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Intensive Care Medicine, 1986
Measurements of added inspiratory work (AIW) of breathing imposed by three different CPAP systems were performed in 10 patients. One system was a continuous flow system while the two others were demand flow systems separated from respirators (Ohmeda VD 101 and Draeger CPAP 800 devices). AIW was calculated from pressure and flow signals recorded at the mouthpiece level. The AIW calculated with the two demand-flow systems was found to be the same as the AIW calculated with the continuous flow system although the results obtained by the Draeger device were less constant. The results obtained with the Ohmeda device in our patients conflicted with data previously published using a lung model.
BMC Research Notes
Objectives A unique dataset of airway flow/pressure from healthy subjects on Continuous Positive Airway Pressure (CPAP) ventilation was collected. This data can be used to develop or validate models of pulmonary mechanics, and/or to develop methods to identify patient-specific parameters which cannot be measured non-invasively, during CPAP therapy. These models and values, particularly if available breath-to-breath in real-time, could assist clinicians in the prescription or optimisation of CPAP therapy, including optimising PEEP settings. Data description Data was obtained from 30 subjects for model-based identification of patient-specific lung mechanics using a specially designed venturi sensor system comprising an array of differential and gauge pressure sensors. Relevant medical information was collected using a questionnaire, including: sex; age; weight; height; smoking history; and history of asthma. Subjects were tasked with breathing at five different rates (including passiv...
CPAP : beneficial effects on different aspects of health
2012
printing supported by . Visit Chiesi at Stand B2.10 SUNDAY, SEPTEMBER 2ND 2012 (REMstar-auto, Respironics Inc. USA) were performed. We also performed a separate cohort study of one hundred patients with OSA (AHI = 54.3±18.9 events/h) by observing the efficacy and safety of CPAP pressure derived from manual titration. Results: The treatment pressure derived from automatic titration (9.8±2.2 cmH2O) was significantly higher than that derived from manual titration (7.3±1.5 cmH2O; p<0.001) in 51 patients. A cohort study of 100 patients showed that AHI was satisfactorily decreased after CPAP treatment using a pressure derived from manual titration (54.3±18.9 events/hour before treatment and 3.3±1.7 events/hour after treatment; P<0.001). Conclusion: Our results suggest that automatic titration pressure derived from REMstar-auto, is usually higher than the pressure derived from manual titration. This work was funded by National Natural Science Foundation of China (Grant No.81120108001...
The use of a predicted CPAP equation improves CPAP titration success
Sleep and Breathing, 2005
Titration of continuous positive airway pressure (CPAP) is performed to determine the CPAP setting to prescribe for an individual patient. A prediction equation has been published that could be used to improve the success rate of CPAP titrations. The goals of this study were: (1) to test the hypothesis that the use of the prediction equation would achieve a higher rate of successful CPAP titrations; (2) to validate the equation as an accurate predictor of the prescribed CPAP setting and determine the factors that influence the accuracy of the prediction equation. A total of 224 patients underwent CPAP titration prior to using the equation, with a starting pressure of 5 cm H 2 O. A total of 192 patients underwent CPAP titration using the equation-predicted CPAP level as the starting pressure (median starting pressure of 8 cm H 2 O [interquartile range 7, 10 cm H 2 O]). The percentage of successful studies, as defined by a 50% decrease in the apnea-hypopnea index (AHI) and a final AHI ≤10 cm H 2 O, increased from 50% to 68% (p<0.001), while the number of patients who were prescribed a CPAP level that had not been tested decreased from 22% to 5% (p<0.001). The equation was not accurate in predicting the prescribed level of CPAP, with only 30.8% of the patients with a prescribed pressure ≤3 cm H 2 O of the predicted pressure. Female gender was the only predictor of a prescribed pressure ≤3 cm H 2 O from the predicted pressure (odds ratio 3.45, 95% confidence intervals 1. 67, 7.13, p<0.001). A CPAP prediction equation modestly increases the rate of successful CPAP titrations by increasing the starting pressure of the titration. The equation does not accurately predict the prescribed CPAP level, reaffirming the need for a titration study to determine the optimal prescribed level in a given patient.
Comparative assessment of several automatic CPAP devices' responses: a bench test study
ERJ Open Research, 2015
Automatic continuous positive airway pressure (APAP) devices adjust the delivered pressure based on the breathing patterns of the patient and, accordingly, they may be more suitable for patients who have a variety of pressure demands during sleep based on factors such as body posture, sleep stage or variability between nights. Devices from different manufacturers incorporate distinct algorithms and may therefore respond differently when subjected to the same disturbed breathing pattern. Our objective was to assess the response of several currently available APAP devices in a bench test.A computer-controlled model mimicking the breathing pattern of a patient with obstructive sleep apnoea (OSA) was connected to different APAP devices for 2-h tests during which flow and pressure readings were recorded. Devices tested were AirSense 10 (ResMed), Dreamstar (Sefam), Icon (Fisher & Paykel), Resmart (BMC), Somnobalance (Weinmann), System One (Respironics) and XT-Auto (Apex). Each device was ...
CHEST Journal, 2004
PURPOSE: The growing epidemic of sleep-related breathing disorders plus the high cost of polysomnography has led most labs across the country to switch to split-night studies(SNS). This has resulted in significant reduction in time allowed for titration. Hence the final effective pressure (Peff)as obtained by SNS may not reflect the ideal pressure needed to consistently overcome the sleep airflow limitation. This may potentially lead to therapeutic failure and poor compliance. Auto-CPAP has emerged as potential alternative which may provide a more physiological background to identify the optimal pressure for CPAP therapy. METHODS: 24 consecutive patients diagnosed with Obstructive apnea hypopnea syndrome (AHI >15/hr) after undergoing split-night study in sleep lab. After SNS patients were prescribed a 2-week Auto CPAP trial (Resmed Auto Set @). The pressures obtained by SNS(Peff) were compared to optimal pressures (95th percentile and maximum)obtained by Auto-CPAP trial at home. Demographics and clinical outcomes were also evaluated. RESULTS: Out of 23 patients (one patient was excluded due to noncompliance with Auto-CPAP) 78% were males. Mean BMI was 34.5 and Mean time spent on CPAP titration was during SNS was 173 mins. Mean AHI (Apnea hypopnea Index) at final CPAP pressure (Peff) was 1.5 versus 6.1 with Auto-CPAP(P<0.001). Mean pressure on (Peff) on SNS titration was 8.8 cm of H2O versus mean 95th percentile pressure on Auto-CPAP of 11.3 cm of H2O (P<0.001) and mean maximum pressure on Auto-CPAP of 12.5 cm of H2O (P<0.001). 20 out of 23 patients (87%) had more than 2 cm H2O difference between SNS titration(Peff) and maximum optimal pressure obtained by Auto-CPAP (P< 0.003). CONCLUSION: There is a significant difference in threapeutic pressures noted between CPAP titration by SNS and subsequent Auto-CPAP trial for 2 weeks. CLINICAL IMPLICATIONS: By allowing greater sleep sampling time and a physiological background, use of Auto-CPAP device to derive maximum optimal pressures may provide an appropriate alternative to SNS.
Pressure stability with CPAP devices: A bench evaluation
Sleep Medicine, 2010
Word count, body of text: 1750 Conflicts of interest: Maud Boucherie and Véronique Grillier-Lanoir are employed by Covidien Inc., which supported this study (Covidien paid INSERM 15 000 euros for this study evaluation).
Respiratory care, 2015
Bubble CPAP, used for spontaneously breathing infants to avoid intubation or postextubation support, can be delivered with different interface types. This study compared the effect that interfaces had on CPAP delivery. We hypothesized that there would be no difference between set and measured levels between interface types. A validated preterm infant nasal airway model was attached to the ASL 5000 breathing simulator. The simulator was programmed to deliver active breathing of a surfactant-deficient premature infant with breathing frequency at 70 breaths/min inspiratory time of 0.30 s, resistance of 150 cm H2O/L/s, compliance of 0.5 mL/cm H2O, tidal volume of 5 mL, and esophageal pressure of -10 cm H2O. Nasal CPAP prongs, size 4030, newborn and infant RAM cannulas were connected to a nasal airway model and a bubble CPAP system. CPAP levels were set at 4, 5, 6, 7, 8, and 9 cm H2O with flows of 6, 8, and 10 L/min each. Measurements were recorded after 1 min of stabilization. The analy...
Pneumatic Performance of the Boussignac CPAP System in Healthy Humans
Respiratory Care, 2011
BACKGROUND: The Boussignac continuous positive airway pressure (CPAP) device effectively treats acute pulmonary edema, but data on airway pressure with the Boussignac CPAP system are sparse. OBJECTIVE: To evaluate the Boussignac CPAP system's ability to maintain stable inspiratory and expiratory pressure levels, and to evaluate perceived exertion during breathing with the Boussignac CPAP system. METHODS: With 18 healthy volunteers we recorded airway pressure and air flow during 10-min sessions at 5.0, 7.5, and 10.0 cm H 2 O. The participants were blinded to the sequence of the CPAP levels. Each session was ended with 10 forced breaths. We measured perceived exertion with the Borg category ratio 10 (Borg CR10) scale. RESULTS: When the participants breathed at 20% of vital capacity and a peak expiratory flow of 14% of FEV 1 , the maximum pressure difference between inspiration and expiration was 4.0 cm H 2 O at CPAP 10 cm H 2 O. The changes in airway pressure were never large enough to reduce airway pressure to below zero. During the forced breaths, the expiratory volume was 38 -42% of vital capacity and peak expiratory flow was 49 -56% of FEV 1 . As air flow increased, both the drop in inspiratory airway pressure and the increase in expiratory airway pressure increased. CONCLUSIONS: With CPAP, pressure changes are considered to be associated with increased work of breathing. The device's pneumatic performance is adequate during normal breathing with low air flow, but during forced breathing (high air flow) it did not maintain stable airway pressure, which could increase the work of breathing and cause respiratory fatigue. Thus, the Boussignac CPAP system might be less suitable for a patient breathing at a higher frequency.