Conventional Continuous Positive Airway Pressure Research Articles

A novel 3D-printed customized nasal mask for improving CPAP adherence and satisfaction for the treatment of obstructive sleep apnea.

To evaluate the performance of a novel 3D-printed customized nasal mask on patient satisfaction and compliance to continuous positive airway pressure (CPAP) therapy for obstructive sleep apnea (OSA). Patients prescribed CPAP therapy with suboptimal CPAP compliance using a conventional CPAP mask (<70% of nights with ≥4 hours per night over 4 weeks) were recruited from the sleep investigation unit of a tertiary hospital. Patients underwent a 3D-facial mapping procedure to have a novel 3D-printed customized nasal mask fabricated which was trialed four weeks. CPAP compliance data download of the same period was conducted with their pre-existing conventional mask and customized mask. Questionnaires assessing symptoms of OSA and mask-related side-effects were administered before and after the trial of the customized mask. Thirty patients (twenty-two males and eight females, age 63.3 ± 12.5 years, BMI 31.7 ± 5.2 kg/m2, apnea-hypopnea index 37.3 ± 21.9 events/h [mean ± standard deviation]) were studied. CPAP was used in a greater proportion of nights with the customized mask (85.7 [66.1, 98.2]% versus 63.2 [13.1, 96.8]%, P=0.009) compared to the conventional mask. Hourly CPAP usage was higher with the customized mask (3.8 [2.7, 5.8] hours versus 2.4 [0.3, 5.0] hours, P=0.016) compared to a conventional mask. Patients preferred the customized mask (P=0.008) and reported less mask-related side effects. The novel 3D-printed customized mask improved CPAP usage in patients with suboptimal CPAP compliance. Customized CPAP masks may be a suitable option for patients experiencing poor CPAP compliance from mask-related side effects. Registry: ANZCTR; Title: Conventional vs custom made nasal Continuous Positive Airway Pressure (CPAP) mask for treatment of Obstructive Sleep Apnoea: Pilot study A; Identifier: ACTRN12621001301853; URL: https://anzctr.org.au/Trial/Registration/TrialReview.aspx?id=382142.

Conventional oxygen therapy versus CPAP as a ceiling of care in ward-based patients with COVID-19: a multi-centre cohort evaluation.

BackgroundContinuous positive airway pressure (CPAP) therapy is commonly used for respiratory failure due to severe COVID-19 pneumonitis, including in patients deemed not likely to benefit from invasive mechanical ventilation (nIMV). Little evidence exists demonstrating superiority over conventional oxygen therapy, whilst ward-level delivery of CPAP presents practical challenges. We sought to compare clinical outcomes of oxygen therapy versus CPAP therapy in patients with COVID-19 who were nIMV.MethodsThis retrospective multi-centre cohort evaluation included patients diagnosed with COVID-19 who were nIMV, had a treatment escalation plan of ward-level care and clinical frailty scale ≤ 6. Recruitment occurred during the first two waves of the UK COVID-19 pandemic in 2020; from 1st March to May 31st, and from 1st September to 31st December. Patients given CPAP were compared to patients receiving oxygen therapy that required FiO2 ≥0.4 for more than 12 hours at hospitals not providing ward-level CPAP. Logistic regression modelling was performed to compare 30-day mortality between treatment groups, accounting for important confounders and within-hospital clustering.FindingsSeven hospitals provided data for 479 patients during the UK COVID-19 pandemic in 2020. Overall 30-day mortality was 75.6% in the oxygen group (186/246 patients) and 77.7% in the CPAP group (181/233 patients). A lack of evidence for a treatment effect persisted in the adjusted model (adjusted odds ratio 0.84 95% CI 0.57-1.23, p=0.37). 49.8% of patients receiving CPAP-therapy (118/237) chose to discontinue it.InterpretationNo survival difference was found between using oxygen alone or CPAP to treat patients with severe COVID-19 who were nIMV. A high patient-initiated discontinuation rate for CPAP suggests a significant treatment burden. Further reflection is warranted on the current treatment guidance and widespread application of CPAP in this setting.FundingL Pearmain is supported by the MRC (MR/R00191X/1). TW Felton is supported by the NIHR Manchester Biomedical Research Centre.

Newborn care technology investments for LMIC settings: a CPAP approach

Globally, it is estimated that 15 million babies are born prematurely each year. Approximately one million of these newborns die due to complications of preterm birth, and these deaths occur...

Comparison of High-Flow Humidified Oxygen With Conventional Continuous Positive Airway Pressure in Nonventilated Lungs During Thoracic Surgery: A Randomized Cross-Over Study

This study assessed the efficacy of high-flow humidified oxygen (HFHO) as an alternative to continuous positive airway pressure (CPAP) for improving oxygenation while preserving nonventilated lung collapse during one-lung ventilation. A prospective randomized cross-over trial. A tertiary medical center. The study comprised 28 patients undergoing elective thoracotomy with one-lung ventilation using a double-lumen endobronchial tube placement. The patients received prophylactic CPAP or HFHO to the nonventilated lung for 20 minutes and were then crossedover to the other oxygenation modality for 20 minutes, with a 20-minute recovery interval between the two modalities. Changes in respiratory parameters and lung deflation quality were recorded. Both CPAP and HFHO increased the partial pressure of arterial oxygen in either sequence in both groups, ranging from 31.8-to-66.0 mmHg. However, the increments from these two interventions were not statistically significant (95% confidence interval -12.84 to 21.87; p = 0.597). There were no differences in other parameters. Half the patients receiving CPAP experienced worsening of the surgical condition, whereas the HFHO patients experienced no change or reported a better lung deflation (p < 0.001). HFHO could be an alternative method to CPAP for improving arterial oxygenation while preserving lung deflation during one-lung ventilation. However, additional studies are warranted in regard to its cost-effectiveness and establishment as a routine treatment.

Custom Three-Dimensional-Printed CPAP Mask Development, Preliminary Comfort and Fit Evaluation

Abstract Obstructive sleep apnea (OSA) is an acute breathing disorder, which causes soft tissue inside the throat to collapse, thus blocking the airways while sleeping. This syndrome is usually treated by the supply of pressurized air delivered by a pump, which is connected to the patient via mouth and/or nose using a mask as an interface. While most of the literature on OSA is focused on the pressure pump and the therapy conditions (pressure, humidity, velocity, etc.) there has been an increased interest in the mask/interface as a key contributing factor to the treatment's effectiveness. Mask-related issues such as skin damage, allergic reactions, or air leaking due to poor fit can deter OSA patients from following this treatment. This study presents a preliminary evaluation of customized mask designs, which are tailored to specific wearer's facial contours. The development process includes the use of three-dimensional scanning/modeling/printing as an integrated workflow. Individual facial features have been digitally acquired and used to generate a custom device, which conforms to predefined facial landmarks of interest, which delimit the mask contour. A trial study was undertaken by recruiting two healthy volunteers for the fit and comfort evaluation of custom mask designs using a randomized fit test with a series of three-dimensional (3D) printed versus commercial standard mask. Results indicate that custom masks exhibit a higher level of comfort compared to conventional continuous positive airway pressure (CPAP) masks particularly on fit, contact pressure and comfort.

A Comparative Study between Postextubation of Preterm Neonates into High-Flow Nasal Cannula versus Nasal Continuous Positive Airway Pressure

Background: For respiratory support in premature newborns, there has been a trend toward less trachealintubation, less mechanical ventilation, and more nasal respiratory support which can result in the improvement ofsuccessful extubation rate. The two commonly known types of nasal respiratory support after extubation are thenasal continuous positive airway pressure (CPAP) and high flow nasal cannula (HFNC). The current study aimed toinvestigate and compare successful extubation using HFNC and conventional nasal CPAP after a period ofendotracheal positive pressure ventilation and detect which of these two methods is better for successfulextubation with fewer side effects.Methods: This randomized controlled study was conducted on 210 preterm newborns in the neonatal intensive careunit (NICU) of Gynecology and Obstetrics Department of Qasr El Eyni Hospital. Post extubation failure rates werecompared between the two groups, namely (HFNC) and (nasal CPAP). The collected data were analyzed in SPSSsoftware (version 20).Results: Neonates who needed re-intubation within 72 h after initial extubation were higher in the HFNC group(72.7%) versus (27.3%) in the CPAP group (P-value=0.063). Moreover, 45.8% of neonates in the HFNC group neededre-intubation within 1 week of initial extubation versus 54.2% in CPAP (P-value=0.970). The mean duration ofrespiratory support using HFNC was 3.7 days, compared to 6.5 days using CPAP (P-value= 0.001). Among neonateswho suffered from nasal trauma, 90.6% of neonates belonged to the CPAP group, while 9.4% of cases belonged to theHFNC group (P-value= 0.001). Conclusion: The use of CPAP and HFNC after the extubation of preterm mechanically ventilated neonates wasstatistically equal regarding extubation failure.

Métodos alternativos de CPAP para el tratamiento de insuficiencia respiratoria grave secundaria a neumonía por COVID-19

IntroductionThe use of devices that provide continuous positive pressure in the airway has shown improvement in various pathologies that cause respiratory failure. In the COVID-19 pandemic episode the use of these devices has become widespread, but, due to the shortage of conventional continuous positive airway pressure (CPAP) devices, alternative devices have been manufactured. The objective of this study is to describe the use of these devices, as well as their efficacy. Material and methodsData are collected from patients admitted for pneumonia due to COVID-19 at the IFEMA Field Hospital. Data are collected from 23 patients with respiratory failure and need for ventilatory support. ResultsStudy carried out on a total of 23 patients, dated admission to IFEMA. Alternative CPAP was used in five patients (21.7%), while ventilatory support with a reservoir mask or Ventimask Venturi effect was used in the remaining 18 patients (78.3%). A progressive increase in saturation is observed in those patients in whom alternative CPAP was used (from 94% on average to 98 and 99% on average after 30 and 60 minutes with the mask, respectively), although this change was not significant (p = 0.058 and p = 0.122, respectively). No significant change in RF was observed at the beginning and end of the measurement in patients who used alternative CPAP (p = 0.423), but among those who did not use alternative CPAP (p = 0.001). A statistically significant improvement in the variable oxygen saturation / fraction inspired by oxygen is observed in patients who used alternative CPAP (p = 0.040) ConclusionThe use of these devices has helped the ventilatory work of several patients by improving their oxygenation parameters. To better observe the evolution of patients undergoing this therapy and compare them with patients with other types of ventilatory support, further studies are necessary.

Home continuous positive airway pressure for cardiopulmonary indications in infants and children

ObjectivesA number of reports exist regarding the use of continuous positive airway pressure (CPAP) to manage obstructive sleep apnoea (OSA) in children, which we term ‘conventional CPAP’. In contrast, there are few reports of home CPAP use for other indications, which we have grouped under the term ‘cardiopulmonary’. The aims of this study were to (1) document cardiopulmonary indications for CPAP use in a cohort of infants and children, and (2) evaluate its effectiveness in this group. MethodsHospital records were reviewed for 645 patients who were commenced on long-term CPAP over a 10-year period at a single-tertiary hospital (Children's Hospital at Westmead). This study evaluated the group where the primary indication for CPAP was not OSA (‘cardiopulmonary CPAP’). Data evaluated included: demographics, diagnoses, indications for CPAP, hours of use (compliance) and sleep study results at baseline and on CPAP. ResultsOf 645 children, 148 (23%) used home CPAP for cardiopulmonary indications; and 130 (87.8%) of these were included. For this group, mean age at CPAP initiation was 18.6 ± 33.6 months (range one week to 16.8 years). Cardiopulmonary indications for CPAP use included: primary airway diseases 65 (50%), chronic lung diseases 33 (25.4%), congenital heart disease (CHD) 20 (15.4%), and both CHD and airway malacia 12 (9.2%). All sleep study variables improved on CPAP relative to the diagnostic sleep study (p < 0.0001), including reduced respiratory rate with CPAP use (p < 0.0001). CPAP was well tolerated (>4 h/night). ConclusionsInterstitial lung diseases and other cardiorespiratory disorders, often of congenital origin, can be effectively treated with home CPAP whether they are associated with OSA or not. Sleep studies demonstrated improved gas exchange, sleep and reduced work of breathing with CPAP use.

Polysomnographic determinants of requirement for advanced positive pressure therapeutic options for obstructive sleep apnea.

A small percentage of adult patients with severe obstructive sleep apnea (OSA) has been recognized to be extraordinarily difficult to treat with conventional continuous or Bi-level positive airway pressure (together referred to as PAP) therapy. The aim of this study was to determine polysomnographic (PSG) characteristics, which may help predict the requirement for advanced therapeutic options for OSA. Consecutive patients who underwent PAP titration at our sleep laboratory over a 2-year period were included. Patients with technically inadequate studies, those with incomplete titration due to intolerance, mask-related problems, or lack of sleep and those with significant co-morbidity and with other primary sleep disorders, were excluded. The PSGs (diagnostic + titration parts) were categorized into three types: type A (respiratory events evenly distributed over all sleep stages), type B (REM dominant respiratory events), and type C (non-REM dominant respiratory events, mainly during cyclic alternating pattern [CAP] sleep). Group A was further subdivided into A1 (those whose hypnogram normalized after adequate titration) and A2 (those whose hypnogram converted to a type C pattern on titration). These were categorized again into treatment group I (adequately PAP titrated) and group II (poor response to conventional PAP) for studying factors determining poor response to PAP. Among 249 patients evaluated in the sleep laboratory over the study period, 123 (103 males, mean age 49.9±10.8years, mean BMI 29.3±4) fulfilled inclusion criteria. These could be grouped as type A (n=85), B (n=33), and C (n=5). On titration, 57 patients of type A and 21 of type B could be successfully titrated, while 24 in type A and 11 in type B, converted into type C. Therefore, in group II (n=43), 38 patients fell in type C, overtly and after titration. Twelve of these had been successfully treated using adaptive servo ventilation (ASV) while another 28 could be treated using the Bi-level PAP-ST mode. The only PSG feature predicting poor response to conventional PAP was the presence of post-arousal central apnea (p=0.001). The main difference between the A1+B groups and A2+C groups was the significantly higher non-REM apnea hypopnea index in the latter. Among these, on 1-year follow-up, eight patients were using Bi-level PAP-ST mode, while four patients were using ASV and were asymptomatic. Non-REM sleep instability and the presence of post-arousal central apneas may be important determinants of poor response to conventional PAP and requirement for advanced therapeutic options among patients with severe OSA.

A novel implantable device for the treatment of obstructive sleep apnea: clinical safety and feasibility.

ObjectiveMany cases of obstructive sleep apnea (OSA) involve collapse of the tongue base and soft palate during sleep, causing occlusion of the upper airway and leading to oxygen desaturation. Existing therapies can be effective, but they are plagued by patient adherence issues and the invasiveness of surgical approaches. A new, minimally invasive implant for OSA has been developed, which is elastic and contracts a few weeks after deployment, stabilizing the surrounding soft tissue. The device has had good outcomes in preclinical testing; this report describes the preliminary feasibility and safety of its implementation in humans.Patients and methodsA prospective, multicenter, single-arm feasibility study was conducted. Subjects were adults with moderate-to-severe OSA who had previously failed or refused conventional continuous positive airway pressure treatment. Intraoperative feasibility data, postoperative pain, and safety information were collected for a 30-day postoperative period.ResultsForty subjects participated (37 men, three women; average age of 46.1 years); each received two tongue-base implants and two soft-palate implants. Surgical procedure time averaged 43 minutes. Postsurgical pain resolved readily in most cases; at 30 days post implantation, <20% of subjects reported pain, which averaged less than two out of ten. Adverse events were generally the mild and expected sequelae of a surgical procedure with general anesthesia and intraoral manipulation. The device was well tolerated. Implant extrusions were reported with soft-palate implants (n=12), while tongue-base implants required few revisions (n=2). Quantitative and qualitative sleep effectiveness outcomes (including full-night polysomnographic and quality-of-life measures) will be presented in a subsequent report.ConclusionImplantation of the device was feasible. Although a relatively high rate of extrusions occurred in the now-discontinued palate implants, tongue-base implants were largely stable and well tolerated. The minimally invasive and maintenance-free implant may provide a new alternative to higher morbidity surgical procedures.

Pressure-Relief Features of Fixed and Autotitrating Continuous Positive Airway Pressure May Impair Their Efficacy: Evaluation with a Respiratory Bench Model.

Pressure-relief features are aimed at improving the patient's comfort during continuous positive airway pressure (CPAP) treatment for obstructive sleep apnea. The objective of this study was to determine the effect of these therapy features on fixed CPAP and autotitrating CPAP (APAP) treatment efficacy. Seven pressure-relief features applied by three CPAP devices were included in our study (Remstar Auto: C-Flex 3, C-Flex+ 3, A-Flex 3, P-Flex; AirSense 10: EPR 3; Prisma 20A: SoftPAP 2 and 3). In fixed CPAP, the devices were subjected to a 10-min bench-simulated obstructive apnea sequence (initial apnea-hypopnea index, AHI = 60/h) with and without pressure-relief features. In APAP, the sequence was lengthened to 4.2 h (initial AHI = 58.6/h). The residual AHI and mean/median pressure were compared with and without pressure-relief features. Compared to conventional CPAP, where pressure was adjusted to be just sufficient to control the simulated obstructive events, C-Flex+ 3, P-Flex, and EPR 3 failed to normalize the breathing flow and did not reduce the AHI. The mean pressures with the three features, respectively, were 1.8, 2.6, and 2.6 cmH2O lower than the conventional CPAP. Compared to conventional APAP, similar levels of control were observed with pressure-relief features, apart from P-Flex where the delivered mean pressure was lower and residual AHI greater. The device-reported mean/median pressures in APAP with A-Flex 3, P-Flex, EPR 3, and SoftPAP 3 were higher than that measured on the bench. Pressure-relief features may attenuate CPAP efficacy if not adjusted for at the time of their introduction. In clinical practice, efficacy can be ensured by increasing the therapeutic pressure delivered by fixed CPAP or by enabling the pressure-relief features prior to initial pressure titration. Device-reported pressures in APAP devices with pressure relief activated may overstate delivered pressures.

Effect of High-Flow Nasal Oxygen on Pulmonary Complications and Outcomes After Adult Cardiothoracic Surgery: A Qualitative Review.

IGH-FLOW NASAL OXYGEN (HFNO) therapy delivers low-level, flow-dependent positive airway pressure and may be tolerated better than continuous positive airway pressure (CPAP) or noninvasive bi-level positive airway pressure (BiPAP) and enhance washout of nasopharyngeal deadspace, thus improving oxygenation. 1,2 The apparatus is composed of an air/oxygen blender, an active heated humidifier, a single heated circuit, and a nasal cannula. At the air/ oxygen blender, the inspiratory fraction of oxygen (FIO2) is set from 0.21 to 1.0 at a flow of up to 60 L/min. The gas is heated and humidified with the active humidifier and delivered through the heated circuit. Theoretically, HFNO has a number of advantages over other respiratory support systems, including conventional nasal cannulae, face masks, or CPAP/BiPAP. First, because gas generally is warmed to 371C and completely humidified in HFNO circuits, mucociliary function remains intact and patients report minimal discomfort. Mechanical splinting of the nasopharynx prevents supraglottic collapse and decreases nasopharyngeal resistance, and at 60 L/min HFNO can generate positive end-expiratory pressure (PEEP) of 4 to 7.4 cmH2O, which may counterbalance auto-PEEP and reduce the work of breathing. 3,4 HFNO therapy has been gaining attention as an innovative form of respiratory support in various clinical settings. It is being used increasingly in critically ill patients and gaining favor in the perioperative period. HFNO has been used for multiple indications, including hypoxemic respiratory failure and cardiogenic pulmonary edema, to counterbalance autoPEEP in patients with chronic obstructive airway disease and as prophylactic therapy or treatment of respiratory failure after surgery and extubation. 5 It has been shown to be both safe and noninferior to conventional CPAP in providing prophylactic support to very preterm neonates after extubation. 6 In this same study, the incidence of nasal trauma also was significantly lower in the nasal cannulae group than in the CPAP group. Little clinical experience has been reported on the use of HFNO in the cardiothoracic surgical patient population. Patients undergoing cardiothoracic surgery are at significant risk of postoperative pulmonary complications, and these complications may increase morbidity and mortality and lead to prolonged intensive care unit and hospital length of stay. 7 The incidence of pulmonary complications ranges from 8% to 79% after cardiac surgery and has been reported to be as high as 50% after lung resection surgery. 8 Postoperative pulmonary complications manifest early as arterial hypoxemia, during the later course as pneumonia, and in rare cases also as acute respiratory distress syndrome. 9 The pathogenesis of

Pneumothoraces in a Neonatal Tertiary Care Unit: Case Series

I have 2 comments on the interesting paper by Ali et al.1 First, Ali et al1 stated that 50% of their studied neonates were on ventilators when pneumothorax (PN) occurred. This frequency is alarmingly high compared to that reported in other developing countries. Further elucidation of that issue by Ali et al1 considering type of ventilation and risk factors contributing to ventilator-associated PN in their studied cohort was solicited. PN has been noticed to develop in 26% of neonates under ventilation. The most common type of ventilation leading to PN was found to be synchronized intermittent mandatory ventilation in 51%. Conventional ventilation and continuous positive airway pressure (CPAP) were seen in 35% and 12.3% of PN, respectively. Also, male sex, prematurity, birth weight below 2500g, cesarean section (CS), and negative history of surfactant therapy were risk factors of ventilatorassociated neonatal PN.2 Second, despite the limited number of neonates in Ali et al's studied cohort,1 they recommended better selection of mothers and waiting until 37 weeks before performing elective CS as that will influence the PN risk. I presume that that point needs further clarification. Actually, the contribution of CS timing to the evolution of PN in full term or preterm babies compared to those delivered vaginally has been recently addressed in a Norwegian study. Among the 26,664 neonates born at term (≥37th gestational week), 4,546 were delivered by CS (17.0%), of whom 0.5% by elective and 0.6% by emergency CS with NP. The incidence of diagnosed NP was significantly higher after CS than after vaginal delivery (0.6% vs. 0.10%, p<0.001). In addition, the need for mechanical ventilation (MV) was significantly increased (0.41% vs. 0.19%; p=0.01) but the use of CPAP was not (0.28% vs. 0.15%; p=0.08). Among 2,694 neonates born preterm (<37th gestational week), 1,266 were delivered by CS (47.0%). The incidence of diagnosed NP was 2.05% when delivered by CS but only 0.63% when delivered vaginally (p<0.01). Among the preterm infants delivered by CS, 17.7% needed CPAP compared to 6.9% when delivered vaginally (p<0.001) and MV was required for 8.1% and 3.7% (p<0.001), respectively. Among neonates delivered at term or moderately preterm (30-36 weeks) by CS, the incidence of NP and other respiratory problems was significantly increased.3

A Randomized Controlled Trial to Compare Heated Humidified High-Flow Nasal Cannulae with Nasal Continuous Positive Airway Pressure Postextubation in Premature Infants

To determine whether postextubation respiratory support via heated, humidified, high-flow nasal cannulae (HHHFNC) results in a greater proportion of infants younger than 32 weeks' gestation being successfully extubated after a period of endotracheal positive pressure ventilation compared with conventional nasal continuous positive airway pressure (NCPAP). We randomly assigned preterm ventilated infants to Vapotherm HHHFNC or NCPAP after extubation. The primary outcome, extubation failure, was defined by prespecified failure criteria in the 7 days after extubation. A total of 132 ventilated infants younger than 32 weeks' gestation were randomized to receive either HHHFNC (n = 67) or NCPAP (n = 65). Extubation failure occurred in 15 (22%) of the HHHFNC group compared with 22 (34%) of the NCPAP group. There was no difference in the number of infants reintubated in the first week. Treatment with HHHFNC reduced the nasal trauma score 3.1 (SD 7.2) versus NCPAP 11.8 (SD 10.7), P < .001. HHHFNC and NCPAP produced similar rates of extubation failure.

Chronic opioid use: a risk factor for central sleep apnoea and successful therapy with adaptive pressure support servo-ventilation

Sleep apnoea is a global health problem with significant morbidity. Obesity is a well-known risk factor for this condition, however chronic intake of opioids as a risk factor for central sleep apnoea is under-recognised. We report a case of a 47-year-old man who developed significant sleep-disordered breathing secondary to opioid use for chronic pain. A sleep study demonstrated a picture of complex sleep apnoea with a prominent central sleep apnoea component. He had no significant improvement with conventional continuous positive airway pressure therapy. However, adaptive servo-ventilation had a dramatic effect on his symptoms and compliance. This case highlights the significant risk of central sleep apnoea with opioid use and illustrates the importance of adaptive servo-ventilation in the management of sleep-disordered breathing secondary to impaired central respiratory drive.

P259 Preference of Patients with Obstructive Sleep Apnoea Syndrome (OSAS) For Conventional Continuous Positive Airway Pressure(CPAP) or Bi-Level CPAP (CFlex) and Changes in Resistance to Expiration

CFlex (Respironics) Bi-Level device lowers expiratory PAP (EPAP) early in expiration returning EPAP to the set inspiratory PAP (IPAP) before the start of the next inspiration. Most patients with OSAS...

Comparison of conventional continuous positive airway pressure to continuous positive airway pressure titration performed with sleep endoscopy

To evaluate the effect and obtain a pressure value of continuous positive airway pressure (CPAP) under direct visualization using drug-induced sleep endoscopy (DISE) and compare the pressure values with values obtained using conventional CPAP. Prospective, double-blinded, cohort study. Sixteen patients with obstructive sleep apnea syndrome (OSAS) were included in the study. Each patient underwent polysomnographic evaluation. After diagnosis of OSAS, patients underwent conventional CPAP titration. Patients were then taken to the operating theatre and put under sedation, where CPAP titration with nasendoscopy was performed (DISE CPAP). There were no statistically significant differences between the two techniques regarding pressure levels that decreased apneas in conventional CPAP and provided sufficient opening during DISE CPAP. Results with conventional CPAP titration and endoscopy-assisted CPAP titration showed no statistically significant difference. Endoscopy-assisted CPAP is a cheaper and less time consuming alternative to conventional CPAP and has similar results.

Bubble vs Conventional Continuous Positive Airway Pressure for Prevention of Extubation Failure in Preterm Very Low Birth Weight Infants: A Pilot Study

To compare the efficacy of bubble and conventional nasal continuous positive airway pressure (CPAP) in preventing extubation failure (EF) in preterm infants. Infants of gestation ≤32wk and birth weight <1500g, ready for initial extubation within first wk of life were randomly allocated to either bubble (n = 16) or conventional (n = 16) CPAP. A standardized protocol was used for extubation. Bubble CPAP was delivered by Fischer and Paykel equipment using short binasal prongs and conventional CPAP was delivered by a ventilator using Argyle short binasal prongs. CPAP was initiated at a pressure of 4-6cm of H(2)O and FiO(2) of 0.4-0.5 and adjusted to maintain normal saturation (90-93%) and comfortable breathing. Primary outcome was EF, defined as need for mechanical ventilation within 72h of extubation. Baseline characteristics including birth weight (g; 1027 ± 243 vs. 1018 ± 227; p = 0.83), gestation (wk; 28.7 ± 1.8 vs. 28.4 ± 1.6; p = 0.30), infants <28wk gestation (6 vs. 7, p = 0.72) were comparable between the two groups. Respiratory distress syndrome was the indication for ventilation in 13 (81%) and 14 (87%) infants on bubble CPAP and conventional CPAP groups respectively. (p = 0.99). There was no difference in the EF rates between the bubble (n = 4) and conventional CPAP (n = 9) groups. (RR 0.49; 95% CI 0.20-1.2; p = 0.14). Median time to extubation failure was also comparable between the two groups (h; median [range]: 29 [14-49] vs. 17 [7-28]; p = 0.35). The possibility that bubble CPAP may be associated with reduced EF as suggested in this pilot study requires further investigation in an adequately powered multicentric study.

Effect on work of breathing of different continuous positive airway pressure devices evaluated in a premature neonatal lung model

A device for the application of continuous positive airway pressure to switch injected breathing gas to the outlet during expiration, known as Infant Flow, claims to reduce work of breathing and peak pressure change. So far the Infant Flow system has been investigated in lung models with tidal volumes of not <12 mL. However, premature neonates below 1000 g of weight generate a tidal volume of approximately 4 mL only. The aim of this study was to compare work of breathing and peak pressure change of the Infant Flow and another system that uses nasal prongs, Baby Flow, with conventional continuous positive airway pressure delivered by a pharyngeal tube. Laboratory investigation, basic research. University research laboratory. A piston pump simulating the spontaneous breathing of premature neonates was connected without leak to three different continuous positive airway pressure devices (pharyngeal tube, Baby Flow, and Infant Flow) and with a produced leak to the systems using nasal prongs (Baby Flow and Infant Flow). The pressures of the airway and continuous positive airway pressure systems and airway flow were recorded. Peak pressure change and work of breathing were determined for all systems and settings. Percentages of reduction of peak pressure change and work of breathing in relation to the continuous positive airway pressure delivered by pharyngeal tube were calculated. The switching of injected breathing gas to the outlet during expiration of Infant Flow systems require a tidal volume of at least 5 mL. It was possible to decrease peak pressure change and work of breathing: Baby Flow system at a tidal volume of 4 mL (Inspiration: peak pressure change 82%, work of breathing 80%; Expiration: peak pressure change: 68%, work of breathing: 61%) and at a tidal volume of 8 mL (Inspiration: peak pressure change 75%, work of breathing 73%; Expiration: peak pressure change: 67%, work of breathing: 57%). Infant Flow system at tidal volume of 4 mL (Inspiration: peak pressure change 50%, work of breathing 55%; Expiration: peak pressure change: 46%, work of breathing: 43%) and at a tidal volume of 8 mL (Inspiration: peak pressure change 47%, work of breathing 46%; Expiration: peak pressure change: 24%, work of breathing: 23%), related to the continuous positive airway pressure delivered by pharyngeal tube without leak.Even under conditions of leak peak pressure change and work of breathing could be reduced: Baby Flow system at a tidal volume of 4 mL (Inspiration: peak pressure change 59%, work of breathing 64%; Expiration: peak pressure change: 68%, work of breathing: 59%) and at a tidal volume of 8 mL (Inspiration: peak pressure change 45%, work of breathing 43%; Expiration: peak pressure change: 54%, work of breathing: 53%). Infant Flow system at a tidal volume of 4 mL (Inspiration: peak pressure change 49%, work of breathing 53%; Expiration: peak pressure change: 44%, work of breathing: 40%) and at a tidal volume of 8 mL (Inspiration: peak pressure change 48%, work of breathing 43%; Expiration: peak pressure change: 36%, work of breathing: 40%), related to the continuous positive airway pressure delivered by pharyngeal tube without leak. Peak pressure change and work of breathing were decreased by Baby Flow and Infant Flow systems, even under conditions of leak.

In vitro Comparison of Noise Levels Produced by Different CPAP Generators

Introduction: Minimization of noise exposure is an important aim of modern neonatal intensive care medicine. Binasal continuous positive airway pressure (CPAP) generators are among the most important sources of continuous noise in neonatal wards. The aim of this study was to find out which CPAP generator creates the least noise. Method: In an experimental setup, two jet CPAP generators (Infant Flow® generator and MediJet®) and two conventional CPAP generators (Bubble CPAP® and Baby Flow®) were compared. Noise production was measured in decibels in an A-weighted scale [dB(A)] in a closed incubator at 2 mm lateral distance from the end of the nasal prongs. Reproduction of constant airway pressure and air leak was achieved by closure of the nasal prongs with a type of adhesive tape that is semipermeable to air. Results: The noise levels produced by the four generators were significantly different (p < 0.001). Values measured at a continuous constant flow rate of 8 l/min averaged 83 dB(A) for the Infant Flow® generator with or without sound absorber, 72 dB(A) for the MediJet®, 62 dB(A) for the Bubble CPAP® and 55 dB(A) for the Baby Flow®. Conclusion: Conventional CPAP generators work more quietly than the currently available jet CPAP generators.