Severe Hypoxemia Research Articles

Arousal characteristics in different OSAHS populations

Objective:This study sought to explore the effect of age on arousal index in patients with OSAHS, and the significance of arousal index among different phenotypes identified through cluster analysis according to clinical symptoms and complications. Methods:A total of 607 adult patients with OSAHS who received polysomnography in the Second Affiliated Hospital of Xi'an Jiaotong University from July 2020 to July 2021 were selected. All patients registered basic human data, symptoms, complaints and complications, completed the Epworth Sleepiness Scale. We explored the distribution of several PSG parameters in different age groups, and included typical symptoms and complications into cluster analysis to explore the parameter differences in patients with different phenotypes. Results:Young patients had the lowest arousal index and arousal frequency in NREM stage, in middle-aged patients, the arousal index was relatively higher, the arousal times during NREM with oxygen desaturation were the highest. Among elderly patients, the wakefulness after sleep onset（WASO） was the longest, the arousal times in REM sleep was the lowest, and the spontaneous arousal times in NREM sleep were the highest（P<0.05）. Among the 3 types according to the cluster analysis, phenotype Ⅰwas characterised by maximally complications, excessive daytime sleepiness and obesity, while memory and attention impairment were obvious in phenotype Ⅱ. Phenotype Ⅲhad minimal complications, relatively better mental state with shorter time-course of snoring and apnea. Phenotype I differed significantly by higher severity, more severe hypoxemia, higher arousal index and longer WASO time（P<0.05）. Conclusion:the arousal index distribution varies among OSAHS patients with different age, and cluster analysis shows that patients with severe symptoms and more complications tend to have higher arousal index.

Defining Physiological Decompensation: An Expert Consensus and Retrospective Outcome Validation.

OBJECTIVES:Physiological decompensation of hospitalized patients is common and is associated with substantial morbidity and mortality. Research surrounding patient decompensation has been hampered by the absence of a robust definition of decompensation and lack of standardized clinical criteria with which to identify patients who have decompensated. We aimed to: 1) develop a consensus definition of physiological decompensation and 2) to develop clinical criteria to identify patients who have decompensated.DESIGN:We utilized a three-phase, modified electronic Delphi (eDelphi) process, followed by a discussion round to generate consensus on the definition of physiological decompensation and on criteria to identify decompensation. We then validated the criteria using a retrospective cohort study of adult patients admitted to the Hospital of the University of Pennsylvania.SETTING:Quaternary academic medical center.PATIENTS:Adult patients admitted to the Hospital of the University of Pennsylvania who had triggered a rapid response team (RRT) response between January 1, 2019, and December 31, 2020.INTERVENTIONS:None.MEASUREMENTS AND MAIN RESULTS:Sixty-nine experts participated in the eDelphi. Participation was high across the three survey rounds (first round: 93%, second round: 94%, and third round: 98%). The expert panel arrived at a consensus definition of physiological decompensation, “An acute worsening of a patient’s clinical status that poses a substantial increase to an individual’s short-term risk of death or serious harm.” Consensus was also reached on criteria for physiological decompensation. Invasive mechanical ventilation, severe hypoxemia, and use of vasopressor or inotrope medication were bundled as criteria for our novel decompensation metric: the adult inpatient decompensation event (AIDE). Patients who met greater than one AIDE criteria within 24 hours of an RRT call had increased adjusted odds of 7-day mortality (adjusted odds ratio [aOR], 4.1 [95% CI, 2.5–6.7]) and intensive care unit transfer (aOR, 20.6 [95% CI, 14.2–30.0]).CONCLUSIONS:Through the eDelphi process, we have reached a consensus definition of physiological decompensation and proposed clinical criteria with which to identify patients who have decompensated using data easily available from the electronic medical record, the AIDE criteria.

Identifying modifiable risk factors for mortality in children aged 1–59 months admitted with WHO-defined severe pneumonia: a single-centre observational cohort study from rural Malawi

ObjectiveAlthough HIV infection, severe malnutrition and hypoxaemia are associated with high mortality in children with WHO-defined severe pneumonia in sub-Saharan Africa, many do not have these conditions and yet mortality...

Long-term outcomes of dexamethasone 12mg versus 6mg in patients with COVID-19 and severe hypoxaemia.

PurposeWe assessed long-term outcomes of dexamethasone 12 mg versus 6 mg given daily for up to 10 days in patients with coronavirus disease 2019 (COVID-19) and severe hypoxaemia.MethodsWe assessed 180-day mortality and health-related quality of life (HRQoL) using EuroQoL (EQ)-5D-5L index values and EQ visual analogue scale (VAS) in the international, stratified, blinded COVID STEROID 2 trial, which randomised 1000 adults with confirmed COVID-19 receiving at least 10 L/min of oxygen or mechanical ventilation in 26 hospitals in Europe and India. In the HRQoL analyses, higher values indicated better outcomes, and deceased patients were given a score of zero.ResultsWe obtained vital status at 180 days for 963 of 982 patients (98.1%) in the intention-to-treat population, EQ-5D-5L index value data for 922 (93.9%) and EQ VAS data for 924 (94.1%). At 180 days, 164 of 486 patients (33.7%) had died in the 12 mg group versus 184 of 477 (38.6%) in the 6 mg group [adjusted risk difference − 4.3%; 99% confidence interval (CI) − 11.7–3.0; relative risk 0.89; 0.72–1.09; P = 0.13]. The adjusted mean differences between the 12 mg and the 6 mg groups in EQ-5D-5L index values were 0.06 (99% CI − 0.01 to 0.12; P = 0.10) and in EQ VAS scores 4 (− 3 to 10; P = 0.22).ConclusionAmong patients with COVID-19 and severe hypoxaemia, dexamethasone 12 mg compared with 6 mg did not result in statistically significant improvements in mortality or HRQoL at 180 days, but the results were most compatible with benefit from the higher dose.Supplementary InformationThe online version contains supplementary material available at 10.1007/s00134-022-06677-2.

Science, Medicine, and the Anesthesiologist

Science, Medicine, and the Anesthesiologist

Prediabetes Is Associated with Increased Prevalence of Sleep-Disordered Breathing.

Type 2 diabetes leads to severe nocturnal hypoxemia, with an increase in apnea events and daytime sleepiness. Hence, we assessed sleep breathing parameters in the prediabetes stage. A cross-sectional study conducted on 966 middle-aged subjects without known pulmonary disease (311 patients with prediabetes and 655 controls with normal glucose metabolism) was conducted. Prediabetes was defined by glycated hemoglobin (HbA1c), and a nonattended overnight home sleep study was performed. Participants with prediabetes (n = 311) displayed a higher apnea–hypopnea index (AHI: 12.7 (6.1;24.3) vs. 9.5 (4.2;19.6) events/h, p < 0.001) and hypopnea index (HI: 8.4 (4.0;14.9) vs. 6.0 (2.7;12.6) events/h, p < 0.001) than controls, without differences in the apnea index. Altogether, the prevalence of obstructive sleep apnea was higher in subjects with prediabetes than in controls (78.1 vs. 69.9%, p = 0.007). Additionally, subjects with prediabetes presented impaired measurements of the median and minimum nocturnal oxygen saturation, the percentage of time spent with oxygen saturations below 90%, and the 4% oxygen desaturation index in comparison with individuals without prediabetes (p < 0.001 for all). After adjusting for age, sex, and the presence of obesity, HbA1c correlated with the HI in the entire population (r = 0.141, p < 0.001), and the presence of prediabetes was independently associated with the AHI (B = 2.20 (0.10 to 4.31), p = 0.040) as well as the HI (B = 1.87 (0.61 to 3.14), p = 0.004) in the multiple linear regression model. We conclude that prediabetes is an independent risk factor for an increased AHI after adjusting for age, sex, and obesity. The enhanced AHI is mainly associated with increments in the hypopnea events.

Segmental Bronchoalveolar Lavage Provided a Favorable Clinical Course in a Case of Autoimmune Pulmonary Alveolar Proteinosis

A 49-year-old man was diagnosed with autoimmune pulmonary alveolar proteinosis. Chest computed tomography (CT) showed typical CT findings of pulmonary alveolar proteinosis: thickening of septa with ground-glass opacities in both lung fields. The diagnosis of autoimmune pulmonary alveolar proteinosis (PAP) was based on findings of bronchoalveolar lavage (BAL) fluid with milky appearance and elevated serum titer of anti-granulocyte-macrophage colony-stimulating factor antibody. We decided to perform segmental BAL via bronchoscopy. The surgery was performed under a general anesthesia since the patient had severe hypoxemia and strong cough reflex. Following 3 repeated courses of therapy, his respiratory condition and the ground-glass opacity in both lung fields improved remarkably, with no recurrence in 3 years. There are only a few published case reports in the world of the usefulness of segmental BAL under general anesthesia for PAP. We consider that segmental BAL is a useful therapeutic method for PAP in cases with severe hypoxemia, such as the present patient.

Blood Transfusion Therapy in Patients with Autoimmune Hemolytic Anemia

Management therapy of autoimmune hemolytic anemia (AIHA) with severe clinical symptoms requires supportive therapy such as blood components transfusion to improve hemodynamic conditions. This literature study aims to explain the role of blood transfusion therapy in AIHA cases. The method used is through searching articles in national and international journals published in the last 10 years that discuss transfusion in AIHA cases using the Google Scholar application. From the search results, it can be concluded that blood transfusion is a supportive therapy in cases of AIHA with symptoms of severe hypoxemia that interfere with hemodynamics and work function of body organ systems and findings of Hb levels &lt; 7 mg/dL with the selection of blood components in the form of packed red cells (PRC), washed packed red cells (WPRC) and Leucoreduction (LR).

Serum interleukin-6 in chronic obstructive pulmonary disease patients and its relation to severity and acute exacerbation

Background and objectivesThe role of interleukins in the severity and clinical profile of chronic obstructive pulmonary disease (COPD) is not known, but evidence supports the contribution of systemic inflammation to disease pathophysiology. This study evaluated the relationship of serum interleukin-6 (IL-6) to the severity and clinical parameters of COPD.Aim of workThe aim of the work is to estimate the level of IL-6 in COPD patients and its relation to COPD severity and acute exacerbation.Patients and methodWe analyzed 45 COPD patients and 45 normal population as control. We estimate the IL-6 level by ELISA and correlate it with the severity and frequency of COPD exacerbation.ResultsIn the current study, we noticed that IL-6 level was high in COPD patients and in those who experience frequent exacerbation. Also, IL-6 show a relation with the parameter of pulmonary function test; there is a statistically significant negative correlation with p-value < 0.05 between the level of IL-6 and the forced expired volume in 1 s/forced vital capacity (EFV1/FVC) among cases with COPD, which indicated that decrease in EFV/FVC will associate with the increase in IL-6 level.ConclusionsThe study revealed that serum IL-6 level elevated with increasing severity of airflow limitation in COPD patients, particularly in acute exacerbation phase. This increase was associated with a reduced quality of life and increased severity of hypoxemia.

Treatment with senicapoc, a KCa 3.1 channel blocker, alleviates hypoxaemia in a mouse model of acute respiratory distress syndrome.

Acute respiratory distress syndrome (ARDS) is characterized by pulmonary oedema and severe hypoxaemia. We investigated whether genetic deficit or blockade of calcium-activated potassium (KCa 3.1) channels would counteract pulmonary oedema and hypoxaemia in ventilator-induced lung injury, an experimental model for ARDS. KCa 3.1 channel knockout (Kccn4-/- ) mice were exposed to ventilator-induced lung injury. Control mice exposed to ventilator-induced lung injury were treated with the KCa 3.1 channel inhibitor, senicapoc. The outcomes were oxygenation (PaO2 /FiO2 ratio), lung compliance, lung wet-to-dry weight and protein and cytokines in bronchoalveolar lavage fluid (BALF). Ventilator-induced lung injury resulted in lung oedema, decreased lung compliance, a severe drop in PaO2 /FiO2 ratio, increased protein, neutrophils and tumour necrosis factor-alpha (TNF-α) in BALF from wild-type mice compared with Kccn4-/- mice. Pretreatment with senicapoc (10-70 mg·kg-1 ) prevented the reduction in PaO2 /FiO2 ratio, decrease in lung compliance, increased protein and TNF-α. Senicapoc (30 mg·kg-1 ) reduced histopathological lung injury score and neutrophils in BALF. After injurious ventilation, administration of 30 mg·kg-1 senicapoc also improved the PaO2 /FiO2 ratio and reduced lung injury score and neutrophils in the BALF compared with vehicle-treated mice. In human lung epithelial cells, senicapoc decreased TNF-α-induced permeability. Genetic deficiency of KCa 3.1 channels and senicapoc improved the PaO2 /FiO2 ratio and decreased the cytokines after a ventilator-induced lung injury. Moreover, senicapoc directly affects lung epithelial cells and blocks neutrophil infiltration in the injured lung. These findings indicate that blocking KCa 3.1 channels is a potential treatment in ARDS-like disease.

A Retrospective Analysis of Respiratory Complications under General Anesthesia during EBUS-TBNA.

BackgroundEBUS-TBNA is an established technique for diagnostically sampling intrathoracic masses and lymph nodes. While the procedure is commonly conducted under general anesthesia (GA), little is known regarding the association between anesthetic management and perioperative respiratory complications. Here, we aim to evaluate this association among patients presenting for EBUS-TBNA.Methods586 patients receiving GA for EBUS-TBNA between 2012 and 2018 were retrospectively evaluated. The primary endpoint was the occurrence of perioperative respiratory complications and the secondary endpoint was procedure end to OR exit time (minutes). Respiratory complications were defined as episodes of severe (SpO2 <85%) or prolonged (SpO2<90% for >5 min) hypoxemia, bronchospasm, and postoperative ventilation that could not be directly attributed to procedural invasiveness.ResultsAmong all patients, 79 (13.5%) had respiratory complications. Four patient characteristics were associated with respiratory complications: home oxygen use (OR 2.39; 95% CI 1.26–4.45; P = 0.007), pre-existing respiratory disease (OR 2.01; CI 1.21–3.29; P = 0.005), ASA class (P = 0.03), and albuterol administration intra-operatively (OR 2.22; CI 1.23–3.92; P = 0.007). No anesthetic factors were found to be statistically significant. Procedures with respiratory complications had a longer duration (mean time 88.7 min vs. 111.8 min; P = 0.00009), prolonged time to extubation (mean time 11.9 min vs. 14.2 min; P = 0.039), and stayed in the room longer after extubation (mean time 18.4 min vs. 23.1 min; P = 0.0016). When comparing types of GA, there were no significant differences between volatile anesthetics versus TIVA (12.7% vs. 14.6%, P = 0.54).ConclusionsPre-existing patient characteristics, as opposed to anesthetic factors, are associated with respiratory complications during EBUS-TBNA.

Hemophagocytic Lymphohistiocytosis and Severe Hypoxemia in a Preterm Infant.

Hemophagocytic Lymphohistiocytosis and Severe Hypoxemia in a Preterm Infant.

Science, Medicine, and the Anesthesiologist

Science, Medicine, and the Anesthesiologist

Home oxygen therapy.

SUMMARYLong-term home oxygen therapy improves survival in patients with chronic obstructive pulmonary disease and persistent, severe hypoxaemia. It is uncertain that this benefit extends to patients with other chronic lung diseases.Oxygen is a treatment for hypoxaemia, not breathlessness. To confirm hypoxaemia, blood gas analysis is recommended before prescribing oxygen.There is limited and conflicting evidence that portable oxygen for exertional use is of benefit to patients with chronic obstructive pulmonary disease who do not have severe hypoxaemia. Laboratory studies show improvements in exercise capacity and dyspnoea, but these do not translate into significant benefits in the home setting.Patients should be educated regarding the expected benefits, risks and burdens of home oxygen therapy. It is particularly important that the patient does not smoke.

Progress in clinical research of REM-related obstructive sleep apnea

REM-related obstructive sleep apnea （REM-OSA） refers to apneas and hypopneas in which most respiratory events occur during REM. The total AHI of REM-OSA is low compared to NREM-OSA, but the duration of apnea hypopnea events is longer and the oxygen saturation is lower. Only focusing on the total AHI value will miss the diagnosis of REM-OSA, and even some patients with severe hypoxemia cannot be effectively treated.REM-OSA may be an early manifestation of OSA, and active early recognition and intervention may benefit patients.The pathophysiology and mechanism of REM-OSA are still unclear. In this article, we reviewed the existing REM-OSA related research.

Clinical analysis and literature review of six cases of neurogenic pulmonary edema

To explore the early diagnosis and correct treatment of neurogenic pulmonary edema (NPE) and review the literature. Retrospective analysis was performed in six patients diagnosed as NPE who were admitted to the emergency department of Tianjin Third Central Hospital from March 2017 to March 2021. Six patients had acute onset, presenting severe dyspnea and hypoxemia, and obvious wet rales could be heard in both lungs. The white blood cell count (WBC) increased to varying degrees (11-22)×109/L, procalcitonin (PCT) was normal, or slightly increased, sputum bacteriological examination was negative, and oxygenation index was < 200 mmHg (1 mmHg ≈ 0.133 kPa). Chest CT mainly showed patchy or patchy exudation. The lesions were of different sizes and were not distributed according to lobes. By reducing intracranial pressure, ventilator assisted breathing, liquid therapy, anti-infection therapy with antibiotics, nutritional support, all six patients were well and discharged, and no one died of NPE. NPE has complex condition, acute onset and rapid development. Early diagnosis and correct treatment can improve the success rate of treatment and prognosis of patients with NPE.

Temporal Changes in the Oxyhemoglobin Dissociation Curve of Critically Ill COVID-19 Patients.

Critical COVID-19 is a life-threatening disease characterized by severe hypoxemia with complex pathophysiological mechanisms that are not yet completely understood. A pathological shift in the oxyhemoglobin curve (ODC) was previously described through the analysis of p50, intended as the oxygen tension at which hemoglobin is saturated by oxygen at 50%. The aim of this study was to analyze Hb-O2 affinity features over time in a cohort of critically ill COVID-19 patients, through the analysis of ODC p50 behavior. A retrospective analysis was performed; through multiple arterial blood gas (ABG) analyses, each p50 was calculated and normalized according to PaCO2, pH and temperature; patients’ p50 evolution over time was reported, comparing the first 3 days (early p50s) with the last 3 days (late p50s) of ICU stay. A total of 3514 ABG analyses of 32 consecutive patients were analyzed. The majority of patients presented a left shift over time (p = 0.03). A difference between early p50s and late p50s was found (20.63 ± 2.1 vs. 18.68 ± 3.3 mmHg, p = 0.03); median p50 of deceased patients showed more right shifts than those of alive patients (24.1 vs. 18.45 mmHg, p = 0.01). One-way ANOVA revealed a p50 variance greater in the early p50s (σ2 = 8.6) than in the late p50s (σ2 = 3.84), associated with a reduction over time (p < 0.001). Comparing the Hb-O2 affinity in critically ill COVID-19 patients between ICU admission and ICU discharge, a temporal shift in the ODC was observed.

Protracted or recurrent COVID-19 associated cytokine storm in a patient with chronic lymphocytic leukemia receiving rituximab-based chemotherapy

A 52-year-old male patient who was diagnosed with chronic lymphocytic leukemia two years ago; admitted to our hospital with complaints of fever (>38C), shortness of breath, and fatigue. He was receiving fludarabine, cyclophosphamide, and rituximab (FCR) regimen for one year after two courses of cyclophosphamide, vincristine, and prednisolone (CVP) regimen. The patient was diagnosed with COVID-19 associated cytokine storm and tocilizumab 800 mg was administered in addition to corticosteroids.Significant improvement was observed in both clinical and laboratory parameters and his hypoxemia resolved. The patient whose complaints recurred on the 13 th day of discharge was admitted to the hospital again with severe hypoxemia (oxygen saturation < 90) and fever (>38C). Pulse steroid (250 mg methylprednisolone for three days, followed by 40 mg/day) and anakinra 400 mg/day intravenously were started.Despite the treatment, the patient progressed to respiratory failure and died on the sixth day of second hospitalization.

Long‐term mechanical ventilation of an 8‐week‐old dog with idiopathic polyradiculoneuritis

AbstractA 2‐month‐old labrador retriever diagnosed with progressive polyradiculoneuritis was anaesthetised and mechanically ventilated with the aid of pressure control ventilation due to severe hypoventilation and hypoxaemia. Anaesthesia was maintained with propofol and midazolam constant‐rate infusions (CRIs). Over time, once the patient was showing spontaneous breathing attempts and arterial partial pressure of carbon dioxide was within normal range, ventilatory mode was switched to pressure support ventilation. The anaesthetic protocol was modified to maintain an appropriate level of anaesthesia with a minimum amount of fluid administered. The midazolam CRI was substituted by a sufentanil CRI, followed by a change to a dexmedetomidine CRI. An intensive nursing care protocol was established. Intermittent hyperthermia and peripheral oedema were the main complications observed. Ventilatory support was reduced until the patient was successfully weaned from the ventilator at the third attempt, after 116 hours of ventilatory support.

Hypoxemia increases blood-brain barrier permeability during extreme apnea in humans

Voluntary asphyxia imposed by static apnea challenges blood-brain barrier (BBB) integrity in humans through transient extremes of hypertension, hypoxemia and hypercapnia. In the present study, ten ultra-elite breath-hold divers performed two maximal dry apneas preceded by normoxic normoventilation (NX: severe hypoxemia and hypercapnia) and hyperoxic hyperventilation (HX: absence of hypoxemia with exacerbating hypercapnia) with measurements obtained before and immediately after apnea. Transcerebral exchange of NVU proteins (ELISA, Single Molecule Array) were calculated as the product of global cerebral blood flow (gCBF, duplex ultrasound) and radial arterial to internal jugular venous concentration gradients. Apnea duration increased from 5 m 6 s in NX to 15 m 59 s in HX (P = <0.001) resulting in marked elevations in gCBF and venous S100B, glial fibrillary acidic protein, ubiquitin carboxy-terminal hydrolase-L1 and total tau (all P < 0.05 vs. baseline). This culminated in net cerebral output reflecting mildly increased BBB permeability and increased neuronal-gliovascular reactivity that was more pronounced in NX due to more severe systemic and intracranial hypertension (P < 0.05 vs. HX). These findings identify the hemodynamic stress to which the apneic brain is exposed, highlighting the critical contribution of hypoxemia and not just hypercapnia to BBB disruption.