Bilevel Positive Airway Pressure Support Research Articles

P010 Delivery of volume assured pressure support (VAPS) through tracheostomy in paediatric patients

Abstract INTRODUCTION Volume assured pressure support (VAPS) allows the ventilator to deliver a constant pre-set tidal volume or alveolar ventilation by automatically adjusting the inspiratory pressures within a set range, providing targeted pressure support. Data on its use in children are limited. We describe a series of four children effectively and safely ventilated using VAPS mode through tracheostomy. METHODS Retrospective review of patient notes. PROGRESS TO DATE Four paediatric patients were identified in our cohort who were successfully and safely ventilated using the VAPS mode through tracheostomy. The patients were between 6-14 years of age inclusive, with four differing underlying disease processes – Prader-Willi syndrome, congenital central hypoventilation syndrome, Guillain-Barré syndrome and Moebius-type syndrome. INTENDED OUTCOME AND IMPACT Whilst there have been previous paediatric case reports and case series which have demonstrated efficacy of VAPS mode used non-invasively, the use of VAPS mode to provide effective and safe ventilation through tracheostomy in children has been described in only one recent case series. The advantages of its use over conventional bilevel positive airway pressure support include its ability to compensate for changes in tidal volume, which can occur with changes in lung compliance and during different stages of sleep. This case series highlights safe and effective use of VAPS mode in children with tracheostomy.

Managing Patients With Sympathetic Crashing Acute Pulmonary Edema (SCAPE) Using the SCAPE Treatment Protocol: A Case Series.

Pulmonary edema refers to the accumulation of excessive fluid in the alveolar walls and alveolar spaces of the lungs. It is a life-threatening condition with a high mortality rate and requires immediate assessment and management. Use of intravenous nitroglycerin has been advocated for such cases. The authors present a case series of 3 patients who presented to the emergency department with sympathetic crashing acute pulmonary edema (SCAPE) and were managed with high-dose intravenous nitroglycerin and bilevel positive airway pressure support using the SCAPE treatment protocol, leading to early correction of blood pressure, avoidance of endotracheal intubation, and no episodes of hypotension or rebound hypertension. The authors recommend emergency physicians utilize the SCAPE treatment protocol while managing patients with SCAPE.

Incidence and Risk Factors Associated with Respiratory Compromise in Planned PICU Admissions Following Tonsillectomy.

Review the incidence and factors associated with respiratory compromise requiring intensive care unit level interventions in children with planned admission to the pediatric intensive care unit (PICU) following tonsillectomy or adenotonsillectomy (T/AT). Retrospective cohort study. Review of all patients with PICU admissions following T/AT from 2015 to 2020 at a tertiary care pediatric hospital. Patient demographics, underlying comorbidities, operative data, and respiratory complications during PICU admission were extracted. Seven hundred and seventy-two patients were admitted to the PICU following T/AT, age 6.1 ± 4.6 years. All children were diagnosed with obstructive sleep apnea or sleep-disordered breathing (mean pre-operative apnea-hypopnea index 29 ± 26.5 and O2 nadir 77.1% ± 11.1). Neuromuscular disease, enteral feed dependence, and obesity were common findings (N = 240 (31%), N = 106 (14%), and N = 209 (27%) respectively). Overall, 29 patients (3.7%) developed respiratory compromise requiring PICU-level support, defined as new-onset continuous or bilevel positive airway pressure support (n = 25) or reintubation (n = 9). Three patients were diagnosed with pulmonary edema. Multivariable regression analysis demonstrated pre-operative oxygen nadir and enteral feed dependence were associated with respiratory compromise (OR = 0.97, 95% CI 0.94-0.99, P = .04; OR = 6.3, 95% CI 2.36-52.6, P = .001 respectively). Our study found respiratory compromise in 3.7% of patients with planned PICU admissions following T/AT. Oxygen nadir and enteral feeds were associated with higher respiratory compromise rates. Attention should be given to these factors in planning for post-operative disposition.

Association of Prolonged Emergency Department Length of Stay with Adverse Events in Patients with Non-ST-Elevation Acute Coronary Syndrome.

ObjectiveTo study the association between prolonged emergency department length of stay (EDLOS) and in-hospital adverse events in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS).MethodsIn this retrospective cohort study, the medical records of 738 patients diagnosed with NSTE-ACS and admitted to the emergency department (ED) from 1 January 2013 to 31 December 2019 were reviewed. The patients were categorized into groups with EDLOS < 4 hours and EDLOS ≥ 4 hours, and baseline characteristics, clinical presentation, Killip classification, Global Registry of Acute Coronary Events score, investigations, use of the European Society of Cardiology (ESC) 0/1-hour and 0/3-hour algorithms, and treatments in the ED were compared between the groups. The associations of in-hospital adverse events with EDLOS were examined using univariate logistic regression.ResultsFour hundred and twenty-three (57.3%) patients had an EDLOS of ≥ 4 hours, and the median (IQR) EDLOS was 4.48 hours (3.03, 6.20 hours). EDLOS ≥ 4 h was associated with a prolonged time to receive P2Y12 inhibitors and anticoagulants (P < 0.001). However, the two groups showed no significant differences in in-hospital adverse events (congestive heart failure [CHF], shock, stroke or transient ischemic attack [TIA], major bleeding, arrhythmia, recurrent myocardial infarction, death, and one or more adverse events). Nevertheless, a non-significant trend for a higher rate of adverse events (CHF, shock, major bleeding, arrhythmia, recurrent myocardial infarction, death, and one or more adverse events) with longer EDLOS was observed in the subgroup of patients who received diuretic or antiarrhythmic drugs, ventilator or bilevel positive airway pressure support, oxygen support, or inotropic/vasopressor drugs in the ED.ConclusionProlonged EDLOS showed a significant association with longer times to receive P2Y12 inhibitors and anticoagulants. However, the EDLOS < 4 hour and EDLOS ≥ 4 hour groups of patients with NSTE-ACS showed no significant differences in the rates of in-hospital adverse events. Patients who receive cardiovascular medications in the ED or are on respiratory support should be hospitalized as soon as practically possible. Proper use of the 0/1-hour algorithm over the 0/3-hour algorithm without unnecessary repeated cardiac troponin tests in the ED could reduce the EDLOS in patients with NSTE-ACS.

A comparison of the effect of bi-level positive airway pressure and synchronized intermittent mandatory ventilation in preterm infants with respiratory distress syndrome

Objective Bi-level positive airway pressure (BiPAP) and synchronized intermittent mandatory ventilation (SIMV) can be used to achieve peak inspiratory pressure and positive end-expiratory pressure to avoid alveolar collapse and improve oxygenation in preterm infants during the treatment of respiratory distress syndrome (RDS), and there is an urgent demand for evaluating the effects and prognoses of these two ventilation modes. Study design We conducted a retrospective study on preterm infants (≤32 weeks and <2500 g) from March 2015 to March 2020 with BiPAP (n = 63) and SIMV (n = 63). The primary outcomes were successful treatment and weaning within 72 h, the demand for a second pulmonary surfactant supply and the need for a second respiratory support. The secondary outcome was the incidence of complications. Results There were no significant differences (p > .05) in the primary outcomes or the incidence of complications (pneumonia, apnea, respiratory failure, air leak syndrome, persistence of patent ductus arteriosus, neonatal sepsis, necrotizing enterocolitis, retinopathy of prematurity, and intraventricular hemorrhage). There were significant differences (p < .05) in the incidence of pulmonary hemorrhage, bronchopulmonary dysplasia and IVH (≥grade II). Conclusions Although both BiPAP and SIMV achieved good early treatment outcomes of RDS in preterm infants, BiPAP support is recommended for reducing the incidence of pulmonary hemorrhage, bronchopulmonary dysplasia and IVH (≥grade II) if infants are tolerant. Attempts should be made to prevent these complications from happening with the use of SIMV support if infants are intolerant.

Enhanced recovery and early extubation after pediatric cardiac surgery using single-dose intravenous methadone.

Background/Aims:Methadone may offer advantages in facilitating early extubation after cardiac surgery, but very few data are available in the pediatric population.Setting/Design:Community tertiary children's hospital, retrospective case series.Materials and Methods:We performed a retrospective analysis of all pediatric cardiac surgical patients for whom early extubation was intended. A multimodal analgesic regimen was used for all patients, consisting of methadone (0.2–0.3 mg/kg), ketamine (0.5 mg/kg plus 0.25 mg/kg/h), lidocaine (1 mg/kg plus 1.5 mg/kg/h), acetaminophen (15 mg/kg), and parasternal ropivacaine (0.5 mL/kg of 0.2%). Outcome variables were collected with descriptive statistics.Results:A total of 24 children [median = 7 (interquartile range = 3.75–13.75) years old, 23.7 (14.8–53.4) kg] were included in the study; 22 (92%) had procedures performed on bypass and 11 (46%) involved a reentry sternotomy. Methadone dosing was 0.26 (0.23–0.29) mg/kg. None of the children required intraoperative supplemental opioids; 23 (96%) were extubated in the operating room. The first paCO2 on pediatric intensive care unit admission was 51 (45–58) mmHg. Time to first supplemental opioid administration was 5.1 (3.5–9.5) h. Cumulative total supplemental opioids (in intravenous morphine equivalents) at 24 and 72 h were 0.2 (0.09–0.32) and 0.42 (0.27–0.68) mg/kg. One child required postoperative bilevel positive airway pressure support, but none required reintubation. None had pruritus; three (13%) experienced nausea.Conclusion:A methadone-based multimodal regimen facilitated early extubation without appreciable adverse events. Further investigations are needed to confirm efficacy of this regimen and to assess whether the excellent safety profile seen here holds in the hands of multiple providers caring for a larger, more heterogeneous population.

Ultrasound Assessment of Respiratory Workload With High-Flow Nasal Oxygen Versus Other Noninvasive Methods After Chest Surgery

To compare the respiratory workload using the diaphragm thickening fraction (DTf) determined by sonography during high-flow nasal oxygen (HFNO), standard oxygen therapy (SOT), and noninvasive bilevel positive airway pressure support (BIPAP) in patients with acute respiratory failure (ARF) after cardiothoracic surgery. Prospective controlled clinical trial. A French 23-bed cardiothoracic surgical intensive care unit. Nonintubated patients with ARF after cardiothoracic surgery or while awaiting lung transplantation. HFNO (50 L/min), SOT via a standard facemask, and BIPAP (pressure support, 4 cmH2O; positive end-expiratory pressure [PEEP], 4 cmH2O), with FIO2 kept constant were successively applied and compared. With BIPAP, pressure support or PEEP increments up to 8 cmH2O were compared with baseline settings. Each measurement was made after stable breathing for 5 minutes. Fifty patients aged 60.0 ± 12.2 years were enrolled, including 14 (28%) with obesity. Mean PaO2/FIO2 was 153 ± 55 mmHg. DTf was lower with HFNO and BIPAP than with SOT (respectively 21.2% ± 15.1% v 30.9% ± 21.1% and 17.8% ± 19.1% v 30.9% ± 21.1%, p < 0.001) and was not different with HFNO versus BIPAP (p = 0.22). With BIPAP, increasing pressure support to 8 cmH2O decreased DTf (21.0% ± 14.3% v 28.8% ± 19.8%, p = 0.009), whereas increasing PEEP to 8 cmH2O did not (25.2% ± 17.2% v 28.8% ± 19.8%, p = 0.79). Tidal volume increased to 10.6 ± 3.4 mL/kg with 8 cmH2O pressure support v 8.8 ± 2.7 mL/kg with 4 cmH2O pressure support (p < 0.001). HFNO provides a comparable respiratory workload decrease compared with BIPAP at lower levels of pressure support and PEEP compared with SOT. Increasing BIPAP pressure support may provide higher levels of assistance but carries a risk of overdistension.

Wrapping newborn infants in cloth and newspaper after delivery led to higher temperatures on arrival at the neonatal intensive care unit.

Neonatal hypothermia is a preventable cause of neonatal mortality and morbidity, and wrapping neonates in newspaper sandwiched between cotton sheets is a simple intervention. This 2017 Indian pilot study tested the heat insulating property of sandwiched sheets. At birth, we randomised 100 neonates who were more than 32 weeks of gestation and needed neonatal intensive care unit (NICU) observation or care without a ventilator or bilevel positive airway pressure support into two groups of 50. The intervention and control groups were wrapped in two prewarmed sheets at birth that did or did not contain a layer of newspaper. Their axillary temperatures on arrival at the NICU and one hour after arrival were measured. Other environmental factors were similar. The neonates wrapped in the sandwiched sheets showed significantly higher temperatures on arrival at the NICU than the control group (35.9°C versus 35.4°C, p < 0.01) and after one hour (36.5°C versus 36.3°C, p < 0.01). No change in behaviour or training was required for the healthcare staff to implement this initiative. Wrapping newborn infants in two cloth sheets with a newspaper layer resulted in a higher body temperature on arrival at the NICU and after one hour.

A proportional assist ventilator to unload respiratory muscles experimentally during exercise in humans.

What is the central question of this study? Can a modern proportional assist ventilator (PAV) function sufficiently well to unload the respiratory muscles during exercise? What is the main finding and its importance? A PAV can be constructed with contemporary hardware and software and be used at all exercise intensities to unload the respiratory muscles by up to 70%. Previously, PAVs have allowed researchers to address many fundamental physiological problems in clinical and healthy populations, but those versions are no longer functional or available. We describe the creation of a PAV that permits researchers to use it as an experimental tool. Manipulation of the normally occurring work of breathing (WOB) during exercise can provide insights into whole-body regulatory mechanisms in clinical patients and healthy subjects. One method to reduce the WOB uses a proportional assist ventilator (PAV). Suitable commercially available units are not capable of being used during heavy exercise. This investigation was undertaken in order to create a PAV and assess the degree to which the WOB could be reduced during exercise. A PAV works by creating a positive mouth pressure (Pm ) during inspiration, which consequently reduces the WOB. Spontaneous breathing patterns can be maintained, and the amplitude of Pm is calculated using the equation of motion and predetermined proportionality constants. We generated positive Pm using a breathing apparatus consisting of rigid tubing, solenoid valves to control the airflow direction and a proportional valve connected to compressed gas. Healthy male and female subjects were able to use the PAV successfully while performing cycling exercise over a range of intensities (50-100% of maximal workload) for different durations (from 30s to 20min) and different protocols (constant versus progressive workload). Inspiratory WOB was reduced up to 90%, while total WOB was reduced by 70%. The greatest reduction in WOB (50-75%) occurred during submaximal exercise, but at maximal ventilations (>180lmin(-1) ) a 50% reduction was still possible. The calculated change in WOB and subsequent reduction in respiratory muscle oxygen consumption resulted in equivalent reductions in whole-body oxygen consumption. With adequate familiarization and practice, our PAV can consistently reduce the WOB across a range of exercise intensities.

Efficacy of noninvasive mechanical ventilation in prevention of intubation and reintubation in the pediatric intensive care unit

PurposeTo determine the efficiency of noninvasive mechanical ventilation (NIV) both in protection from intubation and in preventing reintubation of postextubation in patients in the pediatric intensive care unit (PICU). MethodsA prospective observational study was conducted in a multidisciplinary 10-bed tertiary PICU of a university hospital. All patients were admitted to our unit from June 2012 to May 2014 and deemed to be candidates to receive continuous positive airway pressure or bilevel positive airway pressure. Measurements and ResultsWe performed 160 NIV episodes in 137 patients. Their median age was 9 months (range, 1-240 months), and their median weight was 7.5 kg (range, 2.5-65 kg). Fifty-seven percent of patients were male. Noninvasive mechanical ventilation was successful in 70% (112 episodes) of patients. There was an underlying illness in 83.8% (134 episodes) of the patients. Bilevel positive airway pressure support was given to 57.5% (92 episodes) of the patients, whereas the remaining 42.5% (68 episodes) received continuous positive airway pressure support. Among the causes of respiratory failure in our patients, the most frequent were postextubation, pneumonia, bronchiolitis, atelectasia, and cardiogenic pulmonary edema. Sedation was applied in 43.1% of the episodes. Complications were detected in 29 episodes (18.1 %). The NIV failure group showed higher Pediatric Risk of Mortality III-24 score, shorter NIV duration, more frequent underlying disease, lower number fed, longer length of PICU stay, and hospital stay, and mortality was higher. ConclusionsNoninvasive mechanical ventilation effectively and reliably reduced endotracheal intubation in the treatment of respiratory failure due to different clinical situations. Our results suggest that NIV can play an important role in PICUs in helping to avoid intubation and prevent reintubation. Although there were serious underlying diseases in most of our patients, such as immunosuppression, 70% avoided intubation with use of NIV.

Anaesthetic management of a patient with amyotrophic lateral sclerosis undergoing laparoscopic diaphragmatic pacing.

Sir, Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterised by progressive asymmetric limb weakness, bulbar symptoms such as dysarthria, dysphagia and respiratory muscle weakness.[1,2] The diaphragmatic pacing system (DPS) is used to stimulate the diaphragmatic muscle to prevent atrophy and prolong life by preventing pulmonary complications.[3,4] A 68-year-old, 74 kg, female, diagnosed as ALS since 4 years, was admitted for laparoscopic insertion of DPS and percutaneous endoscopic gastrostomy (PEG). Her disease had progressed to involve all four limbs and developed dysphagia and dysarthria without involving diaphragm. She was on bi-level positive airway pressure (BiPAP) for 6 h each night for obstructive sleep apnoea. She had history of bronchial asthma and was on salbutamol nebulisation and also history of painful muscle spasms. Her speech was difficult to comprehend. She was non-hypertensive and non-diabetic. Airway assessment revealed Mallampati Grade III. Routine biochemistry was normal and pulmonary function tests showed a forced vital capacity of 45%. Arterial blood gas (ABG) analysis showed partial pressure of carbon dioxide (CO2) of 41.2 mmHg and oxygen saturation of 94% on room air. Nebulisation with ipratropium and budesonide was started 48 h before surgery. The patient was asked to take her routine medications, which included clonazepam, glycopyrrolate, fluvoxamine, and antibiotics. On the morning of surgery, nebulisation with 4% lignocaine, ipratropium, and budesonide was administered and glycopyrrolate 0.2 mg was given intravenously. Difficult intubation cart, along with fibreoptic laryngoscope was kept ready. Monitoring included five lead electrocardiogram with ST segment analysis, pulse oximetry, end-tidal CO2, non-invasive blood pressure, and Bi-spectral index (BIS®) monitoring. She was sedated with 60 μg fentanyl and 0.6 mg midazolam. Injection propofol 70 mg was given till loss of eyelid reflex. The possibility of mask ventilation was confirmed and intermittent positive pressure ventilation with 100% oxygen and sevoflurane, (gradually increased to a dial concentration of 3%) was administered. The patient was ventilated for 3 min. At laryngoscopy, the cords were easily visualised, and sprayed with 2% lignocaine. Endotracheal intubation was accomplished with a 7.5 mm tube and 14 gauge nasogastric tube was inserted. The patient was mechanically ventilated with tidal volume of 500 ml and respiratory rate of 12/min. Airway pressures ranged from 0 to 15 cm H2O. The patient was ventilated with oxygen:nitrous oxide (50:50); inhalational agent was changed to desflurane. The fresh gas flow (FGF) was 1.2 L and the desflurane dial settings were adjusted to ensure end-tidal levels around 4.5%. Fentanyl (40 μg) and midazolam (0.4 mg) were repeated. Intraabdominal pressure with CO2 pneumoperitoneum was maintained at 12 mmHg. Diaphragm was stimulated at multiple points to identify optimum electrode placements sites. After the DPS was in place, PEG was performed. Desflurane was reduced gradually; FGF was increased to 5 L/min, and the patient was ventilated with 100% oxygen. When the patient was awake and spontaneous respiration was adequate, she was extubated after obtaining ABG analysis, which was normal. Throughout surgery, her vital parameters remained steady, and BIS® remained at 40. In the recovery room, chest X-ray revealed left sided capnothorax, which resolved spontaneously without intervention. The patient was monitored for 48 h in the intensive care unit, which was uneventful, with DPS working normally and the patient not requiring the BiPAP support. ALS has no direct effect on the lungs but severely affects the mechanical function of the respiratory system. Progressive inspiratory muscle weakness leads to an inability to clear secretions and CO2 retention and hypercapnoeic respiratory failure are the major cause of death in ALS.[2] DPS was developed initially to provide natural negative pressure ventilation in patients with spinal cord injury. It was observed that 98% of them could be weaned off the ventilator.[3,5] Our case was a patient of ALS in which DPS was being performed, which is rare in India. Anaesthesia needed to be modified to avoid muscle relaxants, prevent an unpredictable response to reversal agents and the need to stimulate the diaphragm to identify implantation points. Short-acting agents such as desflurane and fentanyl were used to ensure quick reversal. Desflurane as the inhalational agent was selected as it is least soluble of available volatile anaesthetics which leads to early and predictable recovery of patients from general anaesthesia including early recovery of airway functions.[6] We also utilised the property of desflurane which, when used above one minimum alveolar concentration causes good muscle relaxantion in dose-dependent fashion. This was important as adequate muscle relaxation was required.[7] Thus, in a patient of ALS, we should avoid skeletal muscle relaxants, use shorter-acting agents and should be prepared for continuous positive airway pressure/BiPAP ventilatory support in the post-operative period if the need arises.

Effects of Dynamic Bilevel Positive Airway Pressure Support on Central Sleep Apnea in Men With Heart Failure

Effects of Dynamic Bilevel Positive Airway Pressure Support on Central Sleep Apnea in Men With Heart Failure

Effects of Dynamic Bilevel Positive Airway Pressure Support on Central Sleep Apnea in Men With Heart Failure*

Treatment with continuous positive airway pressure (CPAP) improves cardiac function in chronic heart failure (CHF) patients with central sleep apnea (CSA)-Cheyne-Stokes respiration (CSR) by stabilizing ventilation, but frequently central apneas and hypopneas persist. Our objective was to test the hypothesis that flow-targeted dynamic bilevel positive airway pressure (BPAP) support (BiPAP autoSV; Respironics; Murrysville, PA) effectively suppresses CSR-CSA in CHF patients. We studied 14 CHF patients with CSR-CSA (and residual CSA on positive airway pressure therapy) during 3 consecutive nights: (1) diagnostic polysomnography, (2) CPAP (n=10) or BPAP (n=4) titration, and (3) dynamic flow-targeted dynamic BPAP support with an expiratory positive airway pressure (EPAP) set to suppress obstructive respiratory events, and an inspiratory positive airway pressure (IPAP) dynamically ranging between 0 and 15 cm H2O above the EPAP. CPAP or BPAP significantly reduced the apnea-hypopnea index (AHI) [mean+/-SD, 46+/-4 events/h to 22+/-4 events/h; p=0.001] compared to the first night without treatment. Flow-targeted dynamic BPAP support (mean EPAP, 6.5+/-1.7 cm H2O; maximal IPAP, 21.9+/-2.1 cm H2O) further reduced the AHI to 4+/-1/h of sleep compared to the untreated (p<0.001) and CPAP or BPAP night (p=0.002). After the first night of flow-targeted dynamic BPAP support, patients rated on an analog scale (range, 0 to 10) the treatment as comfortable (6.9+/-0.6), and the sleep quality as improved compared to previous nights (7.4+/-0.6). Flow-targeted dynamic BPAP support effectively suppresses CSR-CSA in patients with CHF and is well tolerated.

Evolution of Patients With Chronic Obstructive Pulmonary Disease, Obesity Hypoventilation Syndrome, or Congestive Heart Failure Undergoing Noninvasive Ventilation in a Respiratory Monitoring Unit

We compared the use of noninvasive ventilation (NIV) for hypercapnic acidosis with hypoxemia in patients with chronic obstructive pulmonary disease (COPD), obesity hypoventilation syndrome (OHS), or congestive heart failure (CHF) in a respiratory medicine monitoring unit. The objective was to evaluate each diagnostic groups response to therapy in terms of clinical course and evolution of blood gases. Prospective, 12-month study of 53 patients with hypercapnic acidosis with hypoxemia. Twenty-seven patients had COPD, 17 OHS, and 9 CHF. Severity was assessed based on initial arterial blood gas analysis. Clinical course was studied by blood gas analysis after conventional treatment and after NIV (1-3 hours and 12-24 hours). Mortality was recorded. All patients received bilevel positive airway pressure support in assist-control mode. No significant differences were observed between mean (SD) initial pH findings in the 3 diagnostic groups: COPD, 7.28 (0.1); OHS, 7.29 (0.09); and CHF, 7.24 (0.07). (nonsignificant differences). After initial conventional treatment, PaCO2 worsened for COPD patients (P = .026) and PaO2 improved for CHF patients (P = .028). After 1 to 3 hours of NIV, pH (P = .002) and PaO2 (P = .041) improved for COPD patients, and pH (P = .03) and PaCO2 (P = .045) improved in OHS patients; no significant changes were observed in CHF patients. After 12 to 24 hours of NIV, the mean pH was 7.36 (0.04) for COPD patients, 7.36 (0.05) for OHS patients, and 7.25 (0.1) for CHF patients (not significant). The mortality rate was 11.1% for COPD, 0% for OHS, and 33.3% for CHS (not significant, P = .076). In this group of patients with similar initial arterial blood gas values, response to NIV was seen to be better in OHS and COPD than in CHF. That the start of NIV is usually preceded by a poor response to conventional COPD treatment suggests that delaying NIV should be reconsidered.

Use of bilevel positive airway pressure (BIPAP) in end-stage patients with cystic fibrosis awaiting lung transplantation.

Nine consecutive end-stage patients with cystic fibrosis (CF) awaiting lung transplantation were admitted to the pediatric intensive care unit (PICU) in respiratory decompensation. They all received noninvasive bilevel positive airway pressure (BIPAP) support and were evaluated to determine whether or not it improved their oxygenation and provided them with long-term respiratory stability. BIPAP was applied to all patients after a brief period of assessment of their respiratory status. Inspiratory and expiratory positive airway pressures (IPAP, EPAP) were initially set at 8 and 4 cm H2O respectively. IPAP was increased by increments of 2 cm H2O and EPAP was increased by 1 cm H2O increments until respiratory comfort was achieved and substantiated by noninvasive monitoring. Patients were observed in the PICU for 48 to 72 hours and then discharged to home with instructions to apply BIPAP during night sleep and whenever subjectively required. Regular follow-up visits were scheduled through the hospital-based CF clinic. The patients' final IPAP and EPAP settings ranged from 14 to 18 cm H2O and 4 to 8 cm H2O, respectively. All nine patients showed a marked improvement in their respiratory status with nocturnal use of BIPAP at the time of discharge from the PICU. Their oxygen requirement dropped from a mean of 4.6 +/- 1.1 L/min to 2.3 +/- 1.5 L/min (P < 0.05). Their mean respiratory rate decreased from 34 +/- 4 to 28 +/- 5 breaths per minute (P < 0.05). The oxygen saturation of hemoglobin measured by pulse oximetry, significantly increased from a mean of 80% +/- 15% to 91% +/- 5% (P < 0.05). The patients have been followed up for a period of 2 to 43 months and have all tolerated the use of home nocturnal BIPAP without any reported discomfort. Six patients underwent successful lung transplantation after having utilized nocturnal BIPAP for 2, 6, 14, 15, 26, and 43 months, respectively. Three patients have utilized home BIPAP support for 2, 3, and 19 months, respectively, and continue to await lung transplantation. An acute development of refractory respiratory failure resulted in the demise of the remaining three patients after having utilized BIPAP for 3, 6, and 10 months, respectively. The authors conclude that BIPAP therapy improves the respiratory status of decompensating end-stage CF patients. It is well tolerated for long-term home use and provides an extended period of respiratory comfort and stability for CF patients awaiting lung transplantation.

Noninvasive ventilation via bilevel positive airway pressure support in pediatric practice.

To evaluate the efficacy of bilevel positive airway pressure support in critically ill children with underlying medical conditions. Prospective, clinical study. Pediatric intensive care unit (ICU). Thirty-four patients (6 mos to 20 yrs, mean 11.06 +/- 0.9 yrs) with impending respiratory failure were enrolled in the study. All patients required airway or oxygenation/ventilation support (awake or asleep) and required admission to our pediatric ICU. Each patient served as his or her own control. Exclusion criteria were absent cough or gag reflex, multiple organ system failure, age of <6 mos, vocal cord paralysis, and noncooperation with nasal mask. Bilevel positive airway pressure support ventilation. Thirty-four patients with 35 episodes of respiratory insufficiency requiring airway support or oxygenation/ventilatory support were treated with bilevel positive airway pressure support ventilation. Dyspnea score decreased at least two deviations in all patients; dyspnea score decreased five deviations in 67% of patients. Resting heart rate decreased from 126 +/- 3.2 to 102 +/- 3.2 beats/min (p < .001), respiratory rate decreased from 39 +/- 3 to 25 +/- 1 breaths/min (p < .004), bicarbonate concentrations decreased from 30.0 +/- 1.0 to 24.0 +/- 0.7 mmol/L (p < .01), and room air saturation increased from 85 +/- 2% to 97 +/- 1%. Bilevel positive airway pressure support ventilation failure was characterized by an inability to stabilize progression of respiratory failure and the subsequent placement of an artificial airway. Three patients required placement of an artificial airway. A decrease in respiratory rate, heart rate, and dyspnea score and an improvement in oxygenation were noted in >90% of patients studied, resulting in only an 8% frequency of intubation. The efficacy of bilevel positive airway pressure support ventilation in selected groups of patients indicates the need to include this form of noninvasive pressure support ventilation in the care offered by pediatric ICUs.

Bi-level positive airway pressure (BiPAP) ventilation in an infant with central hypoventilation syndrome

A 4-month-old baby girl, after a period of apparent good health, began to have aphonia, dyspnea, difficulties with swallowing, cyanosis, apnea, and hypopnea during sleep that resulted in admission to an intensive care unit for intubation and mechanical ventilation. At the age of 9 months she was admitted to our hospital with a possible diagnosis of central hypoventilation syndrome. A polysomnographic study showed apnea and hypopnea (apnea + hypopnea index = 47.1), hypercapnia (mean end-tidal PCO2 89 +/- 15.0 mmHg), and arterial desaturation (mean SaO2 91 +/- 1.7%; lowest SaO2 < 50%; 68% of total sleep time at SaO2 below 93%); the study also showed an absent ventilatory response to CO2, absent cardiac responses to apnea during sleep, and right ventricular hypertrophy. Nocturnal nasal bi-level positive airway pressure (BIPAP), applied initially at 6 cmH2O and gradually increased to 16 cmH2O, caused the sleep-related abnormal respiratory events to disappear. End-tidal PCO2 decreased to 39 mmHg, and SaO2 increased to 94%. After 6 months of nocturnal BiPAP ventricular right hypertrophy reversed and arrested growth and hypotonia normalized. The child has tolerated and has remained on BiPAP support up to her current age of 3 years and continues to use this form of ventilatory assistance without difficulties.

Bi‐level positive airway pressure (BiPAP) ventilation in an infant with central hypoventilation syndrome

A 4-month-old baby girl, after a period of apparent good health, began to have aphonia, dyspnea, difficulties with swallowing, cyanosis, apnea, and hypopnea during sleep that resulted in admission to an intensive care unit for intubation and mechanical ventilation. At the age of 9 months she was admitted to our hospital with a possible diagnosis of central hypoventilation syndrome. A polysomnographic study showed apnea and hypopnea (apnea + hypopnea index = 47.1), hypercapnia (mean end-tidal P 89 ± 15.0 mmHg), and arterial desaturation (mean Sa 91 ± 1.7%; lowest Sa < 50%; 68% of total sleep time at Sa below 93%); the study also showed an absent ventilatory response to CO2, absent cardiac responses to apnea during sleep, and right ventricular hypertrophy. Nocturnal nasal bi-level positive airway pressure (BiPAP), applied initially at 6 cmH2O and gradually increased to 16 cmH2O, caused the sleep-related abnormal respiratory events to disappear. End-tidal Pco2 decreased to 39 mmHg, and Sao2 increased to 94%. After 6 months of nocturnal BiPAP ventricular right hypertrophy reversed and arrested growth and hypotonia normalized. The child has tolerated and has remained on BiPAP support up to her current age of 3 years and continues to use this form of ventilatory assistance without difficulties. Pediatr. Pulmonol. 1997;24:66–69. © 1997 Wiley-Liss, Inc.

Bi-level positive airway pressure support system use in acute congestive heart failure: preliminary case series.

To describe the use of a noninvasive bi-level positive airway pressure (PAP) support system for ED patients with acute congestive heart failure (CHF). Retrospective case series analysis of ED patients presenting with acute CHF in imminent need of endotracheal intubation (ETI) managed with a bi-level PAP system. The bi-level PAP system was applied at the discretion of the treating emergency physician. Management of the bi-level PAP system, including setting of inspiratory PAP (IPAP) and expiratory PAP (EPAP), weaning, adjunct pharmacologic therapy, and failure of bi-level PAP support, was determined by the treating physician. Only two (9%) of 22 patient presentations necessitated ETI. The mean duration of bi-level PAP therapy was 7.9 hours. The mean maximum IPAP and EPAP settings were 10.8 and 5.8 cm H2O, respectively. Mean intensive care unit length of stay (LOS) was 2.4 days, with a median LOS of only 1 day. There were three deaths in the series; none were attributed to the bi-level PAP system. No technical difficulty with the bi-level PAP system was noted. Noninvasive pressure support ventilation with a bi-level PAP support system may avert ETI in acute CHF patients. This device can be effectively used by ED personnel.