Role of venous blood gases in hypercapnic respiratory failure chronic obstructive pulmonary disease patients presenting to the emergency department.

BACKGROUND: Many patients with acute exacerbations of chronic obstructive pulmonary disease (AECOPD) have type 2 respiratory failure (T2RF). Often arterial blood gases are not performed and correlation with venous blood gases (VBG) is controversial. The venous pH and bicarbonate (HCO3 ) are useful, but VBG pCO2 (PvCO2 ) is considered too unpredictable. AIM: To examine the utility of VBG in this cohort of patients. METHODS: A prospective study of AECOPD patients with T2RF presenting to the emergency department was performed. Patients being considered for non-invasive ventilation and who required an arterial blood gas were invited to participate. A subsequent VBG was also taken, and Bland-Altman plots were used for analysis. RESULTS: Sixty-three patients were included in this study. The limits of agreement for pH and HCO3 were narrow. Wider limits of agreement with a systematic bias of 7.7 mmHg were noted with pCO2 . CONCLUSIONS: The utility of VBG pH and HCO3 was again demonstrated. VBG pCO2 in this cohort of patients may have a role in the assessment of patients with AECOPD. Further study is needed on the possible role of VBG in the management of such patients with T2RF particularly those using non-invasive ventilation.

Non-invasive positive pressure ventilation in the home setting.

Noninvasive ventilation is becoming a more commonly used long-term treatment for various conditions in which the patient experiences chronic hypercapnic respiratory failure (type 2 respiratory failure). This article aims to discuss why patients require long-term noninvasive positive pressure ventilation (NPPV), and to describe some of the care considerations required for this patient group, in addition to challenges that nurses in the home care environment face when supporting these patients at home. The article provides a brief pathophysiological overview, while also discussing the use of NPPV as symptom support for patients with severe disease in the later stages of their lives. The term 'noninvasive positive pressure ventilation' is used to cover a number of different noninvasive systems, although the study primarily focuses on bi-level ventilation systems.

An unusual cause of type 2 respiratory failure.

We present a female patient who was referred for management of respiratory failure. She was being evaluated and managed as worsening chronic inflammatory demyelinating polyneuropathy with type 2 respiratory failure. Initial examination showed hypertrichosis, clubbing and papilledema along with severe distal and proximal motor-predominant weakness with impending respiratory failure. She was managed with noninvasive ventilation (NIV) and plasmapheresis awaiting diagnostic investigations. Immunofixation showed an "M band" and free lambda chain levels were elevated. Radiographs showed the classic osteosclerotic lesions of POEMS (polyradiculoneuropathy, organomegaly, endocrinopathy, M-protein and Skin abnormalities) syndrome. Six weeks after commencing radiotherapy to the osteosclerotic lesions, the patient responded favorably and remains off nocturnal NIV support.

Atypical Neuroleptic Malignant Syndrome With Type 2 Respiratory Failure Treated With Non-invasive Ventilation.

Neuroleptic malignant syndrome (NMS) is characterized by hyperthermia, severe rigidity, and autonomic instability that is life-threatening if not treated promptly by intensive supportive care. However, there have been numerous reports of "atypical NMS" where the diagnostic criteria of NMS are only partially satisfied. We present a case of an elderly male who presented with atypical NMS secondary to antidopaminergic drug administration which precipitated acute respiratory failure. Our patient exhibited features of severe rigidity and autonomic instability, without hyperthermia. He developed tachypneic hypoventilation with type 2 hypercapneic respiratory failure which was treated with non-invasive ventilation (NIV). The patient recovered after three days with resolution of rigidity and was transferred to a normal medical ward on oxygen via a facemask, where he gradually improved. This study highlights that non-invasive ventilation may have a role in treating respiratory failure in mild to moderate cases of atypical NMS, avoiding the need for intubation.

Nemaline Myopathy Initially Diagnosed as Right Heart Failure with Type 2 Respiratory Failure.

Nemaline myopathy (NM) is a rare muscle disease with various clinical types. In some cases, NM can lead to type 2 respiratory failure and right heart failure. We herein report a patient with congenital NM with nebulin gene mutation who presented with acute right heart failure and type 2 respiratory failure due to respiratory muscle paralysis after upper respiratory tract infection, needing a permanent ventilator for assistance. However, the limb and trunk muscle strengths were within normal limits. This case showed that NM should be considered as a cause of right heart failure and type 2 respiratory failure.

[Selenoprotein-related myopathy in a patient with old-age-onset type 2 respiratory failure: a case report].

A 71-year-old woman was admitted to our hospital with type2 respiratory failure. Her daily life activities had been normal, although she had noticed mild truncal weakness in her sixties. Her parents were consanguineous, and her sister had suffered similar symptoms. Although Pompe disease was suspected on the basis of the clinical course and CT findings of selective muscular atrophy in the paraspinal, thigh flexor and sartorius muscle, acid alpha-glucosidase activity was normal. The serum creatine kinase level was not elevated, and muscle biopsy showed no specific change. Genetic analysis revealed a novel homozygous variant c.227T>C (p.Phe76Ser) in the SELENON gene, and she was suspected to have selenoprotein-related myopathy, which is reported to develop in childhood. Selenoprotein-related myopathy should be considered as a differential diagnosis in aged patients presenting with respiratory failure of unknown origin.

Predictors of success and failure of non-invasive ventilation use in type-2 respiratory failure.

BACKGROUND: Non-invasive ventilation is widely used now a days in patients with hypercapnic respiratory failure. Non-invasive ventilation can be used in Intensive Care Unit setting and wards provided trained staff is there to monitor. METHODS: This was a prospective observational study of 100 adult patients who were admitted with hypercapnic respiratory failure. Demographic information such as Age, Sex were recorded. Clinical parameters like Respiratory Rate, Heart Rate, Oxygen saturation and Arterial Blood Gas variables like pH, PaCO2, HCO3 were measured at the time of admission and at 1st hour, 4 hours and 24 hours after start of non-invasive ventilation. Outcome was recorded as success and failure with Non invasive ventilation. RESULTS: Out of 100 patients, 76 (76%) managed successfully with non-invasive ventilation and 24 patients (24%) needed intubation and invasive mechanical ventilation in this study. Majority of patients (76%) were with clinical diagnosis of Chronic Obstructive Pulmonary Disease. Respiratory Rate and Heart Rate were significantly lower and showed significant improvement at 1st hour, 4 hours and 24 hours in patients who successfully improved with Non invasive ventilation. Oxygen saturation was found to be significantly higher among patients successfully managed with Non invasive ventilation (84.35 ± 8.55 vs 76.87 ± 7.33) as compared to patients who required intubation. pH was found to be significantly higher (7.28 ± 0.06 vs 7.23 ± 0.05) in patients showing good response to Non invasive ventilation and improvement in pH at 1st hour, 4 hours and 24 hours was observed in patients successfully managed with Non invasive ventilation. PaCO2 level was found to be significantly lower and significant improvement in PaCO2 at 1st hour, 4 hours and 24 hours was seen in patients with Non invasive ventilation success. CONCLUSION: Improvement in clinical parameters like respiratory rate, heart rate, Oxygen saturation and improvement in ABG variables like pH, PaCO2 after 1st and 4 hours of start of Non invasive ventilation and maintaining the improvement at 24 hours are predictors of success of non-invasive ventilation in hypercapnic patients.

High flow nasal oxygen for acute type two respiratory failure: a systematic review.

Background: Acute type two respiratory failure (AT2RF) is characterized by high carbon dioxide levels (PaCO 2 >6kPa). Non-invasive ventilation (NIV), the current standard of care, has a high failure rate. High flow nasal therapy (HFNT) has potential additional benefits such as CO 2 clearance, the ability to communicate and comfort. The primary aim of this systematic review is to determine whether HFNT in AT2RF improves 1) PaCO 2, 2) clinical and patient-centred outcomes and 3) to assess potential harms. Methods: We searched EMBASE, MEDLINE and CENTRAL  (January 1999-January 2021). Randomised controlled trials (RCTs) and cohort studies comparing HFNT with low flow nasal oxygen (LFO) or NIV were included. Two authors independently assessed studies for eligibility, data extraction and risk of bias. We used Cochrane risk of bias tool for RCTs and Ottawa-Newcastle scale for cohort studies. Results: From 727 publications reviewed, four RCTs and one cohort study (n=425) were included. In three trials of HFNT vs NIV, comparing PaCO 2 (kPa) at last follow-up time point, there was a significant reduction at four hours (1 RCT; HFNT median 6.7, IQR 5.6 - 7.7 vs NIV median 7.6, IQR 6.3 - 9.3) and no significant difference at  24-hours or five days. Comparing HFNT with LFO, there was no significant difference at 30-minutes. There was no difference in intubation or mortality. Conclusions: This review identified a small number of studies with low to very low certainty of evidence. A reduction of PaCO 2 at an early time point of four hours post-intervention was demonstrated in one small RCT. Significant limitations of the included studies were lack of adequately powered outcomes and clinically relevant time-points and small sample size. Accordingly, systematic review cannot recommend the use of HFNT as the initial management strategy for AT2RF and trials adequately powered to detect clinical and patient-relevant outcomes are urgently warranted.

Novel destabilizing Dynactin variant (DCTN1 p.Tyr78His) in patient with Perry syndrome.

INTRODUCTION: Perry syndrome, also recognized as Perry disease, is a rare autosomal dominant disorder characterized by midlife-onset atypical parkinsonism, apathy or depression, respiratory failure and weight loss caused by a mutation in the Dynactin (DCTN1) gene. CASE DESCRIPTION: A fifty-six years-old adopted male presented with atypical parkinsonism with bradykinesia and postural instability, apathy, weight loss, and recurrent respiratory failure due to central hypoventilation requiring tracheostomy. METHODS AND RESULTS: Clinical workup revealed a novel DCTN1 p.Tyr78His variant. Using bioinformatic protein structure modeling, we compare our patient's variant to known DCTN1 mutations and predict protein stability of each variant at the CAP-Gly domain of p150Glued. All eight variants causing Perry syndrome, as well as Tyr78His, are located at site expected to interact with MAPRE1 tail and are predicted to be destabilizing. Variants causing atypical parkinsonism with incomplete Perry syndrome phenotype (K56R and K68E) are not significantly destabilizing in silico. CONCLUSION: We propose p.Tyr78His as the ninth pathogenic DCTN1 variant causing Perry syndrome. Bioinformatic protein modeling may provide additional window to understand and interpret DCTN1 variants, as we observed non-destabilizing variants to have different phenotype than destabilizing variants.

Barber's neck manipulation causing bilateral diaphragmatic paralysis and type-2 respiratory failure.

This is a case report of an unusual cause of bilateral diaphragmatic palsy. A 54-year-old gentleman, presented to us with exertional dyspnea and chest heaviness for the past 6 months which had increased in the last 6 days. Dyspnea increased on lying down. He was diagnosed as pneumonia on the basis of X-ray and chest CT scan, received treatment for the same and responded to the therapy. However, breathlessness and hypercapnia persisted. He had unexplained hypercapnia for which extensive investigations were carried out. Neurological and cardiac assessments were essentially normal. On revisit clinical examination, he was found to have paradoxical diaphragmatic movement with respiration. Ultrasound of chest detected no diaphragmatic movement. Detailed history elicited that patient was fond of neck massage and neck cracking wherein his barber would bend his neck with jerk to either side after a haircut.After considering all possible etiologies; we concluded that it was a case of diaphragm palsy induced by barber neck manipulation, leading to Type-2 respiratory failure. The fact that the vital clues to the diagnosis were elicited by detailed history and thorough examination reinforces that history and clinical examination for doctors shall remain a very important tool for clinical diagnosis.

Selective Type 2 Respiratory Failure Followed by Ocular Myasthenia Gravis Diagnosed by Ice Pack Test: A Case Report.

Myasthenia gravis is an autoimmune neuromuscular disorder that can present with skeletal muscle involvement, ocular muscles involvement and can progress to respiratory muscle paralysis. Here, we present a unique case of type 2 respiratory failure due to myasthenia gravis with the delayed ocular presentation. A 46-year-old female patient presented to the outpatient clinic with complaints of dyspnea. On further evaluation, she was found to be hypercapnic on arterial blood gas analysis with no muscular weakness in any of the limbs. The patient further progressed to ocular symptoms. With the use of an ice pack test, a bedside test for improvement of ptosis, the patient was diagnosed with myasthenic ptosis preventing further progression of type 2 respiratory failure and intubation. With this case report, we emphasize the critical role of such simple bedside test in timely diagnosis and management of myasthenia gravis while awaiting the final results.

Restrictive ventilatory impairment improved by laminoplasty for ossification of the posterior longitudinal ligament.

We report a woman with severe restrictive ventilatory impairment because of respiratory muscle paralysis caused by ossification of the posterior longitudinal ligament (OPLL). Laminoplasty improved her respiratory function and quality of life. Cervical myelopathy including OPLL should be considered as an important differential diagnosis in patients with respiratory dysfunction.

Long-term oxygen therapy in COPD patients: population-based cohort study on mortality.

Purpose: Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death worldwide and is associated with a growing and substantial socioeconomic burden. Long-term oxygen therapy (LTOT), recommended by current treatment guidelines for COPD patients with severe chronic hypoxemia, has shown to reduce mortality in this population. The aim of our study was to assess the standardized mortality ratios of incident and prevalent LTOT users and to identify predictors of mortality. Patients and methods: We conducted a 2-year follow-up population-based cohort study comprising all COPD patients receiving LTOT in the canton of Bern, Switzerland. Comparing age- and sex-adjusted standardized mortality ratios, we examined associations between all-cause mortality and patient characteristics at baseline. To avoid immortal time bias, data for incident (receiving LTOT <6 months) and prevalent users were analyzed separately. Results: At baseline, 475 patients (20% incident users, n=93) were receiving LTOT because of COPD (48/100,000 inhabitants). Mortality of incident and prevalent LTOT users was 41% versus 27%, respectively, p<0.007, and standardized mortality ratios were 8.02 (95% CI: 5.64-11.41) versus 5.90 (95% CI: 4.79-7.25), respectively. Type 2 respiratory failure was associated with higher standardized mortality ratios among incident LTOT users (60.57, 95% CI: 11.82-310.45, p=0.038). Conclusion: Two-year mortality rate of COPD patients on incident LTOT was somewhat lower in our study than in older cohorts but remained high compared to the general population, especially in younger patients receiving LTOT <6 months. Type 2 respiratory failure was associated with mortality.

What is the potential role of transcutaneous carbon dioxide in guiding acute noninvasive ventilation?

BACKGROUND: Transcutaneous carbon dioxide (PtcCO2 ) monitoring is rarely used in the acute hospital setting, where serial samples of arterial blood are instead taken to measure carbon dioxide tension (PaCO2 ). In this pilot observational study, we assessed the potential of PtcCO2 monitoring to calculate pH and guide management of acute noninvasive ventilation (NIV). METHODS: Ten subjects with acute hypercapnic respiratory failure were recruited. All had arterial lines placed to guide acute NIV. PtcCO2 was monitored for 12 h (TOSCA TCM4) and compared with PaCO2 . Noninvasive transcutaneous pH was determined from PtcCO2 and calculated bicarbonate and then compared with true arterial pH. Agreements between PCO2 and pH methods were assessed using Bland-Altman analysis of limits of agreement and Pearson correlation coefficients. Hypothetical adjustments to acute NIV settings were based on transcutaneous data alone and evaluated in comparison with true management. Pain scores for each method were compared using the Wilcoxon signed-rank test. RESULTS: PCO2 time trends were concordant. Mean PCO2 bias was -2.33 (95% limits of agreement of -9.60 to 5.03) mm Hg, and r = 0.89 (P < .001). Mean pH bias was 0.012 (95% limits of agreement of -0.070 to 0.094), and r = 0.84 (P < .001). Hypothetical clinical decisions based on transcutaneous data alone matched true management on 85% of 34 occasions. Initiation of transcutaneous monitoring was less painful than the arterial equivalent (P = .008). CONCLUSIONS: This pilot study demonstrates that PtcCO2 monitoring provides a continuous and reliable trend and also allows pH prediction. This patient-friendly approach is a promising alternative to repeated arterial blood gas sampling in patients requiring NIV for acute hypercapnic respiratory failure.

Clinical study of home noninvasive positive pressure ventilation treatment of silicosis patients with respiratory failure / 国际生物医学工程杂志

Objective To study the clinical application value of long term home noninvasive positive pressure ventilation in the therapy of silicosis patients with type 2 respiratory failure. Methods A total of 85 silicosis patients with type 2 respiratory failure were enrolled, and their clinical data were retrospectively analyzed. According to the therapeutic method, they were divided into noninvasive positive pressure ventilation group (group A) and basic therapy group (group B). The various indicators of the patients were analyzed before and after the treatment including vital signs, laboratory indicators, 6-minute walking distance (6MWD), and modified dyspnea index (mMRC). The admission times, length of hospital stay and annual mortality of the patients were also recorded by follow-up after the treatment for one year. Results After the one year follow-up, the heart rate, respiratory rate, PaO2, PaCO2, SO2％, 6MWD, and mMRC of group A were significantly improved than those of group B (all P<0.05). The admission times and the length of hospital stay of group A were lower than those group B (all P<0.05). There was no difference in the annual mortality between the two groups (P>0.05). Conclusions The therapeutic method of home noninvasive positive pressure ventilation has significant effects on silicosis combined with type 2 respiratory failure. It can improve clinical symptoms and the quality of life, and reduce the length of hospital stay and admission times, and reduced medical insurance burden.

Efficacy and safety of humidified high flow nasal cannula in chronic obstructive pulmonary disease complicated with type 2 respiratory failure patients after extubation: A randomized controlled trial / 第二军医大学学报

Objective: To compare the efficacy and safety between humidified high flow nasal cannula (HHFNC) and noninvasive positive pressure ventilation (NPPV) in patients with chronic obstructive pulmonary disease (COPD) complicated with type 2 respiratory failure after extubation. Methods: Seventy-two patients with COPD complicated with type 2 respiratory failure were enrolled after extubation and were randomized into HHFNC group and NPPV group at 1: 1 ratio, with 36 patients in each group. The blood gas analysis index, respiratory rate, heart rate, mean arterial pressure, reintubation rate, incidence of tracheotomy, intensive care unit stay, incidence of adverse events and mortality were compared between the two groups before treatment and 2, 12, 24 h after treatment. Results: The pH at 24 h, partial pressure of oxygen in artery (PaO2) at 2 h and 12 h, and oxygenation index (PaO2/FiO2) at 2 h and 12 h after treatment were significantly higher in the HHFNC group compared with the NPPV group (all P0.05), while the overall incidence of adverse events, intolerance rate, flatulence rate and aspiration rate were significantly lower in the HHFNC group than those in the NPPV group (all P 0.05). Conclusion: The short-time efficacy and safety of HHFNC are better than NPPV in treatment of COPD complicated with type 2 respiratory failure.

Observation on the Clinical Effect of Seretide and Noninvasive Positive Pressure Ventilation on the COPD Combined with Respiratory Failure / 现代生物医学进展

Objective:To analyze the clinical efficacy of Seretide combined with noninvasive positive pressure ventilation (NIPPV) in the treatment of chronic obstructive pulmonary disease (COPD) complicated with type 2 respiratory failure (RF).Methods:120 patients of COPD complicated with type 2 RF were randomly divided into the observation group and the control group.All patients were treated with routine,symptomatic and supportive treatment,based on that NIPPV was used in the control group,and the observation group was treated with Seretide on the basis of NIPPV.The levels of arterial blood gas,inflammatory factors,pulmonary function and CAPS score before and after treatment were compared and analyzed.Results:After treatment,the pH,PaO2 and SaO2 of both groups were significantly increased,PaCO2 levels weresignificantly decreased,serum IL-33,TNF-oα and sICAM-1 levels were significantly decreased,FVC,PEFR,FEV1％ and FEV1/FVC were significantly decreased,and the CAPS scores were significantly decreased;the changes of all the index mentioned above in the observation group were more statistically significant (P＜0.05).Conclusion:Seretide com bined with NIPPV could more effectively decrease the levels of inflammatory factors and improve the blood gas and lung function in the patients of COPD with type 2 respiratory failure.