Why High-Intensity NPPV is Favourable to Low-Intensity NPPV: Clinical and Physiological Reasons

High-intensity non-invasive positive pressure ventilation (NPPV) was originally described for chronic hypercapnic chronic obstructive pulmonary disease (COPD) patients in 2009, and refers to a specific ventilatory approach whereby NPPV settings are aimed at achieving the lowest arterial partial pressure of carbon dioxide (PaCO₂) values possible. Thus, high-intensity NPPV requires ventilator settings to be increased in a stepwise approach to either an individually tolerated maximum, or to the levels necessary to achieve normocapnia. This differs from the classic approach to low-intensity NPPV, which comprises considerably lower ventilator settings and typically fails to lower elevated PaCO₂ values. The ongoing discussion about whether or not long-term NPPV should be used in chronic hypercapnic COPD patients is based on the observation that many studies in the last two decades have failed to provide evidence for this particular patient cohort. In addition, these trials preferably used low-intensity NPPV. There is now, however, increasing evidence to suggest that high-intensity NPPV is capable of improving important physiological parameters such as blood gases and lung function, as well as health-related quality of life. Moreover, this approach also produced positive outcomes following two recent randomized controlled trials, e.g., improved survival rates in stable COPD patients, and admission-free survival in patients with persisting hypercapnia following acute in-hospital NPPV to treat acute acidotic respiratory failure. As a consequence, the time has now come to evaluate the impact of long-term NPPV on both the physiological and clinical outcomes, with emphasis on the different approaches to NPPV. Therefore, the aim of the current review article is to elaborate on the clinical and physiological reasons for why high-intensity NPPV is favourable to low-intensity NPPV.     

High Stroke Volume Variation Is an Independent Predictor for Decreased Blood Pressure During Hemodialysis

It currently remains unclear whether stroke volume variation (SVV) before hemodialysis (HD) is an independent predictor of decreased blood pressure (BP) during HD. Fifty‐two patients were divided into two groups (Decreased BP during HD group: N = 10, Non‐decreased BP group: N = 42). Fractional shortening was lower, and mean arterial pressure (MAP) and SVV were higher in the Decreased BP during HD group. A multiple logistic regression analysis identified low fractional shortening, high MAP, and high SVV as independent predictors of decreased BP during HD. The areas under the ROC curves were as follows: 0.849 for MAP, 0.712 for SVV, and 0.893 for MAP and SVV. Optimal threshold values were 93.0 mm Hg for MAP and 17.3 % for SVV. A multivariate regression analysis identified anemia and a longer dialysis vintage as independently related factors for higher SVV. Our results suggest that high SVV is an independent predictor for decreased BP during HD.     

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??Objective??To select the best predictor of swallowing functions by exploring the correlation between the swallowing function and tongue mobility and tongue pressure of the patients with tongue defects after oral cancer surgery or oropharyngeal cancer surgery. Methods??From July 2017 to March 2018??in Hospital of Stomatology??Sun Yat-sen University??thirty-six cases of patients with tongue defects after oral cancer surgery or oropharyngeal cancer surgery were collected during return visits in the outpatient clinics of our hospital. The swallowing functions were graded by their water swallowing test??WST??results. The tongue mobility scores were evaluated by using the lingual range of motion??LROM??method??while the tongue pressure was measured by using the Iowa oral performance instrument??IOPI??. Spearman rank correlation analysis was applied to calculate the rank correlation coefficient??rs?? between the tongue mobility scores or tongue pressure and WST results??and the corresponding P value. Results??The rs value between WST results and tongue mobility scores or tongue pressure was -0.575 and -0.613 respectively??P??0.05??. The rs value of tongue pressure was larger than that of tongue mobility scores. Conclusion??Both the tongue mobility scores and tongue pressure have a great impact on the swallowing functions of patients with tongue defects after oral cancer surgery or oropharyngeal cancer surgery??and tongue pressure is the best predictor.     

Aggressive systolic blood pressure control in older subjects: benefits and risks

Systolic hypertension, especially isolated systolic hypertension (ISH) is very common in older subjects aged ≥ 65 years and is a major risk factor for cardiovascular disease (CVD), strokes, heart failure (HF) and chronic kidney disease (CKD). It is also, directly and linearly related with these complications irrespective of sex, or ethnicity, but it is worse with the advancement of age. Effective control of systolic blood pressure (SBP), is associated with significant reduction in the incidence of these complications. Currently, there is a debate about the optimal SBP control in view of the Systolic Blood Pressure Intervention Trial (SPRINT) showing beneficial cardiovascular (CV) effects of intensive SBP of < 120 mmHg in older patients. Also, the recently released blood pressure (BP) guidelines by the American College of Cardiology, the American Heart Association and the American Society of Hypertension (ACC/AHA/ASH) recommend a SBP reduction of < 130 mmHg. These SBP treatment recommendations are in contrast with the current (JNC VIII) committee of BP treatment guidelines, which recommend a SBP reduction < 150 mmHg for the same age of patients. All these different recommendations have created a debate regarding the optimal treatment targets for the systolic hypertension of the elderly patients. To gain more information a focused Medline search was conducted from 2010 to 2017 using the terms, systolic blood pressure, aggressive control, older subjects, treatment guidelines, and 37 pertinent papers were retrieved. The findings from these studies suggest a SBP reduction of < 140 mm Hg for persons aged ≥ 60 years, with an attempt for SBP reduction to ≤130 mm Hg in healthier subjects and hose with CVD, DM, and CKD. Care should be taken not to further reduce the SBP in older subjects if their DBP is ≤60 mmHg for the fear of J-curve effect.     

Factors affecting seasonal changes in blood pressure in North India: A population based four-seasons study

ObjectiveThere are no community based, longitudinal, intra individual epidemiological studies on effect of weather and season on blood pressure (BP). We evaluated the effect of season and temperature on prevalence and epidemiology of BP in tropical climate.Methods and resultsIt was a longitudinal cross sectional survey of rural and urban subjects in their native surroundings. BP was measured in four different seasons in same subjects. A total of 978 subjects (452 rural and 521 urban) were included in the current analysis. Demographic characteristics such as age, gender, education, occupational based physical activity and body mass index (BMI) were recorded. Mean BP, both systolic and diastolic were significantly higher in winter season as compared to summer season. Mean difference between winter and summer was 9.01 (95% CI: 7.74–10.28, p < 0.001) in systolic BP and 5.61 (95% CI: 4.75–6.47, p < 0.001) in diastolic BP. This increase in BP was more marked in rural areas and elderly subjects. Prevalence of hypertension was significantly higher during winter (23.72%) than in summer (10.12%).ConclusionBP increases significantly during winter season as compared to summer season. Increase is more marked in rural areas and elderly subjects. Seasonal variation in BP should be taken into account while looking at prevalence of hypertension in epidemiological studies.