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A S Slutsky

Publications and source records attributed to A S Slutsky.

At least 163 records · Page 9Linked to original sources
PubMed1991

Sleep apnea and systemic hypertension: a causal association review.

OBJECTIVE: To critically examine the causal association between sleep apnea syndrome and hypertension. METHODS: A retrospective systematic critique of five epidemiologic studies published in the English literature during 1978 to 1989 identified on Medline and manual literature searches. The evidence was evaluated using the standard observational criteria for causation: strength of association, consistency, dose-response relationship, temporal sequence, specificity, and biologic plausibility. RESULTS: We found evidence to support a causal association between sleep apnea syndrome and hypertension in consistency and specificity and some evidence to suggest a dose-response relationship. Review of the data dealing with the mechanisms important in the pathogenesis of sleep apnea and hypertension allowed us to advance several theories to provide support for biologic plausibility. CONCLUSION: We concluded that there is a positive association--relative risk estimate between 1.3 and 40--for sleep apnea syndrome and hypertension, but the risk association is unstable. Thus, we believe that there is insufficient data to justify doing polysomnography as part of the routine diagnostic work-up for patients with hypertension.

Causality↗
PubMed1991

Warm heart surgery: experience with long cross-clamp times.

Although hypothermic cardioplegic arrest prolongs the period of ischemic arrest by reducing oxygen demands, it leaves the heart dependent solely on anaerobic metabolism for its energy demands and exposes it to the detrimental effects of hypothermia. Consequently, myocardial protection is compromised, and safe aortic occlusion time is limited to 120 minutes. As electromechanical arrest accounts for 90% of myocardial oxygen consumption, we hypothesized that an ideal state of the heart might be chemically arrested and perfused with warm blood, ie, aerobic arrest. We applied this approach to myocardial protection in 308 consecutive procedures. To assess the adequacy of this method, we reviewed the results in a group of 22 patients in whom the aortic cross-clamp time was, of necessity, greater than or equal to 3 hours (mean time, 204 minutes; range, 180 to 393 minutes). Nineteen of the patients represented a high operative risk with grade 3 or 4 left ventricular function and New York Heart Association class III or IV. All hearts resumed spontaneous normal sinus rhythm without defibrillation, and 21 patients were easily weaned from bypass within minutes of removal of the aortic cross-clamp without inotropic or intraaortic balloon pump support. Mortality was 4.5%, low-output syndrome occurred in 4.5%, and there were no perioperative myocardial infarctions. Our results suggest that warm aerobic arrest is safe and effective in prolonged high-risk procedures, virtually eliminating the period of ischemia, limiting the period and injury of reperfusion, and abolishing the detrimental effects of hypothermia.

Aged↗
PubMed1991

Role of basic fibroblast growth factor in revascularization of rabbit tracheal autografts.

Despite omentopexy of the bronchial anastomosis, donor airway ischemia remains a problem after lung transplantation. This study examined the hypothesis that surface abrasion and topical application of basic fibroblast growth factor (bFGF) would enhance omental revascularization of trachea in a rabbit heterotopic autograft model. Tracheal segments were excised, primary tracheal anastomoses performed, and the segments placed in the peritoneal cavity wrapped in omentum. Animals were randomized to one of six groups according to tracheal segment treatment: control, surgical abrasion, Surgicel wrap with topical bFGF, Surgicel wrap with bFGF vehicle, Gelfoam wrap with bFGF, and topical bFGF alone. One week later, animals were heparinized, perfused with Aquablak dye, and killed. Tracheal segments were excised and sectioned for light microscopic quantitative assessment of viability and dye perfusion. There was no significant improvement in viability or perfusion between abraded tracheal segments or segments treated with bFGF/Gelfoam or bFGF alone when compared with control segments. Airways wrapped in Surgicel had significantly greater ischemic injury compared with the control group, regardless of bFGF application. Neither surgical abrasion nor topical bFGF increased omental revascularization of transplanted tracheal segments after 7 days.

Airway Obstruction↗
PubMed1991

The effect of low-potassium-dextran versus Euro-Collins solution for preservation of isolated type II pneumocytes.

Limited availability of donor organs is a major factor restricting the clinical application of lung transplantation. Improvements in preservation techniques are essential for prolonging storage time and improving lung function following transplantation. The present investigation used primary cultures of adult rat alveolar type II cells as a model for evaluating lung-preservation solutions. Type II cells were plated onto tissue-culture plastic at a density 5 x 10(5) cells/cm2 and maintained in Dulbecco's modified Eagle's medium containing 10% fetal bovine serum (D10) for 40 hr. Cells were then exposed to Euro-Collins solution or a low-potassium-dextran solution (LPD). At designated time points, measurements of lactate-dehydrogenase (LDH) release, protein content, and incorporation of 3H-thymidine into cellular DNA were made. During 12 hr of "storage" at 37 degrees C, cells maintained in LPD released less LDH (14.3 +/- 1.2% of cellular total, mean +/- SEM, n = 5) than their counterparts stored in EC (20.6 +/- 1.6%, P less than 0.05). During the 36 hr following a 6-hr exposure to preservative solutions, LPD-treated cells incorporated more thymidine per mg of protein (2566 +/- 419.8 cpm/micrograms protein, mean +/- SEM, n = 6) compared with cells maintained continuously in D10 (1431 +/- 351, P less than 0.05). By contrast, cells exposed to EC incorporated less thymidine (82.2 +/- 62.8 cpm/micrograms protein) than either cells maintained in LPD or D10 (P less than 0.01 for each comparison). These results suggest that LPD solution is less cytotoxic than EC and that LPD enables higher levels of metabolic activity in recovering epithelial cells. In vitro cultures of type II epithelial cells are a useful model system for the study of lung preservation and posttransplantation lung injury.

Alkaline Phosphatase↗
PubMed1991

The effect of PGE1 and temperature on lung function following preservation.

We studied the effect of a vasodilator (prostaglandin E1) as well as flush (F) and storage (S) temperatures (4 degrees C or 10 degrees C) on lung preservation in an isolated rabbit lung perfusion model. Low-potassium dextran (LPD) or Euro-Collins (E-C) solution was used as flush solution. Six groups of six animals were studied: group 1 (LPD, 4 degrees C F-S), group 2 (LPD with PGE1, 4 degrees C F-S), group 3 (E-C with PGE1, 4 degrees C F-S), group 4 (LPD, 10 degrees C F-S), group 5 (LPD with PGE1, 10 degrees C F-S), group 6 (E-C with PGE1, 10 degrees C F-S). After 18-hr preservation, left lungs alone were ventilated, and reperfused with fresh venous blood. PaO2, PaCO2, pulmonary artery pressure (PAP), tracheal pressure (Pt) during reperfusion, and wet/dry weight (W/D) ratios were measured. PaO2 after LPD with or without PGE1 was significantly higher than after E-C with PGE1 at 4 degrees C (95.8 +/- 11.5 mmHg in group 1 or 102.7 +/- 8.6 in group 2 vs. 41.8 +/- 10.5 in group 3, P less than 0.01) and at 10 degrees C (119.3 +/- 2.3 in group 4 or 131.1 +/- 6.2 in group 5 vs. 54.6 +/- 5.2 in group 6, P less than 0.01). PaCO2, PAP, Pt, and W/D ratios in the LPD groups were lower than in the E-C groups. LPD/PGE1 and LPD alone produced similar pulmonary preservation. PaO2 of lungs flushed with LPD and preserved at 10 degrees C was higher than that of lungs stored at 4 degrees C. We conclude that LPD solution is superior to E-C solution in this ex vivo rabbit lung preservation model, even when PGE1 is used. A moderate dose of PGE1 did not improve the performance of LPD as a flush solution. Pulmonary preservation with LPD at 10 degrees C is superior to preservation at 4 degrees C.

Alprostadil↗
PubMed1991

Low-potassium UW solution for lung preservation. Comparison with regular UW, LPD, and Euro-Collins solutions.

University of Wisconsin solution has been used successfully in clinical kidney and liver preservation. The object of this study was to determine if low-potassium UW (LPUW) solution could be applied to pulmonary preservation. Rabbit lungs were stored after hypothermic pulmonary artery (PA) flush with four different solutions (group 1: low-potassium dextran (LPD) solution, group 2: high-potassium UW (HPUW) solution, group 3: LPUW solution, group 4: modified Euro-Collins (E-C) solution). The lungs were preserved at 10 degrees C for 30 hr and evaluated in an ex vivo ventilation/perfusion apparatus using fresh pooled venous rabbit blood. Mean PA flush pressures (MFP) during harvesting were significantly lower in groups 1 and 3 (8.1 +/- 1.0 mmHg and 7.3 +/- 0.6 mmHg, respectively; mean +/- SEM) than in groups 2 and 4 (15.5 +/- 1.7 mmHg and 12.3 +/- 0.9 mmHg, respectively). Lungs in groups 1 and 3 showed significantly higher PaO2 (103.5 +/- 8.0 mmHg and 89.3 +/- 7.2 mmHg) than groups 2 and 4 (48.3 +/- 7.7 mmHg, 66.7 +/- 4.7 mmHg). Groups 1 and 3 showed significantly lower wet/dry weight (W/D) ratios after reperfusion (6.21 +/- 0.15 and 6.39 +/- 0.23) than groups 2 and 4 (7.70 +/- 0.57 and 7.13 +/- 0.21, respectively). There were no significant differences in MFP, PaO2, PaCO2, mean pulmonary artery pressure, or W/D ratio between groups 1 and 3. These results suggest that LPUW solution may be as beneficial as LPD solution for pulmonary arterial flush and lung preservation.

Adenosine↗
PubMed1991

Phrenic neural output during hypoxia in dogs: constant-flow ventilation vs. spontaneous breathing.

We studied the effects of removing cyclic pulmonary afferent neural information on respiratory pattern generation in anesthetized dogs. Phrenic neural output during spontaneous breathing (SB) was compared with that occurring during constant-flow ventilation (CFV) at several levels of eucapnic hypoxemia. Hypoxia caused an increase in both the frequency and the amplitude of the moving time average (MTA) phrenic neurogram during both SB and CFV. The change in frequency as arterial saturation was reduced from 90 to 60% during SB was significantly higher than that during CFV [SB, 32.3 +/- 10.9 (SD) breaths/min; CFV, 10.3 +/- 5.8 breaths/min; P = 0.001]. By contrast, the increase in the amplitude of the MTA phrenic neurogram was smaller (SB, 0.62 +/- 0.68 units; CFV, 1.35 +/- 0.81 units; P = 0.01). The changes in frequency with hypoxia during both modes of ventilation resulted primarily from a shortening of expiratory time. Both inspiratory time and expiratory time were greater during CFV than during SB, but their change in response to hypoxia was not significantly different. We conclude that the amplitude response of the MTA phrenic neurogram to hypoxia is similar to that seen during hypercapnia; in the presence of phasic afferent feedback the MTA amplitude response is decreased and the frequency response is increased relative to the response observed in the absence of phasic afferents.

Afferent Pathways↗
PubMed1991

Respiratory sinus arrhythmia in dogs. Effects of phasic afferents and chemostimulation.

We examined the hypothesis that respiratory sinus arrhythmia (RSA) is primarily a central phenomenon and thus that RSA is directly correlated with respiratory controller output. RSA was measured in nine anesthetized dogs, first during spontaneous breathing (SB) and then during constant flow ventilation (CFV), a technique whereby phasic chest wall movements and thoracic pressure swings are eliminated. Measurements of the heart rate and of the moving time averaged (MTA) phrenic neurogram during these two ventilatory modes were made during progressive hypercapnia and progressive hypoxia. RSA divided by the MTA phrenic amplitude (RSAa) showed a power-law relationship with both arterial carbon dioxide partial pressure (PaCO2) and oxygen saturation (SaO2), but with different exponents for different conditions. However, the power-law relation between RSAa and respiratory frequency had an exponent indistinguishable from -2 whether hypoxia or hypercapnia was the stimulus for increased respiratory drive, and during both CFV and spontaneous breathing (-1.9 +/- 0.4, hypoxia, SB; -1.8 +/- 0.7, hypoxia, CFV; -2.1 +/- 0.8, hypercapnia, SB; -1.9 +/- 0.7, hypercapnia, CFV). We conclude that respiratory sinus arrhythmia is centrally mediated and directly related to respiratory drive, and that changes in blood gases and phasic afferent signals affect RSA primarily by influencing respiratory drive.

Afferent Pathways↗
PubMed1991

The effect of pulmonary arterial flow and positive end-expiratory pressure on retrograde bronchial mucosal blood flow.

Bronchial viability within the first few days after lung transplantation depends on collateral blood flow from the pulmonary to the bronchial circulation. In the present study the relationship between pulmonary arterial flow and retrograde bronchial blood flow, and the effect of positive end-expiratory pressure on bronchial blood flow were evaluated by laser Doppler velocimetry in an isolated in situ lung perfusion model. Nine adult mongrel dogs were exsanguinated by way of a left atrial cannula. Blood was pumped by a roller pump into the main pulmonary artery. Lungs were perfused at random flow (in 0.5 L/min increments) at rates of 1 to 3 L/min. Steady-state laser Doppler velocimetric measurements at each level of flow were made at the tracheal carina and both bronchial carina. Pump flow was then set at baseline cardiac output and positive end-expiratory pressure was applied. Steady-state laser Doppler velocimetric measurements were obtained at each level of positive end-expiratory pressure (5 cm H2O and 10 cm H2O). Bronchial blood flow correlated well with pulmonary arterial flow (for the tracheal carina; rs = 0.912 and p less than 0.0005; for the right bronchial carina, rs = 0.799, p less than 0.0005; for the left bronchial carina, rs = 0.917, p less than 0.0005; where rs is the common correlation coefficient). The bronchial blood flow at the left bronchial carina and the right bronchial carina were significantly higher than at the tracheal carina (p less than 0.005 and p less than 0.05, respectively). At baseline cardiac output, bronchial blood flow in the in situ model was approximately 50% lower than observed in the intact animals. Positive end-expiratory pressure increased the bronchial blood flow at the tracheal carina and both bronchial carina (p less than 0.05).

Animals↗
PubMed1991

Warm heart surgery.

Hypothermia is widely acknowledged to be the fundamental component of myocardial protection during cardiac operations. Although it prolongs the period of ischemic arrest by reducing oxygen demands, hypothermia is associated with a number of major disadvantages, including its detrimental effects on enzymatic function, energy generation, and cellular integrity. We hypothesized that the ideal protected state of the heart would be electromechanically arrested and perfused with blood, that is, aerobic arrest. Under these conditions the fundamental need for hypothermia becomes questionable. We have developed a novel approach to myocardial protection during cardiac operations based on these concepts, in which the chemically arrested heart is perfused continuously with blood and maintained at 37 degrees C. In 121 consecutive coronary bypass procedures we have compared this approach with a historical cohort of 133 consecutive patients treated with hypothermic cardioplegia. Perioperative myocardial infarction was significantly less prevalent (1.7% versus 6.8%; p less than 0.05) in the warm cardioplegic group, as was the use of the intraaortic balloon pump (0.9% versus 9.0%; p less than 0.005) and the prevalence of low output syndrome (13.5% versus 3.3%; p less than 0.005). Cardiac output immediately after bypass was significantly higher than before bypass (3.1 +/- 0.9 versus 4.9 +/- 1.0 L/min; p less than 0.001) only in the warm cardioplegia group. Furthermore, the heartbeat in 99.2% of patients treated with continuous warm cardioplegia converted to normal sinus rhythm spontaneously after removal of the aortic crossclamp compared with only 10.5% of the hypothermic group. The time from removal of the aortic crossclamp to discontinuation of cardiopulmonary bypass (i.e., reperfusion time) was significantly shorter in the warm cardioplegia group (11 +/- 4.3 versus 27 +/- 5.6 minutes; p less than 0.001). Our results suggest that continuous normothermic blood cardioplegia is safe and effective. Conceptually, this represents a new approach to the problem of maintaining excellent myocardial preservation during cardiac operations.

Aged↗
PubMed1990

Control of expiratory duration by arterial CO2 oscillations in vagotomized dogs.

The role of respiratory oscillations of PaCO2 (CO2 oscillations) in the regulation of expiratory duration (TE) was examined in eight anesthetized dogs by measuring instantaneous changes of arterial pH during the respiratory cycle with a catheter-tip ISFET (ion-sensitive field effect transistor) pH electrode. Steady-state changes in arterial pH oscillation were induced by vagotomy, which increased the amplitude of pH oscillation from 0.014 +/- 0.002 (mean +/- SEM) to 0.058 +/- 0.006 units (P less than 0.001), and prolonged TE from 5.12 +/- 0.56 to 9.99 +/- 1.11 sec (P less than 0.005) with little change in average pH (0.021 +/- 0.011 units, P = 0.12). Vagotomy also reversed the phase relationship between arterial pH oscillation at the carotid bodies and tidal ventilation, such that pH rose during early expiration, rather than falling as occurred in the intact state. When the within-breath oscillation of arterial pH was transiently reduced by having the vagotomized dogs inspire a single breath of CO2 enriched air, TE of the same breath was shortened in proportion to the reduction in amplitude of pH oscillation (r = 0.72, P less than 0.001), rather than in proportion to changes in the average pH of the test breath (r = 0.44). The results indicate that the profile of within-breath oscillation of PaCO2 (phase relationship and amplitude) can exert an important influence on TE, and may in part account for the prolongation of TE following vagotomy.

Animals↗
PubMed1990

Radiologic correlation with early physiologic function of the transplanted canine lung.

There is no single reliable method for assessment of the transplanted lung. Multiple modes of assessment are therefore used. In a canine model designed to assess lung preservation, the reliability of information gained from chest radiographs performed in the early post-transplant period was examined. The function of 20 left lung allografts, stored for 12 hours after pulmonary artery flush preservation was studied. Radiographs graded according to disease severity were compared with physiologic function of the transplanted lung assessed immediately and at three days post-transplantation. This protocol enables study of acute preservation-related lung injury and the delayed manifestations of ischemic and reperfusion injury after a three day period of recovery, while avoiding confounding rejection and infectious episodes. The chest radiograph did not reliably reflect function of the flush-preserved transplanted lung. Thus, relying only on this modality may lead to erroneous conclusions. In this study, the progression of radiographic changes associated with the "reimplantation response" differed from previous descriptions, possibly reflecting differences in operative technique or improved lung preservation.

Animals↗
PubMed1990

The superiority of an extracellular fluid solution over Euro-Collins' solution for pulmonary preservation.

Limited donor supply is the major factor restricting the application of lung transplantation. A uniformly reliable method of lung preservation would improve donor organ availability. At present, Euro-Collins' solution, an intracellular fluid-type solution, is most widely used in organ preservation. However, we have previously shown that initial pulmonary flush with an extracellular-type solution (low-potassium dextran solution [LPD]) provided better pulmonary preservation than Euro-C. In the present study, we used an in vitro-ventilated, blood-perfused rabbit lung model to examine whether the mechanism for this improvement was related to the effect of LPD during pulmonary flush or its effect during storage. Rabbit lungs were harvested and stored after pulmonary flush with different solutions (group 1: 400 ml of LPD; group 2: 400 ml of Euro-C; group 4: 300 ml of Euro-C followed by 100 ml of LPD; n = 5 in each group). The lungs were then preserved at 10 degrees C for 18 hr and reperfused with fresh venous blood. After 10 min of reperfusion, lungs in group 1 showed the highest PO2 (group 1: 124.4 +/- 7.7 mmHg; group 2: 46.2 +/- 9.4 mmHg P less than 0.01). Lungs in both group 3 and group 4 showed better lung function and lower wet/dry weight ratio than those in group 2. We conclude that LPD provides better lung preservation by its effects both on pulmonary flush and on storage.

Animals↗
PubMed1990

Mechanisms of gas exchange with different gases during constant-flow ventilation.

To investigate the mechanisms responsible for the difference in gas exchange during constant-flow ventilation (CFV) when using gases with different physical properties, we used mixtures of 70% N2-30% O2 (N2-O2) and 70% He-30% O2 (He-O2) as the insufflating gases in 12 dogs. All dogs but one had higher arterial PCO2 (PaCO2) with He-O2 compared with N2-O2. At a flow of 0.37 +/- 0.12 l/s, the mean PaCO2's with N2-O2 and He-O2 were 41.3 +/- 13.9 and 53.7 +/- 20.3 Torr, respectively (P less than 0.01); at a flow rate of 0.84 +/- 0.17 l/s, the mean PaCO2's were 29.1 +/- 11.3 and 35.3 +/- 13.6 Torr, respectively (P less than 0.01). The chest was then opened to alter the apposition between heart and the lungs, thereby reducing the extent of cardiogenic oscillations by 58.4 +/- 18.4%. This intervention did not significantly alter the difference in PaCO2 between N2-O2 and He-O2 from that observed in the intact animals, although the individual PaCO2 values for each gas mixture did increase. When the PaCO2 was plotted against stagnation pressure (rho V2), the difference in PaCO2 between N2-O2 and He-O2 was nearly abolished in both the closed- and open-chest animals. These findings suggest that the different PaCO2's obtained by insufflating gases with different physical properties at a fixed flow rate, catheter position, and lung volume result mainly from a difference in the properties of the jet.

Animals↗
PubMed1990

Effects of hypercarbia on arterial and alveolar oxygen tensions in a model of gram-negative pneumonia.

Inspired CO2 causing changes from hypo- to normocapnia has previously been shown to improve arterial O2 tension (PaO2) and to reduce alveolar-arterial O2 difference. The effect of further increases in inspired CO2 to hypercarbic levels has not been studied in inflammatory lung disease. Three days after induction of sublobar Pseudomonas pneumonia, Suffolk sheep were anesthetized and ventilated with a fixed-volume ventilator. After 2.5 h, CO2 was added to the inspired gas to raise arterial CO2 tension (PaCO2) to 60-65 Torr. Four hours later the CO2 was withdrawn and ventilation continued for an additional 2 h. Constant minute ventilation and inspired O2 fraction were maintained. Regional lung perfusion was measured by injection of radioactive microspheres. With the administration of CO2, PaO2 increased significantly from 65.5 to 77.5 Torr as did alveolar O2 tension (from 109.7 to 120.0 Torr) with no significant change in alveolar-arterial O2 difference. There were no significant changes in cardiac output, shunt fraction, O2 uptake, O2 delivery, respiratory quotient, or distribution of regional lung perfusion. We conclude that the increases in alveolar O2 tension and PaO2 with the added CO2 resulted from improved alveolar ventilation.

Animals↗
PubMed1990

Do patients with obstructive sleep apnea have thick necks?

During physical examination of patients with suspected obstructive sleep apnea (OSA), a comment is frequently made that they appear to have a short and fat neck. To confirm this subjective impression by objective measurements, we studied a group of 123 patients referred to us because of snoring and suspected OSA, all of whom had nocturnal polysomnography and measurements of external and internal neck circumference. The external neck circumference was measured at the level of the superior border of the cricothyroid cartilage. Internal neck circumferences were calculated from the measurements of pharyngeal, glottic, and tracheal areas obtained by the acoustic reflection technique. Internal pharyngeal circumference was further subdivided into the proximal, middle, and distal thirds. The acoustic technique also permitted us to measure the distance between the teeth and the glottic minimum, which reflects the length of the upper airway. Stepwise multiple linear regression analysis revealed that the apnea/hypopnea index (AHI) correlated only with the external neck circumference, the body mass index, and the internal circumference of the distal pharynx; these three variables accounted for 39% of the variability in AHI. We conclude that the external and internal neck circumferences and the degree of obesity are important predictors of sleep apnea; it is possible that obesity produces its effect via fat in the neck. We speculate that the static pharyngeal size modulated by the dynamic loading of the airway due to the weight of fatty tissue of the neck may contribute to the pathogenesis of OSA.

Adult↗
PubMed1990

An evaluation of flow-volume curves as a screening test for obstructive sleep apnea.

We examined flow-volume curves for their potential as screening tests for obstructive sleep apnea (OSA) in 401 patients referred for investigation of snoring. In all patients, we performed nocturnal polysomnography, maximum inspiratory and maximum expiratory flow-volume curves. The curves were examined for two features: 1) presence of flow oscillations (the "saw-tooth" sign), and 2) changes in their configuration that might suggest upper airway obstruction as documented by the expiratory/inspiratory flow ratios calculated at 50 and 75 percent of exhaled vital capacity (FR50 and FR25, respectively). Based on the results of nocturnal polysomnography, the patients were stratified according to severity into apnea groups, and the flow ratios and flow oscillations were compared among these groups. We found that neither the FR50 nor FR25 were significantly different among the groups. Inspiratory and expiratory flow oscillations were seen infrequently (32 patients) and tended to occur in patients with more severe sleep apnea. Neither the flow ratios nor the flow oscillations had good predictive values for snoring or sleep apnea. The sensitivity of the flow volume curve abnormalities ranged between 0 and 14 percent, but the specificity was high, ranging between 93 and 95 percent. We conclude that because of low sensitivity, flow-volume loops are not a useful screening test for the diagnosis of OSA in snoring patients.

Adult↗