Cerebral perfusion pressure and risk of brain hypoxia in severe head injury: a prospective observational study

INTRODUCTION Higher and lower cerebral perfusion pressure (CPP) thresholds have been proposed to improve brain tissue oxygen pressure (PtiO2) and outcome. We study the distribution of hypoxic PtiO2 samples at different CPP thresholds, using prospective multimodality monitoring in patients with severe traumatic brain injury. METHODS This is a prospective observational study of 22 severely head injured patients admitted to a neurosurgical critical care unit from whom multimodality data was collected during standard management directed at improving intracranial pressure, CPP and PtiO2. Local PtiO2 was continuously measured in uninjured areas and snapshot samples were collected hourly and analyzed in relation to simultaneous CPP. Other variables that influence tissue oxygen availability, mainly arterial oxygen saturation, end tidal carbon dioxide, body temperature and effective hemoglobin, were also monitored to keep them stable in order to avoid non-ischemic hypoxia. RESULTS Our main results indicate that half of PtiO2 samples were at risk of hypoxia (defined by a PtiO2 equal to or less than 15 mmHg) when CPP was below 60 mmHg, and that this percentage decreased to 25% and 10% when CPP was between 60 and 70 mmHg and above 70 mmHg, respectively (p < 0.01). CONCLUSION Our study indicates that the risk of brain tissue hypoxia in severely head injured patients could be really high when CPP is below the normally recommended threshold of 60 mmHg, is still elevated when CPP is slightly over it, but decreases at CPP values above it.

Escalas de valoración del riesgo de desarrollar úlceras por presión

Aim: to find the Risk Assessment Scales (RAS) for pressure ulcers in children published in the literature. To determine which of them have been properly validated. Methods: a systematic review of the literature has been conducted searching in 14 Health Sciences databases. The inclusion criteria were: studies published between 1962 and 2009, with a prospective design, less than a 25 % lost to follow-up, and with data of validity, prognostic or reliability. No language restriction was applied. Methodological quality of the studies was assessed by the CASP guide. Results: seventeen studies were found. In these studies 11 RAS for children were identified. Most of them were developed for the critical care area, based on previous risk assessment scales for adult. There are only 3 scales with one validation study: NSRAS, Braden Q and Starkid Skin. Their sensibility and specificity figures are: Braden Q, sens = 88% and specif. 58%; NSRAS, 83% and 81%; and Starkid Skin, 17% and 98%. Although the NSRAS scale has good validity figures, the simple size of this study was too small, so these results need further validation. The Starkid scale has a sensibility too low. The Braden Q was the only scale with suitable validity and prognostic figures, though its inter-observers reliability has not been tested, so more research to confirm these results is needed. The assessment of pressure ulcers risk in children is recommended, although, with the available evidence, we can not recommend the use of any of these RAS over the others. More research about this topic is needed.

Central corneal thickness, intraocular pressure, and degree of myopia in an adult myopic population aged 20 to 40 years in southeast Spain: determination and relationships

Objective: To determine the values of, and study the relationships among, central corneal thickness (CCT), intraocular pressure (IOP), and degree of myopia (DM) in an adult myopic population aged 20 to 40 years in Almeria (southeast Spain). To our knowledge this is first study of this kind in this region. Methods: An observational, descriptive, cross-sectional study was done in which a sample of 310 myopic patients (620 eyes) aged 20 to 40 years was selected by gender- and age-stratified sampling, which was proportionally fixed to the size of the population strata for which a 20% prevalence of myopia, 5% epsilon, and a 95% confidence interval were hypothesized. We studied IOP, CCT, and DM and their relationships by calculating the mean, standard deviation, 95% confidence interval for the mean, median, Fisher’s asymmetry coefficient, range (maximum, minimum), and the Brown-Forsythe’s robust test for each variable (IOP, CCT, and DM). Results: In the adult myopic population of Almeria aged 20 to 40 years (mean of 29.8), the mean overall CCT was 550.12 μm. The corneas of men were thicker than those of women (P = 0.014). CCT was stable as no significant differences were seen in the 20- to 40-year-old subjects’ CCT values. The mean overall IOP was 13.60 mmHg. Men had a higher IOP than women (P = 0.002). Subjects over 30 years (13.83) had a higher IOP than those under 30 (13.38) (P = 0.04). The mean overall DM was −4.18 diopters. Men had less myopia than women (P < 0.001). Myopia was stable in the 20- to 40-year-old study population (P = 0.089). A linear relationship was found between CCT and IOP (R2 = 0.152, P ≤ 0.001). CCT influenced the IOP value by 15.2%. However no linear relationship between DM and IOP, or between CCT and DM, was found. Conclusions: CCT was found to be similar to that reported in other studies in different populations. IOP tends to increase after the age of 30 and is not accounted for by alterations in CCT values.

Alveolar fluid clearance in healthy pigs and influence of positive end-expiratory pressure

INTRODUCTION The objectives were to characterize alveolar fluid clearance (AFC) in pigs with normal lungs and to analyze the effect of immediate application of positive end-expiratory pressure (PEEP). METHODS Animals (n = 25) were mechanically ventilated and divided into four groups: small edema (SE) group, producing pulmonary edema (PE) by intratracheal instillation of 4 ml/kg of saline solution; small edema with PEEP (SE + PEEP) group, same as previous but applying PEEP of 10 cmH2O; large edema (LE) group, producing PE by instillation of 10 ml/kg of saline solution; and large edema with PEEP (LE + PEEP) group, same as LE group but applying PEEP of 10 cmH2O. AFC was estimated from differences in extravascular lung water values obtained by transpulmonary thermodilution method. RESULTS At one hour, AFC was 19.4% in SE group and 18.0% in LE group. In the SE + PEEP group, the AFC rate was higher at one hour than at subsequent time points and higher than in the SE group (45.4% vs. 19.4% at one hour, P < 0.05). The AFC rate was also significantly higher in the LE + PEEP than in the LE group at three hours and four hours. CONCLUSIONS In this pig model, the AFC rate is around 20% at one hour and around 50% at four hours, regardless of the amount of edema, and is increased by the application of PEEP.

Ambulatory blood pressure monitoring in the elderly

The incidence of hypertension is high in the elderly and is present in 2/3 of the patients older than 65 years. Prevalence can reach 90% in patients older than 80 years. The presence of isolated systolic hypertension (ISH) is characteristic of this population. However, the prevalence of hypertension by ambulatory blood pressure monitoring (ABPM) is not well known. In this study, we analyzed the special characteristics of hypertension in this population, giving special emphasis on ABPM readings

Dynamic arterial elastance to predict arterial pressure response to volume loading in preload-dependent patients

INTRODUCTION Hemodynamic resuscitation should be aimed at achieving not only adequate cardiac output but also sufficient mean arterial pressure (MAP) to guarantee adequate tissue perfusion pressure. Since the arterial pressure response to volume expansion (VE) depends on arterial tone, knowing whether a patient is preload-dependent provides only a partial solution to the problem. The objective of this study was to assess the ability of a functional evaluation of arterial tone by dynamic arterial elastance (Ea(dyn)), defined as the pulse pressure variation (PPV) to stroke volume variation (SVV) ratio, to predict the hemodynamic response in MAP to fluid administration in hypotensive, preload-dependent patients with acute circulatory failure. METHODS We performed a prospective clinical study in an adult medical/surgical intensive care unit in a tertiary care teaching hospital, including 25 patients with controlled mechanical ventilation who were monitored with the Vigileo(®) monitor, for whom the decision to give fluids was made because of the presence of acute circulatory failure, including arterial hypotension (MAP ≤65 mmHg or systolic arterial pressure <90 mmHg) and preserved preload responsiveness condition, defined as a SVV value ≥10%. RESULTS Before fluid infusion, Ea(dyn) was significantly different between MAP responders (MAP increase ≥15% after VE) and MAP nonresponders. VE-induced increases in MAP were strongly correlated with baseline Ea(dyn) (r(2) = 0.83; P < 0.0001). The only predictor of MAP increase was Ea(dyn) (area under the curve, 0.986 ± 0.02; 95% confidence interval (CI), 0.84-1). A baseline Ea(dyn) value >0.89 predicted a MAP increase after fluid administration with a sensitivity of 93.75% (95% CI, 69.8%-99.8%) and a specificity of 100% (95% CI, 66.4%-100%). CONCLUSIONS Functional assessment of arterial tone by Ea(dyn), measured as the PVV to SVV ratio, predicted arterial pressure response after volume loading in hypotensive, preload-dependent patients under controlled mechanical ventilation.

Surgical menopause increases salt sensitivity of blood pressure

Salt sensitivity of blood pressure is associated with an elevated risk of developing hypertension (HTN) and is an independent risk factor for cardiovascular disease. The prevalence of HTN increases after menopause. The aim of this study was to investigate prospectively whether the loss of ovarian hormones increases the occurrence of salt sensitivity among healthy premenopausal women. We enrolled 40 normotensive, nondiabetic women (age 47.2+/-3.5), undergoing hysterectomy-oophorectomy for nonneoplastic processes and not on hormone replacement, to determine the effect of changes in sodium intake on blood pressure the day before and subsequently 4 months after surgical menopause. Salt loading was achieved using a 2-L normal saline infusion and salt depletion produced by 40 mg of intravenous furosemide. A decrease >10 mm Hg in systolic blood pressure between salt loading and salt depletion was used to define salt sensitivity. Before and after menopause, salt-sensitive women exhibited higher waist/hip and waist/thigh ratios (P<0.01). Although all of the women remained normotensive, the prevalence of salt sensitivity was significantly higher after surgical menopause (21 women; 52.5%) than before (9 women; 22.5%; P=0.01), because 12 (38.7%) salt-resistant women developed salt sensitivity after menopause. In summary, we demonstrated that the prevalence of salt sensitivity doubled as early as 4 months after surgical menopause, without an associated increase in blood pressure. Epidemiological studies indicate that development of HTN may not occur until 5 to 10 years after menopause. The loss of ovarian hormones may unmask a population of women prone to salt sensitivity who, with aging, would be at higher risk for the subsequent development of HTN and cardiovascular disease.

Prevalence and factors associated with circadian blood pressure patterns in hypertensive patients.

Ambulatory blood pressure (BP) monitoring has become useful in the diagnosis and management of hypertensive individuals. In addition to 24-hour values, the circadian variation of BP adds prognostic significance in predicting cardiovascular outcome. However, the magnitude of circadian BP patterns in large studies has hardly been noticed. Our aims were to determine the prevalence of circadian BP patterns and to assess clinical conditions associated with the nondipping status in groups of both treated and untreated hypertensive subjects, studied separately. Clinical data and 24-hour ambulatory BP monitoring were obtained from 42,947 hypertensive patients included in the Spanish Society of Hypertension Ambulatory Blood Pressure Monitoring Registry. They were 8384 previously untreated and 34,563 treated hypertensives. Twenty-four-hour ambulatory BP monitoring was performed with an oscillometric device (SpaceLabs 90207). A nondipping pattern was defined when nocturnal systolic BP dip was <10% of daytime systolic BP. The prevalence of nondipping was 41% in the untreated group and 53% in treated patients. In both groups, advanced age, obesity, diabetes mellitus, and overt cardiovascular or renal disease were associated with a blunted nocturnal BP decline (P<0.001). In treated patients, nondipping was associated with the use of a higher number of antihypertensive drugs but not with the time of the day at which antihypertensive drugs were administered. In conclusion, a blunted nocturnal BP dip (the nondipping pattern) is common in hypertensive patients. A clinical pattern of high cardiovascular risk is associated with nondipping, suggesting that the blunted nocturnal BP dip may be merely a marker of high cardiovascular risk.

Influence of physical activity and dietary habits on lipid profile, blood pressure and BMI in subjects with metabolic syndrome

BACKGROUND The present study was determined the influence of physical activity and dietary habits on lipid profile, blood pressure (BP) and body mass index (BMI) in subjects with metabolic syndrome (MS). AIMS Identify the relationship between physical activity and proper nutrition and the probability of suffering from myocardial infarction (MI). METHODS Hundred chronically ill with MS who were active and followed a healthy diet were classified as compliant, while the remaining subjects were classified as non-compliant. RESULTS The compliant subjects show lower BMI values (30.8±4.9 vs 32.5±4.6), as well as lower levels of triacylglycerol (130.4±48.2 vs 242.1±90.1), total cholesterol (193.5±39 vs 220.2±52.3) and low-density lipoprotein cholesterol (105.2±38.3 vs 139.2±45). They show higher values in terms of high-density lipoprotein cholesterol levels (62.2±20.1 vs 36.6±15.3), with statistically significant differences. In terms of both systolic and diastolic pressure, no differences were revealed between the groups; however, those who maintain proper dietary habits show lower systolic blood pressure levels than the inactive subjects. The probability of suffering from MI greatly increases among the group of non-compliant subjects. CONCLUSIONS Our results demonstrate how performing aerobic physical activity and following an individualized, Mediterranean diet significantly reduces MS indicators and the chances of suffering from MI.

Compliance with guidelines-recommended processes in pneumonia: impact of health status and initial signs

Initial care has been associated with improved survival of community-acquired pneumonia (CAP). We aimed to investigate patient comorbidities and health status measured by the Charlson index and clinical signs at diagnosis associated with adherence to recommended processes of care in CAP. We studied 3844 patients hospitalized with CAP. The evaluated recommendations were antibiotic adherence to Spanish guidelines, first antibiotic dose <6 hours and oxygen assessment. Antibiotic adherence was 72.6%, first dose <6 h was 73.4% and oxygen assessment was 90.2%. Antibiotic adherence was negatively associated with a high Charlson score (Odds ratio [OR], 0.91), confusion (OR, 0.66) and tachycardia ≥100 bpm (OR, 0.77). Delayed first dose was significantly lower in those with tachycardia (OR, 0.75). Initial oxygen assessment was negatively associated with fever (OR, 0.61), whereas tachypnea ≥30 (OR, 1.58), tachycardia (OR, 1.39), age >65 (OR, 1.51) and COPD (OR, 1.80) were protective factors. The combination of antibiotic adherence and timing <6 hours was negatively associated with confusion (OR, 0.69) and a high Charlson score (OR, 0.92) adjusting for severity and hospital effect, whereas age was not an independent factor. Deficient health status and confusion, rather than age, are associated with lower compliance with antibiotic therapy recommendations and timing, thus identifying a subpopulation more prone to receiving lower quality care.

Effectiveness of olive oil for the prevention of pressure ulcers caused in immobilized patients within the scope of primary health care: study protocol for a randomized controlled trial.

BACKGROUND Pressure ulcers are considered an important issue, mainly affecting immobilized older patients. These pressure ulcers increase the care burden for the professional health service staff as well as pharmaceutical expenditure. There are a number of studies on the effectiveness of different products used for the prevention of pressure ulcers; however, most of these studies were carried out at a hospital level, basically using hyperoxygenated fatty acids (HOFA). There are no studies focused specifically on the use of olive-oil-based products and therefore this research is intended to find the most cost-effective treatment and achieve an alternative treatment. METHODS/DESIGN The main objective is to assess the effectiveness of olive oil, comparing it with HOFA, to treat immobilized patients at home who are at risk of pressure ulcers. As a secondary objective, the cost-effectiveness balance of this new application with regard to the HOFA will be assessed. The study is designed as a noninferiority, triple-blinded, parallel, multi-center, randomized clinical trial. The scope of the study is the population attending primary health centers in Andalucía (Spain) in the regional areas of Malaga, Granada, Seville, and Cadiz. Immobilized patients at risk of pressure ulcers will be targeted. The target group will be treated by application of an olive-oil-based formula whereas the control group will be treated by application of HOFA to the control group. The follow-up period will be 16 weeks. The main variable will be the presence of pressure ulcers in the patient. Secondary variables include sociodemographic and clinical information, caregiver information, and whether technical support exists. Statistical analysis will include the Kolmogorov-Smirnov test, symmetry and kurtosis analysis, bivariate analysis using the Student's t and chi-squared tests as well as the Wilcoxon and the Man-Whitney U tests, ANOVA and multivariate logistic regression analysis. DISCUSSION The regular use of olive-oil-based formulas should be effective in preventing pressure ulcers in immobilized patients, thus leading to a more cost-effective product and an alternative treatment. TRIAL REGISTRATION Clinicaltrials.gov identifier: NCT01595347.

Should screening for Chlamydia trachomatis and Neisseria gonorrhoeae in HIV-men who have sex with men be recommended?

INTRODUCTION Sexually transmitted infections (STI) like Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) have been associated with increased risk of HIV acquisition (1). It has been also described as a high prevalence of asymptomatic CT and NG infections in men who have sex with men (MSM) (2). The aim of this study was to know the prevalence of CT and/or NG infections in asymptomatic HIV-MSM and the related factors. MATERIALS AND METHODS Prospective study of a cohort of asymptomatic HIV-MSM with follow-up in Malaga (southern Spain) during October 2012-May 2014. Patients with an opportunistic event or who received active antibiotic therapy for CT and/or NG in the previous month were excluded. All of them completed a questionnaire about sexual behaviour, barrier methods and recreational drugs use. Demographical, epidemiological, clinical, analytical and therapeutic data were also collected. Pharyngeal and rectal swabs, and urine samples were collected to be tested for CT and NG by nucleic acid amplification test (c4800 CT/NG. Roche Diagnostics, Mannheim, Germany) (3). STATISTICS ANALYSIS SPSS 17.0. RESULTS 255 patients were asked to participate and 248 of them accepted. Median age was 37.7 (30.6-46.3) years, median time since HIV diagnosis was 47.7 (10.5-104.1) months, and median CD4 cells count was 607 (440-824) cell/µL. There were 195 (78.6%) patients on antiretroviral therapy; 81.5% of them had undetectable viral load. 80.5% of the patients had a past history of STI. Infection by CT and/or NG was diagnosed in 24 (9.7%) patients. Overall four urine samples, two pharyngeal, and 15 rectal ones were positive for CT, and five pharyngeal and five rectal swabs were positive for NG. Two patients were co-infected by CT and NG: one with CT in urine and both in rectum, another with CT in urine and rectum and NG in pharynx. One patient presented CT in pharynx and rectum, and two patients NG in pharynx and rectum. Positive CT and/or NG tests were only related with detectable HIV viral load (OR 3.08, 95% CI 1.2-7.4; p=0.01). It was not related with sexual behaviour, nor with alcohol or recreational drugs use. CONCLUSIONS STI screening had a great acceptance in this population. There was a high prevalence of asymptomatic CT and/or NG infections. Rectum sample was the most effective one. Viral suppression could protect from these STI. Screening should be recommended in HIV-MSM.

Dapagliflozina

Dapagliflozin is a new oral antidiabetic agent whose mechanism of action increases renal glucose excretion, independently of insulin secretion or insulin action. The efficacy of dapagliflozin is dependent on renal function. The use of dapagliflozin has been licensed to improve glycaemic control in patients with type 2 diabetes mellitus as: - monotherapy when diet and exercise alone do not provide adequate glycaemic control in patients for whom the use of metformin is considered inappropriate due to intolerance. - Add-on combination therapy with other glucose-lowering agents including insulin, when these, together with diet and exercise, do not provide adequate glycaemic control. Funding has been restricted to the use of dapagliflozin, prior approval, as dual therapy in combination with metformin. This report aims to assess the efficacy and safety of dapagliflozin in the treatment of type 2 diabetes mellitus, rate the added therapeutic value of dapagliflozin in type 2 diabetes mellitus and identify its current place in therapy. A systematic literature search was carried out, for the purpose of this evaluation, using PubMed, Embase, Cochrane and IDIS databases as well as other secondary sources of evidence-based medicine, therapeutic bulletins and national and international drug agencies. Following the critical reading and analysis of the selected articles, a summary is made out of the scientific evidence available, using Scottish Intercollegiate Guidelines Network (SIGN) criteria. Only one randomised clinical trial, out of the ten trials found, was considered to be a suitable comparison (versus a dual therapy in combination with the sulfonylurea glipizide in patients inadequately controlled with metformin, diet and exercise). No trials have evaluated variables of relevance to patients, except for safety variables. The main efficacy variable in the trials was the change from baseline in HbA1c, except for a study which evaluated the change from baseline in total body weight as main variable. Baseline characteristics of the patients enrolled in the trials significantly differ from those of the population with diabetes in our society which tend to be of an older age and have a longer history of type 2 diabetes mellitus. The major limitation of dapagliflozin derives from its mechanism of action, since its efficacy decreases as renal function declines. The use of dapagliflozin is not recommended in patients with moderate to severe renal impairment ((CrCl<60ml/min or GFG <60 ml/min/1.73 m2) nor in elderly patients, in which a decrease in renal function can be expected. The assessment of safety includes the incidence and rate of discontinuations due to adverse events, episodes of hypoglycaemia, signs or symptoms of genital and urinary tract infections, dehydration, hypovolaemia and hypotension. Further pharmacoepidemiological studies are to be carried out to clarify the long-term effects of dapagliflozin on renal function and the potential effect in the development of breast and bladder tumours. Dapagliflozin as monotherapy has not been evaluated against adequate comparators (sulfonylureas, pioglitazone, gliptins). In combination therapy with metformin, the efficacy of dapagliflozin was shown to be non-inferior to glipizide plus metformin, resulting in a mean reduction of 0.52% in HbA1c, with a difference of 0.00 among both groups (95% CI: -0.11 a 0.11). There are no comparative data against other second-line treatment options. As shown in the studies, the overall incidence of adverse events with dapagliflozin as monotherapy (21.5%) was similar to that observed with placebo, and greater to that observed with metformin (15.4%). Hypoglycaemia of any type was the adverse event more frequently reported. The incidence of severe hypoglycaemic events observed in most of the studies was low. The overall incidence of adverse events observed in the study that compared dapagliflozin+metformin against glipizide+metformin was similar for both groups (27%) and incidence of hypoglycaemic events with dapagliflozin (3.5%) was significantly lower to that observed with glipizide (40.8%). Reductions of body weight of about 2 to 3 kg and a slight decrease in blood pressure (1 to 5 mmHg) have been observed in all studies in the groups treated with dapagliflozin together with diet and exercise. Dosing scheme (every 24 hours) is similar to other oral antidiabetic agents and its cost is similar to that for gliptines and higher to that for sulfonylureas or generic pioglitazone. Funding has been limited to the use of dapagliflozin as dual therapy regimen in combination with metformin as an option for patients with contraindication or intolerance to sulfonylureas, such a those experiencing frequent hypoglycaemic events, weight loss associated risks, as long as they are under 75 years of age and have no moderate to severe renal impairment. In the light of the above, we consider dapagliflozin means no therapeutic innovation in the therapy of type 2 diabetes mellitus over other therapeutic alternatives available.

Central corneal thickness, intraocular pressure, and degree of myopia in an adult myopic population aged 20 to 40 years in southeast Spain: determination and relationships.

Objective: To determine the values of, and study the relationships among, central corneal thickness (CCT), intraocular pressure (IOP), and degree of myopia (DM) in an adult myopic population aged 20 to 40 years in Almeria (southeast Spain). To our knowledge this is first study of this kind in this region. Methods: An observational, descriptive, cross-sectional study was done in which a sample of 310 myopic patients (620 eyes) aged 20 to 40 years was selected by gender- and age-stratified sampling, which was proportionally fixed to the size of the population strata for which a 20% prevalence of myopia, 5% epsilon, and a 95% confidence interval were hypothesized. We studied IOP, CCT, and DM and their relationships by calculating the mean, standard deviation, 95% confidence interval for the mean, median, Fisher’s asymmetry coefficient, range (maximum, minimum), and the Brown-Forsythe’s robust test for each variable (IOP, CCT, and DM). Results: In the adult myopic population of Almeria aged 20 to 40 years (mean of 29.8), the mean overall CCT was 550.12 μm. The corneas of men were thicker than those of women (P = 0.014). CCT was stable as no significant differences were seen in the 20- to 40-year-old subjects’ CCT values. The mean overall IOP was 13.60 mmHg. Men had a higher IOP than women (P = 0.002). Subjects over 30 years (13.83) had a higher IOP than those under 30 (13.38) (P = 0.04). The mean overall DM was −4.18 diopters. Men had less myopia than women (P < 0.001). Myopia was stable in the 20- to 40-year-old study population (P = 0.089). A linear relationship was found between CCT and IOP (R2 = 0.152, P ≤ 0.001). CCT influenced the IOP value by 15.2%. However no linear relationship between DM and IOP, or between CCT and DM, was found. Conclusions: CCT was found to be similar to that reported in other studies in different populations. IOP tends to increase after the age of 30 and is not accounted for by alterations in CCT values.