Decreased respiratory rate variability during mechanical ventilation is associated with increased mortality

Objective

Patients on ventilatory support often experience significant changes in respiratory rate. Our aim was to determine the possible association between respiratory rate variability (RRV) and outcomes in these patients.

Design

A longitudinal, prospective, observational study of patients mechanically ventilated for at least 12 h performed in a medical-surgical intensive care unit. Patients were enrolled within 24 h of the initiation of ventilatory support. We measured airway signals continuously for the duration of ventilatory support and calculated expiratory flow frequency spectra at 2.5-min intervals. We assessed RRV using the amplitude ratio of the flow spectrum’s first harmonic to the zero frequency component. Measures of the amplitude ratio were averaged over the total monitored time. Patients with time-averaged amplitude ratios <40 % were classified as high RRV and those ≥40 % as low RRV. All-cause mortality rates were assessed at 28 and 180 days from enrollment with a Cox proportional hazards model adjusted for disease acuity by the simplified acute physiology score II.

Results

We enrolled 178 patients, of whom 47 had high RRV and 131 low RRV. Both groups had similar disease acuity upon enrollment. The 28- and 180-day mortality rates were greater for low RRV patients with hazard ratios of 4.81 (95 % CI 1.85–12.65, p = 0.001) and 2.26 (95 % CI 1.21–4.20, p = 0.01), respectively. Independent predictors of 28-day mortality were low RRV, i.v. vasopressin, and SAPS II.

Conclusions

Decreased RRV during ventilatory support is associated with increased mortality. The mechanisms responsible for this finding remain to be determined.     

Usefulness of the epicardial fat tissue thickness as a diagnostic criterion for geriatric patients with metabolic syndrome

Objective To evaluate the epicardial fat tissue thickness (EFTT) as a diagnostic criterion for geriatric patients with metabolic syndrome (MetS). Methods Sixty geriatric patients over 65 years of age were recruited for the study. Patients were divided into two groups: Group 1 (n = 30) consisted of patients with MetS; Group 2 (n = 30) consisted of patients without MetS. Echocardiography was used to measure EFTT in all patients, and blood samples were analyzed for biochemical parameters. Results Compared to Group 2, EFTT levels of Group 1 were statistically higher (P < 0.05). In a binary logistic regression analysis, EFTT levels served as the independent factor for metabolic syndrome (B = 17.35, SE = 4.93, Wald = 12.36, P < 0.001). Receivers operating characteristic Curve (ROC-curve) analysis revealed that EFTT predicted MetS with 96.7% sensitivity and 86.7% specificity above the level of 7.3 mm [area under the curve = 0.969; 95% confidence interval (CI): 0.928–1.00]. Conclusions The present study demonstrated that serum EFTT levels were higher in geriatric patients with MetS and can therefore be used as a diagnostic criterion for MetS.     

Acute Aortic Regurgitation with Myocardial Infarction: An Important Clue for Aortic Dissection

Background

Aortic dissection is an important cause of acute chest pain that should be rapidly diagnosed, as mortality increases with each hour this condition is left untreated. The diagnosis can be challenging, especially if concomitant myocardial infarction is present. Echocardiography is an important tool for the differential diagnosis.

Objectives

To stress the importance of recognizing aortic regurgitation for the differentiation of myocardial infarction and aortic dissection.

Case Report

An 80-year-old woman was admitted to our hospital with chest pain that was diagnosed as inferior and lateral wall myocardial infarction based on electrocardiographic findings. The diagnosis was reevaluated when aortic regurgitation was detected on echocardiography. Closer inspection of the ascending aorta revealed a dissection flap as the cause of aortic regurgitation.

Conclusion

Detection of aortic regurgitation in a patient with myocardial infarction and normal valves should prompt the search for a possible aortic dissection, whether or not the dissection flap can be visualized.     

Is vitamin D deficiency associated with development of Acinetobacter baumannii infections in critically ill patients?

Purpose

A growing number of evidence demonstrates deficiency of vitamin D in critically ill patients. We aimed to evaluate the vitamin D status of our critically ill patients and its relevance to infections in these patients.

Material and Methods

We conducted a prospective observational study in 201 critically ill patients admitted to the medical intensive care unit of Gazi University Hospital between October 2009 through March 2011.

Results

Sixty-nine percent of the patients were found to be vitamin D deficient. Infection rate was higher in the deficient group, though without statistical significance (P = .117). Infections with Acinetobacter baumannii was significantly more frequent in patients with Vitamin D deficiency (25% vs 10%, P = .012). The median level of 25-hydroxyvitamin D levels was 11.8 [6.3-17.2] ng/mL and 15.7 [8.1-28.9] ng/mL in patients with and without A baumannii infections respectively (P = .024). Logistic regression analysis demonstrated that vitamin D deficiency (P = .042) and invasive mechanical ventilation (P = .001) were the 2 independent risk factors in the development of A baumannii infections, in addition.

Conclusions

Vitamin D deficiency is common in critically ill patients. Even though there was no statistical difference between vitamin D deficient and sufficient patients regarding development of infections in general, A baumannii infections were significantly more frequent in the deficient group. Vitamin D deficiency was found as one of the independent risk factors for A baumannii infections. Further multicenter studies with a larger sample size are required to validate our data.     

Poor Nutritional Status Is Associated with Arrhythmic Events on 24-Hour Holter Recording

BackgroundMalnutrition is associated with cardiovascular disease morbidity and mortality. Arrhythmias may be the cardiac consequences of malnutrition.ObjectivesThe objective of the study was to evaluate the association between prognostic nutritional index (PNI), Controlling Nutritional Status (CONUT) score, and arrhythmic events on 24-h electrocardiography (ECG) Holter recording in patients without manifested arrhythmia.MethodsIn this retrospective analysis of 477 patients who underwent 24-h ECG Holter monitoring, PNI and CONUT score were calculated and patients were divided into tertiles according to PNI and into three groups according to CONUT score; 0: normal, 1–2: mild risk of malnutrition, ≥3: moderate-severe risk of malnutrition. Arrhythmic events were compared between PNI tertiles and CONUT score groups.ResultsTotal number of premature atrial contractions, premature ventricular contractions (PVCs), PVC burden, and incidence of paroxysmal atrial fibrillation (PAF) were significantly higher in patients within the lowest PNI tertile. Total number of PVCs, PVC burden, and incidence of PAF were significantly higher in patients with CONUT score ≥3. The cut-off value for PNI to predict the presence of PVC was defined as 39.41 using ROC curve analysis. The area under the curve was 0.650 (p < 0.001). Multivariate analysis showed that PNI was independent predictor of the presence of PVC and PAF. Also, CONUT score was independent predictor of the presence of PVC and PAF. Incidence of nonsustained ventricular tachycardia did not differ between PNI tertiles or CONUT score groups.ConclusionPoor nutritional status, assessed by PNI and CONUT score, is associated with arrhythmic events on 24-h ECG Holter recording in patients without manifested arrhythmia.     

Disruption of the ovarian follicle reservoir of prepubertal rats following prenatal exposure to a continuous 900-MHz electromagnetic field

The effects on human health of electromagnetic field (EMF) have begun to be seriously questioned with the entry into daily life of devices establishing EMF, such as cell phones, wireless fidelity, and masts. Recent studies have reported that exposure to EMF, particularly during pregnancy, affects the developing embryo/fetus. The aim of this study was therefore to examine the effects of exposure to continuous 900-Megahertz (MHz) EMF applied in the prenatal period on ovarian follicle development and oocyte differentiation. Six pregnant Sprague Dawley rats were divided equally into a non-exposed control group (CNGr) and a group (EMFGr) exposed to continuous 900-MHz EMF for 1?h daily, at the same time every day, on days 13–21 of pregnancy. New groups were established from pups obtained from both groups after birth. One group consisting of female pups from CNGr rats was adopted as newborn CNGr (New-CNGr, n?=?6), and another group consisting of female pups from EMFGr rats was adopted as newborn EMFGr (New-EMFGr, n?=?6). No procedure was performed on New-CNGr or New-EMFGr rats. All rat pups were sacrificed on the postnatal 34th day, and their ovarian tissues were removed. Follicle count, histological injury scoring and morphological assessment with apoptotic index criteria were performed with sections obtained following routine histological tissue preparation. Follicle count results revealed a statistically significant decrease in primordial and tertiary follicle numbers in New-EMFGr compared to New-CNGr (p?p?相似文献   

Malignancy risk of oncocytic changes in thyroid nodules: who should we offer surgery to?

Background Oncocytic (Hürthle) cell in fine-needle aspiration biopsy (FNAB) remains challenging for surgeons. Surgical treatment is recommended for oncocytic change in FNAB, since it can sometimes be a struggle to determine the nature of thyroid nodules. We aimed to investigate the clinical significance of oncocytic changes in FNAB in terms of management of patients.

Methods The FNAB samples of 172 patients with thyroid nodules were reviewed. Of these, 39 patients with cytologic findings of oncocytic changes on FNAB [POC: predominance of oncocytic cells; SFON-H: suspicious for follicular or oncocytic neoplasm (Hürthle cell type), SM-O: suspicious for malignancy-papillary or follicular carcinoma; oncocytic variant)] were included.

Results FNAB demonstrated POC in 14 (35.8%), SFON-H in 15 (38.4%), and SM-O in 10 (25.6%) patients. The overall malignancy rate was 35.8% (n?=?14). Clinical and laboratory data were not found to be associated with thyroid cancer while nodule size was significantly higher in patients with thyroid malignancy (15.2 versus 23.3?mm, p?=?0.032). Regarding FNAB results including oncocytic changes, the rate of malignancy was significantly different and almost three-fold higher in nodules classified as SFON-H and SM-O [48% versus 14.2% with POC, p?=?0.044]. Besides, there was a positive correlation between SFON-H and SM-O cytology and malignancy (p?=?0.036, r?=?0.337).

Conclusions It is hard to discern the significance of oncocytic changes in FNAB report and to determine an optimal approach as a surgeon. We recommend surgery for the patients with an FNAB showing SFON-H and SM-O whereas POC should be better to be followed-up.     

Coronary collateral vessel development after acute myocardial infarction

OBJECTIVE

The aim of the present study was to assess the factors affecting collateral vessel development in patients with acute myocardial infarction.METHODS AND RESULTS: Between May 2001 and April 2004, coronary angiography was performed on 74 patients following myocardial infarction. Only patients with total proximal occlusion in the left anterior descending coronary artery (LAD) or right coronary artery (RCA) in angiography were included in the study. Patients were separated into two groups according to the development of coronary collateral circulation (CCC). In group 1, CCC was inadequate (Rentrop 0, 1 and 2); and in group 2, CCC was adequate (Rentrop 3). Although CCC was adequate in 20 of 28 (71%) patients who had RCA occlusion (P=0.015), it was adequate in only 14 of 46 (30%) patients who had LAD occlusion (P>0.05). The presence of angina pectoris was positively correlated with the development of CCC (P=0.03). Diabetes mellitus (DM) was present in 14 of 40 (35%) patients with inadequate CCC and four of 34 (11%) patients with adequate CCC. The presence of DM was significantly higher in the group with inadequate development of CCC (P=0.017).

CONCLUSIONS

While DM was associated with an inadequate development of CCC, the presence of angina pectoris and RCA occlusion were associated with an adequate development of CCC.     

Comparison of adhesion and virulence of two predominant hospital-acquired methicillin-resistant Staphylococcus aureus clones and clonal methicillin-susceptible S. aureus isolates

The virulence of SCCmec type IV hospital-acquired methicillin-resistant Staphylococcus aureus (MRSA) clinical isolates belonging to the major sequence type 8 (ST8 [Lyon clone]) and to a minor upcoming clone, ST5, was compared with that of methicillin-susceptible S. aureus (MSSA) isolates of matching sequence types. In vitro adhesion to human airway epithelial cells (HAECs) as an indicator of dissemination and mortality in a murine sepsis model as an indicator of virulence were evaluated. Ten MRSA isolates and 8 MSSA isolates of ST8 and 8 MRSA isolates and 8 MSSA isolates of ST5 were characterized with respect to multilocus sequence type; agr, spa, and capsule typing; in vitro doubling time; toxin and adhesin gene profiles; and adherence to HAECs. Adherence was significantly lower in the MRSA ST5 group than in the ST8 groups. Infections with MRSA and MSSA isolates ST8 and ST5 were compared. No change in virulence related to the presence of SCCmec was observed, since ST8 but not ST5 caused a significantly lower mortality in its presence. Despite their similar genetic backgrounds, individual clonal MRSA and MSSA isolates were heterogeneous in adherence and virulence. No one of these specific virulence factors determined in vitro was related to mouse mortality. In conclusion, in a bacteremic model, mortality was dependent on the ST and was differentially modulated by SCCmec; within an ST, clonality was not associated with a homogenous outcome.     

Toll-like receptor 2 induces mucosal homing receptor expression and IgA production by human B cells

There is a need for developing vaccines that elicit mucosal immunity. Although oral or nasal vaccination methods would be ideal, current strategies have yielded mixed success. Toll-like receptor 2 (TLR2) ligands are effective adjuvants and are currently used in the Haemophilus influenzae type B vaccine. Induction of humoral immunity in the mucosa is critical for effective vaccination; thus, we sought to determine the effects of TLR2 ligands on human mucosal B cell differentiation. We demonstrate that TLR2 ligands induce CCR9 and CCR10 expression by circulating B cells and increased chemotaxis to cognate chemokines CCL25 and CCL28 suggesting that TLR2 induces B cell homing to the gastrointestinal tract. TLR2 stimulation of B cells also induced J chain and IgA production demonstrating the induction of mucosal-like antibody secreting cells. These observations suggest that vaccines containing TLR2-ligands as adjuvants could induce mucosal B cell immunity even when delivered in a non-mucosal manner.