The effect of hypoxia on hearing function

Background/aim

This study was conducted to determine the critical partial oxygen pressure (pO2) value that would impair hearing function by evaluating the effects of hypoxia on hearing function in subjects diagnosed with chronic obstructive pulmonary disease (CPOD).

Materials and methods

The study included 25 male and 5 female patients referred to our clinic who were diagnosed with COPD, according to spirometry and PaO2 values, and who did not show pathology upon autoscopic examination. The control group consisted of 14 female and 16 male patients who had no lung disease and were in the same age range as the COPD group.

Results

A statistically significant difference was found between the two groups for distortion-product otoacoustic emission (DPOAE) (P < 0.001). The COPD group was divided into two groups according to pO2 levels (pO2 ≤ 70 and pO2 > 70) in order to find a critical pO2 level which might cause significant change at a certain audiological extent.

Conclusion

Hypoxia causes long-term decline in hearing thresholds, deterioration of DPOAE results, and prolongation of I–V interpeak latency in auditory brainstem response. However, the critical oxygen level that disrupts hearing function could not be determined.

The effect of adding gender item to Berlin Questionnaire in determining obstructive sleep apnea in sleep clinics

BACKGROUND AND AIM

We aimed to validate the Turkish version of Berlin Questionnaire (BQ) and developped a BQ-gender (BQ-G) form by adding gender component. We aimed to compare the two forms in defining patients with moderate to severe obstructive sleep apnea (OSA) in sleep clinics.

METHODS

Four hundred and eighty five consecutive patients, refered to our sleep clinic for snoring, witnessed apnea and/or excessive daytime sleepiness were enrolled to the study. All patients underwent in-laboratory polysomnography (PSG). Patients with sleep efficiency less than 40% and total sleep time less than 4 hours, chronic anxiolitic/sedative drug usage, respiratory tract infection within past two weeks were excluded from the study. All the patients fulfilled BQ. The test and retest for BQ were applied in 15-day interval in 30 patients.

RESULTS

Totally 433 patients were enrolled to the study (285 male, 148 female). The mean age of the patients was 47,5 ± 10.5 (21-79). 180 patients (41.6%) had apnea-hypopnea index (AHI) ≤ 15, while 253 patients (58,4%) had AHI > 15. The κ value was 48-94 and the the truth value was 69-94% for the test-retest procedure. Sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), and area under the curve AUC were 84.2%, 31.7%, 48.7%, 63.4%, and 0.579 in order for BQ and 79.9 %, 51.7%, 63.2% , 69.6%, and 0.652 for BQ-G.

CONCLUSION

The results showed that BQ-G is relatively better than BQ in determining moderate to severe OSA in sleep clinics where most of the patients are sleep apneic but both of the tests were found to have insufficient validities in defining moderate to severe OSA in sleep clinics.

Clinical update on pulmonary embolism

Pulmonary embolism (PE) is a major cause of cardiovascular mortality and financial burden that affects the community. The diagnosis of PE can be difficult because of the nonspecific symptoms, which include cough, dyspnea, hemoptysis and pleuritic chest pain. Hereditary and acquired risk factors are associated with PE. Incidence of PE is increasing, associated with the development in the diagnostic methods. Evidence-based algorithms can help clinicians diagnose PE. Serum D-dimer level, computed tomography pulmonary angiogram (CTPA), ventilation-perfusion scintigraphy or echocardiography help to establish clinical probability and the severity of PE. Anticoagulation is the standard treatment for PE. However, thrombolytic treatment is a significant alternative in high risk of PE as it provides rapid clot resolution. This article reviews the risk factors, diagnostic algorithms, and methods of treatment in PE in the light of current information.

Does AHI Value Enough for Evaluating the Obstructive Sleep Apnea Severity?

Obstructive sleep apnea/hypopnea syndrome (OSAHS) is an important and more common public health problem with increasing incidence. Polysomonography (PSG) is the gold standard test in OSAHS diagnosis. Apnea-hypopnea index (AHI) is the main parameter of PSG, which is correlated with OSAHS severity. The main complaint of OSAHS patients is daytime sleepiness and the Epworth Sleepiness Scale (ESS) used for evaluation of disease severity. The correlation of AHI with daytime sleepiness and ESS is well known. But there are many patients, which have uncorrelated daytime sleepiness with AHI. This data calls this hypothesis; Are there any other parameters which may affect daytime sleepiness. 648 patients with complaining of snoring and apnea were evaluated by polysomnography and anthropometric measurements. The cut-off value of ESS was accepted 10 as an indicator of severe daytime sleepiness. Patients were divided to groups with the aim of homogenization, according to AHI values. The patients with similar AHI values were analyzed according to their ESS scores. BMI and neck circumference were elevated in daytime sleepiness patients. The nocturnal hypoxemia markers; apnea number/index, maximum duration of apnea, at least SO2 concentration, duration of SO2 less than 90 % were much effected in the group of daytime sleepiness. Beside the fact that our research, AHI is not enough for predicting the daytime sleepiness; anthropometric measurements and the nocturnal hypoxemia markers should be evaluated.

Association of obstructive sleep apnea with homocystein, nitric oxide and total antioxidant capacity levels in patients with or without coronary artery disease

INTRODUCTION

Obstructive sleep apnea (OSA) is associated with cardiovascular morbidity and mortality. Deficiency of nitric oxide (NO) and plasma levels of homocystein have been implicated in the pathogenesis of cardiovascular disease. OSA results in oxygen desaturation and arousal from sleep. Free oxygen radicals can be produced by hypoxia-reoxygenation. To test for the hypothesis that OSA is associated with cardiovascular morbidity, we investigated levels of homocystein, NO and total antioxidant capacity in OSA patients with and without coronary artery disease (CAD) in comparison with normal subjects and patients with CAD without OSA.

MATERIALS AND METHODS

Polysomnography was performed in 27 patients who had a myocardial infarction and in 25 patients without evidence of CAD. Patients were grouped according their polysomnography results as OSA with CAD (group 1), OSA without CAD (group 2), CAD (group 3), and normal (group 4) . Levels of homocystein, NO and total antioxidant capacity were determined after an overnight fasting. Data were analysed with parametric and non parametric statistical tests.

RESULTS

According to apnea-hypopnea index (AHI) 44.4% of CAD patients were OSA. After polysomnographic evaluation, the patients were re-distributed as follows: OSA with CAD (n= 12), OSA without CAD (n= 14), CAD (n= 15), and normal (n= 11). Homocystein levels were higher in 3 groups compared to controls. AHI, MDI and desaturation time was higher in three -vessel disease compared to one and two- vessel diseases (p< 0.05). NO levels were correlated with the period of oxygen desaturation (r: -0.45, p= 0.031). The antioxidant capacity did not differ between OSA and healthy groups.

CONCLUSION

OSA is frequent in CAD. AHI, MDI and desaturation time are higher in patients with severe CAD. It is important to evaluate OSA patients for CAD.

Proton magnetic resonance spectroscopy of periventricular white matter and hippocampus in obstructive sleep apnea patients

BACKGROUND

The purpose of this study was to diagnose the hypoxic impairment by Magnetic resonance spectroscopy (MRS), an advanced MR imaging technique, which could not be visualised by routine imaging methods in patients with obstructive sleep apnea (OSA).

MATERIAL/METHODS

20 OSA patients and 5 controls were included in this prospective research. MRS was performed on these 25 subjects to examine cerebral hypoxemia in specific regions (periventricular white matter and both hippocampi). Polysomnography was assumed as the gold standard. Statistical analysis was assessed by Mann-Whitney U test and Receiver operating characteristics (ROC) curve for NAA/Cho, NAA/Cr and Cho/Cr ratios.

RESULTS

In the periventricular white matter, NAA/Cho ratio in OSA patients was significantly lower than in the control group (p<0.05). There were no statistical differences between the OSA and the control group for NAA/Cho, NAA/Cr and Cho/Cr ratios for both hippocampal regions. Additionally, Cho/Cr ratio in the periventricular white matter region of OSA group was higher than in the control group (p<0.05).

CONCLUSIONS

Hypoxic impairment induced by repeated episodes of apnea leads to significant neuronal damage in OSA patients. MRS provides valuable information in the assessment of hypoxic ischemic impairment by revealing important metabolite ratios for the specific areas of the brain.

Chitinases and lung diseases

Chitinase enzymes that hydrolize chitin and some articficial substrates are expressed in human despite lacking of the endogenous chitin within the body. Chitinases phatophysiological functions within human are not fully known. Recent evidence revealed that chitinases may have role into some processes of immune responses and inflammatory system. In this review, we discuss the role of chitinases in lung diseases based on the available information from the literature.

Rapid eye movement dependent central apnea with periodic leg movements

Central sleep apnea is a period of at least 10 s without airflow, during which no ventilatory effort is present. Most of the central apneas occur in Non-Rapid eye movement (NREM) sleep. Central apnea occuring in Rapid eye movement (REM) sleep is extremely rare. We present our patient who had a diagnosis of obstructive sleep apnea in another sleep center since 2003. His Auto Continuous Positive Airway Pressure (CPAP) machine was disrupted so he admitted to our center to renew his machine and for daytime sleepiness while using his machine. The polysomnography revealed central apneas ending with respiratory arousals and periodic leg movements in rapid eye movement (REM) stage. We found no cause for central apneas. The patient benefited from servo ventilator therapy. We present this case as an unusual form of central apnea with the review of the literatures. Even the patients diagnosed as obstructive sleep apnea should be analyzed carefully. The diagnosis and the therapeutic approach may change in the favor of the patient.

Quick Diagnosis in Obstructive Sleep Apnea Syndrome: WatchPAT-200

BACKGROUND

Obstructive sleep apnea syndrome (OSAS) is a highly prevelant disorder and found in approximately 2-4% of middle-aged adults.

OBJECTIVES

To assess the efficacy of Watch-PAT-200 in the diagnosis of obstructive sleep apnea syndrome (OSAS).

PATIENTS AND METHODS

Patients suspected of having OSAS underwent overnight Level I polisomnography and simultaneously wore Watch-PAT-200 in the sleep laboratory.

RESULTS

51 adult patients included in the study. The average age was 45.3±10.5 years and the average body mass index (BMI) was 29.4±4.0 kg/m2. There was a high agreement between PSG and Watch PAT regarding apnea-hypopnea index, respiratory disturbance index and oxygen desaturation index. Significant but a low agreement was found in stage 1 and 2 of non-REM sleep when two methods compared. No agreement was found between PSG and Watch-PAT regarding stage 3 and 4 of non-REM sleep. Very low agreement was found between PSG and Watch-PAT regarding the REM sleep.

CONCLUSIONS

Watch-PAT-200 is an effective method in the diagnosis of OSAS.

[Asymptomatic vena cava inferior aneurysm, case report]

Venous aneurysms are uncommon, whereas localized aneurysms of the inferior vena cava are extremely rare. Localized aneurysm of inferior vena cava was first publisheded in 1973 by Oh et al. Though venous aneurysms are generally asymptomatic, it is clinically important because of showing the symptoms of abdominal pain, gastrointestinal bleeding, acute venous obstruction, pulmonary embolism and even sudden death. Our case is also asymptomatic and localized aneurysm of the inferior vena cava is detected incidentally.

[Clinical, laboratory and computed tomography pulmonary angiography results in pulmonary embolism: retrospective evaluation of 205 patients]

OBJECTIVE

With this study, we aimed at evaluating demographic data, clinical, laboratory findings in pulmonary embolism (PE) and the relationship of these findings with the embolism location region and responses of the patients to the treatment of the embolism in order to contribute to the patient management in decreasing mortality.

METHODS

Clinical findings, accompanying diseases, risk factors, serum D-dimer and creatinine levels, imaging modalities and mortality rates of 205 patients (female: 98, male: 107) diagnosed with PE were examined retrospectively. The relationship between the qualifier variables was evaluated using Chi-square test.

RESULTS

Average age of the patients was 61.55±14.44 years and 86 (42%) patients were above 65 years. Most common complaint was dyspnea (85%), most frequent coexisting disease was congestive heart failure (19%). Deep vein thrombosis (DVT) (30.7%) was the most frequently seen risk factor. Pulmonary embolism was mostly in the right lobe pulmonary artery (32.1%). It was observed that the higher ages of patients the more frequency of proximal located embolism was (p<0.005), especially lobar artery involvement was observed to be high (p=0.032). An early mortality rate was 4.9% and late mortality rate was 11.2%.

CONCLUSION

In the patients with complaint of dyspnea who are at elder ages and have accompanying diseases, PE should be considered. PE is generally localized in the main pulmonary arteries, which emphasizes crucial importance of early diagnosis and treatment in reduction of mortality.

Bilateral multiple tumor-like endobronchial tuberculosis, diagnosed with bronchoscopic examination

Endobronchial tuberculosis is defined as tuberculosis infection of tracheobronchial tree and it is not seen often in adult population. In the absence of parenchymal disease endobronchial tuberculosis is less well-recognized and can lead to difficulties in diagnosis. Our aim is to introduce a rare form of tuberculosis that is important because of high probability of developing severe bronchostenosis during its course. We report a 20-year-old woman who presented with two-month history of severe non-productive cough, shortness of breath, and hemoptysis. After clinical and radiological evaluation, flexible bronchoscopy showed bilateral multiple tumorous lesions that were seen from main carina down to the both main bronchus. The biopsy samples revealed EBTB diagnosis and antituberculosis therapy was given. At the second month of the therapy, rebronchoscopy revealed almost disappearance of the polypoid lesions. The patient healed without any stenosis. This case report is a reminder that endobronchial tuberculosis must take into consideration in differential diagnosis of endobronchial lesions. In patients with endobronchial tuberculosis healing without any complication could be achieved with timely diagnosis and commencement of early treatment.