On the rise and fall of the apnea−hypopnea index: A historical review and critical appraisal

The publication of “The Sleep Apnea Syndromes” by Guilleminault et al. in the 1970s hallmarked the discovery of a new disease entity involving serious health consequences. Obstructive sleep apnea was shown to be the most important disorder among the sleep apnea syndromes (SAS). In the course of time, it was found that the prevalence of obstructive sleep apnea reached the proportions of a global epidemic, with a major impact on public health, safety and the economy. Early on, a metric was introduced to gauge the seriousness of obstructive sleep apnea, based on the objective measurement of respiratory events during nocturnal sleep. The apnea index and later on the apnea?hypopnea index, being the total count of overnight respiratory events divided by the total sleep time in hours, were embraced as principle measures to establish the diagnosis of obstructive sleep apnea and to rate its severity. The current review summarises the historical evolution of the apnea?hypopnea index, which has been subject to many changes, and has been criticised for not capturing relevant clinical features of obstructive sleep apnea. In fact, the application of the apnea?hypopnea index as a continuous exposure variable is based on assumptions that it represents a disease state of obstructive sleep apnea and that evocative clinical manifestations are invariably caused by obstructive sleep apnea if the apnea?hypopnea index is above diagnostic threshold. A critical appraisal of the extensive literature shows that both assumptions are invalid. This conclusion prompts a reconsideration of the role of the apnea?hypopnea index as the prime diagnostic metric of clinically relevant obstructive sleep apnea.     

Characteristics and clinical significance of augmentation spectra in solar urticaria

Solar urticaria has unique spectra, such as inhibition and augmentation. The clinical significance of these spectra, especially augmentation, is not well understood. Reported cases of solar urticaria with augmentation spectra are extremely rare in the published English-language work. The purposes of this study were to evaluate the clinical features of solar urticaria with augmentation spectra and to elucidate the mechanisms and clinical importance of the spectra. We experienced 11 cases (five females, six males; mean age, 40.1 years; range, 1–74) of solar urticaria with augmentation spectra from April 2007 to July 2019. Augmentation spectra were UV-B in three cases, UV-A in two, visible light in four, UV-A and UV-B in one, and UV-A and visible light in one. Augmentation spectra were observed before action spectra in four cases, after in six, and before and after in one. Injection of sera irradiated with action spectra and augmentation spectra in vitro induced stronger immediate reactions than those of only action spectrum-irradiated sera in four of five cases. The results of injection tests suggested that augmentation spectra enhance the production of urticaria-forming factor. Clinically, we observed severe urticarial reactions in four cases, including anaphylaxis in three and moderate urticarial reactions in three. These results suggest that augmentation spectra are not as rare as previously thought and that they are associated with the severity of solar urticaria. Therefore, phototesting for both augmentation and action spectra should be performed to provide appropriate guidance for patients with solar urticaria.     

血清Lp-PLA2,BDNF及Ang1-7表达水平与血管性痴呆患者病情严重程度的相关性

目的 探讨血管性痴呆(VD)患者血清脂蛋白相关磷脂酶A2(Lp-PLA2)、脑源性神经营养因子(BDNF)及血管紧张素1-7(Ang1-7)表达水平及其与VD患者病情严重程度的相关性。方法 选取本院2017年10月-2019年10月收治的120例VD患者,依照简易精神状态检查量表(MMSE)分为轻度组、中度组和重度组,各40例,比较各组相关危险因素,颈动脉超声检测颈动脉内膜中层厚度(IMT),检测血清生化指标[低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)、总胆固醇(TC)、三酰甘油(TG)、糖化血红蛋白(GHb)、空腹血糖(GLU)]、血清指标[Lp-PLA2,BDNF,Ang1-7、神经元特异性烯醇化酶(NSE)、C反应蛋白(CRP)、白细胞介素6(IL-6)、肿瘤坏死因子α(TNF-α)、同型半胱氨酸(Hcy)]水平, 分析Lp-PLA2,BDNF及Ang1-7水平之间的相关性,也分析血清Lp-PLA2,BDNF及Ang1-7水平与MMSE评分的相关性。结果 3组患者年龄、受教育程度、高血压病史、高血脂症史、饮酒、吸烟等临床资料比较均无明显差异(P>0.05),冠心病史、糖尿病史、IMT比较均有明显差异(P<0.05); 3组患者血清LDL-C,HDL-C,TC,TG,GHb,GLU水平比较均无明显差异(P>0.05),血清Lp-PLA2,BDNF,Ang1-7,NSE,CRP,IL-6,TNF-α及Hcy水平比较均有明显差异(P<0.05)。相关性分析显示,血清Lp-PLA2,BDNF及Ang1-7与冠心病史、糖尿病史、血清NSE,CRP,IL-6,TNF-α,LDL-C,TC水平及MMSE评分存在明显相关性。结论 血清Lp-PLA2、BDNF及Ang1-7水平与血管性痴呆患者血清因子水平及VD患者的病情严重程度存在明显相关性,检测血清Lp-PLA2,BDNF及Ang1-7水平有助于VD患者的预防和治疗     

The Malawi trauma score: A model for predicting trauma-associated mortality in a resource-poor setting

BackgroundGlobally, traumatic injury is a leading cause of morbidity and mortality in low-income countries. Current tools for predicting trauma-associated mortality are often not applicable in low-resource environments due to a lack of diagnostic adjuncts. This study sought to derive and validate a model for predicting mortality that requires only a history and physical exam.MethodsWe conducted a retrospective analysis of all patients recorded in the Kamuzu Central Hospital trauma surveillance registry in Lilongwe, Malawi from 2011 through 2014. Using statistical randomization, 80% of patients were used for derivation and 20% were used for validation. Logistic regression modeling was used to derive factors associated with mortality and the Malawi Trauma Score (MTS) was constructed. The model fitness was tested.Results62,354 patients are included. Patients are young (mean age 23.0, SD 15.9 years) with a male preponderance (72%). Overall mortality is 1.8%. The MTS is tabulated based on initial mental status (alert, responds to voice, responds only to pain or worse), anatomical location of the most severe injury, the presence or absence of a radial pulse on examination, age, and sex. The score range is 2–32. A mental status exam of only responding to pain or worse, head injury, the absence of a radial pulse, extremes of age, and male sex all conferred a higher probability of mortality. The ROC area under the curve for the derivation cohort and validation cohort were 0.83 (95% CI 0.78, 0.87) and 0.83 (95% CI 0.75, 0.92), respectively. A MTS of 25 confers a 50% probability of death.ConclusionsThe MTS provides a reliable tool for trauma triage in sub-Saharan Africa and helps risk stratify patient populations. Unlike other models previously developed, its strength is its utility in virtually any environment, while reliably predicting injury- associated mortality.     

Peri-ictal heart rate variability parameters as surrogate markers of seizure severity

This study aims at defining objective parameters reflecting the severity of peri-ictal autonomic changes and their relation to post-ictal generalized electroencephalography (EEG) suppression (PGES), with the view that such changes could be detected by wearable seizure detection systems and prove useful to assess the risk of sudden unexpected death in epilepsy (SUDEP). To this purpose, we assessed peri-ictal changes in heart rate variability (HRV) and correlated them with seizure duration, intensity of electromyography-based ictal muscle activity, and presence and duration of post-ictal generalized EEG suppression (PGES). We evaluated 75 motor seizures from 40 patients, including 61 generalized tonic-clonic seizures (GTCS) and 14 other major motor seizure types. For all major motor seizures, HRV measurements demonstrated a significantly decreased parasympathetic activity and increased sympathetic activity in the post-ictal period. The post-ictal increased sympathetic activity was significantly higher for GTCS as compared with non-GTCS. The degree of peri-ictal decreased parasympathetic activity and increased sympathetic activity was associated with longer PGES (>20 s), longer seizure duration, and greater intensity of ictal muscle activity. Mean post-ictal heart rate (HR) was an independent predictor of PGES duration, seizure duration, and intensity of ictal muscle contraction. Our results indicate that peri-ictal changes in HRV are potential biomarkers of major motor seizure severity.     

Outcome measures from experimental traumatic brain injury in male rats vary with the complete temporal biomechanical profile of the injury event

Millions suffer a traumatic brain injury (TBI) each year wherein the outcomes associated with injury can vary greatly between individuals. This study postulates that variations in each biomechanical parameter of a head trauma lead to differences in histological and behavioral outcome measures that should be considered collectively in assessing injury. While trauma severity typically scales with the magnitude of injury, much less is known about the effects of rate and duration of the mechanical insult. In this study, a newly developed voice-coil fluid percussion injury system was used to investigate the effects of injury rate and fluid percussion impulse on a collection of post-injury outcomes in male rats. Collectively the data suggest a potential shift in the specificity and progression of neuronal injury and function rather than a general scaling of injury severity. While a faster, shorter fluid percussion first presents as a mild TBI, neuronal loss and some behavioral tasks were similar among the slower and faster fluid percussion injuries. This study concludes that the sequelae of neuronal degeneration and behavioral outcomes are related to the complete temporal profile of the fluid percussion and do not scale only with peak pressure.     

Major trauma associated with mobility scooters: An analysis of the trauma audit research network

AimsTo establish the incidence and nature of injuries seen in patients following mobility scooter incidents.MethodsThe Trauma Audit and Research Network (TARN) database was used to collect data concerning injuries associated with mobility scooters. The data was taken from incidents that occurred between February 2014 and November 2020. The data analysed included: patient demographics, injury mechanism and patterns and associated mortality rates.Results1,504 patients were identified of which 61.4% were male. The median age was 76.2 years (IQR 63.5–84.9). The median injury severity score (ISS) was 9 (IQR 9–17), with major trauma (ISS ≥16) being observed in 29.4% of patients. Injuries to the limb were most common, although injuries to the head were most severe. Vehicle collisions accounted for 65.4% of injuries and were most closely associated with the most severe incidents. The median length of stay in hospital was 12 days, excluding the patients who died. Overall, mortality following injury was 10.6%, but the mortality rate was 15.4% in those aged 75 years and over, and 24.2% in those sustaining severe trauma.ConclusionAs the population ages, injury characteristics of those with both major and non-major trauma changes. Mobility scooter use is prevalent amongst older people, and we provided a detailed analysis of injuries sustained with their use across a national database. The length of stay and the inherent resource use, because of admission following mobility scooter trauma, is considerable. These injuries particularly affect the ‘most elderly’ and carry a considerable mortality burden.