Role of Prophylactic Noninvasive Ventilation in Patients at High Risk of Extubation Failure

How to cite this article: Singh L. Role of Prophylactic Noninvasive Ventilation in Patients at High Risk of Extubation Failure. Indian J Crit Care Med 2020;24(12):1158–1160.

Prolonged mechanical ventilation (MV) has serious side effects and complications. Thus, one opts for an early extubation after correcting the causes and stabilizing the patient.¹ Extubation is commonly uneventful especially in an odds ratio (OR) but in intensive care unit (ICU) it is often associated with respiratory failure development post post extubation which may very often require reintubation. The rule of thumb about reintubation risk cannot be applied to all patients as the pathophysiology of extubation failure is poorly understood.An average of 15% patients may need reintubation among which 25–30% are at high risk.¹ The high-risk patients of extubation failure include preterm infants, age ≥65 years, any respiratory disease, cardiac disease.² A major cause of weaning failure is acute respiratory failure (ARF) due to respiratory muscle fatigue or increased work of breathing due to decreased pulmonary compliance or increased resistance. Other causes include inadequate cough, airway obstruction, excess secretions, neurologic impairment. An important factor responsible for mortality in ICU patients after extubation is ARF. Noninvasive ventilation (NIV) is used for both management and prevention of post-extubation respiratory failure.After extubation, oxygenation can be improved by three methods available: conventional oxygen therapy, high-flow oxygen therapy, and NIV. Respiratory support is most commonly provided by conventional oxygen therapy. However, in recent years, high-flow oxygen therapy (HFOT) and NIV are being used increasingly. These methods are speculated to prevent extubation failure by promoting alveolar recruitment, preventing alveolar collapse, and reducing the work of breathing. Noninvasive ventilation (NIV) causes an increase in the intrathoracic pressure preventing alveolar collapse, improving oxygenation, and reducing the workload of the heart. It also prevents complications of invasive MV.³ The protocol of using prophylactic NIV can involve the immediate application of NIV within 1 hour of extubation for a duration of 8–24 hours depending upon the improvement in the respiratory parameters, such as, respiratory rate, pH, partial pressures of oxygen, and carbon dioxide. The prophylactic use of NIV has been adopted for reducing the rates of reintubation, duration of MV, and improving the overall prognosis of patients at high risk of post-extubation failure.^1,3–5The International Consensus Conference in intensive care medicine in 2001 suggested that NIV is a promising therapy to prevent respiratory failure after weaning.⁶ It can ameliorate some of the pathophysiologic derangements that occur following extubation. It has been used as an adjunct to weaning or as a part of early extubation approach.Since the need for reintubation has been associated with significantly poor outcomes in terms of prolongation of the ICU stay, hospital stay, use of MV and its associated complications like pneumonia and lung damage, the requirement of tracheotomy, and financial implications, two studies have used different methods for preventing it; among which the prophylactic use of NIV has been found to be is successful.^4,5,7 The successful use of prophylactic NIV has been most pronounced in high-risk patients of extubation failure.⁸ Post-extubation respiratory failure and reintubation prevention by using NIV is supported by weak evidence. NIV can decrease reintubation rates was concluded in two meta-analyses, but these studies had both high risk (only 35%) as well as the general population.^9,10 NIV compared to with conventional oxygen therapy in ICU patients at high risk of reintubation was found to be more effective.⁴ However, a meta-analysis conducted in 2014 with 1,382 patients found that the use of NIV as a preemptive measure after extubation or after respiratory failure which developed post-extubation was not beneficial either in reducing mortality or intubation rate.¹⁰Liu et al.³ found that prophylactic NIV brings about a significant reduction in the atelectasis (OR = 0.43, p = 0.02) and rate of reintubation (OR = 0.33, p = 0.02). The reduction in atelectasis rate is an additional advantage since the development of atelectasis is associated with further complications, such as, pneumonia and atelectrauma.¹¹ One of the previous review studies backed up the improved outcomes of the use of prophylactic NIV in major abdominal surgeries.¹² This was even seen on the patients undergoing cardiothoracic surgeries where prophylactic NIV reduced the rate of reintubation.¹³ In a landmark study by Thille et al.¹ which compared the use of prophylactic NIV in 150 high-risk extubated patients with 83 control extubated patients in an ICU setting, there was a significant reduction in reintubation in the study group (15% vs 28%, p = 0.02). The study is important since it included high-risk patients with cardiac disease and respiratory disease, and found that prophylactic NIV was an independent predictor of extubation success. Their findings were backed up by two studies prior to before it which showed a significant reduction in the reintubation from 24 to 8%, p = 0.027 and from 39 to 5%, p = 0.016, respectively.^4,5In an RCT, Ferrer et al.¹⁴ concluded that early use of NIV averted respiratory failure after extubation and decreased mortality in high-risk patients. Another RCT of 648 patients at high risk of extubation failure concluded that the use of high-flow nasal oxygen with NIV immediately after extubation significantly decreased the risk of reintubation.¹⁵ Nava et al. in a randomized controlled trial studied the use of prophylactic NIV in patients at high risk of extubation failure following at least 48 hours of invasive ventilation and extubation after a successful spontaneous breath trial. They observed that the rate of reintubation was significantly lower in the prophylactic NIV group (8%) compared to with the control group (24%) and NIV was associated with significantly lower ICU mortality and ICU length of stay.⁴ Ferrer et al.¹⁴ applied NIV immediately post-extubation, with age >65 years and APACHE II score >12 at extubation as a factor for high risk of extubation failure and observed that post-extubation respiratory failure was lower in the NIV group (16% vs 33%) but there was no difference in the rate of re-intubation and ICU mortality and 90-days mortality was significantly lower in NIV group. Ferrer et al. in their RCT, used prophylactic NIV in patients with underlying chronic respiratory illness and hypercapnia at extubation. Prophylactic NIV was associated with lower respiratory failure at 48 hours post-extubation and significantly lower 90-day mortality.¹⁶In this issue, Ghosh et al.¹⁷ studied outcomes of prophylactic NIV at extubation after a planned extubation, in patients at a high risk of extubation failure. They observed extubation success in 88.2% of patients at 72 hours. Higher age, longer duration of invasive ventilation, and higher SOFA score at extubation were the factors associated with extubation failure. They also observed organ failure and higher cumulative fluid balance in the first 72 hours post-extubation in the extubation failure group. Ghosh et al.¹⁷ and Upadya et al.¹⁸ observed in their studies that higher cumulative fluid balance at extubation was an independent risk factor for extubation failure in patients after planned extubation.Among the newer modalities, Ali et al.¹⁹ studied the use of nasal high-frequency oscillatory ventilation (NHFOV) as a prophylactic NIV or “rescue mode of NIV” after extubation. The NHFOV is a “noninvasive ventilation mode that applies an oscillatory pressure waveform to the airways using a nasal interface”. The results were promising which showed a decreased requirement of reintubation. It is suggested that NHFOW may be a feasible modality that in is being used as prophylactic NIV following extubation for the prevention of apnea and reintubation. But still, the practical applications need randomized controlled trials to lay down the indications and guidelines for its use in other populations. Prophylactic NIV has emerged as an promising modality and its practical use is welcome. Its efficacy has been seen in diverse age groups ranging from pediatric to adults to elderly.Appropriate patient selection, i.e., those who are at high risk of extubation failure is important, because it is not useful in low-risk patients, but also that its use may be detrimental in some patients.     

Spiked helmet sign: An under-recognized electrocardiogram finding in critically ill patients

A 77-year-old male patient presented with rhabdomyolysis. He developed progressive respiratory failure and acute respiratory distress syndrome during his hospital stay requiring mechanical ventilation. An electrocardiogram during mechanical ventilation showed findings suggestive of ST elevation myocardial infarction. Closer review showed dome and spike findings that have been likened to a “spiked helmet.” This finding has been associated with significant mortality. We discuss this under-recognized finding and the potential contributing mechanisms.     

A rare case of leptospirosis with isolated lung involvement

Leptospirosis is a zoonosis caused by a pathogenic spirochete “leptospira interrogans.” Severe form of leprospira infection is usually associated with jaundice and renal involvement, leading to major hemorrhagic complications. Lung involvement can vary from subtle clinical features to deadly pulmonary hemorrhage and acute respiratory distress syndrome (ARDS). We recently managed a case of leptospirosis with isolated lung involvement as alveolar hemorrhage and ARDS. Our patient had acute febrile illness with respiratory symptoms associated with radiological picture of pulmonary hemorrhage. Patient was managed with noninvasive ventilation with high flow oxygen, antibiotic and pulse steroids therapy. In conclusion, leptospirosis can present with predominant pulmonary involvement, instead of the classical triad of Weil disease. High index of suspicion should be kept in acute febrile illness patients with respiratory symptoms and alveolar hemorrhage. Early diagnosis and management with oxygenation, antibiotics and immunosuppresents can prevent complications and mortality.     

The implementation of a nurse-provided, ward-based bilevel non-invasive ventilation service

Bilevel non-invasive ventilation (NIV) is now standard of care for patients with acute hypercapnic respiratory failure (AHRF), and has an increasing role to play in patients with stable chronic hypercapnic respiratory failure (CHRF). The institution of an NIV service in a hospital setting requires major infrastructural and multidisciplinary input to be effective. This paper describes our experiences in setting up a 24-hour, nurse-provided, ward-based NIV service in a new acute teaching hospital in Dublin over a 39-month period. In addition, we provide audit data on 78 patients with AHRF treated with NIV by this service over this time period. The majority of patients (65) had their respiratory acidosis corrected and were discharged home; 11 patients failed NIV and were intubated and mechanically ventilated in the ITU; 13 patients died, 8 from respiratory causes and 5 from non-respiratory causes, indicating the critical nature of this condition.     

A study on the role of noninvasive ventilation in mild-to-moderate acute respiratory distress syndrome

Aim:There is sparse data on the role of noninvasive ventilation (NIV) in acute respiratory distress syndrome (ARDS) from India. Herein, we report our experience with the use of NIV in mild to moderate ARDS.Results:A total of 41 subjects (27 women, mean age: 30.9 years) were included in the study. Tropical infections followed by abdominal sepsis were the most common causes of ARDS. The use of NIV was successful in 18 (44%) subjects, while 23 subjects required intubation. The median time to intubation was 3 h. Overall, 19 (46.3%) deaths were encountered, all in those requiring invasive ventilation. The mean duration of ventilation was significantly higher in the intubated patients (7.1 vs. 2.6 days, P = 0.004). Univariate analysis revealed a lack of improvement in PaO₂/FiO₂ at 1 h and high baseline Acute Physiology and Chronic Health Evaluation II (APACHE II) as predictors of NIV failure.Conclusions:Use of NIV in mild to moderate ARDS helped in avoiding intubation in about 44% of the subjects. A baseline APACHE II score of >17 and a PaO₂/FiO₂ ratio <150 at 1 h predicts NIV failure.     

Early non-invasive ventilation treatment for severe influenza pneumonia

The role of non-invasive ventilation (NIV) in acute respiratory failure caused by viral pneumonia remains controversial. Our objective was to evaluate the use of NIV in a cohort of (H1N1)v pneumonia. Usefulness and success of NIV were assessed in a prospective, observational registry of patients with influenza A (H1N1) virus pneumonia in 148 Spanish intensive care units (ICUs) in 2009–10. Significant variables for NIV success were included in a multivariate analysis. In all, 685 patients with confirmed influenza A (H1N1)v viral pneumonia were admitted to participating ICUs; 489 were ventilated, 177 with NIV. The NIV was successful in 72 patients (40.7%), the rest required intubation. Low Acute Physiology and Chronic Health Evaluation (APACHE) II, low Sequential Organ Failure Assessment (SOFA) and absence of renal failure were associated with NIV success. Success of NIV was independently associated with fewer than two chest X-ray quadrant opacities (OR 3.5) and no vasopressor requirement (OR 8.1). However, among patients with two or more quadrant opacities, a SOFA score ≤7 presented a higher success rate than those with SOFA score >7 (OR 10.7). Patients in whom NIV was successful required shorter ventilation time, shorter ICU stay and hospital stay than NIV failure. In patients in whom NIV failed, the delay in intubation did not increase mortality (26.5% versus 24.2%). Clinicians used NIV in 25.8% of influenza A (H1N1)v viral pneumonia admitted to ICU, and treatment was effective in 40.6% of them. NIV success was associated with shorter hospital stay and mortality similar to non-ventilated patients. NIV failure was associated with a mortality similar to those who were intubated from the start.     

Domiciliary non-invasive ventilation and the quality of life outcome of patients suffering from chronic respiratory failure

Non-invasive ventilation assists breathing and hence improves oxygenation in patients with respiratory failure. Its role in the hospital is well established. Our study examined whether Non-invasive ventilation improves the quality of life in patients with chronic respiratory failure treated in the community. We followed up 17 patients suffering from chronic respiratory failure due to various medical conditions who were treated with community-based non-invasive ventilation. The diagnostic categories were severe kyphoscoliosis (2), healed pulmonary T.B plus lobectomy/pneumonectomy (4), healed pulmonary T.B with thoracoplasty and severe kyphoscoliosis (3), severe COAD (5) and muscular dystrophy (3). Activities of daily life (ADL) of all these patients had been affected by chronic respiratory failure. Quality of life (QOL) assessment both Pre and Post NIV was made using the Chronic Respiratory Disease Questionnaire (CRDQ). The arterial blood gases were used as an objective measure in these patients. The mean dyspnoea score was (pre and post) 3.47 and 4.76 (p = .0003), Emotional Function 3.24 and 4.65 (p = 0), Fatigue was 3.00 and 4.74 (p = .0003), Mastery 3.22 and 4.5(p = .0003) respectively. The median CRDQ score (pre and post NIV) was 12.94 and 19.04 (p =.0001). The mean paCO2 (pre and post-NIV) was 7.70 kpa and 6.44 kPa (p = .0001), the mean paO2 was 6.79 kpa and 9.39 kpa (p < .003). Conclusions: The data in our study showed that community-based NIV significantly improved Quality Of Life (QOL) including dyspnoea, fatigue, mastery, emotional function as well as arterial blood gases.     

Quantitative Segmentation Analysis of the Radiological Changes by Using ITK-SNAP: Risk Assessment of the Severity and Recurrence of Medication-related Osteonecrosis of the Jaw

Background and purpose: Medication-related osteonecrosis of the jaw (MRONJ) severely impairs patients'' quality of life and is remarkably refractory to treatment. There are lots of studies about identification of the radiographic features of MRONJ, yet reports about quantitative radiographic analysis for the risk assessment of the severity and recurrence of MRONJ are rarely heard. The aim of this study was to investigate the volumes of osteolytic lesions and radiodensity values of osteosclerotic lesions in MRONJ patients by using ITK-SNAP for severity prediction and prognosis evaluation.Materials and methods: Of 78 MRONJ patients (78 lesions) involved in this retrospective study, 53 were presented as osteolytic lesions and 25 were presented as osteosclerotic changes alone. Comprehensive CBCT images, demographics and clinical data of patients were investigated. The volumetric analysis and radiodensity measurement were performed by ITK-SNAP. SPSS 25.0 were used for statistical analysis.Results: The osteolytic lesion volumes in MRONJ patients receiving intravenous bisphosphonates (P=0.004) and patients without osteoporosis (P=0.027) were significantly large. No significant correlation between the volumes and bisphosphonates duration was found (P=0.094). The radiodensity values of osteosclerotic lesions was significantly correlated with bisphosphonates duration (P=0.040). The surrounding area of post-surgical lesions in MRONJ patients with recurrence showed significantly great radiodensity values (P=0.025). No significant correlation between the radiodensity values and the transformation from osteosclerotic lesions to osteolytic lesions was observed (P=0.507).Conclusion: MRONJ patients receiving intravenous bisphosphonates develop into large volumes of osteolytic lesions more easily. Long-term bisphosphonates duration is possibly related with higher bone density of osteosclerotic lesions, while higher density is not associated with the transformation from osteosclerotic lesions to osteolytic lesions. A rise of bone mineral density nearby post-surgical lesions is probably a predictor for MRONJ recurrence.     

A multicentered study on efficiency of noninvasive ventilation procedures(SAFE-NIV)

Background/aim To characterize the clinical course of noninvasive positive pressure ventilation (NIPPV) and high flow humidified nasal cannula ventilation (HFNC) procedures; perform risk analysis for ventilation failure.Material and methodsThis prospective, multi-centered, observational study was conducted in 352 PICU admissions (1 month-18 years) between 2016 and 2017. SPSS-22 was used to assess clinical data, define thresholds for ventilation parameters and perform risk analysis.Results Patient age, onset of disease, previous intubation and hypoxia influenced the choice of therapy mode: NIPPV was preferred in older children (p = 0.002) with longer intubation (p < 0.001), ARDS (p = 0.001), lower respiratory tract infections (p < 0.001), chronic respiratory disease, (p = 0.005), malignancy (p = 0.048) and immune deficiency (p = 0.026). The failure rate was 13.4%. sepsis, ARDS, prolonged intubation, and use of nasal masks were associated with NIV failure (p = 0.001, p < 0.001, p < 0.001, p = 0.025). The call of intubation or re-intubation was given due to respiratory failure in twenty-seven (57.5%), hemodynamic instability in eight (17%), bulbar dysfunction or aspiration in 5 (10.6%), neurological deterioration in 4 (8.5%) and developing ARDS in 3 (6.4%) children. A reduction of less than 10% in the respiration within an hour increased the odds of failure by 9.841 times (OR: 9.841, 95% CI: 2.0021–48.3742). FiO2 > 55% at 6th hours and PRISM-3 >8 were other failure predictors. Of the 9.9% complication rate, the most common complication was pressure ulcerations (4.8%) and mainly observed when using full-face masks (p = 0.047). Fifteen (4.3%) patients died of miscellaneous causes. Tracheostomy cannulation was performed on 16 children due to prolonged mechanical ventilation (8% in NIPPV, 2.6% in HFNC)ConclusionAbsence of reduction in the respiration rate within an hour, FiO2 requirement >55% at 6th hours and PRISM-3 score >8 predict NIV failure.     

Respiratory hyperinfection caused by Strongyloides stercoralis in a patient with pemphigus vulgaris and minireview on diagnosis and treatment of strongyloidiasis

We explain a case of strongyloidiasis in a woman with pemphigus vulgaris from the north of Iran. The patient, aged 59 years old, had been receiving immunosuppressive therapy (oral prednisone) for the last 1 year. She presented with a recent history of diarrhea, epigastric pain, vomiting, fever, loss of consciousness, and respiratory failure. Biochemical and hematological findings were abnormal, and eosinophilia was remarkable. Bronchoscopic alveolar lavage and stool examination revealed larval forms of Strongyloides stercoralis as well as severe acute inflammation. A chest X-ray revealed alveolar opacity in the bilateral mid- and lower zones and bilateral blunting of the costopherenic angle. The high-resolution computed tomography findings showed diffuse ground glass and alveolar opacity, bilateral pleural effusion, and multiple cavitary lesions in mid- and lower zones of the lung. The patient responded well to the treatment with ivermectin plus albendazole.     

Idiopathic diaphragmatic paralysis—Satisfactory improvement of inspiratory muscle function by inspiratory muscle training

Daily inspiratory muscle strength and endurance training (IMT) was performed in a 44-year-old patient with idiopathic bilateral diaphragmatic paralysis (BDP) in addition to nocturnal non-invasive ventilation (NIV). After 4 months of training inspiratory muscle function improved satisfactorily whereas phrenic nerve latency remained pathological. Due to the improvement of inspiratory muscle capacity nocturnal NIV could be stopped without inducing nocturnal respiratory insufficiency.     

Acute concentrated phenol dermal burns: Complications and management

Phenol burns can result in multiple organ failure. This is a case report of acute severe phenol dermal burn after accidental splash of 94% phenol on 35-year-old patient''s body who was brought to hospital after 90 min of exposure. Decontamination was done with high-density water and glycerol. Early complications in form of metabolic acidosis and acute renal failure required hemodialysis. Extensive protein denaturation was managed with IV albumin and high protein diet. Patient also developed pleural effusion and acute respiratory distress syndrome, but these were successfully managed by intercostal drain tube insertion and noninvasive ventilation. The patient survived after multiple organ failures and widespread burns despite the fact that it has been observed that outcome of phenol burns with >60² inches of skin affected or two or more organs failure involving renal system is nearly fatal.     

无创通气对老年重度心力衰竭患者血浆脑钠素、内皮素-1和血管紧张素II水平的影响

探讨老年重度心力衰竭时血浆脑钠素（brain natriuretic peptide,BNP）、内皮素-1（endothelin—1,ET-1）和血管紧张素II（angiotensin II,AngII）水平的变化及无创通气（non—invasive ventilation,NIV）对其影响。老年重度心力衰竭患者42例,随机分为无创通气（NIV）治疗组（21例）和常规治疗组（21例）。常规治疗组为强心、利尿剂、血管扩张剂等药物并加用鼻导管给氧治疗;NIV治疗组为在常规治疗同时加用NIV治疗,分别观察治疗3～5天后两组患者临床症状、体征、心率（HR）、呼吸频率（RR）、血压、血气分析和左室射血分数（left vertricular ejection fraction,LVEF）,以及血浆BNP、ET-1和AngII的变化。结果显示,与常规治疗组比较,NIV组治疗3～5天后,患者临床症状与体征改善明显,其SaO2、PaO2和LVEF显著升高（P〈0．05）,HR、RR显著下降（P〈0．05）。NIV治疗后血浆BNP、ET-1和AngII水平随心衰的纠正而显著降低（P〈0．01）,与LVEF呈显著负相关（P〈0．01）。结论：NIV在改善老年重度心力衰竭患者心功能同时,也降低患者血浆BNP、ET-1和AngII水平,NIV对老年重度心力衰竭患者神经内分泌的影响可能在治疗过程中发挥一定作用。     

Clustering Patterns of Comorbidities Associated with In-Hospital Death in Hospitalizations of US Adults with Venous Thromboembolism

Background: Venous thromboembolism (VTE) is a significant source of mortality, morbidity, disability, and impaired health-related quality of life in the world.Objective: We aimed to evaluate the clustering patterns and associations of 29 comorbidities with in-hospital death among adult hospitalizations with a diagnosis of VTE in the United States by analyzing data from the 2009 Nationwide Inpatient Sample.Methods: This cross-sectional study included 153,124 adult hospitalizations with a diagnosis of VTE. Adjusted rate ratios and 95% confidence intervals (CI) for in-hospital death were generated by using multivariable log-linear regression models to measure independent associations between comorbidities and in-hospital death.Results: We estimated that 44,200 in-hospital deaths occurred in 2009 among 773,273 US adult hospitalizations with a diagnosis of VTE. Subgroups of hospitalizations with comorbidities of “congestive heart failure,” “chronic pulmonary disease,” “coagulopathy,” “liver disease,” “lymphoma,” “fluid and electrolyte disorders,” “metastatic cancer,” “peripheral vascular disorders,” “pulmonary circulation disorders,” “renal failure,” “solid tumor without metastasis,” or “weight loss” were positively and independently associated with 1.07 (95% CI: 1.02-1.12 ) to 2.06 (95% CI: 1.97-2.16) times increased likelihoods of in-hospital death, when compared to those without the corresponding comorbidities. The clustering patterns of these comorbidities by 4 disease categories (i.e., “cancer,” “cardiovascular/respiratory/blood,” “gastrointestinal/urologic,” and “nutritional/bodyweight”) were associated with 2.74 to 10.28 times increased likelihoods of in-hospital death, as compared to hospitalizations without any of these comorbidities. The overall increase in the cumulative number of comorbidities corresponded to significantly elevated risks (P-trend<0.01) for in-hospital death among hospitalizations with a diagnosis of VTE.Conclusion: The presence of multiple comorbidities is ubiquitous among hospitalizations of adults with VTE and among in-hospital deaths with VTE in the United States. The findings of our study further suggest that, among hospitalizations of adults with VTE, the presence of certain comorbidities or clustering of these comorbidities significantly elevates the risk of in-hospital death.     

Using respiratory rate and thoracic movement to assess respiratory insufficiency in amyotrophic lateral sclerosis: a preliminary study

Background

Hypoventilation due to respiratory insufficiency is the most common cause of death in amyotrophic lateral sclerosis (ALS) and non-invasive ventilation (NIV) can be used as a palliative treatment. The current guidelines recommend performing spirometry, and recording nocturnal oxyhemoglobin saturation and arterial blood gas analysis to assess the severity of the hypoventilation. We examined whether the respiratory rate and thoracic movement were reliable preliminary clinical signs in the development of respiratory insufficiency in patients with ALS.

Methods

We measured the respiratory rate and thoracic movement, performed respiratory function tests and blood gas analysis, and recorded subjective hypoventilation symptoms in 42 ALS patients over a 7-year period. We recommended NIV if the patient presented with hypoventilation matching the current guidelines. We divided patients retrospectively into two groups: those to whom NIV was recommended within 6 months of the diagnosis (Group 1) and those to whom NIV was recommended 6 months after the diagnosis (Group 2). We used the Mann Whitney U test for comparisons between the two groups.

Results

The mean partial pressure of arterial carbon dioxide in the morning in Group 1 was 6.3 (95% confidence interval 5.6–6.9) kPa and in Group 2 5.3 (5.0–5.6) kPa (p = 0.007). The mean respiratory rate at the time of diagnosis in Group 1 was 21 (18–24) breaths per minute and 16 (14–18) breaths per minute in Group 2 (p = 0.005). The mean thoracic movement was 2.9 (2.2–3.6) cm in Group 1 and 4.0 (3.4–4.8) cm in Group 2 (p = 0.01). We observed no other differences between the groups.

Conclusions

Patients who received NIV within six months of the diagnosis of ALS had higher respiratory rates and smaller thoracic movement compared with patients who received NIV later. Further studies with larger numbers of patients are needed to establish if these measurements can be used as a marker of hypoventilation in ALS.

     

Erdheim-Chester disease with extensive marrow necrosis: a case report and literature review

Erdheim-Chester disease is a rare systemic disorder characterized by a fibrosing xanthogranulomatous infiltration of multiple organs. We report a case of Erdheim-Chester disease with diffuse necrosis leading to difficulty in making a prompt diagnosis. Radiologically, osteosclerotic lesions with osteolytic element involved metadiaphyses of both proximal tibia, and retroperitoneal infiltrations encasing both kidneys, both adrenals, and aorta were found. A biopsy of the tibia showed diffuse infiltration of foamy histiocytes, Touton-type giant cells, and fibroblastic cells associated with extensive coagulative necrosis. Immunohistochemically, foamy histiocytes were positive for CD68 and peanut agglutinin and negative for S-100 protein. A few Langerhans' cells, which were difficult to identify in hematoxylin-eosin stain, were highlighted by immunostain for S-100 protein. The patient received supportive therapy and was alive 1 1/2 years after diagnosis, with newly developed bilateral retrobulbar lesions and worsened heart failure.     

Lethal persistent pulmonary hypertension of the newborn in Bohring–Opitz syndrome

Bohring–Opitz syndrome (BOS) is a rare disease with a number of characteristic features, including hypertelorism, prominent metopic suture, exophthalmos, cleft palate, abnormal posture, and developmental retardation. Here, we report a BOS patient presenting with lethal persistent pulmonary hypertension of the newborn (PPHN) and inspiratory respiratory failure. The female infant was treated with nitric oxide and vasodilator, which did not improve her condition. The inspiratory respiratory failure required management with deep sedation. She died on postnatal day 60 due to progressed heart failure. Whole exome sequencing revealed de novo mutation in the ASXL1 gene, c.1934dupG, p.Gly646TrpfsTer12.     

POEMS syndrome--a case report.

POEMS syndrome is a multisystem disorder associated with polyneuropathy, organomegaly, endocrinopathy, a monoclonal protein (M-protein), and skin changes. The authors describe a patient with POEMS syndrome who had osteosclerotic myeloma confirmed by open bone biopsy. Magnetic resonance imaging (MRI) showed discrete lesions of low signal intensity in both T1 and T2-weighted images. This patient is now being successfully treated with melphalan and prednisone with much improvement in skin thickening and sensory change in the lower extremities.     

Corona viruses: reaching far beyond the common cold

BackgroundHuman coronaviruses (HCoVs) are one of the most common causes of the “common cold”. Some HCoV strains, however, can cause fatal respiratory disease. Some examples of these diseases are severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), and Coronavirus Disease 19 (COVID-19). This article will review the etiology, clinical features, diagnosis, and management of HCoVs.MethodsA systematic literature review was performed using the terms “human coronaviruses”, “MERS-CoV”, “SARSCoV”, “SARS-CoV2”, “COVID-19”, and “common cold” in OVID MEDLINE, PubMed, and Cochrane Library.FindingsMost HCoVs cause mild upper respiratory infections which resolve with supportive care and no sequelae. In recent decades, however, there have been outbreaks of novel HCoVs that cause more severe disease. This is largely due to HCoVs having large genomes which undergo frequent recombination events, leading to the emergence of novel and more virulent strains of the virus. These severe respiratory illnesses can lead to acute respiratory distress requiring invasive intervention, such as mechanical ventilation. These severe infections can lead to long-lasting sequelae in patients. Scientists continue to investigate potential treatments for these viruses, though supportive care remains the gold standard. Scientists have succeeded in developing numerous vaccines for the SARS-CoV-2 virus, and ongoing data collection and analysis will shed even more light on the next steps in fighting the COVID-19 pandemic.ConclusionDue to the frequency of recombination events and the subsequent emergence of novel strains, HCoVs are becoming more prevalent, making them a global health concern as they can lead to epidemics and pandemics. Understanding the epidemiology, etiology, clinical features, diagnosis, and management of HCoVs is important, especially during this worldwide pandemic.