whether extubation to nasal continuous airway pressure (NCPAP) results
in a greater proportion of infants remaining free of additional
ventilatory support for one week after extubation compared with those
extubated directly to headbox oxygen.
controlled, clinical trial was conducted at the neonatal intensive care
unit of the Royal Women's Hospital, Melbourne, of infants with
birthweights between 600 and 1250 g, ventilated via an endotracheal
tube for more than 12 hours, requiring less than 50% oxygen, a
ventilator rate ⩽ 20/minute, considered by the clinical management
team to be ready for extubation. Infants were randomly allocated either
to NCPAP or to oxygen administered via a headbox. Success was defined
by no requirement for additional ventilatory support over the week
following extubation. Failure criteria were (i) apnoea; (ii) absolute
increase in oxygen requirement greater than 15% above that required
before extubation; or (iii) respiratory acidosis (pH<7.25 with
pCO2 >6.67 kPa).
RESULTS—Thirty one of
47 (66%) infants were successfully extubated to NCPAP compared with 18 of 45 (40%) for headbox oxygen. The increase in failure rate in the
headbox group was due primarily to increased oxygen requirements in
this group. Of the 27 who failed headbox oxygen, 26 were given a trial
of NCPAP and 13 did not require endotracheal reintubation. There was no
significant difference between the groups in the total number of days
of assisted ventilation or the duration of inpatient stay.
applied prophylactically after endotracheal extubation reduces the
incidence of adverse clinical events that lead to failure of extubation
in the seven days after extubation. This reduction is clinically
important. The benefits of NCPAP do not seem to be associated with an
increased incidence of unwanted side effects.
Some studies have suggested that the early sustained lung inflation (SLI) procedure is effective in decreasing the need for mechanical ventilation (MV) and improving respiratory outcome in preterm infants. We planned the present randomized controlled trial to confirm or refute these findings.
In this study, 276 infants born at 25+0 to 28+6 weeks’ gestation at high risk of respiratory distress syndrome (RDS) will be randomized to receive the SLI maneuver (25 cmH2O for 15 seconds) followed by nasal continuous positive airway pressure (NCPAP) or NCPAP alone in the delivery room. SLI and NCPAP will be delivered using a neonatal mask and a T-piece ventilator.
The primary endpoint is the need for MV in the first 72 hours of life. The secondary endpoints include the need and duration of respiratory support (NCPAP, MV and surfactant), and the occurrence of bronchopulmonary dysplasia (BPD).
Trial registration number:
Sustained lung inflation; Preterm infants, Resuscitation; Delivery room; Mechanical ventilation
Early use of nasal continuous positive airway pressure (nCPAP) may reduce lung damage, but it is not clear how many extremely preterm infants can be cared for without mechanical ventilation on the first days after delivery.
To describe our experience of nCPAP in infants born at <27 weeks' gestation and to determine the chance of reintubation of this group of extremely preterm infants.
A retrospective, observational study examined the period from November 2002 to October 2003, when efforts were made to extubate infants to nCPAP at the earliest opportunity. Data were collected on all infants born at <27 weeks' and gestation admitted to The Neonatal Intensive Care Unit, Queen Charlotte's and Chelsea Hospital, London, UK. The chance of an individual infant requiring reintubation within 48 h of delivery was estimated, calculating the predictive probability using a Bayesian approach, and oxygen requirements at 36 weeks' postmenstrual age were examined.
60 infants, 34 inborn and 26 ex utero transfers, were admitted; 7 infants admitted 24 h after birth were excluded and 5 died within 48 h. The mean birth weight was 788 g and the gestational age was 25.3 weeks. Extubation was attempted on day 1 in 21 of 52 infants on ventilators and was successful in 14; and on day 2 in 14 of 35 and successful in 10 of infants extubated within 48 h of delivery survived to discharge. 5 of 23 infants on mechanical ventilation at 48 h of age were on air at 36 weeks postmenstrual age, and 12 of 26 of those were on nCPAP at 48 h of age. The probability of an individual baby remaining on nCPAP was 66% (95% CI 46% to 86%) on day 1 and 80% (95% CI 60% to 99%) on day 2. The smallest infant to be successfully extubated was 660 g and the youngest gestational age was 23.8 weeks.
Extremely preterm infants can be extubated to nCPAP soon after delivery, with a reasonable probability of not requiring immediate reintubation.
Current literature suggests that use of synchronized nasal intermittent positive pressure ventilation (SNIPPV), following extubation, reduces the rate of reintubation compared to nasal continuous positive airway pressure (NCPAP). However, there is limited information available on the outcomes of infants managed with SNIPPV.
To compare the outcomes of infants managed with SNIPPV (postextubation or for apnea) to infants not treated with SNIPPV at 2 sites.
Clinical retrospective data was used to evaluate the use of SNIPPV in infants ≤1250 g birth weight (BW); and 3 BW subgroups (500 –750, 751–1000, and 1001–1250 g, decided a priori). SNIPPV was not assigned randomly. Bronchopulmonary dysplasia (BPD) was defined as treatment with supplemental oxygen at 36 weeks’ postmenstrual age.
Overall, infants who were treated with SNIPPV had significantly lower mean BW (863g vs. 964g) and gestational age (26.4 weeks vs. 27.9 weeks), more frequently received surfactant (85% vs. 68%), and had a higher incidence of BPD or death (39% vs. 27%) (all p<0.01), compared to infants treated with NCPAP. In the subgroup analysis, SNIPPV was associated with lower rates of BPD (43% vs 67%, P = .03) and BPD/death (51% vs 76%, P = .02) in the 500- to 750g infants, with no significant differences in the other BW groups. Logistic regression analysis, adjusting for significant covariates, revealed infants with 500 –700-g BW who received SNIPPV were significantly less likely to have the outcomes of BPD (OR: 0.29 [95% CI: 0.11– 0.77]; P = .01), BPD/death (OR: 0.30 [95% CI: 0.11– 0.79]; P = .01), neurodevelopmental impairment (NDI) (OR: 0.29 [95% CI: 0.09–0.94]; P = .04), and NDI/death (OR: 0.18 [95% CI: 0.05– 0.62]; P = .006).
SNIPPV use in infants at greatest risk of BPD or death (500-750g) was associated with decreased BPD, BPD/death, NDI, and NDI/death when compared to infants managed with NCPAP.
premature newborn; respiratory distress syndrome; non-invasive ventilation
the effectiveness of the Infant Flow Driver (IFD) with single prong
nasal continuous positive airway pressure (nCPAP) in preterm neonates
affected by respiratory distress syndrome.
September 1997 and March 1999, 36 preterm infants who were eligible for
CPAP treatment were randomly selected for either nCPAP or IFD and
studied prospectively for changes in oxygen requirement and/or
respiratory rate. The requirement for mechanical ventilation,
complications of treatment, and effects on mid-term outcome were also evaluated.
RESULTS—Use of the IFD
had a significantly beneficial effect on both oxygen requirement and
respiratory rate (p < 0.0001) when compared with nCPAP. Moreover,
O2 requirement and respiratory rate were significantly
decreased by four hours (p < 0.001 and p < 0.03 respectively).
The probability of remaining supplementary oxygen free over the first
48 hours of treatment was significantly higher in patients treated with
the IFD than with nCPAP (p < 0.02). IFD treated patients had a
higher success (weaning) rate (94% v 72%)
and shorter duration of treatment (49.3 (31)
v 56 (29.7) hours respectively; mean (SD)),
although the difference was not significant.
appears to be a feasible device for managing respiratory distress
syndrome in preterm infants, and benefits may be had with regard to
oxygen requirement and respiratory rate when compared with nCPAP. The
trend towards reduced requirement for mechanical ventilation, shorter
clinical recovery time, and shorter duration of treatment requires
further evaluation in a multicentre randomised clinical trial.
Background: The role of nasal continuous positive airways pressure (nCPAP) in the management of respiratory distress syndrome in preterm infants is not completely defined.
Objective: To evaluate the benefits and risks of prophylactic nCPAP in infants of 28–31 weeks gestation.
Design: Multicentre randomised controlled clinical trial.
Setting: Seventeen Italian neonatal intensive care units.
Patients: A total of 230 newborns of 28–31 weeks gestation, not intubated in the delivery room and without major malformations, were randomly assigned to prophylactic or rescue nCPAP.
Interventions: Prophylactic nCPAP was started within 30 minutes of birth, irrespective of oxygen requirement and clinical status. Rescue nCPAP was started when FIO2 requirement was > 0.4, for more than 30 minutes, to maintain transcutaneous oxygen saturation between 93% and 96%. Exogenous surfactant was given when FIO2 requirement was > 0.4 in nCPAP in the presence of radiological signs of respiratory distress syndrome.
Main outcome measures: Primary end point: need for exogenous surfactant. Secondary end points: need for mechanical ventilation and incidence of air leaks.
Results: Surfactant was needed by 22.6% in the prophylaxis group and 21.7% in the rescue group. Mechanical ventilation was required by 12.2% in both the prophylaxis and rescue group. The incidence of air leaks was 2.6% in both groups. More than 80% of both groups had received prenatal steroids.
Conclusions: In newborns of 28–31 weeks gestation, there is no greater benefit in giving prophylactic nCPAP than in starting nCPAP when the oxygen requirement increases to a FIO2 > 0.4.
Objective: To compare the incidence of nasal trauma associated with the use of prong or mask during nasal continuous positive airway pressure (nCPAP) support in very low birthweight (<1501 g) infants.
Design: Randomised controlled clinical trial.
Setting: Tertiary care university hospital, Department of Paediatrics, Kuala Lumpur, Malaysia.
Methods: All very low birthweight infants admitted to the neonatal intensive care unit between July 2001 and December 2003 who received nCPAP through the Infant Flow Driver were randomised to the use of either nasal prong or mask. The nasal cavity of these infants was inspected daily during the first week and then weekly until they were weaned off nCPAP.
Results: Of the 89 infants recruited, 41 were randomised to the mask group and 48 to the prong group. There was no significant difference in the incidence of nasal trauma between the two groups (p = 0.5). The primary site of trauma was at the junction between the nasal septum and the philtrum in infants in the mask group and the walls of the nasal septum in the prong group. Logistic regression analysis showed that duration of nCPAP was the only significant risk factor associated with development of nasal injury, after birth weight, gestational age, and nasal device used had been controlled for (adjusted odds ratio 1.04; 95% confidence interval 1.01 to 1.07; p = 0.003).
Conclusion: Irrespective of the type of nasal device used, nasal trauma is common during nCPAP treatment, which should therefore be terminated as soon as possible.
BACKGROUND: Manual titration of nasal continuous positive airway pressure (NCPAP) treatment for obstructive sleep apnoea (OSA) is time consuming and expensive. There are now "intelligent" NCPAP machines that try to find the ideal pressure for a patient by monitoring a combination of apnoeas, hypopnoeas, inspiratory flow limitation, and snoring. Although these machines usually find similar pressures to skilled technicians, it is not clear if their use in the sleep laboratory influences subsequent acceptance by patients. This study addresses this question. METHODS: One hundred and twenty two patients undergoing a trial of NCPAP were randomly allocated to either manual or automatic (Horizon, DeVilbiss) titration of pressure during their first night on NCPAP in a hospital sleep laboratory. The primary outcome (available on 112 patients) was the acceptance of NCPAP or otherwise six weeks following the initial titration night. Baseline indicators of severity were compared between the groups, as were the pressures selected and the subsequent improvement in the sleepiness of the patients. RESULTS: The initial severity of OSA was not significantly different in the two groups and the mean (SD) NCPAP pressures were similar (manual 8.7 (2.5) cm H2O, automatic 8.2 (2.1) cm H2O). The percentage of patients successfully established on CPAP at six weeks was 64% and 73% for the manual and automatic groups, respectively; 13% and 2%, respectively, in the manual and automatic groups had given up completely (p < 0.05), and there were about equal numbers (23% versus 25%) in the two groups who were still undecided. CONCLUSIONS: The substitution of automatic NCPAP titration for manual titration during the first night of NCPAP in patients with OSA does not reduce the number accepting the treatment at six weeks and may slightly improve it. This has important cost saving potential.
Survival and outcomes for preterm infants with respiratory distress syndrome (RDS) have improved over the past 30 years. We conducted a study to assess the changes in perinatal care and delivery room management and their impact on respiratory outcome of very low birth weight newborns, over the last 15 years. A comparison between two epochs was performed, the periods before and after 2005, when early nasal continuous positive airway pressure (NCPAP) and Intubation-SURfactant-Extubation (INSURE) were introduced in our center. Three hundred ninety-five clinical records were assessed, 198 (50.1%) females, gestational age 29.1 weeks (22–36), and birth weight 1130 g (360–1498). RDS was diagnosed in 247 (62.5%) newborns and exogenous surfactant was administered to 217 (54.9%). Thirty-three (8.4%) developed bronchopulmonary dysplasia (BPD), and 92 (23%) were deceased. With the introduction of early NCPAP and INSURE, there was a decrease on the endotracheal intubation need and invasive ventilation (P < 0.0001), oxygen therapy (P = 0.002), and mortality (P < 0.0001). The multivariate model revealed a nonsignificant reduction in BPD between the two epochs (OR = 0.86; 95% CI 0.074–9.95; P = 0.9). The changes in perinatal care over the last 15 years were associated to an improvement of respiratory outcome and survival, despite a nonsignificant decrease in BPD rate.
The pattern of breathing was studied in 13 premature newborns treated by variable‐flow Nasal Continuous Positive Airway Pressure (NCPAP), conventional NCPAP, and nasal cannulae. Compared to constant‐flow NCPAP and nasal cannulae, the variable‐flow NCPAP increases tidal volume and improves thoraco‐abdominal synchrony, suggesting that variable‐flow NCPAP provides more effective ventilatory support than conventional NCPAP or nasal cannulae.
To determine the accuracy of three tests used to predict successful extubation of preterm infants.
Mechanically ventilated infants with birth weight <1250 g and considered ready for extubation were changed to endotracheal continuous positive airway pressure (ET CPAP) for three minutes. Tidal volumes, minute ventilation (V̇e), heart rate, and oxygen saturation were recorded before and during ET CPAP. Three tests of extubation success were evaluated: (a) expired V̇e during ET CPAP; (b) ratio of V̇e during ET CPAP to V̇e during mechanical ventilation (V̇e ratio); (c) the spontaneous breathing test (SBT)—the infant passed this test if there was no hypoxia or bradycardia during ET CPAP. The clinical team were blinded to the results, and all infants were extubated. Extubation failure was defined as reintubation within 72 hours of extubation.
Fifty infants were studied and extubated. Eleven (22%) were reintubated. The SBT was the most accurate of the three tests, with a sensitivity of 97% and specificity of 73% and a positive and negative predictive value for extubation success of 93% and 89% respectively.
The SBT used just before extubation of infants <1250 g may reduce the number of extubation failures. Further studies are required to establish whether the SBT can be used as the primary determinant of an infant's readiness for extubation.
newborn; positive pressure respiration; respiratory function tests; extubation; very low birth weight
Using a preset protocol for early extubation, 50 babies were randomly selected to post-extubation headbox or post-extubation nasal continuous positive airway pressure (N-CPAP). All infants weighed less than 1500 g, had a gestational age of less than 34 weeks, and had been weaning from mechanical ventilation within seven days of life. The criteria for extubation included stable condition, fraction of inspired oxygen (FIO2) of < or = 35%, peak inspiratory pressure (PIP) of < or = 15 cm H2O (1.47 kPa), and ventilator rate of 6/minute. Before extubation, a loading dose of aminophylline was given followed by maintenance treatment. If reintubation was not required within 72 hours of the initial extubation the procedure was considered successful. The reintubation criteria included FIO2 > or = 70% to maintain arterial oxygen tension (PaO2) of > or = 50 mm Hg (6.67 kPa) or pulse oximetry between 90-96% and pH of < 7.25, and arterial carbon dioxide tension (PACO2) of > 60 mm Hg (8.00 kPa) and severe or recurring apnoea. The overall success rate of early extubation was 66% (33/50). The individual successful extubation rate of post-extubation in the N-CPAP group and the post-extubation headbox group were 84% (21/25) and 48% (12/25), respectively (p = 0.017; chi 2). There were no significant differences in clinical characteristics between the two groups. The most common cause of failure in early extubation was apnoea, and most occurred in the headbox group (9/12). These results suggest that application of N-CPAP to a preset protocol for extubation can achieve a better success rate of early extubation in very low birthweight (VLBW) infants.
Respiratory distress syndrome remains a significant problem among premature infants. Mechanical ventilation through an endotracheal tube remains the mainstay of respiratory support but may be associated with lung injury and the development of chronic lung disease of prematurity. Efforts are needed to reduce the duration of mechanical ventilation in favour of less invasive forms of respiratory support and to improve rates of successful extubation.
Non-invasive respiratory support has been demonstrated to be less injurious to the premature lung. Standard practice is to use nasal continuous positive airway pressure (n-CPAP) following extubation to support the baby's breathing. Many clinicians also use nasal biphasic positive airway pressure (n-BiPAP) in efforts to improve rates of successful extubation. However, there is currently no evidence that this confers any advantage over conventional nasal continuous positive airway pressure.
We propose an unblinded multi-centre randomised trial comparing n-CPAP with n-BiPAP in babies born before 30 weeks' gestation and less than two weeks old. Babies with congenital abnormalities and severe intra-ventricular haemorrhage will be excluded. 540 babies admitted to neonatal centres in England will be randomised at the time of first extubation attempt. The primary aim of this study is to compare the rate of extubation failure within 48 hours following the first attempt at extubation. The secondary aims are to compare the effect of n-BiPAP and n-CPAP on the following outcomes:
1. Maintenance of successful extubation for 7 days post extubation
2. Oxygen requirement at 28 days of age and at 36 weeks' corrected gestational age
3. Total days on ventilator, n-CPAP/n-BiPAP
4. Number of ventilator days following first extubation attempt
5. pH and partial pressure of carbon dioxide in the first post extubation blood gas
6. Duration of hospital stay
7. Rate of abdominal distension requiring cessation of feeds
8. Rate of apnoea and bradycardia
9. The age at transfer back to referral centre in days
The trial will determine whether n-BiPAP is safe and superior to n-CPAP in preventing extubation failure in babies born before 30 weeks' gestation and less than two weeks old.
Trial registration number
Preterm birth Infant; Newborn; Humans; Clinical trials; Randomized; Neonatal Intensive Care; Biphasic Continuous Positive Airway Pressure; Continuous Positive Airway Pressure
Aim: To review 66 children with obstructive sleep apnoea (OSA) for whom a trial of nasal continuous positive airway pressure (nCPAP) was proposed.
Methods: Baseline sleep studies were performed to assess OSA severity; a trial of nCPAP was performed where moderate to severe OSA, not relieved by adenotonsillectomy, was found. The nCPAP trial was considered either technically successful (ST), if the child accepted the mask for sufficient time to determine nCPAP efficacy, or a technical failure (FT) if otherwise. Patients with an initial FT were offered a period of home acclimatisation to familiarise them with wearing the mask during sleep. ST patients in whom nCPAP was effective were established on long term therapy.
Results: Nasal CPAP trials were successful (ST) in 49/66 (74%) patients. Nasal CPAP efficacy could not be determined in the remaining 17 FT patients (26%), generally because of their poor nCPAP tolerance. These patients were subsequently considered for other treatment. A total of 42/49 (86%) ST patients were established on long term nCPAP therapy, 2/49 (4%) derived no benefit from nCPAP, while 5/49 (10%) refused long term nCPAP therapy. Of patients on long term nCPAP, the most frequently reported side effects were skin irritation and nasal dryness; however, these were not serious enough to require any patients to discontinue therapy. A period of home acclimatisation was found to be effective in increasing nCPAP acceptance, with 26% of FT children being subsequently successfully reassessed for nCPAP.
Conclusion: The use of nCPAP was feasible in a significant proportion of a paediatric OSA population. Failure was usually because of the child's intolerance of the nCPAP equipment. Nasal CPAP was an effective treatment in the majority of patients where it could be assessed, and was adopted as a long term therapy in most cases. We have successfully used nCPAP to treat OSA across a wide range of ages. Motivated parents and skilled support staff have proved essential for the success of nCPAP in a paediatric setting.
Aim. To evaluate whether synchronized-NIPPV (SNIPPV) used after the INSURE procedure can reduce mechanical ventilation (MV) need in preterm infants with RDS more effectively than NCPAP and to compare the clinical course and the incidence of short-term outcomes of infants managed with SNIPPV or NCPAP. Methods. Chart data of inborn infants <32 weeks undergoing INSURE approach in the period January 2009–December 2010 were reviewed. After INSURE, newborns born January –December 2009 received NCPAP, whereas those born January–December 2010 received SNIPPV. INSURE failure was defined as FiO2 need >0.4, respiratory acidosis, or intractable apnoea that occurred within 72 hours of surfactant administration. Results. Eleven out of 31 (35.5%) infants in the NCPAP group and 2 out of 33 (6.1%) infants in the SNIPPV group failed the INSURE approach and underwent MV (P < 0.004). Fewer infants in the INSURE/SNIPPV group needed a second dose of surfactant, a high caffeine maintenance dose, and pharmacological treatment for PDA. Differences in O2 dependency at 28 days and 36 weeks of postmenstrual age were at the limit of significance in favor of SNIPPV treated infants. Conclusions. SNIPPV use after INSURE technique in our NICU reduced MV need and favorably affected short-term morbidities of our premature infants.
The aim of the present retrospective study was to describe the use of nasal continuous positive airway pressure (NCPAP) and the prevalence of bronchopulmonary dysplasia (BPD).
Data from 1526 neonates with gestational age less than 32 weeks, admitted to Children’s and Women’s Health Centre of British Columbia (Vancouver, British Columbia) between period 1 (1996 to 2000) and period 2 (2000 to 2004) were analyzed. The use of respiratory therapies and outcomes were retrospectively compared before and after the introduction of a NCPAP approach to respiratory support.
A significant increase in the use of NCPAP was noted between periods 1 and 2 (60% versus 71%), as well as a significant reduction in the use of surfactant (50% versus 41%), postnatal steroids (30% versus 10%) and the need for mechanical ventilation (77% versus 64%). In period 2, there was a significant reduction in the prevalence of BPD at 28 days (33% versus 26%), higher prevalence of severe retinopathy of prematurity (3% versus 6%) and less periventricular leukomalacia (4% versus 2%).
A significant increase in the use of NCPAP therapy in the neonatal unit has been associated with a decrease in the use of more invasive therapies. The incidence of BPD has decreased if defined as need for supplemental oxygen at 28 days of age, but not when the 36 weeks’ postconceptional age criterion was used. NCPAP therapy may decrease the use of more invasive therapies and may improve respiratory outcomes. The impact of this intervention on nonrespiratory outcomes warrants further investigation.
Bronchopulmonary dysplasia; CPAP; Neonatology; Premature infants; Retinopathy of prematurity
BACKGROUND--A study was performed to evaluate the effect of discontinuation of nasal continuous positive airway pressure (NCPAP) treatment on snoring characteristics. METHODS--Eighteen non-apnoeic snoring subjects were randomly allocated to either a no treatment control group or an NCPAP treatment group. The control group was studied twice (baseline and day 30 of follow up). In the NCPAP group the level of NCPAP that abolished snoring was determined and part abolished snoring was determined and patients were placed on NCPAP every night for one month. A sleep study was performed on the first night without NCPAP after completing 30 days of treatment (follow up 1). A fourth polysomnographic study was performed 8-10 days after NCPAP was stopped (follow up 2) in six subjects. RESULTS--In both groups total sleep time (TST) and sleep architecture remained unchanged at the different visits. Baseline snoring characteristics in the two groups were similar. In the control group the mean (SE) number of snoring episodes/hour of sleep (snoring index) and the percentage of TST > 60 decibels (dB) were 380 (36)/h and 11.1 (2.0)% TST respectively at baseline, and was unchanged at follow up. In the NCPAP group the snoring index decreased from 387 (50)/h to 320 (57)/h after NCPAP therapy, but the % TSTS > 60 dB decreased from 10.3 (1.8)% to 7.4 (1.5)%. The snoring index and intensity returned to baseline values at follow up 2 (374 (74)/h, 9.8 (2.1)% TST). Changes in snoring characteristics could not be explained by changes in body position between the different sleep studies. CONCLUSIONS--NCPAP improves snoring but this effect is lost soon after stopping treatment.
Obstructive sleep apnea (OSA) has been associated with cardiovascular disease (CVD), but whether OSA is an independent risk factor for CVD is controversial. The purpose of this study is to determine if patients with OSA have subclinical cardiovascular disease that is detectable by multi-modality cardiovascular imaging and whether these abnormalities improve after nasal continuous positive airway pressure (nCPAP).
Of the 35 consecutive subjects with newly diagnosed moderate to severe OSA recruited from the Stanford Sleep Disorders Clinic, 20 patients were randomized to active vs. sham nCPAP. Active nCPAP was titrated to pressures that would prevent sleep disordered breathing based on inpatient polysomnography. OSA patients had baseline vascular function abnormalities including decreased myocardial perfusion reserve (MPR), brachial flow mediated dilation (FMD) and nitroglycerin-induced coronary vasodilation. Patients randomized to active nCPAP had improvement of MPR (1.5 ± 0.5 vs. 3.0 ± 1.3, p = 0.02) and brachial FMD (2.5% ± 5.7% vs. 9.0% ± 6.5%, p = 0.03) after treatment, but those randomized to sham nCPAP showed no significant improvement. There were no significant changes seen in chamber sizes, systolic and diastolic function, valvular function and coronary vasodilation to nitroglycerin.
Patients with moderate to severe OSA had decreased MPR and brachial FMD that improved after 3 months of nCPAP. These findings suggest that relief of apnea in OSA may improve microvascular disease and endothelial dysfunction, which may prevent the development of overt cardiovascular disease. Further study in a larger patient population may be warranted.
The use of mechanical ventilation for the treatment of respiratory distress syndrome (RDS) in low birth weight infants may cause barotrauma, volutrauma, and chronic lung disease. Different continuous positive airway pressure (CPAP) delivery systems exist, each with its own practical and clinical advantages and disadvantages. CPAP can be used as either a primary or an adjunctive respiratory support for RDS. Research demonstrates that CPAP decreases the incidence of respiratory failure after extubation. Clinical trials indicate that the optimal management of neonatal RDS consists of early surfactant treatment followed quickly by extubation and stabilization on CPAP. Early surfactant treatment combined with CPAP reduces the need for mechanical ventilation, compared to later surfactant treatment. Evidence suggests a synergistic effect between early surfactant administration and rapid extubation to nasal CPAP.
continuous positive airway pressure; extremely premature infants; surfactant; respiratory distress syndrome
Objective: To compare the resistance in vitro of different devices used for the delivery of nasal continuous positive airway pressure (NCPAP) in neonates.
Design: Flows of 4–8 litres/min were passed through a selection of neonatal NCPAP devices (single prong, Duotube, Argyle prong, Hudson prong, Infant Flow Driver), and the resultant fall in pressure measured using a calibrated pressure transducer.
Results: The decrease in pressure (cm H2O) for each device (size in parentheses) at a constant flow of 6 litres/min was: Duotube: (2.5), 21; (3.0), 6.2; (3.5), 2.3; single prong: (2.5), 4.4; (3.0), 2.1; (3.5), 1.2; Argyle prong: (XS), 3.6; (S), 1.9; (L), 1.5; Hudson prong: (0), 3.1; (1), 1.8; (2), 0.6; (3), 0.4; (4), 0.3; Infant Flow Driver: (small), 0.3; (medium), -0.3; (large), -0.5.
Conclusions: A large variation in the potential fall in pressure may occur in the clinical setting. Devices with short double prongs had the lowest resistance to flow. These results have implications in the selection of the optimal device/s for clinical application and for future comparisons in randomised trials of NCPAP in neonates.
Nasal continuous positive airway pressure is used as a standard of care after extubation in very-low-birth-weight infants. A pressure of 5 cmH2O is usually applied regardless of individual differences in lung compliance. Current methods for evaluation of lung compliance and air distribution in the lungs are thus imprecise for preterm infants. This study used electrical impedance tomography to determine the feasibility of evaluating the positive end-expiratory pressure level associated with a more homogeneous air distribution within the lungs before extubation.
Ventilation homogeneity was defined by electrical impedance tomography as the ratio of ventilation between dependent and non-dependent lung areas. The best ventilation homogeneity was achieved when this ratio was equal to 1. Just before extubation, decremental expiratory pressure levels were applied (8, 7, 6 and 5 cmH20; 3 minutes each step), and the pressure that determined the best ventilation homogeneity was defined as the best positive end-expiratory pressure.
The best positive end-expiratory pressure value was 6.3±1.1 cmH20, and the mean continuous positive airway pressure applied after extubation was 5.2±0.4 cmH20 (p = 0.002). The extubation failure rate was 21.4%. X-Ray and blood gases after extubation were also checked.
This study demonstrates that electrical impedance tomography can be safely and successfully used in patients ready for extubation to suggest the best ventilation homogeneity, which is influenced by the level of expiratory pressure applied. In this feasibility study, the best lung compliance was found with pressure levels higher than the continuous positive airway pressure levels that are usually applied for routine extubation.
Infant; Premature; Electric Impedance; Continuous Positive Airway Pressure
BACKGROUND—Some previous reports have
indicated beneficial cardiac effects of nasal continuous positive
airway pressure (NCPAP) in patients with severe congestive heart
failure (CHF), but others have reported deleterious cardiac effects,
particularly among patients in atrial fibrillation (AF). The aim of
this study was to determine if differences in cardiac rhythm influence
the acute cardiac response to NCPAP.
METHODS—Eleven consecutive patients with CHF were
recruited, six in atrial fibrillation (AF) and five with sinus rhythm
(SR). Cardiac index was measured during awake NCPAP application by the
thermodilution technique during cardiac catheterisation. NCPAP was
applied in a randomised sequence at pressures of 0, 5, and 10 cm
H2O with three 30 minute applications separated by 20 minute recovery periods without NCPAP.
RESULTS—Significant differences were found between
the AF and SR groups for cardiac index responses to NCPAP (p = 0.004, ANOVA) with a fall in cardiac index in the AF group (p = 0.02) and a
trend towards an increase in the SR group (p = 0.10). Similar
differences were seen between the groups in stroke volume index
responses but not in heart rate responses. Changes in systemic vascular resistance were also significantly different between the two groups (p< 0.005, ANOVA), rising in the AF group but falling in the SR group.
CONCLUSIONS—These data indicate an important
effect of underlying cardiac rhythm on the awake haemodynamic effects
of NCPAP in patients with CHF.
Background: Mandibular advancement devices (MADs) can successfully control both snoring and obstructive sleep apnoea (OSA). Many patients on nasal continuous positive airway pressure (NCPAP) for OSA would like a more portable alternative, even if only temporarily. This study assesses what proportion of patients with OSA already on NCPAP can successfully use a MAD for short periods (up to 1 month) as a temporary alternative to NCPAP.
Methods: Fifty patients with OSA, already on NCPAP for at least 3 months, were recruited by invitation. They were provided with a simple fixed MAD estimated to provide 75% of maximum mandibular protrusion. Sleep studies using a portable home recorder were performed on and after three nights without NCPAP to provide control data. Following acclimatisation to the MAD, sleep studies were also planned after 3, 7, and 28 days while using the MAD. If their overnight >4% SaO2 dips per hour deteriorated to >20 or the Epworth sleepiness score (ESS) rose to >9 (or increased by >4 over baseline) on nights 3 or 7, they were then deemed to have failed the trial and were withdrawn.
Results: Of the 50 patients entered, one had inadequate teeth for a MAD and 31 gave up trying to use the device during the acclimatisation period because of side effects. Of the 18 prepared to use the device, two patients failed at night 3, five at night 7, and two at night 28. Thus, nine patients remained controlled by our criteria at night 28. On average, sleep study indices while using the MAD were poor compared with the night on NCPAP.
Conclusions: Simple MADs are poorly tolerated by patients with OSA already on NCPAP. OSA was adequately controlled by our criteria in 32% of those recruited for the equivalent of a weekend, in 22% for 1 week, and in 18% for up to 1 month. Better tolerated devices would be likely to improve on these figures.
Residual excessive sleepiness (ES) and impaired cognition can occur despite effective and regular nasal continuous positive airway pressure (nCPAP) therapy in some patients with obstructive sleep apnea (OSA). A pooled analysis of two 12-week, randomized, double-blind studies in nCPAP-adherent patients with ES associated with OSA evaluated the effect of armodafinil on wakefulness and cognition. Three hundred and ninety-one patients received armodafinil (150 or 250 mg) and 260 patients received placebo once daily for 12 weeks. Efficacy assessments included the Maintenance of Wakefulness Test (MWT), Cognitive Drug Research cognitive performance battery, Epworth Sleepiness Scale, and Brief Fatigue Inventory. Adverse events were monitored. Armodafinil increased mean MWT sleep latency from baseline to final visit by 2.0 min vs a decrease of 1.5 min with placebo (P < 0.0001). Compared with placebo, armodafinil significantly improved quality of episodic secondary memory (P < 0.05) and patients’ ability to engage in activities of daily living (P < 0.0001) and reduced fatigue (P < 0.01). The most common adverse events were headache, nausea, and insomnia. Armodafinil did not adversely affect desired nighttime sleep, and nCPAP use remained high (approximately 7 h/night). Adjunct treatment with armodafinil significantly improved wakefulness, long-term memory, and patients’ ability to engage in activities of daily living in nCPAP-adherent individuals with ES associated with OSA. Armodafinil also reduced patient-reported fatigue and was well tolerated.
Armodafinil; Fatigue; Obstructive sleep apnea syndrome; Sleepiness; Wakefulness
sleep apnoea (OSA) impairs vigilance and may lead to an increased rate
of driving accidents. In uncontrolled studies accident rates and
simulated steering performance improve following treatment with nasal
continuous positive airway pressure (NCPAP). This study seeks to
confirm the improvement in steering performance in a randomised
controlled trial using subtherapeutic NCPAP as a control treatment.
METHODS—Fifty nine men
with OSA (Epworth Sleepiness Score (ESS) of ⩾10, and ⩾10/h dips in
SaO2 of >4% due to OSA) received therapeutic or subtherapeutic NCPAP (≈1 cm H2O) for one month.
Simulated steering performance over three 30-minute "drives" was
quantified as: standard deviation (SD) of road position, deterioration
in SD across the drive, length of drive before "crashing", and
number of off-road events. The reaction times to peripheral target
stimuli during the drive were also measured.
NCPAP did not improve overnight >4% SaO2
dips/h compared with baseline values, thus acting as a control. The SD
of the steering position improved from 0.36 to 0.21 on therapeutic NCPAP, and from 0.35 to 0.30 on subtherapeutic NCPAP (p = 0.03). Deterioration in SD of the steering position improved from 0.18to
0.06 SD/h with therapeutic NCPAP and worsened from 0.18 to 0.24 with
subtherapeutic NCPAP (p = 0.04). The reaction time to target stimuli
was quicker after therapeutic than after subtherapeutic NCPAP (2.3 versus 2.7 seconds, p = 0.04).
NCPAP improves steering performance and reaction time to target stimuli
in patients with OSA, lending further support to the hypothesis that
OSA impairs driving, increases driving accident rates, and that these
improve following treatment with NCPAP.