were repeated 6 weeks later and compared to preoperative pattern. Apnea-hypopnea index showed more than 50% improvement in 13 patients postoperatively. Spirometric features in OSA group were: Vital capacity [VC] was less in supine [2.4 +/- 0.5] than sitting position [2.7 +/- 0.6]. Both were less than normal group [4.2 +/- 0.9] p<0.05. Postoperatively, there was insignificantly increase in both supine [2.5 +/- 0.4] and sitting [2.8 +/- 0.5] VC in responders. The expiratory and inspiratory flow rates were less in supine position than sitting position throughout VC especially at higher lung volumes, both were less than normal group. The Expiratory flow curve showed an expiratory flow plateau which could be identified between 85-61% of VC in 83% of OSA in supine position and in 66% in sitting positions. The mid portion of expiratory curve was convex away from volume axis in 89% of cases of OSA compared to slightly concave one in normal group. On the other hand, the inspiratory flow curve showed an inspiratory plateau occurred in 66% of sitting OSA patients. It extended over 55% VC. Expiratory flow ratio MEF[50]/ M1F[50] ratio was higher in OSA[0.71 in sitting and 0.78 in supine] compared to control group [0.3 in sitting and 0.6 in supine]. In the postoperatively group the pattern of FVL was still retaining the preoperative features specially in the bad responders group. FVL reflects the dynamic upper airway narrowing in OSA patients. Two features are added to previously reported FVL characteristics in OSA patients. The pattern is more evident in supine position. It is persistent after surgical treatment. FVL is useful physiological test for studying behavior of upper airways in individual OSA patients rather than diagnostic tool for screening these patients. Supine FVL may be used as a helping tool to predict the postoperative success when sitting FVL is not fully informative in a Suspicious case

Combined liberatory repositioning procedure in treatment of benign paroxysmal positional vertigo

The development of optimal treatment for benign paroxysmal positional vertigo [BPPV] has been delayed because its pathophysiology has been clarified only recently liberatory maneuver of Semont [LM], which depends on "canalithiasis" theory, and canalith repositioning procedure of Epley [CRP], which depends on "cupulolithiasis" theory, were equally effective to a great extent in treatment of BPPV. However, both still have a considerable degree of failure and relatively high incidence of recurrence. Therefore, we suggest that canalithiasis and cupulolithiasis may sequentially and concurrently occur in the same semicircular canal "cupulocanalithiasis". To prove that, we designed a maneuver developed from both LM and CRP with some modifications and we named it combined liberatory repositioning maneuver [LRM]. Dix-Hailpike's provocative maneuver was used for selection of 78 patients having BPPV. The patients were randomly assigned to one of four treatment strategies: our LRM [n = 21], CRP [n = 18], LM [n = 19] or they were left for spontaneous cure [n = 20].The patients were followed up for 6 months and the treatment outcome, in the form of improvement of symptoms and the disappearance of nystagmus on Hailpike's maneuver, was recorded throughout the follow up period. Repetition of LRM, or LM or CRP on the second visit, after one week, was planned to be done in case of failure of the first trial. Audiological assessment was done before and after the treatment. The mean age of the patients was 51 +/- 14 years. There was no significant difference in the age, distribution of the sex and duration of the disease between the treatment groups. After the first visit, the rate of complete improvement was 85.71% [18/21] in LRM group, 47.37% [9/19] in LM group and 55.56% [10/18] in CRP group. The difference was statistically significant. After the second visit and repetition of the maneuver the complete improvement increased to 90.48% [19/21] in LRM, 78.95% [15/19] in LM group and 72.22% [13/18] in CRP group. However, the difference was statistically insignificant. In the control group, the spontaneous improvement was 10% [2/20] after one week following the onset of the disease and it increased to [35%] [n = 7/20] after two weeks. The audiological changes after the maneuvers were insignificant. There was a highly significant difference between LRM, LM or CRP in comparison with the medical control group on the first and second weeks. The low incidence of recurrence after LRM [10.53% [6/13]] was statistically significant corresponding to that of CRP [46.15% [6/13]] or LM [46.67% [7/15]]. LRM can relieve BPPV within the first weeks that helps in speeding the diagnostic work up with relatively low incidence of recurrence. The significant difference and superiority of LRM over CRP and LM in improvement and recurrence could justify and confirm our suggestion that BPPV is not necessarily due to either cupulolithiasis theory or Canalithiasis theory alone, but both may be combined either sequentially or concurrently along the course of this disease

Retrospective study for the predictive value of magnetic resonance imaging in selection of patients for uvulopalatopharyngoplasty

Uvulopalatopharyngoplasty [UPPP] is the most commonly performed surgical procedure for obstructive sleep apnea [OSA]. However, a successful outcome of UPPP is not simply correlated with the extent of surgery. The main problem is the selection of patients likely to benefit from UPPP. This study was performed aiming to find definite preoperative predictive factors for the outcome of UPPP. This was done through retrospective analysis of the preoperative anthropometric data and magnetic resonance imaging [MRI] measures of the upper airway [UA] dimensions. Thirty patients [28 males and 2 females] had a detailed preoperative overnight polysomnography [PSG], awake fibroptic nasopharyngoscopy with Muller maneuver [FNMM] and awake MRI scan of the UA. Patients were selected using FNMM according to the previous traditional criteria of selection. Through MRI examination 16 linear, areal and volumetric variables have been measured for each patient. Six weeks after UPPP, clinical examination, FNMM and PSG were repeated. The success rate of UPPP was 56.7%. We did not find any significant value for the FNMM in predicting the outcome of UPPP. However, the body mass index [BMI] was significantly higher in poor responders than in good responders [P<0.05]. On the other hand, the UA cross-sectional area [CSA], oropharyngeal CSA and hypopharyngeal CSA were significantly s mailer in the poor responders [P<0 05]. There was also significant difference in the volumes of the oropharynx, hypopharynx, total UA and the tongue. Moreover, there was a highly significant difference in ratio of UA volume/tongue volume [P<0.02]. The latter was smaller in the poor responders. There was also a highly statistically significant difference between good responders and poor responders in the ratio of orohypopharyngeal volume/tongue volume [OH-V/T-V] which was much reduced in poor responders [p<0.001]. All these variables were presented in the equation of forward stepwise multiple linear regression analysis as independent variables in corresponding to the degree of improvement. OH-V/T-V and the preoperative BMI were found significantly correlated with the outcome of UPPP. It was found that 46% of the variation in postoperative improvement could be explained by the variation in OH-V/T-V and the BMI collectively. The correlation between OH-V/T-V and the success was positive indicating that the smaller the ratio, the smaller the degree of success. However, the correlation between the BMI and the results was negative i.e. the larger the BMI the lower the success rate. A low OH-V/T-V ratio below 0.07 and a high BMI more than 30 Kg/m[2] were noticed to be nearly cut-off predictive values for the postoperative failure of UPPP. MRI seems to be worthy in the selection of UPPP candidates. The literature and the present study indicated that no single variable could safely predict the outcome of UPPP, but that a combination of anthropometric and anatomical variables is needed. We expect that our model with BMI and OH-VT-V could increase considerably the degree of prediction of the outcome of UPPP