Mm Hg Range Research Articles

Brain Interstitial Matrix Hydration Inversely Correlates with Neuronal Excytability

Interstitial flux of cerebrospinal fluid (CSF) mediates optimal transfer, clearance, and exchange of molecules in the brain. To determine whether disturbances during dehydration or edema lead to neuronal dysfunction, we quantified hydration in the brains of mice subjected to mild water deprivation and measured neuronal excitability in the dehydrated and rehydrated hippocampus. Specifically, we titrated water activity ex vivo using artificial CSF solutions of nonpenetrating inert polymers adjusted to give colloidosmotic pressures in the 0-200 mmHg range. Compared to nondeprived controls, the brains of water-deprived mice had hydration potentials of 94.5 ± 5.4 and 103.8 ± 3.5 mmHg after 12 and 24 hours, respectively, corresponding to 23 and 28 mmHg increases in potential, or 20% and 27% decreases in hydration. The brain-matrix hydraulic conductance, 0.051 ± 0.0019 µl/min/g/mmHg, did not change significantly (n = 6 hydrated/dehydrated pairs). The field excitatory postsynaptic potentials (fEPSP) in the hippocampus, adjusted to hydrations 25 and 125 mmHg below controls, increased 47% and 66%, respectively, but did not change at hydrations up to 75 mmHg above control. In addition, the level of phosphorylated CREB (cAMP response-binding protein), a key mediator of neuronal excitatory pathways, increased in dehydrated hippocampus after subthreshold stimulation.These results show that brain dehydration levels comparable to those measured following short-term water deprivation in mice increase neuronal excitability. Neurons appear very sensitive to water-activity changes, suggesting local dehydration in the interstitial matrix contributes to the cognitive deficits seen in dehydrated humans. As a plausible mechanism, we suggest that lower water activity in dehydrated brains increases the effective concentration of all solutes, modifying the timing, diffusivities, and probabilities of neurotransmitters binding to their cognate receptors.

Development of an Ergonomic Tool to Predict Carpal Tunnel Syndrome Risk Based on Estimated Carpal Tunnel Pressure

OCCUPATIONAL APPLICATIONS An ergonomic tool that predicts Carpal Tunnel Syndrome (CTS) risk based on predicted carpal tunnel pressure (CTP) was developed and a preliminary evaluation was made in a large manufacturing environment. Elevated CTP has been associated with CTS. However, CTP is invasive to measure in vivo, and is thus not practical in an applied setting. This project represents the development of an ergonomic tool based on predicted CTP that could be an asset to ergonomists both in job evaluation and (re)design to reduce occupational CTS risk in workers with otherwise normal wrists.TECHNICAL ABSTRACT Background: CTS remains an important issue in the workplace. Increased carpal tunnel pressure (CTP) may lead to the aggravation or development of CTS. A CTP of 30 mmHg has been used as a threshold limit value for CTS risk. Deviation from a neutral wrist, neutral forearm, and relaxed fingers results in an increase in CTP. Fingertip loading has also been shown to increase CTP independently of posture. Purpose: To develop an ergonomic tool to predict carpal tunnel syndrome (CTS) risk based on the predicted carpal tunnel pressure (CTP) in healthy wrists. Method: A tool was developed to predict CTS-risk based on CTP determined from the literature. The tool was evaluated by comparing the output of the tool (CTS risk) to the incidence of CTS in a large manufacturing environment. Results: The model predicted a mean (S), time-weighted CTP of 21.3 (0.4) mmHg (range 18.5–27.8 mmHg). Evaluative results were promising, as CTS risk was slightly higher in jobs with a historical incidence of CTS. Conclusion: While the tool predicted CTS risk based on CTP, too few CTS claims existed to develop a strong correlation. Further refinement and investigation are needed to include combined postures and mechanical compression, and to further validate the tool.

Ocular Biometric Factors and its Association with Intraocular Pressure

Aim: To study the role of ocular biometric factors like, central corneal thickness, corneal curvature, anterior chamber depth and axial length and to evaluate its association with intraocular pressure. Materials and method: The study was done at a tertiary care hospital in North India. A detailed history from all the patients was elicited and complete ocular examination like visual acuity, slit lamp examination, tonometry, fundus examination, visual field evaluation, keratometry, gonioscopy, central corneal thickness, A-scan for axial length was performed. Observation and results: A total of 800 subjects falling in sampling frame were enrolled in the study. Central corneal thickness was 600 μm in 0.7% cases. Axial length ranged from 20.1 to 33.9 with a mean of 23.02 ± 1.27 units. Anterior chamber depth was normal in 94.7%, deep in 2.2% and shallow in 3.1% cases. IOP of patients ranged from 10.1 to 37.5 mmHg. Maximum number of cases had IOP in 16-20 mmHg range (44.1%) followed by those having IOP in 12-16 mmHg range (40.1%), 20-24 mmHg range (11.4%), >24 mmHg (3.8%) and 16 mmHg) was projected as a dependent variable with central corneal thickness, axial length and anterior chamber depth as independent variables, only anterior chamber depth showed a significant association with the outcome IOP Conclusion: A significant association was found between IOP and CCT and anterior chamber depth, while we did not find a significant association between IOP and axial length.

Laparoscopic cholecystectomy under spinal anesthesia in high risk patients: A single center experience

Aim: Laparoscopic cholecystectomy is routinely done with general anesthesia except for patients that are considered too sick for general anesthesia. The goal of this study was to investigate the availability, safety, and side effects of spinal anesthesia in laparoscopic cholecystectomy. Material and Methods: Patients with high risk for general anesthesia who admitted for laparoscopic cholecystectomy were given the choice of spinal anesthesia instead of general anesthesia. In Ortadogu Private Hospital, Adana, Turkey; 371 subjects were prospectively admitted for laparoscopic cholecystectomy under spinal anesthesia between January 2015 and January 2018. All volunteers provided informed consent. The spinal anesthesia procedure was done similar to the general anesthesia protocol with no modifications. Intra-abdominal pressure was sustained within the 8-10 mmHg range. A 3.5mL bupivacaine (0.5%)/fentanyl (20 μg) mixture was used for spinal anesthesia. Data collected for demographics, ASA scores, surgery duration, comorbidities, and sedation medication/dosage were reviewed. Results: A total of 232 women (62.6%) and 139 men (37.4%) comprised the study. The subjects averaged 51 years of age (range: 37-89). Patients were classified into the following ASA categories: ASA II: 48 subjects (12.9%), ASA III: 197 subjects (53.1%), ASA IV: 126 subjects (34.0%). Surgery was performed successfully in 371 patients. Spinal anesthesia was adapted to general anesthesia for 2 (0.5%) subjects. The average operation time was 38.1 minutes (range: 16-74 minutes). O2 saturation was 97.8% on average for all patients. Right shoulder pain was documented in 14.5% of the patients, and a shoulder massage alleviated the discomfort in most subjects. Conclusions: Spinal anesthesia should be the anesthesia of choice dues to its numerous advantages in high-risk patients related to general anesthesia.

Splenoadrenal Shunt for Noncirrhotic Portal Hypertension

Portosystemic shunt surgery is an established treatment option for preventing variceal rebleeding in patients with noncirrhotic portal hypertension (NCPH). The proximal splenorenal shunt is a widely performed procedure in these patients. In this study, the use of adrenal vein as an alternative conduit has been investigated. A retrospective analysis of patients with NCPH who underwent proximal splenoadrenal and splenorenal shunt between 2011 and 2015 was performed. Demographic findings, etiology of portal hypertension, clinical presentation, hematological parameters, liver function test, intraoperative findings, postoperative morbidity, and shunt patency were studied and compared between the two groups. All patients were followed up for a minimum of 12 months with Doppler study of the shunt to assess shunt patency and upper gastrointestinal endoscopy to assess regression of varices. During the study period, 97 patients with NCPH underwent shunt surgery (proximal splenoadrenal shunt, 8; proximal splenorenal shunt, 74; and interposition mesocaval shunt, 15). Anomalous anatomy of the left renal vein was the main indication (5/8 patients) for a splenoadrenal shunt. Median fall in portal pressure in patients who underwent splenoadrenal shunt was 11.5 mmHg (range, 2–14 mmHg). The median (range) operative time was 4.5 (3–6) hours and median (range) intraoperative blood loss was 160 (100–200) mL. During a median (range) follow-up of 32 (12–48) months, shunt thrombosis developed in one patient. Comparison of intraoperative parameters and postoperative outcomes showed no significant difference in median fall in portal pressure (p = 0.39), median operative time (p = 0.51), median blood loss (p = 0.80), Grade III/IV postoperative complications (p = 0.56), shunt thrombosis (p = 0.93), and varices regression rate (p = 0.72) between patients undergoing proximal splenorenal and splenoadrenal shunt. In conclusion, left adrenal vein is a suitable vascular conduit for porto-systemic shunt surgery. This is especially so if the performance of splenorenal shunt is precluded because of anatomic abnormality of the renal vein.

The role of interventional angiography and embolisation in the management of high-energy pelvic ring injuries with uncontrolled haemorrhage

BACKGROUND: The availability of and advances in interventional angiography and embolisation for the management of high-energy pelvic ring injuries with uncontrolled haemorrhage have expanded considerably during the last decade. Its routine use, however, still remains controversial. The delay in performing angiography is often cited as a major limitation for this intervention. PURPOSE OF THE STUDY: We aim to determine the mean time to interventional angiography and embolisation and report on the success rate thereof in patients with pelvic ring injuries and associated haemorrhage in a Level 1 Trauma Unit. METHODOLOGY: Between 1997 and 2012, we identified a total of seven patients who were managed with interventional angiography for the treatment of pelvic ring injuries associated with massive haemorrhage that did not respond to fluids and blood products resuscitation alone. Data was collected retrospectively, with respect to the injury pattern, resuscitative parameters, survival rates and efficacy of the angiography. RESULTS: All seven patients presented with high energy injuries and had rotationally as well as vertically unstable pelvic fractures. The average systolic blood pressure on admission was 80 mmHg (range 60-140). On average 8.75 (range 2-21) units of packed red blood cells were transfused per patient. Three patients required a laparotomy for associated intra-abdominal injuries. The time from admission to an emergency laparotomy was 4.5 h (range 2-12). The time from admission to angiography was 14 h (range 4-24). Three of the seven patients had a successful pelvic angio-embolisation. Six patients survived until discharge and one patient demised due to multi-organ failure on day 14 after embolisation. DISCUSSION: Only seven patients with pelvic ring injuries were managed with angiography and embolisation in a period of 15 years, suggesting that we seldom use this modality for haemorrhage control. The delay from admission to angiography was 14 hours (range 4-24). An arterial bleed was successfully identified and embolised in three patients (43%). CONCLUSION: While it is used with greater frequency in other centres, in our hospital setting angiography in the management of haemorrhage in pelvic ring injuries is rarely used. Our success rate with this intervention is fair.

Association Between Blood Pressure and Adverse Renal Events in Type 1 Diabetes.

OBJECTIVETo compare different blood pressure (BP) levels in their association with the risk of renal outcomes in type 1 diabetes and to determine whether an intensive glycemic control strategy modifies this association.RESEARCH DESIGN AND METHODSWe included 1,441 participants with type 1 diabetes between the ages of 13 and 39 years who had previously been randomized to receive intensive versus conventional glycemic control in the Diabetes Control and Complications Trial (DCCT). The exposures of interest were time-updated systolic BP (SBP) and diastolic BP (DBP) categories. Outcomes included macroalbuminuria (>300 mg/24 h) or stage III chronic kidney disease (CKD) (sustained estimated glomerular filtration rate <60 mL/min/1.73 m2).RESULTSDuring a median follow-up time of 24 years, there were 84 cases of stage III CKD and 169 cases of macroalbuminuria. In adjusted models, SBP in the <120 mmHg range was associated with a 0.59 times higher risk of macroalbuminuria (95% CI 0.37–0.95) and a 0.32 times higher risk of stage III CKD (95% CI 0.14–0.75) compared with SBPs between 130 and 140 mmHg. DBP in the <70 mmHg range were associated with a 0.73 times higher risk of macroalbuminuria (95% CI 0.44–1.18) and a 0.47 times higher risk of stage III CKD (95% CI 0.21–1.05) compared with DBPs between 80 and 90 mmHg. No interaction was noted between BP and prior DCCT-assigned glycemic control strategy (all P > 0.05).CONCLUSIONSA lower BP (<120/70 mmHg) was associated with a substantially lower risk of adverse renal outcomes, regardless of the prior assigned glycemic control strategy. Interventional trials may be useful to help determine whether the currently recommended BP target of 140/90 mmHg may be too high for optimal renal protection in type 1 diabetes.

THE ADVANTAGES OF USING THE TONO-PEN VET TONOMETER IN THE MEASUREMENT OF IOP IN VETERINARY PRACTICE

Objective The aim of this study was to evaluate and to validate the accuracy of the Tono-Pen Vet applanation tonometer in the measurement of IOP in dogs and to observe the advantages and disadvantages of using the Tono-Pen Vet tonometer in clinical practice.Animals Both eyes of 41 conscious and healthy dogs were evaluated.Procedure Readings of IOP were taken using tonometry (measured with a Tono-Pen Vet applanation tonometer). The IOP measurement with Tono-Pen Vet tonometer in conscious dogs was accomplished by instillation of 0,5% Alcaine eye drops.Results The mean IOP readings with the Tono-Pen Vet were 18,5 ± 3,7 mmHg (range 11,5 – 24,5 mmHg).The correlation coefficient (r²) between both eyes was 0,26826 in dogs.Conclusion Mean values measured by Tono-Pen Vet where in the correct range for dogs, but we conclude in comparison with the data of other studies, that values measured with a Tono-Pen Vet could be 5-6 mmHg higher than measured by another tonometers, like Perkins or TonoVet.The advantages of using the Tono-Pen Vet tonometer include the ease of taking the IOP measurement reading, ease of visualization of measurement readings, ease of disinfecting and long-term battery life. The disadvantages include frequent calibration, reduced accuracy and underestimation of true IOP compared to manometry and cost of the Tono-Pen Vet is higher, than for example Schiotz Tonometer or Perkins.

PL 02-3 MANAGEMENT OF ELDERLY HYPERTENSION

Age is the most powerful cardiovascular risk factor. Based on a meta-analysis of a million control patients in hypertension trials, the Clinical Trialists Collaboration has estimated that doubling of major cardiac and stroke events occurs with age increments of 70 (mean: 75.2), compared with those 60 with isolated systolic hypertension (mean baseline systolic BP = 170mmHg) demonstrated that active treatment with chlorthalidone reduced systolic BP to 143mmHg and, compared with placebo (systolic BP = 155 mmHg), significantly reduced stroke by 36%. Similarly, in the SystEUR trial (3), also conducted in older patients with isolated systolic hypertension, the calcium channel blocker nitrendipine was significantly superior to placebo in preventing stokes.The ACCOMPLISH trial has compared cardiovascular outcomes rates according to achieved systolic BPs. In patients aged 140 mmHg; and was reduced by a further 27% at 70, there was also a significant 34% reduction in events when systolic BP was reduced to 80 (average: 84). In patients randomised to active treatment, indapamide and perindopril were used to achieve a systolic target of 75. In this older cohort (average age: 80), intensive treatment (systolic target < 120 mmHg), compared with standard treatment (target < 140 mmHg) reduced systolic BP to 123.4 mmHg and significantly decreased the composite CV outcome by 34%, heart failure by 38% and total mortality by 33%. The treatment was well tolerated symptomatically, but there was a significant adverse effect on renal function. Similar decreases in renal function were also observed in ACCOMPLISH when systolic bps were outside the optimal 130-139 mmHg range (4).It is important to note that BP in SPRINT was measured by an automated device with patients seated alone and unobserved by professional personnel. This method appears to provide systolic BPs around 5-10 mmHg lower than well-measured standard office BPs, so the achieved value of 123.4 mmHg in the older patient group in SPRINT corresponds to around 130 mmHg in usual clinical practice. Another issue in interpreting the SPRINT results is that the patients in the intensively treated group were significantly more likely to receive agents like renin-angiotensin system blockers, calcium channel blockers and thiazide-like diuretics that are known to exhibit CV benefits independent of BP reduction. So, how much of the benefit in the intensively treated group was due to its lower BP, and how much to the cardioprotective actions of the additional drugs? We now know that treating patients into their 80 s, and possibly beyond, is well justified. Mortality and major cardiovascular outcomes are reduced. It is appropriate to recommend an office-measured systolic BP target of around 130 mmHg in older patients. Any of the major antihypertensive drug classes can be used: in particular calcium channel blockers, RAS blockers, and thiazides are indicated. In general, treatment in older patients is well tolerated, although it is wise to check for orthostatic symptoms in older patients and to monitor renal function when pursuing aggressive BP targets.

OS 14-01 AN ESTIMATED OPTIMAL HYPERTENSION LEVEL OF GOALS ON DRUG THERAPY FROM THE FEVER TRIAL

Abstract There is some debate as to optimal BP goals with antihypertensive treatment derived mostly in post-hoc analysis of large trials. Because there was limited number of subjects and outcomes within the larger study which may cloud the analytical accuracy of the findings. We suggest a new method to estimate the J-curve. Felodipine Event Reduction (FEVER) study randomized 9711 Chinese hypertensive patients to more or less intense anti-hypertensive treatment with 159,844 BP measurements. A new approach to evaluate events per 1000 patient (MEPPO) instead of previous methodology, which calculated overall means in fixed intervals. MEPPO was then based on observations from each visit in which event and BP data was collected. Therefore, event data corresponded with BP measured prior to the visits. BP 10 mmHg range to which events were referred and the range was moving with 1 mmHg steps. Each observation to enter 10 times into 10 consecutive 10 mmHg BP ranges. Thus, the overall number of analyzed data is greatly increased. There is a steep decrease in incidence of all outcomes (all CV events, strokes, cardiac events, CV and all deaths) to reach a rather flat nadir at SBP 129-138 mmHg and DBP 79-88 mmHg. The J-curves in relationship between events and BPs were drown with high precision. The new approach was more sensitive for J-curve assessment, because all observations were used. The optimal BP goals with antihypertensive treatment are 134 ± 5 (SBP) and 84 ± 5 (SBP) from the FEVER study.

Abstract 515: Comparison of Aging and Disturbed Flow Effects on Arterial Wall Biomechanics

Introduction: Arterial stiffness is an age related disease that doubles ones cardiovascular mortality and functions as an intermediary step in the formation of atherosclerosis. We have recently demonstrated that low and oscillatory wall shear stress, termed disturbed flow (d-flow), leads to arterial stiffness in otherwise normal arteries. Since d-flow has been linked to atherosclerotic plaque formation, our objective is to compare the carotid artery mechanics of 12 week arteries exposed to 4 weeks of d-flow to that of untreated 80 week old s129 mice. We hypothesize that low and oscillatory shear governs the remodeling of the arteries in a way that mimics the effect of arterial stiffening associated with aging. Materials and Methods: We used a partial carotid ligation model in 12-week-old s129 male (n=3) and female (n=3) mice. 4 weeks post surgery we euthanized the animals and performed biaxial extension-inflation biomechanical testing, confocal imaging, histological studies and opening angle studies on the left (partially ligated) carotid artery (LCA) and right (non-ligated) carotid artery (RCA) in order to characterize their biomechanical behavior. The same testing was performed on s129 80-week-old male animals (n=4). Pressure-diameter (P-d) data were collected from cyclic pressurization ramps from 0 to 160 mmHg at constant axial extension levels ranging from 1.3 to 1.9. Compliance was calculated at the in-vivo axial stretch level of 1.7 for both age groups. Intima media thickness was analyzed from H&amp;E stained histological slides. Results were compared with the unpaired, two-tailed t-test and significance was taken at p&lt;0.05. Results and Conclusions: Partial ligation for 4 weeks drastically decreased the compliance of the 12-week-old left carotid in a way that exactly follows the stiffening of the arteries in the 80-week-old mice. The compliance of the non-manipulated right carotid arteries reflected the age related difference in the stiffness of young vs old arteries with statistical difference in the 30 - 90 mmHg range. We have established that low shear stress and oscillatory flow promote the increase in arterial stiffening in the partially ligated young mice in a way that mimics the age-related decrease in arterial compliance in old mice.

Total and methylmercury partitioning between colloids and true solution: From case studies in sediment overlying and porewaters to a generalized model.

Tangential flow ultrafiltration was used to determine the partitioning of total mercury (THg) and monomethylmercury (MMHg) between colloids and true solution in sediment overlying and porewaters collected in Lake Geneva (Switzerland and France), Venice Lagoon (Italy), and Baihua Reservoir (China). Overlying water and porewater spanned different ranges of THg and MMHg concentrations, redox conditions, and salinity. Total Hg, MMHg, and dissolved organic carbon (DOC) concentrations were measured in filter-passing (<0.45 μm), colloidal (3 kDa-0.45 μm), and truly dissolved (<3 kDa) fractions. The percentages of filterable Hg and MMHg associated with colloids (arithmetic means ±1 standard deviation [SD]) were 29 ± 11% for THg (range, 4-60%) and 44 ± 17% for MMHg (range, 15-65%). Ultrafiltration DOC mass balances were often not satisfactory. However, this was apparently without consequences on THg/MMHg fractionation, suggesting that only a part of total DOC controlled THg/MMHg partitioning in overlying water and porewater. Linear relationships existed between filter passing and truly dissolved concentrations of THg and MMHg, suggesting that mechanisms controlling their partitioning are, at least partly, similar across aquatic systems. These linear relationships could be extended to data from published studies and ultrafilterable concentrations often could be predicted, within a factor of 2, from the measurement of filter-passing ones. The possibility to easily model THg/MMHg partitioning across aquatic systems will facilitate its consideration in general biogeochemical THg/MMHg models.

Positive Airway Pressure Therapy for Sleep Disordered Breathing in Congestive Heart Failure is Associated with Reduction in Pulmonary Artery Systolic Pressure

Background: Sleep disordered breathing and pulmonary hypertension are both highly prevalent in patients with congestive heart failure (CHF). Since (SDB) has been shown to increase pulmonary pressures, we hypothesized that initiation of positive airway pressure (PAP) may reduce pulmonary artery systolic pressure (PASP) in compliant patients. Methods: A total of 125 consecutive CHF patients admitted for decompensation were screened. Of these patients, 18 met inclusion criteria for the study which included a PASP ≥ 36 and polysomnogram-proven SDB. A repeat echocardiogram performed at mean 8 weeks post intervention was reviewed to compare PASP. Results: There was no statistically significant difference in mean age, BMI, AHI, baseline PASP, and ejection fraction between the PAP-compliant group and PAP non-compliant group. A statistically significant mean reduction in PASP of 13.8 ± 7.0 mmHg (range: -25, -1) was observed in CHF patients with SDB who were compliant with PAP therapy, versus a mean increase of 0.9 ± 8.7 mmHg (range: -8, 15) in heart failure patients with SDB who were noncompliant with PAP therapy. Conclusions: The findings suggest that PAP therapy is associated with improvement in pulmonary hypertension with congestive heart failure and sleep disordered breathing.

Biomechanical Measurement of Rabbit Cornea by a Modified Scheimpflug Device.

Purpose. To explore the probability and variation in biomechanical measurements of rabbit cornea by a modified Scheimpflug device. Methods. A modified Scheimpflug device was developed by imaging anterior segment of the model imitating the intact eye at various posterior pressures. The eight isolated rabbit corneas were mounted on the Barron artificial chamber and images of the anterior segment were taken at posterior pressures of 15, 30, 45, 60, and 75 mmHg by the device. The repeatability and reliability of the parameters including CCT, ACD, ACV, and CV were evaluated at each posterior pressure. All the variations of the parameters at the different posterior pressures were calculated. Results. All parameters showed good intraobserver reliability (Cronbach's alpha; intraclass correlation coefficient, α, ICC > 0.96) and repeatability in the modified Scheimpflug device. With the increase of posterior pressures, the ratio of CCT decreased linearly and the bulk modulus gradually reduced to a platform. The increase of ACD was almost linear with the posterior pressures elevated. Conclusions. The modified Scheimpflug device was a valuable tool to investigate the biomechanics of the cornea. The posterior pressure 15–75 mmHg range produced small viscoelastic deformations and nearly linear pressure-deformation response in the rabbit cornea.

Abstract 15897: Identification of Candidates for Novel Interatrial Shunt Devices Through Non-invasive Testing in Patients With Heart Failure and Preserved Ejection Fraction

Introduction: Interatrial shunt devices (IASD) are a novel therapeutic option for heart failure and preserved ejection fraction (HFpEF). IASDs work by decompressing the overloaded left atrium (LA) via shunting of blood to the right atrium (RA). Thus, optimal candidates for the IASD intervention will have an elevated pressure gradient between the LA and RA. We hypothesized that increased LA-RA gradient could be diagnosed non-invasively by echo. Methods: A total of 293 consecutive patients with HFpEF who also underwent invasive hemodynamic testing were were identified. All patients underwent comprehensive echo, including tissue Doppler. Patients were categorized into 2 groups based on the LA-RA pressure gradient (PCWP-RA pressure) at time of invasive hemodynamic testing (PCWP-RAP &gt; 10 mmHg [large pressure gradient] vs. PCWP 0-5 mmHg [low pressure gradient]), and clinical, laboratory, and echocardiography parameters were compared between groups. Results: Mean age was 64±12 years, 59% were female, 36% were African American, and comorbidities were common. Of the 293 patients, n=58 had PCWP-RAP gradient of 0-5 mmHg and n=114 had PCWP-RAP &gt; 10 mmHg, with the rest of the patients (n=56) in the PCWP-RAP 5-10 mmHg range. Patients with an elevated PCWP-RAP gradient were more often female and obese and less likely to have a history of atrial fibrillation (Table). On echocardiography, the 2 parameters that were most different between groups were TAPSE and lateral e’ velocity such that an elevated ratio of TAPSE to lateral e’ velocity identified patients with HFpEF who were most likely to have an elevated PCWP-RAP gradient &gt; 10 mmHg (area under the ROC curve = 0.69 [95% CI 0.60-0.78]; P=0.001). Conclusions: An elevated TAPSE/lateral e’ velocity ratio on echo in HFpEF is associated with invasive PCWP-RAP gradient &gt; 10 mmHg at rest and may aid in the identifying suitable HFpEF candidates who would benefit from an IASD.

Abstract 17110: Risk Factors for Hepatic Fibrosis in Children and Adolescents After Fontan Operation

Introduction: Congestive hepatopathy is increasingly recognized as a complication of Fontan physiology. Prospective data regarding the incidence of hepatopathy and risk factors for its development are lacking. Methods: Liver biopsies were obtained as part of a routine program of comprehensive end-organ evaluation offered to all patients &gt;10 years after Fontan operation (FO) through the Single Ventricle Survivorship Program. Evaluation included cardiac catheterization and contemporaneous percutaneous liver biopsy. Quantitative determination of hepatic fibrosis was performed using Sirius red staining for collagen with automated calculation of percent positive staining per slide. Patient specific characteristics, echocardiographic findings, and hemodynamic measures were assessed and evaluated as potential risk factors for collagen deposition using Pearson correlation. Differences in collagen deposition (%CD) between subgroups were assessed using the student t-test. Results: The cohort consisted of 67 patients (36 male) at mean age of 17.3 ±4.5 years and mean time from Fontan of 14.9 ±4.5 years. Right ventricular morphology was present in 37 subjects; 30 with hypoplastic left heart syndrome. Mean %CD by Sirius red staining was 23.8 ±9.5% (range 8.7-49.4%) as compared to 2.6 ±0.3% in controls. There was significant correlation between time from Fontan and degree of Sirius red staining (r=0.33, p=0.006). Serum liver enzymes and platelet count did not correlate with %CD. The median inferior vena cava (IVC) pressure was 13 mmHg (range 6-24 mmHg) and did not correlate with %CD. There was no difference in %CD between those with a measured IVC pressure ≥13 mmHg versus those with a pressure &lt;13 mmHg. There was no difference in %CD based on ventricular morphology or severity of atrioventricular valve insufficiency. Conclusion: In this cohort of predominantly asymptomatic children and adolescents electively evaluated after FO, all exhibited evidence for hepatic fibrosis as measured by collagen deposition in the liver. Time from FO was the only factor in this cohort that was significantly associated with collagen. These findings demonstrate that liver fibrosis is an inherent feature of Fontan physiology and that the degree of fibrosis increases over time.

Interface pressure mapping pilot study to select surfaces that effectively redistribute pediatric occipital pressure

AimThe aim of this pilot study was to better inform clinical decisions to prevent pediatric occipital pressure ulcers with quantitative data to choose an appropriate reactive support surface. MaterialsA commercially available capacitive pressure mapping system (XSENSOR, X3 Medical Seat System, Calgary, Canada) was used to evaluate a standard pediatric mattress and four commercially available pressure-redistributing support surfaces. MethodsThe pressure mapping system was validated for use in the pediatric population through studies on sensitivity, accuracy, creep, and repeatability. Then, a pilot pressure mapping study on healthy children under 6 years old (n = 22) was performed to determine interface pressure and pressure distribution between the occipital region of the skull and each surface: standard mattress, gel, foam, air and fluidized. ResultsThe sensor was adequate to measure pressure generated by pediatric occipital loading, with 0.5–9% error in accuracy in the 25–95 mmHg range. The air surface had the lowest mean interface pressure (p < .005) and lowest peak pressure index (PPI), defined as the peak pressure averaged over four sensels, (p < .005). Mean interface pressure for mattress, foam, fluidized, gel, and air materials were 24.8 ± 4.42, 24.1 ± 1.89, 19.4 ± 3.25, 17.9 ± 3.10, and 14.2 ± 1.41 mmHg, respectively. The air surface also had the most homogenous pressure distribution, with the highest mean to PPI ratio (p < .005) and relatively high contact area compared to the other surfaces (p < .005). ConclusionThe air surface was the most effective pressure-redistributing material for pediatric occipital pressure as it had the lowest interface pressure and a homogeneous pressure distribution. This implies effective envelopment of the bony prominence of the occiput and increasing contact area to decrease peak pressure points.

The Outcome of Intravitreal Ranibizumab Injection for Branch Retinal Vein Occlusion Related Macular Edema

Branch retinal vein occlusion related macular edema (BRVO-ME) is the leading cause of visual loss in patients with Branch retinal vein occlusion (BRVO). In the current study, our aim was to investigate the outcome of intravitreal ranibizumab injection for BRVO-ME. The medical records of randomised thirteen eyes of thirteen patients (7 women and 6 men) with BRVO-ME were reviewed retrospectively. Three and 10 eyes had inferior temporal and superior temporal branch retinal vein occlusion-related macular edema, respectively. At the enrollment visit, all patients received a complete ophthalmic examination, including central subfield (CSF) thickness and average cube thickness measurements using spectral-domain optical coherence tomography (SD-OCT), best corrected visual acuity (BCVA) and intraocular pressure (IOP) measurements. The median patient age was 53 years (range, 38-74). Of the patients, median CSF thickness was 453 μ (range, 221-907), median average cube thickness was 293 μ (range, 237-433), median BCVA was 0.30 logMAR unit (range, 0.05-1.00 logMAR unit), and median IOP scores was 18 mmHg (range, 15-25) at baseline. Compared with baseline, a statistical significance in median CSF thickness scores at week 1 (p=0.015), months 1 (p=0.015), 2 (p=0.030), and 3 (p=0.045) was noted. Compared with baseline, a statistical significance in median BCVA scores at months 2 (p=0.045), 3 (p=0.030), and 6 (p=0.045) was noted. Compared with baseline, no statistical significance in median IOP scores and median average cube thickness scores at week 1, months 1, 2, 3, and 6 was noted (p>0.05, for all). No statistical significance in median CSF thickness scores, median BCVA scores, median IOP scores, or median average cube thickness scores was noted between the other follow-up periods. No complication related to ranibizumab injections was detected during the follow-up period. The treatment method does not cause any increase in IOP score. Besides ranibizumab injection can cause a dramatic decrease in CSF thickness scores and a dramatic increase in BCVA scores as early as at week 1 postoperatively.

Improved oxygenation in patients with acute respiratory failure: the prone position.

To assess the potential benefits of the prone position for gas exchange in patients with acute respiratory failure, we turned 6 patients from supine to prone, supporting the upper thorax and pelvis and allowing the abdomen to protrude. Arterial PO2 increased by a mean of 69 mm Hg (range, 2 to 178 mm Hg) at the same tidal volume, same inspired oxygen concentration, and same level of positive end-expiratory pressure. The maneuver made it possible to reduce the inspired oxygen concentration in 4 of the 5 patients who required mechanical ventilation of the lungs and to defer intubation in the patient who was breathing spontaneously. After subsequent turns from supine to prone, arterial PO2 increased by a mean of 35 mm Hg (range, 4 to 110 mm Hg), permitting a decrease in inspired oxygen concentration or positive end-expiratory pressure when prone (4 patients); arterial PO2 decreased in 12 of 14 instances after the patient was turned from prone to supine. No significant change in mean arterial carbon dioxide tension, respiratory frequency, or effective compliance was observed.

Abstract 20260: The Effect of Lifestyle Recommendations on Blood Pressure and Blood Pressure Control in Patients With Stage I Hypertension: The Prever Treatment Trial

Introduction: Lifestyle recommendations are recommended for patients with Stage I hypertension before starting blood pressure-lowering drugs in patients free of cardiovascular disease. The proportion of patients that have blood pressure (BP) controlled with these recommendations was scarcely reported in a clinical context. Hypothesis: To investigate the rate of response to a short-term lifestyle intervention (LsI) in the first phase of a randomized clinical trial. Methods: PREVER prevention is a double blind, multicenter, randomized clinical trial of effectiveness of drug treatment to control hypertension and target organ damage among individuals with hypertension. It was conducted in 22 centers distributed in 10 Brazilian states. Participants were enrolled in the study if they had hypertension (≥140 of systolic blood pressure or ≥90 mmHg of diastolic blood pressure), confirmed in two visits in the clinics of the study, or if they had normal BP but were using BP-lowering agents. BP measurements were carried out using an oscillometric monitor, and anthropometric measurements were taken in duplicate. All participants were submitted to a lifestyle intervention (LsI) phase, which included detailed recommendations to lose weight, to reduce salt, to adopt a DASH-type diet and to practice physical activities. Blood pressure and control of hypertension were verified after three months. In this analysis, we present the results of blood pressure control and variation in the subsample of participants who had BP higher or equal to 140/90 mmHg. Results: 4 867 volunteers were screened and 1 835 evaluated for enrollment. From these, 685 (37%) had BP within stage I hypertension. After three months of intensive LsI, 420 (61.3%) remained with uncontrolled BP, 249 (36.4%) had BP in the 120-139/80-89 mmHg range, and 16 (2.3%) had normal BP. Systolic and diastolic BP reduced from 143.8 ±7.1 to 138.7 ±12.2 mmHg and 90.4 ±5.9 to 87.7 ±8.7, respectively. Conclusion: Approximately 1/3 of patients with Stage I hypertension have blood pressure controlled after three months of lifestyle recommendations to lose weight, reduce salt intake, adopt a DASH diet and practice physical activities.