Positive Airway Pressure Mode Research Articles

Perioperative assessment of diaphragmatic dysfunction in cardiac surgery patients and its effect on outcome; a prospective observational study

Objectives: While the assessment of the diaphragm in different clinical scenarios is quite frequent, there remains a scarcity of studies focused on assessing diaphragm dysfunction using ultrasound in cardiac surgery patients. We investigated the impact of cardiopulmonary bypass (CPB) surgery on diaphragm function and evaluated its effects on mechanical ventilation. Methodology: A prospective cohort study, on 100 consecutive adult cardiac surgery patients, was conducted at National Heart Institute. Diaphragmatic displacement (DD) or excursion and diaphragmatic thickening fraction (DTF) were measured using motion-mode ultrasound during quite normal breathing pre-operatively (the day before surgery) and post-operatively on mechanical ventilation, while the patient was fully conscious and spontaneously breathing on continuous positive airway pressure (CPAP) mode + pressure support 10 cmH2O. Then, the results were correlated to CBP time and important patient outcomes. Results: Post-operative DD was significantly less as compared to the pre-operative reading; (1.39 ± 0.42 cm vs. 2.3 ± 0.52 cm; P < 0.001), as was DTF (23% ± 10% vs. 40% ± 13%; P < 0.001). The incidence of diaphragmatic dysfunction post-cardiac surgery was 17% by the definition of DD < 1 cm, and 49% by the definition of DTF ≤ 20%. DD was positively correlated with CBP time, as well as total ventilation time and ICU stay, indicating a negative impact on overall patient outcomes. Conclusion: The results suggest that diaphragmatic dysfunction is positively correlated with CPB time, total ventilation time and ICU stay, underscoring the importance of monitoring diaphragmatic function in post-operative patients, who are difficult to wean from mechanical ventilation with apparently normal chest X-ray, particularly those with prolonged CPB time. Keywords: cardiac surgery; cardiopulmonary bypass; diaphragm dysfunction; diaphragmatic displacement; diaphragm ultrasound; mechanical ventilation. Citation: Omara ISM, Nagi HK, Mohamed KAA, Abd El Haq HH, Awdallah FF. Perioperative assessment of diaphragmatic dysfunction in cardiac surgery patients and its effect on outcome; a prospective observational study. Anaesth. pain intensive care 2024;28(5):816−823; DOI: 10.35975/apic.v28i5.2555 Received: June 28, 2024; Reviewed: September 04, 2024; Accepted: September 06, 2024

Impact of Pressure Targeted Modes of Ventilation on Diaphragmatic Function as Assessed Using Ultrasonography in Critically Ill Patients with Cerebral Insult

Abstract Background Mechanical ventilation (MV) causes diaphragmatic atrophy and reduces diaphragmatic efficiency. Patients with diaphragmatic dysfunction (DD) have longer MV durations and intensive care unit (ICU) stay. There is currently a scarcity of data on the effect of different modes of MV on diaphragmatic function and ultrasound-guided assessment of diaphragmatic efficiency. Methodology Sixty mechanically ventilated patients were randomly divided into four equal groups (15 each), patients were ventilated using either Assist Control Pressure Controlled mode (ACPC group)(Group A), Synchronized Intermittent Mandatory Ventilation Pressure Controlled mode (SIMV)(Group S), Bi-level Positive Airway Pressure mode (BiPAP)(Group B), or Pressure Support Ventilation mode (PSV)(Group P). The primary outcomes were diaphragmatic motion & structure in terms of Diaphragmatic Excursion (DE) & Diaphragmatic Thickness Fraction (DTF) respectively. The duration of the ICU stay was the secondary outcome. Results The PSV group had the highest DE indicating better diaphragmatic function. In addition, MV for longer durations led to diaphragmatic thinning and decreased DTF resulting in DD. Conclusion Among the various modes of ventilation employed in the study, PSV was found to be the mode with the lowest risk of DD. Trial Registry PACTR202112653971335.

Machine learning algorithm for ventilator mode selection, pressure and volume control.

Mechanical ventilation techniques are vital for preserving individuals with a serious condition lives in the prolonged hospitalization unit. Nevertheless, an imbalance amid the hospitalized people demands and the respiratory structure could cause to inconsistencies in the patient's inhalation. To tackle this problem, this study presents an Iterative Learning PID Controller (ILC-PID), a unique current cycle feedback type controller that helps in gaining the correct pressure and volume. The paper also offers a clear and complete examination of the primarily efficient neural approach for generating optimal inhalation strategies. Moreover, machine learning-based classifiers are used to evaluate the precision and performance of the ILC-PID controller. These classifiers able to forecast and choose the perfect type for various inhalation modes, eliminating the likelihood that patients will require mechanical ventilation. In pressure control, the suggested accurate neural categorization exhibited an average accuracy rate of 88.2% in continuous positive airway pressure (CPAP) mode and 91.7% in proportional assist ventilation (PAV) mode while comparing with the other classifiers like ensemble classifier has reduced accuracy rate of 69.5% in CPAP mode and also 71.7% in PAV mode. An average accuracy of 78.9% rate in other classifiers compared to neutral network in CPAP. The neural model had an typical range of 81.6% in CPAP mode and 84.59% in PAV mode for 20 cm H2O of volume created by the neural network classifier in the volume investigation. Compared to the other classifiers, an average of 72.17% was in CPAP mode, and 77.83% was in PAV mode in volume control. Different approaches, such as decision trees, optimizable Bayes trees, naive Bayes trees, nearest neighbour trees, and an ensemble of trees, were also evaluated regarding the accuracy by confusion matrix concept, training duration, specificity, sensitivity, and F1 score.

The role of soluble guanylate cyclase stimulator riociguat in preventing the development of reperfusion lung injury after balloon pulmonary angioplasty in patients with chronic thromboembolic pulmonary hypertension

Aim. To evaluate the effect of prior administration of the soluble guanylate cyclase stimulator riociguat on the incidence and severity of reperfusion lung injury after balloon pulmonary angioplasty (BPA) in patients with inoperable form of chronic thromboembolic pulmonary hypertension (CTEPH).Materials and methods. 70 patients with inoperable CTEPH were included in the study. Patients were divided into 2 groups: Group 1 (n=41) – patients who had received PAH-specific therapy with riociguat at the time of BPA, Group 2 (n=29) – patients who underwent BPA without prior administration of riociguat. In the postoperative period all the patients underwent noninvasive artificial ventilation in continuous positive airway pressure mode in order to prevent the development of reperfusion damage of lungs.Results. Patients of group 1 received treatment with riocigiat for 6 months. At the time of BPA patients of both groups were matched for hemodynamic characteristics. In group 1, reperfusion edema above grade 1 occurred in 17.1% of patients, in group 2 – in 20.7% of patients, p=0.702. In group 1, manifestations of grade 3 reperfusion edema were found in 9.8% patients vs. 6.9% patients in group 2, (p=0.638). None of the patients in both groups had grade 4 or 5 reperfusion edema. Values of the index predicting the probability of reperfusion injury (PEPSI) were not significantly different in the group of patients who were pretreated with riociguat and in the group of patients who did not get PAH-specific therapy (p=0,588).Conclusion. There was no reliable evidence that administration of riociguat in recommended doses at least 6 months before BPA results in additional reduction in the incidence and severity of reperfusion pulmonary edema in patients with inoperable CTEPH.

Enhanced expiratory rebreathing space for high loop gain sleep apnea treatment

The pathophysiology of sleep apnea goes beyond anatomic predisposition to airway collapse and includes additional factors such as arousal threshold and loop gain. High loop gain is a prominent feature in central and complex sleep apnea (with a mixture of obstructive and central features) where relative hypocapnia can lead to respiratory instability and periodic breathing. Existing therapies, including continuous positive airway pressure (CPAP) and adaptive servo-ventilators, often inadequately treat sleep apnea with high loop gain features. Enhanced expiratory rebreathing space (EERS) targets prevention of the hypocapnia that triggers central events in sleep by increasing dead space in amounts less than typical tidal volumes. This is accomplished by covering traditional exhalation ports on positive airway pressure masks and adding small additional tubing with distal exhalation and safety valves. This technique reduces carbon dioxide (CO2) blow-off during arousals and the associated large recovery breaths, typically producing a maximal increase in resting CO2 by 1–2 mmHg, thus increasing the CO2 reserve and making it less likely to encounter the hypocapnic apneic threshold. Typically, the amount of EERS is titrated in response to central events and periodic breathing rather than aiming for a goal CO2 level. Ideally CO2 monitoring is used during titration of EERS and the technique is avoided in the setting of baseline hypercapnia. This method has been used in clinical practice at our sleep center for over 15 years, and retrospective data suggests an excellent safety profile and high rates of successful therapy including in patients who have previously failed CPAP therapy. Limitations include decreased effectiveness in the setting of leak and decreased tolerance of the bulkier circuit. EERS represents a simple, affordable modification of existing positive airway pressure modalities for treatment of central and complex sleep apnea. Areas of future study include randomized controlled trials of the technique and study of use of EERS in combination with adaptive ventilation, and pharmacologic adjuncts targeting high loop gain physiology.

Lung morphology changes in patients with COVID-induced acute respiratory distress syndrome depending on the respiratory therapy options

Background. Morphologic examination of lung tissue in COVID-related acute respiratory distress syndrome is shown in publications predominantly regarding the course of disease but not the type of respiratory support. The aim of the single center study was to determine the influence of different types of respiratory therapy on morphologic findings in lung tissue of patients, who had died from COVID-19. Material and methods. The examined patients with COVID-related related acute respiratory distress syndrome (n = 30) were divided into three groups. Group 1 included those who received non-invasive lung ventilation in continuous positive airway pressure (CPAP) mode through a face mask (n = 10), group 2 consisted of patients who received oxygen therapy with a flow of 15 l/min through a rebreather mask (n = 10), and group 3 included people who underwent invasive lung ventilation through an endotracheal tube (n = 10). Results. In lung tissue of patients of group 1, we revealed prevalence of edema and hemorrhagic changes as well as discrepancy of diffuse alveolar damage (DAD) manifestations and duration of the disease. So, morphological manifestations of exudative phase of DAD were found even after 14 days of disease, and interstitial pneumonia with fibrosing alveolitis was observed only in 12.5 % of patients. The presence of dystelectasis, compensatory emphysema and thinning of the alveolar wall were typical morphological findings in the patients of group 2. Numerous hyaline membranes covered alveolar walls and led to a decrease in gas exchange area, alveolar-capillary block and were the cause of impaired lung ventilation function. Morphological signs of proliferative phase of DAD in patients of group 3 were accompanied by the development of alveolar fibrosis and secondary bacterial bronchopneumonia, especially in prolonged invasive lung ventilation. Conclusions. Low-flow oxygen therapy may lead to the progression of respiratory failure due to self-damaging of intact lung tissue. We have also revealed negative impact of invasive pulmonary ventilation on the number of bacterial complications and fibrosis stimulation. The most favorable morphologic changes were found in patients with non-invasive CPAP ventilation.

Obstructive Sleep Apnea.

Obstructive sleep apnea (OSA) is the most common type of sleep-disordered breathing. This article describes advances in the diagnosis, testing, treatment, and monitoring of OSA. Home sleep apnea testing and in-laboratory polysomnography are the most commonly used diagnostic tools in the identification and monitoring of OSA, but new methods for diagnosis and at-home monitoring of treatment response are being developed and validated. While the apnea-hypopnea index is regularly used to define OSA severity, recognition is increasing of its inability to risk-stratify patients. Other sleep study data including arousal threshold, hypoxic burden, and pulse rate variability as well as clinical characteristics can help with risk stratification. The most effective treatment is continuous positive airway pressure (CPAP), which can be limited by adherence and tolerance in some patients. Newer masks and comfort features including heated tubing and expiratory pressure relief may improve tolerance to positive airway pressure (PAP) therapy. Additional treatment options include other PAP modalities, mandibular advancement devices, tongue stimulation therapy, negative inspiratory pressure, nasal expiratory pressure valves, nasal congestion treatments, upper airway surgeries including hypoglossal nerve stimulation, and medications. OSA is a common disorder that causes sleep and daytime symptoms and increases the risk of neurologic and medical complications. Neurologists should be aware of atypical presentations and understand the diagnostic and treatment options.

Advances in Management of Respiratory Failure in Children.

Providing the right respiratory support is an essential skill, vital for anyone treating sick children. Recent advances in respiratory support include developments in both non-invasive and invasive ventilatory strategies. In non-invasive ventilation, newer modalities are being developed, in an attempt to decrease the need for invasive ventilation. This include newer techniques like Heated humidified high-flow nasal cannula (HHHFNC) and improvements in existing modes. The success of Continuous positive airway pressure (CPAP) and other non-invasive modes depend to a large extent on choosing and maintaining a suitable interface. When it comes to invasive ventilation, recent advances are focussing on increasing automation, improving patient comfort and minimising lung injury. Concepts like mechanical power are attempts at understanding the mechanisms of unintended injuries resulting from respiratory support and newer monitoring methods like transpulmonary pressure, thoracic impedance tomography are attempts at measuring potential markers of lung injury. Using the vast arrays of available ventilatory options judiciously, considering their advantages and drawbacks in every individual case will be the prime responsibility of clinicians in the future. Simultaneously, efforts have been made to identify potential drugs that can favourably modify the pathophysiology of acute respiratory distress syndrome (ARDS). Unfortunately, though eagerly awaited, most pharmaceutical agents tried in pediatric ARDS have not shown definite benefit. Pulmonary local drug and gene therapy using liquid ventilation strategies may revolutionize our future understanding and management of lung diseases.

Clinical and radiological aspects of reperfusion pulmonary edema after balloon pulmonary angioplasty in patients with chronic thromboembolic pulmonary hypertension

Aim. To study the frequency of clinical and radiological signs of reperfusion pulmonary edema and compare them with the volume of endovascular intervention after balloon pulmonary angioplasty (BPA) in patients with chronic thromboembolic pulmonary hypertension (CTEPH).Materials and methods. The study included 50 patients with CTEPH, who underwent stage 1 PLA. To prevent severe reperfusion edema, the number of segmental arteries planned for angioplasty was taken into account, the Pulmonary Edema Predictive Scoring Index (PEPSI) was determined, and after the intervention, noninvasive ventilation was performed in the Continuous positive airway pressure (СPAP) mode for 24 hours. Clinical manifestations of reperfusion edema were assessed 1, 24, 48 and 72 hours after BPA. Radiological signs of edema were considered based on the results of multislice computed tomography (MSCT) or chest x-ray.Results. Angioplasty was performed on 97 segmental, 6 lobar pulmonary arteries, incl. by 45 (46,4%) – with occlusive lesions. The number of arteries undergoing angioplasty ranged from 1 to 7 in each patient, on average 1,9 ± 1,4, change in pulmonary flow grade (ΔPFG) – 4,3 ± 3,4, PEPSI 58,4 ± 51,0, which exceeded the recommended value of 35,5. During the 72-hour observation period, 28 (56%) patients had grade 1 edema, grade 2 reperfusion edema was observed in 15 (30%), grade 3 – in 5 (10%), grade 4 – in 2 (4%) patients. Patients with grade 2-4 edema had higher baseline mPAP (p = 0,015) and PEPSI (p = 0,046). All manifestations of reperfusion edema of 2-4 degrees were stopped due to the prolonged regimen of CPAP therapy for 3 ± 2 days. None of the patients reached grade 5 edema, and there were no deaths. Clinical manifestations of reperfusion injury were observed in 25 (50%) patients, their highest frequency was observed after 24 hoursConclusion. Balloon pulmonary angioplasty of the pulmonary arteries is a safe method for the treatment of inoperable patients with chronic thromboembolic pulmonary hypertension, provided that recommendations for the prevention of reperfusion pulmonary edema are observed. CPAP therapy can successfully prevent and stop the development of severe reperfusion injuries after BPA even when the risk index for reperfusion pulmonary edema is exceeded.

Role of Average Volume Assured Pressure Support Mode (AVAPS) in the Management of Acute Exacerbation of Chronic Obstructive Pulmonary Disease With Type 2 Respiratory Failure.

Background Non-invasive ventilation (NIV) is a well-established approach in the treatment of acute exacerbation of chronic obstructive pulmonary disease (COPD) with type 2 respiratory failure. Average volume-assured pressure support (AVAPS) mode integrates the characteristics of both volume and pressure-controlled modes of NIV. In bilevel positive airway pressure (BiPAP) mode, volume is the dependent variable, whereas in AVAPS mode, pressure is the dependent variable. In this study, we aimed to compare the role of AVAPS mode with BiPAP spontaneous/timed (S/T) mode for the management of patients with acute exacerbation of COPD with type 2 respiratory failure. Methodology A hospital-based comparative and analytical study was carried out on 100 patients with acute exacerbation of COPD with type 2 respiratory failure admitted to respiratory disease hospital, Sardar Patel Medical College, Bikaner (Rajasthan, India). Patients were randomly divided into two groups of 50 patients each. Group A patients were treated with AVAPS mode and group B patients with BiPAP (S/T) mode. Arterial blood gases, average duration of hospital stay, and need for invasive mechanical ventilation were compared between the two groups. Results There was a statistically significant difference in favor of group A in terms of improvement in pH andpCO2as compared to group B at 6 h (pH, p=0.027; pCO2, p=0.012) and 24 h (pH, p=0.032; pCO2, p=0.013). The duration of hospital stay was found to be lower in group A(p=0.003). However, no significant difference was found in terms of need for invasive mechanical ventilation between both groups (p=0.338). Conclusion Application of AVAPS mode results inmore rapid and steady improvement inpatients of COPD as compared to BiPAP (S/T) mode. Thus, managementthrough non-invasive ventilation AVAPS mode should be considered inpatients with acute exacerbation of COPD with type 2 respiratory failure.

Patient-Centered Therapy for Obstructive Sleep Apnea: A Review.

Obstructive sleep apnea (OSA) is one of the most common sleep problems defined by cessation or decreased airflow despite breathing efforts. It is known to be related to multiple adverse health consequences. Positive airway pressure (PAP) is considered an effective treatment that is widely used. Various modes of PAP and other emerging treatment options are now available. A multidisciplinary approach, understanding diverse phenotypes of OSA, and shared decision-making are necessary for successful OSA treatment. Patient-centered care is an essential modality to support patient care that can be utilized in patients with OSA to help improve outcomes, treatment adherence, and patient satisfaction.

0541 Auto PAP adherence determinants of children during the pandemic: A single center experience

Abstract Introduction Obstructive sleep apnea (OSA) is characterized by episodes of partial or complete upper airway obstruction, associated with gas exchange abnormalities, and sleep disruption resulting in OSA syndrome. OSA in majority of children improves after adenotonsillectomy, but with comorbidities or severe OSA, there is a high risk of residual OSA. Positive airway pressure (PAP) is a more definitive therapy for residual OSA when well tolerated. Reported CPAP adherence in children varies from 11-78%, but data on AutoPAP (APAP) acceptability and adherence has not been described. Methods Due to the limitations placed on PAP titration during the SARS-COV-2 pandemic, children (range 2-18 years) diagnosed with OSA at our institution were placed on APAP therapy (Auto CPAP or Auto BiPAP). We performed a retrospective analysis of APAP download data of children who met the criteria (adherence at 90 days>4 hours). Adherent (usage>70%) and non-adherent children were compared using Wilcoxon rank sum test. Logistic regression analyses were performed the effect of covariates including age, PSG AHI, Day 1-7 usage, Day 1-7 residual AHI, Day 1-14 usage, Day 1-14 residual AHI, Day 1-30 usage, Day 1-30 residual AHI or mean pressure at 90 day on compliance at 90 days. Results On day 90, 73 out of 90 children (40 boys) were using APAP >4 hours. Age, diagnostic PSG AHI, residual AHI (days 1-7; 1-14, 1-30), APAP median pressure, pressure (95% centile), and pressure (maximum) had no effect on adherence. Adherence at days (1-7; 1-14; 1-30) and day 1-90 residual AHI had a positive effect on adherence at day 90. There was no statistically significant difference in BMI z-score, age, PSG AHI, median pressure between the two groups. However, residual AHI was lower in the compliant group. Conclusion APAP was fairly well accepted in our study with the majority of children with usage > 4 hours at day 90. Adherence on (days 1-7 and 1-30) predicted APAP usage at day 90. This mirrors adherence data from adult OSA patients. APAP was effective in the compliant group with lower residual AHI. Further analysis of adherence characteristics such as; family history of PAP, PAP mode, mask, surgery and comorbidities is planned. Support (If Any)

0820 Sleep and Oculopharyngeal Muscular Dystrophy: disease progression affecting ventilatory needs and treatment of sleep-disordered breathing

Abstract Introduction Oculopharyngeal muscular dystrophy (OPMD) is an autosomal-dominant, late-onset, and progressive disease characterized by ptosis and dysphagia, sometimes proximal limb weakness and gait abnormalities. It often presents in patients in their 50s. The progressive functional decline of the pharyngeal muscles results in feeding difficulties and aspiration; however, patients may also have risk of nocturnal hypoventilation and sleep apnea, complicated by variable airway obstruction and compliance. Report of Cases: Using retrospective chart review, we identified patients with a known diagnosis of OPMD treated at the Raymond G. Murphy VA Sleep Center. We present a case where OPMD progression necessitated increased ventilatory support and affected positive airway pressure (PAP) compliance. A 58-year-old male with OPMD, DMT2, depression, and memory impairment underwent home sleep apnea testing showing severe OSA (REI 32.7, SpO2 nadir 72%). He started Auto-PAP 6-16 cwp and presented to discuss issues tolerating PAP. Pressures were lowered, but he continued to require maximum pressures without increased utilization. An in-lab CPAP titration showed treatment-emergent centrals but did not find optimal pressures due to limited sleep time. Having failed CPAP, he returned for an ASV titration which controlled his apnea in lateral position. Patient was switched to auto ASV to increase efficacy and comfort. Two months later he discontinued ASV due to frustration with disease progression and feeling unable to breathe deeply with the machine. Nocturnal oxygen at 1L was ordered while he awaited Neurology consult for OPMD. Later, concerned about progressive dyspnea, he resumed ASV, now with 3L O2 bleed. Given suspicion of hypoventilation (bicarbs 27-30), and that ASV could not adjust to his continually changing airway tone with his OPMD, he was switched to iVAPS. This resulted in good control of his sleep apnea, tidal volumes and minute ventilation. However, he reported pressures felt too high, returned to ASV for a period, then discontinued PAP altogether. Conclusion Patients with OPMD and sleep apnea require close follow-up as their disease progression may affect their ventilatory support needs. These patients may require more complex PAP modalities, such as AVAPs, and routine PFTs to help determine timing of ENT involvement for surgical airway planning. Support (If Any)

Treatment of COVID-19 Acute Respiratory Distress Syndrome With a Tabletop Noninvasive Ventilation Device in a Respiratory Intermediate Care Unit.

ObjectiveTo study the outcomes of noninvasive ventilation (NIV) administered through a tabletop device for coronavirus disease 2019 acute respiratory distress syndrome in the respiratory intermediate care unit (RIMCU) at a tertiary care hospital in India.Patients and MethodsWe retrospectively studied a cohort of hospitalized patients deteriorating despite low-flow oxygen support who received protocolized management with positive airway pressure using a tabletop NIV device in the RIMCU as a step-up rescue therapy from July 30, 2020 to November 14, 2020. Treatment was commenced on the continuous positive airway pressure mode up to a pressure of 10 cm of H2O, and if required, inspiratory pressures were added using the bilevel positive air pressure mode. Success was defined as weaning from NIV and stepping down to the ward, and failure was defined as escalation to the intensive care unit, the need for intubation, or death.ResultsIn total, 246 patients were treated in the RIMCU during the study period. Of these, 168 received respiratory support via a tabletop NIV device as a step-up rescue therapy. Their mean age was 54 years, and 83% were men. Diabetes mellitus (78%) and hypertension (44%) were the commonest comorbidities. Treatment was successful with tabletop NIV in 77% (129/168) of the patients; of them, 41% (69/168) received treatment with continuous positive airway pressure alone and 36% (60/168) received additional increased inspiratory pressure via the bilevel positive air pressure mode.ConclusionRespiratory support using the tabletop NIV device was an effective and economical treatment for coronavirus disease 2019 acute respiratory distress syndrome. Further studies are required to assess the appropriate time of initiation for maximal benefits and judicious utilization of resources.

Effect of pressures and type of ventilation on aerosol delivery to chronic obstructive pulmonary disease patients

BackgroundContinuous Positive Airway Pressure (CPAP), BiPhasic Positive Airway Pressure (BiPAP), and high flow nasal cannula (HFNC) show some evidence to have efficacy in COVID-19 patients. Delivery during noninvasive mechanical ventilation (NIV) or HFNC gives faster and more enhanced clinical effects than when aerosols are given without assisted breath. The present work aimed to compare the effect of BiPhasic Positive Airway Pressure (BiPAP) mode at two different pressures; low BiPAP (Inspiratory Positive Airway Pressure (IPAP)/Expiratory Positive Airway Pressure (EPAP) of 10/5 cm water) and high BiPAP (IPAP/EPAP of 20/5 cm water), with HFNC system on pulmonary and systemic drug delivery of salbutamol. On the first day of the experiment, all patients received 2500 μg salbutamol using Aerogen Solo vibrating mesh nebulizer. Urine samples 30 min post-dose and cumulative urinary salbutamol during the next 24 h were collected on the next day. On the third day, the ex-vivo filter was inserted before the patient to collect the delivered dose to the patient of the 2500 μg salbutamol. Salbutamol was quantified using high-performance liquid chromatography (HPLC).ResultsLow-pressure BiPAP showed the highest amount delivered to the lung after 30 min followed by HFNC then high-pressure BiPAP. But the significant difference was only observed between low and high-pressure BiPAP modes (p = 0.012). Low-pressure BiPAP showed the highest delivered systemic delivery amount followed by HFNC then high-pressure BiPAP. Low-pressure BiPAP was significantly higher than HFNC (p = 0.017) and high-pressure BiPAP (p = 0.008). No significant difference was reported between HFNC and high-pressure BiPAP. The ex-vivo filter was the greatest in the case of low-pressure BiPAP followed by HFNC then high-pressure BiPAP. Low-pressure BiPAP was significantly higher than HFNC (p = 0.033) and high-pressure BiPAP (p = 0.008). Also, no significant difference was found between HFNC and high-pressure BiPAP.ConclusionsOur results of pulmonary, systemic, and ex-vivo drug delivery were found to be consistent. The low BiPAP delivered the highest amount followed by the HFNC then the high BiPAP with the least amount. However, no significant difference was found between HFNC and high BiPAP.

Analytical Study of Different Modes of Continuous Positive Airway Pressure (CPAP) in Management of Respiratory Distress Syndrome (RDS) Preterm Neonates

Analytical Study of Different Modes of Continuous Positive Airway Pressure (CPAP) in Management of Respiratory Distress Syndrome (RDS) Preterm Neonates

Efficacy of high-flow nasal cannula therapy in bedridden patients.

A growing number of studies have demonstrated the efficacy of high-flow nasal cannula therapy (HFNC) for treating children with acute respiratory distress. However, it remains unknown whether HFNC is effective in bedridden patients with acute respiratory distress. We retrospectively reviewed the medical records of bedridden patients with acute respiratory distress who were treated with HFNC using a home ventilator in continuous positive airway pressure mode at our center between March 2014 and August 2016. We assessed heart rate, respiratory rate, oxygen saturation measured using a pulse oximeter, the partial pressure of venous carbon dioxide, or the transcutaneous partial pressure of carbon dioxide, and symptoms of respiratory distress before and after the initiation of HFNC. During the 2-year-study period, 25 patients were treated with HFNC. The patients' mean heart rate, respiratory rate, oxygen saturation measured using a pulse oximeter, and pressure of venous carbon dioxide/the transcutaneous partial pressure of carbon dioxide values improved significantly (P < 0.05). Symptoms of respiratory distress were considerably ameliorated at 1-3 h after the HFNC initiation, except in two patients. In these two patients, the HFNC was replaced with non-invasive positive pressure ventilation. Non-invasive positive pressure was also required at 16 to 168 h after the initiation of HFNC in five of the 28 episodes in which the patient was initially responsive to HFNC, as the patients' respiratory symptoms gradually deteriorated. Performing HFNC with a home ventilator in continuous positive airway pressure mode is effective at treating bedridden patients with acute respiratory distress. However, it is essential that the HFNC can be switched to non-invasive positive pressure if needed.

Accuracy of pulse pressure variations for fluid responsiveness prediction in mechanically ventilated patients with biphasic positive airway pressure mode.

The accuracy of pulse pressure variation (PPV) to predict fluid responsiveness using pressure-controlled (PC) instead of volume-controlled modes is under debate. To specifically address this issue, we designed a study to evaluate the accuracy of PPV to predict fluid responsiveness in severe septic patients who were mechanically ventilated with biphasic positive airway pressure (BIPAP) PC-ventilation mode. 45 patients with sepsis or septic shock and who were mechanically ventilated with BIPAP mode and a target tidal volume of 7-8ml/kg were included. PPV was automatically assessed at baseline and after a standard fluid challenge (Ringer's lactate 500ml). A 15% increase in stroke volume (SV) defined fluid responsiveness. The predictive value of PPV was evaluated through a receiver operating characteristic (ROC) curve analysis and "gray zone" statistical approach. 20 (44%) patients were considered fluid responders. We identified a significant relationship between PPV decrease after volume expansion and SV increase (spearman ρ = -0.5, p < 0.001). The area under ROC curve for PPV was 0.71 (95%CI 0.56-0.87, p = 0.007). The best cut-off (based on Youden's index) was 8%, with a sensitivity of 80% and specificity of 60%. Using a gray zone approach, we identified that PPV values comprised between 5 and 15% do not allow a reliable fluid responsiveness prediction. In critically ill septic patients ventilated under BIPAP mode, PPV appears to be an accurate method for fluid responsiveness prediction. However, PPV values comprised between 5 and 15% constitute a gray zone that does not allow a reliable fluid responsiveness prediction.

Clinical utility of repeated positive airway pressure titrations in children with obstructive sleep apnea syndrome.

Positive airway pressure (PAP) is the second line of treatment for obstructive sleep apnea syndrome in children. It is common practice following initiation of PAP to perform repeat titration polysomnography to re-evaluate the patient's therapeutic pressure; however, data supporting this practice are lacking. We hypothesized that repeat PAP titration would result in significant setting changes in children with obstructive sleep apnea syndrome. We retrospectively analyzed demographic, polysomnographic, and PAP data of children with obstructive sleep apnea syndrome aged 0-18 years who were initiated on PAP and underwent 2 titration studies over a 2-year period. PAP mode and recommended pressure differences between the 2 titrations were compared. 64 children met inclusion criteria. The median (interquartile range) baseline obstructive apnea-hypopnea index and SpO2 nadir were 14.8 (8.7-32.7) events/h and 88.5% (85-92%), respectively. The mean differences in obstructive apnea-hypopnea index, SpO2 nadir, and % total sleep time with SpO2 < 90% between both titrations were negligible, including children with obesity, adenotonsillar hypertrophy, and trisomy 21. Additionally, there was no significant difference in mean PAP pressure between 2 separate titration studies for those on continuous PAP or bilevel PAP. Overall, repeat PAP titration in children with obstructive sleep apnea syndrome within the timeframe here described did not result in significant changes in PAP mode, continuous PAP pressure, or obstructive apnea-hypopnea index. Based on these data, repeat PAP titration within 2 years of an initial titration does not appear to be necessary. Yendur O, Feld L, Miranda-Schaeubinger M, etal. Clinical utility of repeated positive airway pressure titrations in children with obstructive sleep apnea syndrome. J Clin Sleep Med. 2022;18(4):1021-1026.

Тривалість штучної вентиляції легень та функціонування діафрагми у дітей з гострою дихальною недостатністю

Актуальність. Пацієнти з комбінованими формами дихальної недостатності часто мають довготривале чи навіть невдале відлучення від штучної вентиляції легень (ШВЛ). Мета дослідження: порівняти тривалість проведення ШВЛ, а також показники функціонування діафрагми при використанні технологій P-SIMV та BIPAP у пацієнтів на етапі відлучення від ШВЛ. Матеріали та методи. Проведено проспективне обсерваційне нерандомізоване когортне дослідження серед 27 пацієнтів з гострою дихальною недостатністю. До І (режим P-SIMV) та ІІ груп пацієнтів (режим BIPAP ) увійшло по 10 пацієнтів. Первинними точками оцінювання результатів лікування були тривалість проведення інвазивної ШВЛ; вторинними точками — амплітуда рухів обох куполів діафрагми, фракція стоншення діафрагми, виникнення декомпенсованого респіраторного чи змішаного ацидозу. Результати. Середня тривалість проведення ШВЛ у пацієнтів першої групи становила 14,14 ± 1,83 доби, у пацієнтів другої групи — 13,2 ± 2,56 доби (p = 0,32). Амплітуда рухів куполів діафрагми в першу добу дослідження становила в І групі пацієнтів 7,2 ± 1,8 мм, у ІІ групі — 6,8 ± 1,5 (p = 0,42); на 5-ту добу лікування цей показник вірогідно не відрізнявся між групами та в І групі зростав до 8,1 ± 2,1 мм, у ІІ — до 8,4 ± 1,9 мм (p = 0,12 та p = 0,89). Вже на 9-ту добу лікування амплітуда рухів правого купола діафрагми вірогідно (р = 0,04) відрізнялася у І групі пацієнтів щодо ІІ групи (9,0 ± 2,1 мм та 10,0 ± 1,3 мм відповідно) та щодо попереднього етапу обстеження (p = 0,05 та p = 0,04). Амплітуда рухів правого купола діафрагми залишалася на рівні понад 10 мм у ІІ групі пацієнтів і на 13-ту та 17-ту добу спостереження за пацієнтами. Висновки. Тривалість проведення ШВЛ у дітей з поєднанням обструктивного та рестриктивного типів дихальної недостатності в І та ІІ групах вірогідно не відрізнялася. Спонтанні дихальні зусилля були вірогідно вищими у пацієнтів ІІ групи починаючи з 9-ї доби порівняно з пацієнтами І групи.