Noninvasive Bilevel Positive Airway Pressure Research Articles

SNAP: Implementation of Supportive Non-Invasive Ventilation for Acute Chest Syndrome Prevention in Adults with Sickle Cell Disease

Introduction Acute chest syndrome (ACS) is the 2 nd most common cause of hospitalization and a major cause of mortality in sickle cell disease (SCD). ACS commonly occurs during a hospitalization for a vaso-occlusive crisis (VOC) when the combination of chest wall pain and intravenous opioids may lead to hypoventilation and atelectasis. Incentive spirometry may prevent ACS by encouraging patients to take deep breaths to reduce atelectasis and improve oxygenation, but requires active participation by an awake patient. Non-invasive bi-level positive airway pressure [BiPAP] provides positive pressure breaths via a mask to improve ventilation and prevent atelectasis during sleep. Hospitalized pediatric SCD patients who were at risk for ACS have used nocturnal BiPAP for ACS prevention on the Boston Medical Center (BMC) general pediatric unit since February 2017. In January 2023, BMC instituted the use of nocturnal BiPAP in hospitalized adult patients with SCD who are at high risk for ACS. Methods This is a prospective observational cohort study to examine the safety, acceptability, and tolerability of BiPAP in high-risk adult patients with SCD hospitalized with a VOC. Criteria for increased ACS risk included: 1) Oxygen saturation < 94% on room air at presentation; 2) History of pulmonary hypertension diagnosed by right heart catheterization; 3) Known obstructive sleep apnea (OSA) not currently treated with positive airway pressure; 4) Prior severe ACS requiring invasive or non-invasive ventilation, high-flow oxygen, and/or exchange transfusion; or 5) History of fat emboli syndrome. Exclusion criteria were: 1) OSA being treated with outpatient positive airway pressure, 2) Surgery within the last 30 days, 3) Direct admission to the intensive care unit (ICU). Manual chart extraction was used to collect patient demographic data, medical history, symptoms, vital signs, chest radiography, laboratory data, indications for BiPAP use, and acceptability and use of BiPAP. Results BiPAP was offered during 38 hospitalizations to 25 individual patients (14 (56%) female) between February and July 2023. The mean age was 35.8 years (SD 10.2); 16 (64%) were HbSS, 8 (32%) HbSC and 1 (4%) HbS-β 0. Nineteen patients (76%) were using >1 SCD-modifying therapy; 16 (64%) reported hydroxyurea use. ACS was present on admission in 7 hospitalizations. Patients agreed to try BiPAP in 22/38 hospitalizations (58%) and BiPAP was used for 1 night in 3 hospitalizations, 2 nights in 3 hospitalizations and more than 2 nights in 7 hospitalizations. In 9/22 hospitalizations, attempts at BiPAP use were unsuccessful. Of the 38 hospitalizations in which BiPAP was offered, 3 patients who did not use BiPAP were transferred to the ICU, 2 for ACS and 1 for ketamine infusion for pain that was refractory to high doses of opioids. Three episodes of ACS developed after admission to the hospital: 2 when BiPAP use had not been attempted and 1 when BiPAP was used for 6 days. Blood transfusions were administered during 7 hospitalizations; 5 of which BiPAP was not used. No deaths occurred during this study period. No adverse events were directly attributable to this novel use of BiPAP for ACS prevention. In the 22 encounters where BiPAP use was attempted, four patients noted difficulties with the continuous airflow and feeling suffocated, one reported lightheadedness. One patient who used BiPAP developed oral pain related to periodontal disease. Conclusion Medically stable, adult hospitalized patients with SCD and VOC were willing to try BiPAP to prevent the development of ACS. In 13/22 (59%) BiPAP was tolerated for >1 one night with no adverse events noted. Future directions include optimizing implementation and studying the efficacy of this intervention.

Modeling the noninvasive bi-level positive airway pressure ventilation therapy system and simulated application

Without artificial airway though oral, nasal or airway incision, the bi-level positive airway pressure (Bi-PAP) has been widely employed for respiratory patients. In an effort to investigate the therapeutic effects and measures for the respiratory patients under the noninvasive Bi-PAP ventilation, a therapy system model was designed for virtual ventilation experiments. In this system model, it includes a sub-model of noninvasive Bi-PAP respirator, a sub-model of respiratory patient, and a sub-model of the breath circuit and mask. And based on the Matlab Simulink, a simulation platform for the noninvasive Bi-PAP therapy system was developed to conduct the virtual experiments in simulated respiratory patient with no spontaneous breathing (NSB), chronic obstructive pulmonary disease (COPD) and acute respiratory distress syndrome (ARDS). The simulated outputs such as the respiratory flows, pressures, volumes, etc, were collected and compared to the outputs which were obtained in the physical experiments with the active servo lung. By statistically analyzed with SPSS, the results demonstrated that there was no significant difference ( P > 0.1) and was in high similarity ( R > 0.7) between the data collected in simulations and physical experiments. The therapy system model of noninvasive Bi-PAP is probably applied for simulating the practical clinical experiment, and maybe conveniently applied to study the technology of noninvasive Bi-PAP for clinicians.

A POTENTIALLY UNDER-RECOGNIZED COMPLICATION OF POSITIVE PRESSURE VENTILATION: ACUTE HYPOCALCEMIA

A POTENTIALLY UNDER-RECOGNIZED COMPLICATION OF POSITIVE PRESSURE VENTILATION: ACUTE HYPOCALCEMIA

Clinical Study on Early Extubation and Sequential Non-Invasive Respiratory Support for Children with Acute Respiratory Failure Receiving Invasive Mechanical Ventilation

To explore the treatment outcome of the strategy of early extubation and then switching to non-invasive mechanical ventilation in children with acute respiratory failure, and the safety and feasibility of using the strategy to replace traditional methods. A total of 102 children, aged between 1 month to 14 years old, who had acute respiratory failure and were admitted to the pediatric ICU of West China Second University Hospital, Sichuan University between January 2019 and December 2020 were enrolled and randomly assigned to treatment group 1 (n=55) and treatment group 2 (n=47). In addition, 53 children who had the same condition in the 12 month prior to the beginning of the study were included in the control group. In the two treatment groups, the patients were extubated first, and then weaned off the ventilator. In group 1, when the patient met the invasive-non-invasive switching criteria, the tracheal tube was pulled out and non-invasive bi-level positive airway pressure (BiPAP) ventilation was used for respiratory support. In group 2, high-flow nasal cannula (HFNC) oxygen therapy was used for respiratory support. The traditional progressive weaning method was adopted for the control group (extubing and weaning were performed at the same time). The incidence of ventilator-associated pneumonia (VAP) during the period of tracheal intubation was compared and the mortality of the two groups was evaluated from the point when the patients were recruited. At the time of extubation in the treatment groups and extubation plus weaning in the control group, the pressure support levels, or PC above PEEP, intubation time, sequential time (between 2 treatment groups only), weaning failure rate, and the incidence of laryngeal edema and nasal pressure ulcer were compared. The subjects of the study were predominantly infants (93 cases, 60%) and young children (31 cases, 20%). Among the 155 cases, 82 (53%) were male. There was no statistical difference in age distribution or gender among the groups. There was no significant difference in the clinical indicators among the three groups before tracheal intubation. At the time of extubation, the PC above PEEP in the two treatment groups was higher than that in the control group, and higher in group 1 than that of group 2, the difference being statistically significant (P<0.05). The intubation time of the two treatment groups was shorter than that of the control group, and shorter in group 1 than that of group 2 (P<0.05). The sequential time of group 2 was shorter than that of group 1 (P<0.05). The extubation failure rate and the incidence of VAP in the two treatment groups were lower than those in the control group, and there was no statistically significant difference between the two treatment groups. The incidence of nasal pressure ulcers in group 1 was higher than that in the other two groups (P<0.05). There was 1 death in treatment group 1, and no deaths in treatment group 2 or the control group. There was no significant difference in mortality or the incidence of laryngeal edema after extubation in the three groups. Early extubation and then switching to non-invasive mechanical ventilation can be well tolerated by the patients, and can be used in clinical practice as an effective weaning method for children with acute respiratory failure.

A Quantitative Study of Particle Dispersion due to Respiratory Support Modalities in PC-12 Aircraft: Prehospital Patient Transport

ObjectiveIt is unclear whether supplemental oxygen and noninvasive ventilation respiratory support devices increase the dispersion of potentially infectious bioaerosols in a pressurized air medical cabin. This study quantitatively compared particle dispersion from respiratory support modalities in an air medical cabin during flight. MethodsDispersion was measured in a fixed wing air ambulance during flight with a breathing medical mannequin simulator exhaling nebulized saline from the lower respiratory tract with the following respiratory support modalities: a nasal cannula with a surgical mask, high-flow nasal oxygen (HFNO) with a surgical mask, and noninvasive bilevel positive airway pressure (BiPAP) ventilation. ResultsNasal cannula oxygen with a surgical mask was associated with the highest particle concentrations. In the absence of mask seal leaks, BiPAP was associated with 1 order of magnitude lower particle concentration compared with a nasal cannula with a surgical mask. Particle concentrations associated with HFNO with a surgical mask were lower than a nasal cannula with a surgical mask but higher than BiPAP. ConclusionsParticle dispersion associated with the use of BiPAP and HFNO with a surgical mask is lower than nasal cannula oxygen with a surgical mask. These findings may assist air medical organizations with operational decisions where little data exist about respiratory particle dispersion.

P0437 / #2122: OUTCOMES OF NON-INVASIVE BI-LEVEL POSITIVE AIRWAY PRESSURE VENTILATION AS INITIAL MANAGEMENT OF ACUTE RESPIRATORY FAILURE IN PEDIATRIC CRITICAL CARE

Aims & Objectives: To assess the outcomes of non-invasive bi-level positive airway pressure (BLPAP) ventilation as first-line therapy in children with acute respiratory failure (ARF). Methods: Design: A retrospective observational study. Setting: Pediatric Intensive Care Unit (PICU) of a university hospital. Patients: Eighty-seven patients subjected to non-invasive ventilation (NIV) as the initial management in a total of 92 ARF episodes were included, from July-2017 to June-2020. Each episode was treated as an independent event. Main Outcome Measures: We evaluated changes of heart rate, respiratory rate and SpO2/FiO2 ratio (S/F) at 3, 6, 12, and 24 hours after NIV onset, and compared patients using BLAP vs CPAP as first-line therapy. Results: BLPAP was started in 63 episodes (68.5%). Ten of 29 episodes (34.5%) that started CPAP were escalated to BLPAP. Baseline characteristics, initial physiologic parameters and severity score did not differ between groups. The S/F ratio increase at 6 hours was significantly greater in the BLPAP group (mean 48; CI95% 29-66) compared to the CPAP group (mean 21; CI95% -17-59; p=0,011). The trend continued over time, S/F ratio increase was greater in the BLPAP group at 24 hours. No difference was found in the intubation rate (BLPAP 4.4% vs CPAP 3.2%). The mean length of stay in the PICU was 1 day longer in the CPAP group, although it was not a significant difference. Conclusions: In children with ARF, the initial use of BLPAP rapidly improves the S/F ratio compared to CPAP. BLPAP as first-line therapy could be the best option for the management of patients with ARF.

Invasive mechanical ventilation using a bilevel PAP ST device in a healthy swine model.

PurposeThe Coronavirus Disease 2019 (COVID-19) pandemic may cause an acute shortage of ventilators. Standard noninvasive bilevel positive airway pressure devices with spontaneous and timed respirations (bilevel PAP ST) could provide invasive ventilation but evidence on their effectiveness in this capacity is limited. We sought to evaluate the ability of bilevel PAP ST to effect gas exchange via invasive ventilation in a healthy swine model.MethodsTwo single limb respiratory circuits with passive filtered exhalation were constructed and evaluated. Next, two bilevel PAP ST devices, designed for sleep laboratory and home use, were tested on an intubated healthy swine model using these circuits. These devices were compared to an anesthesia ventilator.ResultsWe evaluated respiratory mechanics, minute ventilation, oxygenation, and presence of rebreathing for all of these devices. Both bilevel PAP ST devices were able to control the measured parameters. There were noted differences in performance between the two devices. Despite these differences, both devices provided effective invasive ventilation by controlling minute ventilation and providing adequate oxygenation in the animal model.ConclusionsCommercially available bilevel PAP ST can provide invasive ventilation with a single limb respiratory circuit and in-line filters to control oxygenation and ventilation without significant rebreathing in a swine model. Further study is needed to evaluate safety and efficacy in clinical disease models. In the setting of a ventilator shortage during the COVID-19 pandemic, and in other resource-constrained situations, these devices may be considered as an effective alternative means for invasive ventilation.

Acute Bilateral Diaphragmatic Palsy :Unusual Cause of Orthopnea

A middle aged lady presented with acute onset respiratory insufficiency without any predisposing factors. Pulmonary, cardiac,neurological and infectious causes were excluded after detailed examination.Bilateral diaphragmatic palsy was considered after meticulous survey.She benefited with non invasive bilevel positive airway pressure(BiPAP) support.High degree of clinical suspicion is stressed in diagnosing bilateral diphragmatic palsy and execellent results on treatment with non invasive ventilation.

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.

Oblique-axis view should be the preferred view for ultrasound-guided internal jugular vein cannulation in intensive care unit.

Sir, In our view oblique-axis (OAX) plane should be the standard approach for ultrasound-guided internal jugular vein (IJV) puncture in critically ill patients. It combines the benefit of both short-axis plane (SAX) and long-axis plane (LAX). Short-axis plane (SAX) is more traditional approach and is used more commonly in teaching practice. The short-axis approach (SAX) allows simultaneous visualization of both artery and vein, but can make needle tip control difficult.[1] The course of the guidewire also cannot be followed by this approach. The long-axis approach (LAX) can optimize needle visualization, but it can be challenging to perform owing to certain anatomical limitations (such as neck length). In addition, LAX only displays the vein in the ultrasound image (unless the artery lies directly underneath) and if the operator strays medially, accidental arterial cannulation can occur.[1] In intensive care unit (ICU) we get multiple patients with history of long-term prior central line catheterization and multiple times central line catheterization. In these patients there is possibility of thrombus formation in the central vein.[23] We report here a case with easy puncture of IJV, but difficulty in the insertion of guidewire due to IJV thrombus. A 68-year-old male post-renal transplantation was admitted to our ICU with breathlessness. He was diagnosed with end-stage renal disease 10 years back and had undergone renal transplantation. Currently, he was showing features of graft-rejection and respiratory infection. His deranged investigations were serum urea –104 mg/dl, serum creatinine –3.5 mg/dl, and total leucocyte count –18,000. Patients respiratory rate was 23/min and arterial blood gas pH 7.55, paO2 – 58, pCO2 – 22, HCO3 – 21. He was put on noninvasive bilevel positive airway pressure ventilation (inspiratory positive airway pressure: 15, expiratory positive airway pressure: 7). His urine output was also on lower side, so it was planned to give fluids and antibiotics from central venous line. Nephrologist suggested that dialysis may be required in the patient, so we planned to insert a hemodialysis catheter in right IJV. We routinely use ultrasound for the procedure in our ICU. After adequate aseptic and analgesic preparation, we localized right IJV by ultrasound in SAX view and immediately punctured the vein, but guidewire could not be negotiated beyond 7 cm. We rotated the probe for long-axis view but due to short neck and less space it was difficult to visualize and do the procedure. So we kept midway, i.e., oblique-view and tried to insert the guidewire and were able to localize the point beyond which guidewire was not moving. There was a partial thrombus in IJV. We abandoned the procedure for right IJV. In OAX view if we face resistance in guidewire insertion, after successful puncture of the vein, we can successfully negotiate the guidewire under ultrasonic view without creating a new puncture.[4] We consider that OAX plane approach of IJV cannulation is safe and effective and that it should be encouraged in clinical teaching. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

Favorable Outcomes in Blunt Chest Injury with Noninvasive Bi-Level Positive Airway Pressure Ventilation

Recent clinical research in patients with blunt chest injury has focused on the benefits of surgical fixation of rib fractures. Noninvasive ventilation (NIV) has been demonstrated to prevent the need for intubation and ventilation in posttraumatic respiratory failure. The preemptive use of NIV in patients with rib fractures has not been extensively studied. Our study evaluated the outcomes of patients with ≥3 rib fractures and hospitalized for ≥ 4 days. Seventy-one patients treated with NIV were compared with 270 patients without NIV. NIV patients were older (65.8 vs 56.5 years) had more rib fractures (6.25 vs 5.32) and a higher body mass index (31 vs 27.8) than the comparison group, P < 0.05, but did not have an increased mortality or incidence of respiratory failure. NIV patients did have a statistically significant increase in length of stay compared to control (12.8 vs 8.8, P < 0.05). In the total sample, worse clinical outcomes were associated with older age, increased number of and bilateral rib fractures, higher Injury Severity Score, lower Glasgow Coma Scale, and higher body mass index. Outcomes in the most severely injured group of patients treated with NIV were comparable to other studies using surgical fixation of rib fractures and epidural pain control.

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

Acute neuromuscular respiratory failure

Purpose of review Neurologists working in the hospital are often called to evaluate patients with severe muscle weakness. Some of these patients can develop ventilatory compromise and require admission to the intensive care unit (ICU). This article reviews the general evaluation of neuromuscular respiratory failure, discusses its differential diagnosis, and provides practical advice on the management of its most common causes. Recent findings Determining the cause of acute neuromuscular respiratory failure is crucial because functional prognosis is poor in patients for whom the cause cannot be defined. The differential diagnosis is extensive, but the first step is to discriminate between cases related to a primary neurologic disease (primary neuromuscular respiratory failure) and those provoked by systemic disease, most often critical illness from sepsis and multiorgan failure (secondary neuromuscular respiratory failure). Guillain-Barre syndrome (GBS) and myasthenic crisis are the two most frequent causes of primary neuromuscular respiratory failure. Although they are both autoimmune conditions that benefit from the administration of plasma exchange or IV immunoglobulin (IVIg), they are otherwise very different disorders with unique features and distinct complications. Optimal strategies for mechanical ventilation also differ between these two conditions; while myasthenic crisis is ideally managed with noninvasive bilevel positive airway pressure (BiPAP) ventilation, GBS demands early intubation. Summary Prompt recognition of neuromuscular respiratory failure can be lifesaving, and identification of its cause has substantial prognostic implications. Adequate management of these patients requires a multidisciplinary team with the neurologist at its center, not only to guide the diagnostic evaluation but often also to prescribe the optimal management.

Acute Neuromuscular Respiratory Failure.

Neurologists working in the hospital are often called to evaluate patients with severe muscle weakness. Some of these patients can develop ventilatory compromise and require admission to the intensive care unit (ICU). This article reviews the general evaluation of neuromuscular respiratory failure, discusses its differential diagnosis, and provides practical advice on the management of its most common causes. Determining the cause of acute neuromuscular respiratory failure is crucial because functional prognosis is poor in patients for whom the cause cannot be defined. The differential diagnosis is extensive, but the first step is to discriminate between cases related to a primary neurologic disease (primary neuromuscular respiratory failure) and those provoked by systemic disease, most often critical illness from sepsis and multiorgan failure (secondary neuromuscular respiratory failure). Guillain-Barré syndrome (GBS) and myasthenic crisis are the two most frequent causes of primary neuromuscular respiratory failure. Although they are both autoimmune conditions that benefit from the administration of plasma exchange or IV immunoglobulin (IVIg), they are otherwise very different disorders with unique features and distinct complications. Optimal strategies for mechanical ventilation also differ between these two conditions; while myasthenic crisis is ideally managed with noninvasive bilevel positive airway pressure (BiPAP) ventilation, GBS demands early intubation. Prompt recognition of neuromuscular respiratory failure can be lifesaving, and identification of its cause has substantial prognostic implications. Adequate management of these patients requires a multidisciplinary team with the neurologist at its center, not only to guide the diagnostic evaluation but often also to prescribe the optimal management.

Ventimask in exacerbation of chronic obstructive pulmonary disease and mild acidosis before starting with bilevel positive airway pressure

Patients with chronic obstructive pulmonary disease (COPD) during an episode of acute or acute on chronic respiratory failure due to infection present a special problem with regard to the relief of hypoxia. In a prospective, randomized, multicenter controlled trial, we evaluated the efficacy of oxygen delivery by Ventimask compared with Venturi mask in patients affected by exacerbation of COPD and mild acidosis before starting with non-invasive bilevel-positive airway pressure (PAP). The study involved 80 patients with exacerbation of COPD divided in two groups: Group A=40 patients randomized to Ventimask plus standard therapy and Group B=40 patients randomised to Ventury mask plus standard therapy. The primary endpoint was to evaluate the efficacy of oxygen therapy with Ventimask compared with Venturi mask in terms of avoiding the need for non-invasive bilevel-PAP during the 1st h and reducing PaCO2 retention. Twenty-five patients (62%) started with bilevel-PAP in Group A and 28 (70%) in Group B (not significant). There were no significant changes in arterial blood gases values between the two groups. In Group A, pH and PaCO2 were 7.32±0.11 and 68.5±13.6 mmHg at admission, and 7.33±0.05 and 64.8±4.9 mmHg after 1 h (not significant). In Group B, pH and PaCO2 were, respectively, 7.32±0.11 and 65.7±13.6 mmHg at admission, and 7.33±0.03 and 64.0±5.5 mmHg after 1 h (not significant). Our conclusion did not show any significant differences between the two oxygen masks delivery in terms of preventing the need of bilevel-PAP and reducing PaCO2, despite the trend towards a reduction of the utilization of non-invasive positive pressure ventilation was in favor of Ventimask.

Effect of non-invasive bi-level positive airway pressure ventilation combined with naloxone in the treatment of AECOPD complicated with pulmonary encephalopathy: a meta-analysis

Objective To review the effect of non-invasive bi-level positive airway pressure ventilation combined with naloxone in the treatment of acute exacerbation of chronic obstructive pulmonary disease (AECOPD) complicated with pulmonary encephalopathy (PE). Methods Related published studies involving BiPAP combined with naloxone in the treatment of AECOPD complicated with PE were recruited and identified from Pubmed, ISI Web of knowledge, CBM Disc, CNKI, Wanfang Data, and randomized controlled trails(RCTs) primarily collected were screened according to inclusive criteria and exclusive criteria.Valid data were extracted after quality evaluation for meta-analysis utilizing RevMan 5.2. Results A total of 10 Chinese RCTs were enrolled, including 697 patients (353 patients in experimental group while 343 patients in control group). The results of meta-analysis indicated that BiPAP combined with naloxone improved PaO2(WMD=4.10, 95%CI(2.83, 5.38), P<0.00001), PH value(WMD=0.04, 95%CI(0.02, 0.05), P<0.00001) and clinical efficiency rate(OR=3.58, 95% CI((2.22, 5.76), P<0.00001), and reduced PaCO2(WMD=-5.78, 95%CI(-6.87, 4.69), P<0.00001), re-endotracheal intubation rate (OR=0.19, 95%CI(0.11, 0.35), P<0.00001), but failed to decrease mortality(OR=0.38, 95%CI(0.11, 1.34), P=0.13) of patients with AECOPD complicated with PE. Conclusions BiPAP combined with naloxone play a protective role in enhancing arterial blood gas indexes, improving clinical efficiency rate and limiting re-endotracheal intubation rate.However, the mortality of patients cannot be reduced. Key words: BiPAP; Naloxone; AECOPD; Pulmonary encephalopathy; Meta-analysis

Characteristics of Patients With the “Malignant Obesity Hypoventilation Syndrome” Admitted to an ICU

The incidence of obesity in westernized nations is increasing at an alarming rate. We have noted an increasing number of patients admitted to our intensive care unit (ICU) with hypercapnic respiratory failure and multisystem organ dysfunction related to obesity. We have coined the term the malignant obesity hypoventilation syndrome (MOHS) to describe this entity. We reviewed the hospital records of all patients who were admitted to our ICU over an 8-month period, with a body mass index (BMI) greater than 40 kg/m² and a PaCO₂ greater than 45 mm Hg. We excluded patients with musculoskeletal disease, intrinsic lung disease, and those with >20 pack-year smoking history. Sixty-one patients (8% of all admissions) met the inclusion criteria for our study. The patients' mean BMI was 48.9 ± 8.6 kg/m². The patients' mean age was 59 ± 11; 47 (77%) were female and 56 (92%) were black. All patients were admitted to the ICU with hypercapnic respiratory failure. The patients had been admitted to our hospital on average 6 times over the previous 2 years; 75% had been erroneously diagnosed and treated for chronic obstructive pulmonary disease (COPD)/asthma and 86% had been treated with diuretics for congestive cardiac failure. All patients had type 2 diabetes and the metabolic syndrome. Three patients had a tracheotomy in place at admission and required mechanical ventilation. All of the remaining patients were treated with noninvasive bilevel positive airway pressure (BiPAP), with 23 patients failing BiPAP and requiring mechanical ventilation. Seven patients had a tracheotomy performed. On the basis of unexplained abnormalities of liver function tests, 39 patients (64%) were presumptively diagnosed with nonalcoholic steatohepatitis (NASH). Pulmonary function tests were suggestive of a restrictive pattern in all patients tested. By echocardiography 43 (71%) patients had left ventricular hypertrophy and 37 (61%) patients had features of left ventricular diastolic dysfunction. Forty-seven (77%) patients had pulmonary hypertension, which was moderate to severe (pulmonary systolic pressure >45 mm Hg) in 25 cases. All patients had an elevated C-reactive protein (9.4 ± 6.9 mg/dL), and all but 1 were vitamin D deficient (13.5 ± 8.5 ng/mL). Eleven patients (18%) died during the index hospitalization. MOHS is a serious multisystem disorder with a high mortality that appears to be relatively common, frequently misdiagnosed, and inadequately treated.

Adjunctive tadalafil therapy for managing pulmonary hypertension in a patient with obesity hypoventilation syndrome

Obesity hypoventilation syndrome (OHS) is often associated with pulmonary hypertension (PH), and noninvasive bi-level positive airway pressure therapy is indicated as first-line treatment. However, its effect in reducing pulmonary arterial pressure is insufficient in many cases, thus adjunctive therapies should be evaluated. In this report, we present a patient with OHS-associated PH who was successfully treated by tadalafil in conjunction with weight reduction and bi-level positive airway pressure therapy.

Severe Mixed Sleep Apnea After Bilateral Lung Transplantation in a Cystic Fibrosis Patient: A Case Report

Background Lung transplantation is the only treatment for end-stage lung disease in selected patients. After lung transplantation, patient recovery is often slow owing to severe underlying diseases in the patient producing hypoxemia before, during, and after surgery, as well as infections and rejection episodes. Postoperative breathing and ventillatory disorders are also associated with diaphragmatic dysfunction and/or phrenic nerve damage. Methods Herein we have reported a case of a 35-year-old man undergoing bilateral lung transplantation owing to worsening of chronic respiratory failure from cystic fibrosis. After uncomplicated surgery, weaning was delayed due to nighttime dyspnea and hypoxemia attributed to diaphragm dysfunction. After improvement of diaphragm function, the symptoms persisted, requiring noninvasive nocturnal ventilatory support. Polysomnography confirmed severe mixed sleep apnea. Results Effective treatment with noninvasive bi-level positive airway pressure spontaneous/timed mode (BiPAP S/T) ventilation during the nights rendered the patient symptom free. Polysomnography confirmed successful treatment. Conclusion Disordered breathing while sleeping is common after solid organ transplantation. BiPAP S/T ventilator therapy was effective to the treat dominantly central sleep apnea in our patient.

The application of bi-level positive airway pressure in patients with severe pneumonia and acute respiratory failure caused by influenza A (H1N1) virus.

To evaluate the effect of noninvasive Bi-level Positive Airway Pressure (BiPAP) ventilation on the severe influenza A virus associated with pneumonia and acute respiratory failure (ARF). Based on conventional therapy via face mask using BiPAP ventilator positive airway pressure ventilation in the treatment of severe pneumonia caused by influenza A (H1N1) virus with acute respiratory failure (ARF) in 18 cases, we observed and evaluated the therapeutic effects. PaO2 and SaO2 before and after treatment were (48.85 ± 12.15)mmHg, (68.56 ± 16.25) mmHg and (80 ± 6)%, (92 ± 5)%, respectively. The results were significantly different (P<0.05) before and after treatment. Endotracheal intubation rate was 25% (6/24) and case-fatality rate was 8.3% (2/24). BiPAP ventilator airway pressure by face mask ventilation can reduce the rate of endotracheal intubation in the treatment of severe pneumonia caused by influenza A (H1N1) virus in acute respiratory failure. It could be an effective approach in the emergency treatment with clinical value.