Indication of CPAP without a sleep study in patients with high pretest probability of obstructive sleep apnea.

OBJECTIVE: To evaluate the performance of clinical criteria (CC) for diagnosis and initiation of empirical treatment with continuous positive airway pressure (CPAP) in patients with suspected obstructive sleep apnea (OSA) compared with the treatment decision based on sleep studies (polysomnography or respiratory polygraphy), guidelines, and experience of participating physicians. METHODS: This was a simulated intention-to-treat study in a retrospective (G1) and prospective (G2) cohort. Four observers (two per group) called CC1 and CC2 reviewed the sleep questionnaires and indicated CPAP if the patients presented snoring, frequent apneas (≥ 3-4/week), body mass index (BMI) > 25 kg/m2, sleepiness (Epworth > 11), or tiredness (at least 3-4 times per week) and some comorbidity (hypertension, coronary/cerebrovascular event, diabetes). Ten independent observers formed two groups of five (FD1 and FD2) and were blinded to each other's opinion. These observers in FD1 and FD2 decided CPAP treatment based on guidelines of the Spanish Society of Pulmonology and Thoracic Surgery (SEPAR) or guidelines of the American Academy of Sleep Medicine (AASM) and factored in their own opinion. Sensitivity (S), specificity (Sp), and positive/negative likelihood ratios (LR+/-) were calculated with the test method: CC1/2, and the reference method: majority decision of FD1/2. RESULTS: A total of 653 patients (264 women, 40%) were studied. Median age was 54 years, BMI 28 kg/m2, and apnea hypopnea index (AHI) 16.5 events/h. S ranged from 21 to 25% (p 0.60), Sp 96.1 to 97.6% (p 0.39), and LR+ of clinical criteria 6.4 to 8.9 (p 0.52). CONCLUSION: CPAP indication without a previous sleep study showed a low sensitivity (≅ 22%) but a specificity greater than 95% in patients with high pretest probability for OSA (snoring, report of frequent apneas, BMI > 25 kg/m2 and sleepiness or tiredness plus comorbidity).

Tratamiento con presión positiva de la Apnea Obstructiva del Sueño. Posición de la Asociación Argentina de Medicina Respiratoria / Treatment of Obstructive Sleep Apnea with Positive Pressure. Position of the Argentinian Association of Respiratory Medicine

La Sección de Sueño, Oxigenoterapia y Otros Tratamientos Crónicos Domiciliarios, de la Asociación Argentina de Medicina Respiratoria (AAMR) se planteó desarrollar en nuestro país un documento formal que exponga la base científica y costo económica de la cobertura del tratamiento del síndrome de apneas e hipopneas obstructivas durante el sueño (SAHOS). Esta iniciativa se basó en la necesidad de analizar la visión de expertos locales que se desempeñan en la realidad coyuntural cotidiana de nuestro país, para elaborar un documento informativo para miembros del equipo de salud. A su vez, exhorta a los diferentes actores del sistema a determinar pautas claras que sirvan de referencia para la generación de políticas públicas. La agenda se inició en septiembre de 2018 en un grupo de redacción. Luego, revisores de cinco provincias argentinas efectuaron una extensa valoración de la evidencia publicada. Para la edición final se realizó una reunión presencial de discusión y generación de consenso. Se plantearon como objetivos; actualizar la base científica que define al SAHOS como problema de salud de proporciones epidémicas con consecuencias demostrables en la salud, analizar los datos de costo-efectividad del tratamiento con CPAP para las formas moderadas a severas y leves con síntomas y unificar conceptos en relación con la calidad mínima necesaria en los tratamientos que se ofrecen. Finalmente, se analiza la situación en la Argentina sobre la base a datos publicados y se presenta una propuesta de mejora en tres niveles: social y económico, logístico-administrativo y clínico

The Sleep, Oxygen Therapy and Other Home Chronic Treatments Section of the Argentinian Association of Respiratory Medicine (AAMR, for its acronym in Spanish) proposed the development in our country of a formal document exposing the scientific and cost-economical foundation of the coverage for the treatment of obstructive sleep apnea and hypopnea syndrome (OSAHS). This initiative was based on the need to analyze the vision of local experts who work in the daily current reality of our country, in order to create an informative document for the members of the medical staff. In turn, it encourages the different members of the system to determine clear guidelines that could be used as reference for generating public policies. The agenda began in September, 2018 within a writing staff. Then, editors from five Argentinian provinces made a thorough assessment of published evidence. For the final edition, a face-to-face meeting was arranged to discuss and reach a consensus. The suggested objectives were: to update the scientific base that defines the OSAHS as a health problem of epidemic proportions with health consequences; to analyze cost-efficacy data of CPAP treatment for moderate to severe and mild-with-symptoms forms of the disease and to unify concepts in relation to the minimum necessary quality of treatments to be offered. Finally, the situation in Argentina is analyzed basing on published data, and a proposal is presented for improvement in three levels: social and economic, logistic-administrative and clinical.

Guías prácticas de diagnóstico y tratamiento del síndrome de apneas e hipopneas obstructivas del sueño: Actualización 2019: Sección Sueño, Oxigenoterapia y Tratamientos Crónicos Domiciliarios. Asociación Argentina de Medicina Respiratoria / Practical guides for diagnosis and treatment of obstructive sleep apneas and hypopneas syndrome: 2019 update. Sleep, Oxygen Therapy and Chronic Home Treatments Section. Argentine Association of Respiratory Medicine

Las apneas del sueño constituyen uno de los trastornos respiratorios crónicos de mayor relevancia en la población general, por su prevalencia, los efectos que produce en los pacientes que las padecen y su impacto en la salud pública. En el año 2013 se publicaron las primeras Guías Prácticas de diagnóstico y tratamiento del síndrome de apneas e hipopneas obstructivas del sueño de la AAMR. Desde entonces se ha generado un volumen significativo de evidencia científica sobre estos trastornos, lo que ha motivado la actualización de estas Guías Prácticas. Un grupo de trabajo, conformado por profesionales entrenados y con experiencia en trastornos respiratorios del sueño, revisó la bibliografía y actualizó los conceptos vertidos en las guías 2013. En su desarrollo se define el cuadro, los criterios diagnósticos y de gravedad, los factores de riesgo, las formas de presentación y sus consecuencias. Se detalla la metodología diagnóstica, sus distintas variables e indicaciones y los requisitos técnicos para su validación e interpretación. Por último se desarrollan las alternativas terapéuticas, así como también aspectos prácticos de su implementación. El objetivo central fue generar una herramienta de divulgación científica, que determine pautas claras que sirvan de referencia para la formación de profesionales, la atención de pacientes con esta enfermedad y la generación de políticas públicas.

Sleep apnea is one of the most relevant chronic respiratory disorders in the general population, given its prevalence, the effects it produces in patients and their impact on public health. In 2013, the first Practical Guidelines for diagnosis and treatment of obstructive sleep apnea syndrome of the AAMR were published. Since then, a significant volume of scientific evidence on these disorders has been generated, which has motivated the updating of these Practical Guidelines. A working group of trained professionals with experience in sleep breathing disorders reviewed the literature and updated the concepts included in the 2013 guidelines. Clinical aspects, diagnostic and severity criteria, risk factors, consequences and diagnostic strategy are addressed, as well as therapeutic alternatives and practical aspects of their implementation. The main objective was to generate practical guidelines that constitute a reference for the training of professionals, the care of patients with this disease and the generation of public policies.

CPAP indication based on clinical data and oximetry for patients with suspicion of obstructive sleep apnea: A multicenter trial.

BACKGROUND AND OBJECTIVE: The usefulness of pulse oximetry for the management of obstructive sleep apnea is controversial. The aim of this study was to assess the accuracy for indication of Continuous Positive Airway Pressure (CPAP) treatment in patients with suspected obstructive sleep apnea (OSA) based on clinical and oximetry data as compared to polysomnography (PSG). METHODS: This multicenter observational study involved seven sleep laboratories. Patients with suspicion of OSA who completed a standardized sleep questionnaire and a diagnostic PSG were enrolled. Eight observers logged on to a website independently and blindly. Seven observers only accessed the clinical data, curve and pulse oximetry results (Os-SO2-test method), while the eighth observer had full access to all indicators of PSG (O-PSG-reference method). Once observers assessed the information available on the website, they had to choose between three CPAP treatment options (yes/no/do not know) based on their knowledge and criteria. RESULTS: 411 subjects (228 men), median age 54 years, were available for evaluation. Os-SO2 had lower sensitivity (S), greater specificity (Sp) and positive likelihood ratio (PLR) to prescribe CPAP in patients more symptomatic (Epworth Sleepiness Scale-ESS > 10 or comorbidities) than those with fewer symptoms (ESS < 11 without comorbidities) (S 45-75% versus 45-91%, p 0.028); Sp 93.8-100% versus 68.5-96.6%, p 0.004; PLR > 10 versus 2.9-17, p<0.01). CONCLUSIONS: Due to its low false positive rate, a strategy based on pulse oximetry and clinical data was a consistent tool to indicate CPAP treatment in most symptomatic patients with a suspicion of OSA.

The influence of gender on symptoms associated with obstructive sleep apnea.

BACKGROUND: It has been reported that the clinical expression of obstructive sleep apnea (OSA) may differ in women and men. OBJECTIVE: The objective of this study was to evaluate the influence of gender on reported OSA-related symptoms in a large clinical population of patients. METHODS: The database from the sleep laboratory of a tertiary care center was examined. Adult patients who had undergone a diagnostic polysomnography and completed the Berlin questionnaire, a sleep questionnaire, and the Epworth sleepiness scale were selected. Multiple logistic regression analysis was performed to assess the relationship between OSA-associated symptoms and different potential explanatory variables. RESULTS: The study sample included 1084 patients, median age was 53 years, 46.5% (504) were women, 72.7% (788) had OSA (apnea/hypopnea index ≥ 5), and 31.2% were obese. After adjusting for age, body mass index, and apnea/hypopnea index, men were more likely to report snoring (OR 4.06, p < 0.001), habitual or loud snoring (OR 2.34, p < 0.001; 2.14, p < 0.001, respectively) and apneas (OR 2.44, p < 0.001), than women. After controlling for multiple variables, female gender was an independent predictive factor for reported tiredness (OR 0.57, p 0.001), sleep onset insomnia (OR 0.59, p 0.0035), and morning headaches (OR 0.32, p < 0.001). Reports of excessive daytime sleepiness, nocturia, midnight insomnia, and subjective cognitive complaints were not significantly associated with gender. CONCLUSION: Women with OSA were more likely to report tiredness, initial insomnia, and morning headaches, and less likely to complain of typical OSA symptoms (snoring, apneas) than men.

Can CPAP be indicated in adult patients with suspected obstructive sleep apnea only on the basis of clinical data?

BACKGROUND: There is scarce information about whether the diagnosis of OSA supported only by medical record data can be a useful and reliable tool to initiate a CPAP treatment. OBJECTIVES: The aim of this study is to develop and assess the accuracy of clinical parameters for the diagnosis and prescription of CPAP in patients with suspected OSA. METHODS: Adult patients who underwent polysomnography and completed the Berlin questionnaire, a clinical record, and the Epworth sleepiness scale were included in the study. A situation was simulated in which two blinded and independent observers would be able to indicate CPAP treatment if the patients were snorers with frequent apnea reports (≥3-4 times a week) and overweight (BMI > 25 kg/m(2)) plus one of the following: diurnal symptoms (tiredness after sleeping or at waking time ≥3-4 times a week or Epworth sleepiness scale >11), arterial hypertension, cerebrovascular accident, coronary event, type II diabetes or cardiac arrhythmias (observer 1, clinical criteria) or on the basis of the respiratory disturbance index, significant tiredness (≥3-4 times a week) or sleepiness (Epworth >11) and associated comorbidities (observer 2, reference method). The area under the ROC curve (ABC-ROC), sensitivity, specificity, and likelihood ratios were calculated. RESULTS: Among 516 subjects (72 % men), the median age was 52 years, BMI 28.3 kg/m(2), and RDI 19.7 events/h. The ABC-ROC, sensitivity, specificity, and positive likelihood ratio of the clinical parameters were of 0.64 to 0.65, 31 to 33 %, 97 to 98 %, and 11 to15 respectively. No differences in the diagnostic performance of the clinical criteria were observed between men and women. CONCLUSIONS: These clinical parameters made it possible to indicate CPAP in approximately one third of the population with OSA which would have required it on the basis of their PSG and clinical history. This approach showed high specificity; hence, few patients who did not meet the criteria for CPAP use would have received this treatment.

Validation of ApneaLink Ox™ for the diagnosis of obstructive sleep apnea.

OBJECTIVE: The aim of the study was to validate the automatic and manual analysis of ApneaLink Ox™ (ALOX) in patients with suspected obstructive sleep apnea (OSA). METHODS: All patients with suspected OSA had a polysomnography (PSG) and an ALOX performed in the sleep laboratory. For automatic analysis, hypopnea was defined as a decrease in airflow ≥30 % of baseline for at least 10 s plus oxygen desaturation ≥3 or 4 %. While for the manual analysis, hypopnoea was considered when a reduction of airflow ≥30 % of ≥10 s plus oxygen desaturation ≥3 % or increase in cardiac rate ≥5 beats/min were identified or, when only a reduction of airflow ≥50 % was observed. OSA was defined as a respiratory disturbance index (RDI) ≥5. The apnea/hypopnea automatic index (AHI3-a, AHI4-a) and manual index were estimated. Receiver operating characteristics (ROC) analysis and the agreement between ALOX and PSG were performed. RESULTS: Fifty-five patients were included (38 men; mean age, 48.2; median, RDI 15.1; median BMI, 30 Kg/m(2)). The automatic analysis of ALOX under-estimated the RDI from PSG, mainly for the criterion of oxygen desaturation ≥4 % (AHI3-a-RDI, -3.6 ± 10.1; AHI4-a-RDI, -6.5 ± 10.9, p < 0.05). The autoscoring from ALOX device showed a better performance when it was set up to identify hypopneas with an oxygen desaturation criterion of ≥3 % than when it was configured with an oxygen desaturation criterion of ≥4 % (area under the receiver operator curves, 0.87 vs. 0.84). Also, the manual analysis was found to be better than the autoscoring set up with an oxygen desaturation of ≥3 % (0.923 vs. 0.87). The manual analysis showed a good interobserver agreement for the classification of patients with or without OSA (k = 0.81). CONCLUSION: The AHI obtained automatically from the ApneaLink Ox™ using oxygen desaturation ≥3 % as a criterion of hypopnea had a good performance to diagnose OSA. The manual scoring from ApneaLink Ox™ was better than the automatic scoring to discriminate patients with OSA.

How reliable is the manual correction of the autoscoring of a level IV sleep study (ApneaLink™) by an observer without experience in polysomnography?

OBJECTIVE: This study aims to compare the manual correction of the automatic analysis of ApneaLink™ between a skilled observer in the interpretation of sleep studies and a subject trained only in the scoring of ApneaLink™ device. METHODS: Ninety-six subjects performed the ApneaLink™ and polysomnography (PSG) simultaneously in the sleep laboratory. Two blind observers, who were independent from the results of the PSG, performed first the automatic scoring and then the hand correction from the ApneaLink™ device. The scorers of ApneaLink™ represented two physicians with different levels of training (scorer A: 20 years of experience in reading polysomnography plus 3 years of experience in the interpretation of ApneaLink™, scorer B: 1 year of experience in the analysis of ApneaLink™). The interobserver agreement was assessed with the intraclass correlation coefficient (ICC) and kappa statistics. The diagnostic accuracy of the manual analysis ApneaLink™ device was evaluated by the area under the receiver operator curve (AUC-ROC). RESULTS: Ninety patients were included (69 men; mean age, 49.6; median RDI, 13.9; median BMI, 29.3 Kg/m(2)). The ICC between the manual apnea/hypopnea index from ApneaLink™ and the respiratory disturbance index of the PSG for each observer was similar (scorer A, 0.902; CI 95% 0.80-0.95; vs. scorer B, 0.904; CI 95% 0.86-0.94; p = 0.9). The agreement between the observers on the presence or absence of obstructive sleep apnea syndrome (OSAS) was very good (kappa, 0.83; CI 95% 0.69-0.98). The AUC-ROC was similar between the observers (scorer A, 0.88; CI 95% 0.78-0.98; scorer B, 0.83; CI 95% 0.71-0.95; p = 0.5). CONCLUSIONS: The non-expert observer showed a very good agreement with the expert observer on the results of the manual correction of the ApneaLink™ autoscoring. Both observers had similar diagnostic accuracy to identify subjects with OSAS when compared with PSG.

Indication of CPAP in Patients with Suspected Obstructive Sleep Apnea, Based on Clinical Parameters and a Novel Two-Channel Recording Device (ApneaLink): A Pilot Study.

Objective. To evaluate the accuracy and reliability of the medical decision based on the results of the hand scoring from a two-channel recording device (ApneaLink) plus clinical data for the prescription of a CPAP assay in patients with suspected OSA. Methods. 39 subjects were assessed in the sleep laboratory with polysomnography and ApneaLink. The patients completed the Epworth sleepiness scale and a clinical history. Two blinded independent observers decided to prescribe CPAP according to the results of the PSG (gold standard, observer A), ApneaLink (alternative method, observer B), and the clinical parameters. Sensitivity and specificity of observer B on the indication of CPAP were calculated. The interobserver agreement for the indication of CPAP was assessed using kappa statistics. Results. 38 subjects were included (26 men, mean age 47.5, mean RDI 28.7, mean BMI 31.4 kg/m(2)). The prevalence of OSA was 84%. The sensitivity and specificity of observer B to initiate a CPAP trial were 90.6% and 100%, respectively. The interrater agreement for the prescription of CPAP was good (kappa: 0.75). Conclusion. This study has shown that the use of ApneaLink plus clinical data has made it possible to indicate CPAP reliably in most patients with high-clinical pretest for OSA.

Accuracy of the clinical parameters and oximetry to initiate CPAP in patients with suspected obstructive sleep apnea.

OBJECTIVE: The aim of this study was to assess the accuracy of oximetry and the clinical parameters for the prescription of continuous positive airway pressure (CPAP) in patients with suspected obstructive sleep apnea syndrome (OSAS). METHODS: All participants (135) performed oximetry (WristOx 3100™) and polysomnography (PSG) simultaneously in the sleep laboratory. The patients completed the Epworth sleepiness scale, the Berlin questionnaire, and a clinical history. Two blind independent observers decided to prescribe CPAP according to the results of the PSG (gold standard, observer A), oximetry (alternative method, observer B), and the clinical parameters. The accuracy of observer B on the indication of CPAP, using different cutoff points of the adjusted desaturation index (ADI3 and ADI4), was evaluated by the area under the receiver operating characteristics curve (AUC-ROC). The interobserver agreement for the indication of CPAP was assessed using kappa statistics. RESULTS: One hundred nineteen subjects were included (92 men; mean age, 53; median respiratory disturbance index, 22.6; median BMI, 27.5 kg/m(2)). Depending on the criteria used in oximetry, the sensitivity and specificity of observer B to initiate a CPAP trial ranged from 79.8% to 92.5% and of 92% to 96%, respectively. The best performance for the indication of CPAP was noted with the adjusted O(2) desaturation index ≥ 3% (AUC-ROC, 0.923). The inter-rater agreement for the prescription of CPAP was good (kappa, 0.60 to 0.79). CONCLUSION: This simulated study has shown that the use of oximetry plus clinical data has made it possible to indicate CPAP reliably in nearly 90% of the population with OSAS.

Comparison of the automatic analysis versus the manual scoring from ApneaLink™ device for the diagnosis of obstructive sleep apnoea syndrome.

OBJECTIVE: The purpose of this study was to compare the performance of the automated detection versus the manual scoring from the ApneaLink™ device to diagnose obstructive sleep apnoea syndrome (OSAS). METHODS: All participants (96) performed the ApneaLink™ (AL) and polysomnography (PSG) simultaneously in the sleep laboratory. The two recordings were interpreted blindly. The hypopnoea criterion used for the analysis of both automatic and manual ApneaLink™ was a fall in airflow ≥50% of baseline for ≥10 s. The agreement between AL and PSG and the interobserver concordance was calculated. ROC analysis, sensitivity and specificity were assessed for the different ApneaLink™ and OSAS criteria. RESULTS: Ninety patients were included (69 men; mean age, 49.6; median RDI, 13.9; median BMI, 29.3 kg/m(2)). The automatic apnoea/hypopnoea index (AHI-a) showed a lower agreement with the respiratory disturbance index (RDI) than the manual apnoea/hypopnoea (AHI-m) [AHI-a/RDI: intraclass correlation coefficient (ICC) 0.88 versus AHI-m/RDI: ICC 0.91]. The manual scoring (MS) showed a similar sensitivity and a higher specificity than the automatic scoring (AA) for the detection of OSAS, defined as an RDI ≥ 5 (sensitivity and specificity AA and MS: 89%/89%, 60%/86.7%, respectively). The accuracy of the automatic and manual scoring of the AL was similar when OSAS was defined as an RDI ≥ 20 or 30. The ApneaLink™ manual scoring had a very good interobserver agreement (k = 0.86). CONCLUSIONS: The manual scoring of an ApneaLink™ recording was better than the automatic scoring in terms of agreement with RDI and to discriminate patients with OSAS. The hand scoring did not improve the accuracy of automatic scoring in patients with severe OSAS.

Pulse oximetry for the detection of obstructive sleep apnea syndrome: can the memory capacity of oxygen saturation influence their diagnostic accuracy?

Objective. To assess the diagnostic ability of WristOx 3100 using its three different recording settings in patients with suspected obstructive sleep apnea syndrome (OSAS). Methods. All participants (135) performed the oximetry (three oximeters WristOx 3100) and polysomnography (PSG) simultaneously in the sleep laboratory. Both recordings were interpreted blindly. Each oximeter was set to one of three different recording settings (memory capabilities 0.25, 0.5, and 1 Hz). The software (nVision 5.1) calculated the adjusted O2 desaturation index-mean number of O2 desaturation per hour of analyzed recording ≥2, 3, and 4% (ADI2, 3, and 4). The ADI2, 3, and 4 cutoff points that better discriminated between subjects with or without OSAS arose from the receiver-operator characteristics (ROCs) curve analysis. OSAS was defined as a respiratory disturbance index (RDI) ≥ 5. Results. 101 patients were included (77 men, mean age 52, median RDI 22.6, median BMI 27.4 kg/m(2)). The area under the ROCs curves (AUC-ROCs) of ADI2, 3, and 4 with different data storage rates were similar (AUC-ROCs with data storage rates of 0.25/0.5/1 Hz: ADI2: 0.958/0.948/0.965, ADI3: 0.961/0.95/0.966, and ADI4: 0.957/0.949/0.963, P NS). Conclusions. The ability of WristOx 3100 to detect patients with OSAS was not affected by the data storage rate of the oxygen saturation signal. Both memory capacity of 0.25, 0.5, or 1 Hz showed a similar performance for the diagnosis of OSAS.

Overestimation of thoracic gas volume during the airway resistance maneuver. A potential error in the diagnosis of air trapping.

There are no data published about the agreement between the measurement of thoracic gas volume (TGV) during the airway resistance (TGV-Raw) and the conventional technique described by Dubois. The aim of this study was to establish the agreement between both methods to measure TGV. We studied eighty consecutive subjects. Only sixty-six performed acceptable plethysmography maneuvers. The patients were measured with a constant volume plethysmograph (Medical Graphics 1085 DL). TGV was performed in the same patient with two techniques: 1) during the airway resistance (Raw) measurement (TGV-Raw) and 2) during quiet breathing at the end of expiration (TGV). The panting frequency was 1 to 2 Hz with both maneuvers. The differences between both techniques were expressed in percentage (deltaTGV %) and absolute values (deltaTGV). The TGV-Raw of the whole group was higher than TGV (3.69 +/- 1.08 l vs 3.28 +/- 1.05 l, p < 0.001). Similarly, the subgroups of patients had a greater TGV-Raw than TGV (Normal: 3.44 +/- 0.77 l vs 2.98 +/- 0.72 l , p < 0.001; Obstructive: 4.08 +/- 1.19 l vs 3.71 +/- 1.15 l, p < 0.001; Restrictive: 2.62 +/- 0.49 l vs 2.25 +/- 0.51 l, p < 0.01). There was a considerable lack of agreement between the TGV-Raw and TGV, with discrepancies of up to +0.95 l or +34%. The deltaTGV % was similar between the patients' subgroups and between the subjects with different degree of airflow obstruction (Normal: 16.5 +/- 10%, Obstructive: 10.8 +/- 9.4%, Restrictive: 18 +/- 14.3%, p NS; mild obstruction: 10.7 +/- 11%, moderate obstruction: 12.3 +/- 5.7, severe obstruction: 10.1+/- 6.6, p NS). In conclusion, TGV-Raw was larger than TGV. This was because the patients generally panted at a volume above FRC when performing the TGV-Raw maneuver. TGV-Raw should not be used to estimate FRC because FRC would be overestimated and the diagnosis of air trapping may be erroneous.

Overestimation of thoracic gas volume during the airway resistance maneuver. A potential error in the diagnosis of air trapping.

There are no data published about the agreement between the measurement of thoracic gas volume (TGV) during the airway resistance (TGV-Raw) and the conventional technique described by Dubois. The aim of this study was to establish the agreement between both methods to measure TGV. We studied eighty consecutive subjects. Only sixty-six performed acceptable plethysmography maneuvers. The patients were measured with a constant volume plethysmograph (Medical Graphics 1085 DL). TGV was performed in the same patient with two techniques: 1) during the airway resistance (Raw) measurement (TGV-Raw) and 2) during quiet breathing at the end of expiration (TGV). The panting frequency was 1 to 2 Hz with both maneuvers. The differences between both techniques were expressed in percentage (deltaTGV

) and absolute values (deltaTGV). The TGV-Raw of the whole group was higher than TGV (3.69 +/- 1.08 l vs 3.28 +/- 1.05 l, p < 0.001). Similarly, the subgroups of patients had a greater TGV-Raw than TGV (Normal: 3.44 +/- 0.77 l vs 2.98 +/- 0.72 l , p < 0.001; Obstructive: 4.08 +/- 1.19 l vs 3.71 +/- 1.15 l, p < 0.001; Restrictive: 2.62 +/- 0.49 l vs 2.25 +/- 0.51 l, p < 0.01). There was a considerable lack of agreement between the TGV-Raw and TGV, with discrepancies of up to +0.95 l or +34

. The deltaTGV

was similar between the patients subgroups and between the subjects with different degree of airflow obstruction (Normal: 16.5 +/- 10

, Obstructive: 10.8 +/- 9.4

, Restrictive: 18 +/- 14.3

, p NS; mild obstruction: 10.7 +/- 11

, moderate obstruction: 12.3 +/- 5.7, severe obstruction: 10.1+/- 6.6, p NS). In conclusion, TGV-Raw was larger than TGV. This was because the patients generally panted at a volume above FRC when performing the TGV-Raw maneuver. TGV-Raw should not be used to estimate FRC because FRC would be overestimated and the diagnosis of air trapping may be erroneous.

[Compliance with continuous positive airway pressure therapy in patients with sleep apnea/hypopnea syndrome]. / Adherencia al tratamiento con presión positiva continua nasal en pacientes con sindrome de apnea/hipopnea del sueño.

Predictive factors and compliance level were evaluated in a group of patients with sleep apnea syndrome under CPAP treatment, assessing side effects and equipment condition: silicone interface (SI), mask-conectors (M-C), air tube (AT) and head strap (HS). Patients with >3mo treatment were included, clock counter reading was registered at the beginning, 2 and 4 mo. Patients were considered compliant (C+) when usage was >4h/day and >5day/week. Of 46 patients (male 34; age 62 +/- 9years; BMI 33 +/- 7kg/m2; AHI 38 +/- 18/h; time of therapy 2.1 +/- 1.7years; CPAP 9 +/- 1.4 cmH2O), 34 had a clock counter and 24 (71%) were C+. Initial symptoms included: somnolence (65%), snoring (39%), bed-partner witnessed apneas (28%). Comparing C+ and C- we didn't find significant difference in age, BMI, CPAP pressure, length of therapy, AHI and pre-treatment Epworth classification. Referred vs. measured time of use in C+ and C- were 6.6 +/- 1 vs. 6.1 +/- 1 h/d (p=0.02) and 5.6 +/- 1 vs. 2.4 +/- 1 h/d (p<0.005). Compliant patients reported more resolution of somnolence (p<0.005) and nocturia (p<0.05), lower post CPAP Epworth (p<0.05), more frequent somnolence as initial symptom (p<0.05) and a higher education level (p=0.01). Side effects (SE) (n=45): dry mouth 36%, nasal congestion 27%, sleep disruption 11%, CPAP noisy 9%, dry nose, rhinorrhea and skin irritation 7%. Twenty seven percent of patients reduced the CPAP use because of the SE. Correction strategies included: humidifier, nasal steroid, surgery or infiltration of turbinates. Comparing the condition of SI, M-C, AT and HS between < or =1 vs. >1year of use, we observed a lower percentage of fine elements (87 to 44%, 74 to 44%, 83 to 44%, 91 to 78%, respectively). Most common defects included stiffness of SI, cracks in SI, M-C and AT, loose conexions. The study confirms the importance of objective monitoring in patients with CPAP. Side effects and equipment condition require special attention because this could affect an effective treatment.

Adherencia al tratamiento con presión positiva continua nasal en pacientes con sindrome de apnea/hipopnea del sueño. / [Compliance with continuous positive airway pressure therapy in patients with sleep apnea/hypopnea syndrome]

Predictive factors and compliance level were evaluated in a group of patients with sleep apnea syndrome under CPAP treatment, assessing side effects and equipment condition: silicone interface (SI), mask-conectors (M-C), air tube (AT) and head strap (HS). Patients with >3mo treatment were included, clock counter reading was registered at the beginning, 2 and 4 mo. Patients were considered compliant (C+) when usage was >4h/day and >5day/week. Of 46 patients (male 34; age 62 +/- 9years; BMI 33 +/- 7kg/m2; AHI 38 +/- 18/h; time of therapy 2.1 +/- 1.7years; CPAP 9 +/- 1.4 cmH2O), 34 had a clock counter and 24 (71

) were C+. Initial symptoms included: somnolence (65

), snoring (39

), bed-partner witnessed apneas (28

). Comparing C+ and C- we didnt find significant difference in age, BMI, CPAP pressure, length of therapy, AHI and pre-treatment Epworth classification. Referred vs. measured time of use in C+ and C- were 6.6 +/- 1 vs. 6.1 +/- 1 h/d (p=0.02) and 5.6 +/- 1 vs. 2.4 +/- 1 h/d (p<0.005). Compliant patients reported more resolution of somnolence (p<0.005) and nocturia (p<0.05), lower post CPAP Epworth (p<0.05), more frequent somnolence as initial symptom (p<0.05) and a higher education level (p=0.01). Side effects (SE) (n=45): dry mouth 36

, nasal congestion 27

, sleep disruption 11

, CPAP noisy 9

, dry nose, rhinorrhea and skin irritation 7

. Twenty seven percent of patients reduced the CPAP use because of the SE. Correction strategies included: humidifier, nasal steroid, surgery or infiltration of turbinates. Comparing the condition of SI, M-C, AT and HS between < or =1 vs. >1year of use, we observed a lower percentage of fine elements (87 to 44

, 74 to 44

, 83 to 44

, 91 to 78

, respectively). Most common defects included stiffness of SI, cracks in SI, M-C and AT, loose conexions. The study confirms the importance of objective monitoring in patients with CPAP. Side effects and equipment condition require special attention because this could affect an effective treatment.

Adherencia al tratamiento con presion positiva continua nasal en pacientes con sindrome de apnea/hipopnea del sueño / Compliance with continuous positive airway pressure therapy in patients with sleep apnea/hypopnea syndrome

Se evalúan prospectivamente los factores predictores y nivel de cumplimiento del tratamiento con presión positiva continua nasal (CPAP) en un grupo de pacientes con síndrome de apnea del sueño. Valora efectos adversos y estado del equipamiento: interfase siliconada (IS), máscara-conectores (M-C), tubuladura (TU) Y arnés (A). Se incluyeron pacinetes con >3 meses de tratamiento, se registraron las horas de encendido mediante el contador horario al inicio, 2 y 4 meses. Definimos paciente cumplidor (C+) al que usara el CPAP >4h/d y >5d/semana. De los 46 pacientes estudiados (hombres 34; edad 62+/-9años; IMC 33 +/- 7kg/m2; IAH 38 +/- 18/h; inicio 2.1 +/- 1.7 años; CPAP 9 +/- 1.4 cmH2O), 34 tenían contador horario y 24 (71%) eran C+. El motivo de consulta fue: hipersomnolencia (65%), ronquio (39%), apneas vistas por cónyuge (28%). Entre C+ y C- no hallamos diferencias significativas en edad, IMC, presión de CPAP, tiempo de tratamiento, IAH, y clasificación de Epworth pre-tratamiento. Las horas de uso referidas vs. medidas para C+ y C- fueron 6.6 +/- 1 vs 6.6 +/- 1 (p=0.02) y 5.6 +/- vs 2.4 +/- 1 (p<0.005). Los C+ refirieron mayor disminición de somnolencia diurna (p<0.005) y de nocturia (p<0.05), menor Epworth post-tratamiento (p<0.05), tuvieron más frecuente consulta inicial por somnolencia (p<0.05) y poseían mayor grado de instrucción (p=0.01). Efectos adversos (EA) (n=45): sequedad bucal 36%, congestón nasal 27%, disrupción del sueño 11%, ruido 9%, sequedad nasal, rinorrea y abrasión cutánea 7%. El 27% de los pacientes referían disminuir el tiempo de uso del CPAP debido a EA. Las medidas tomadas incluyeron: humidificador, corticoides nasales, cirugía o infiltración de cornetes. Al comparar el estado de IS, M-C, TU y A entre < or =1 vs. > 1 año de uso, observamos un menor porcentaje de elementos categorizados como óptimos (87 a 44%, 74 a 44%, 83 a 44%, 91 a 78%, respectivamente). Los defectos más frecuentes fueron: endurecimiento de IS, rajaduras en IS, M-C y TU, conexiones flojas. El estudio confirma la importancia del monitoreo objetivo en pacientes con CPAP. Especial atención merece la presencia de efectos adversos y el control del estado del equipo que podrían afectar el tratamiento eficaz. (AU)

Adherencia al tratamiento con presion positiva continua nasal en pacientes con sindrome de apnea/hipopnea del sueño / Compliance with continuous positive airway pressure therapy in patients with sleep apnea/hypopnea syndrome

Se evalúan prospectivamente los factores predictores y nivel de cumplimiento del tratamiento con presión positiva continua nasal (CPAP) en un grupo de pacientes con síndrome de apnea del sueño. Valora efectos adversos y estado del equipamiento: interfase siliconada (IS), máscara-conectores (M-C), tubuladura (TU) Y arnés (A). Se incluyeron pacinetes con >3 meses de tratamiento, se registraron las horas de encendido mediante el contador horario al inicio, 2 y 4 meses. Definimos paciente cumplidor (C+) al que usara el CPAP >4h/d y >5d/semana. De los 46 pacientes estudiados (hombres 34; edad 62+/-9años; IMC 33 +/- 7kg/m2; IAH 38 +/- 18/h; inicio 2.1 +/- 1.7 años; CPAP 9 +/- 1.4 cmH2O), 34 tenían contador horario y 24 (71%) eran C+. El motivo de consulta fue: hipersomnolencia (65%), ronquio (39%), apneas vistas por cónyuge (28%). Entre C+ y C- no hallamos diferencias significativas en edad, IMC, presión de CPAP, tiempo de tratamiento, IAH, y clasificación de Epworth pre-tratamiento. Las horas de uso referidas vs. medidas para C+ y C- fueron 6.6 +/- 1 vs 6.6 +/- 1 (p=0.02) y 5.6 +/- vs 2.4 +/- 1 (p<0.005). Los C+ refirieron mayor disminición de somnolencia diurna (p<0.005) y de nocturia (p<0.05), menor Epworth post-tratamiento (p<0.05), tuvieron más frecuente consulta inicial por somnolencia (p<0.05) y poseían mayor grado de instrucción (p=0.01). Efectos adversos (EA) (n=45): sequedad bucal 36%, congestón nasal 27%, disrupción del sueño 11%, ruido 9%, sequedad nasal, rinorrea y abrasión cutánea 7%. El 27% de los pacientes referían disminuir el tiempo de uso del CPAP debido a EA. Las medidas tomadas incluyeron: humidificador, corticoides nasales, cirugía o infiltración de cornetes. Al comparar el estado de IS, M-C, TU y A entre < or =1 vs. > 1 año de uso, observamos un menor porcentaje de elementos categorizados como óptimos (87 a 44%, 74 a 44%, 83 a 44%, 91 a 78%, respectivamente). Los defectos más frecuentes fueron: endurecimiento de IS, rajaduras en IS, M-C y TU, conexiones flojas. El estudio confirma la importancia del monitoreo objetivo en pacientes con CPAP. Especial atención merece la presencia de efectos adversos y el control del estado del equipo que podrían afectar el tratamiento eficaz.

Derrame pleural neoplásico (DPN): normatización para su tratamiento / Neoplasic pleural effusion: treatment guide

El derrame pleural neoplásico es una manifestación de enfermedad avanzada y su tratamiento debe dirigirse a mejorar la calidad de vida con baja morbilidad. Se expone la conducta seguida utilizando un flujograma terapéutico para la indicación del sellamiento pleural con tetraciclinas o pleurectomia. Se trataron 32 pacientes con derrame y sintomatología invalidante, en 29 se realizó pleurodesis con tetraciclina con un 97// de respuestas. La hipertemia (28//) y el dolor (24//) fueron complicaciones más frecuentes. En los 3 restantes se efectuó pleurectomía y no recidivó el derrame, pero dos se complicaron (infección de herida y defecto de reexpansión). La supervivencia media fue de 9,2 meses