Browsing by Subject "Blood Pressure"
Now showing 1 - 17 of 17
- Results Per Page
- Sort Options
Item Acute Effect of High vs Low Dialysate Sodium on Endothelial Cell Function During Hemodialysis(2013-01-22) D'Silva, Kristin; Molina, Christopher; van Buren, Peter; Kim, Catherine; Inrig, JulaBACKGROUND: Intradialytic hypertension (HTN), a rise in blood pressure that occurs during hemodialysis (HD) treatments in up to 15% of patients, is associated with higher morbidity and mortality. The cause of intradialytic HTN is unknown but may be due to endothelial cell (EC) dysfunction. In vitro exposure of ECs to high sodium (Na+) concentration promotes EC stiffness and imbalances in vasoconstrictors (endothelin-1 [ET-1]) and vasodilators (nitric oxide [NO]). We hypothesized that, among patients with intradialytic HTN, exposure to high dialysate Na+ would lead to a decrease in NO and increase in ET-1 during HD. METHODS: We performed a 3-week, 2-arm, randomized crossover study among 16 HD patients with intradialytic HTN and compared the effects of high dialysate-to-serum Na+ gradients (5 mEq/L above participants' baseline Na+) vs low dialysate-to-serum Na+ gradients (5 mEq/L below baseline Na+ with lower limit of 134 mEq/L) on intradialytic changes in nitrite and ET-1. Differences between treatments were compared with repeated measures mixed linear regression and included randomization arm (high - low Na+ vs low - high Na+), treatment effect (high vs low Na+), subject, time and session. RESULTS: Study participants (N=16) had an average age of 58.8 years, 38% were black, 56% were Hispanic, and 94% were male. Intradialytic changes in NO and ET-1 with high and low dialysate-to-plasma Na+ gradients are shown in Figure 1. In the primary comparison of high vs low dialysate-to-serum Na+ gradient, there were no significant differences in intradialytic levels of NO or ET-1 (Table 1). However, when compared by randomization arm, participants who received the low dialysate-to-serum Na+ gradient followed by high compared to those who received the high dialysate-to-serum Na+ gradient followed by low had a significant decrease in ET-1 (parameter estimate -0.49 pg/mL, p=0.04) and significant increase in nitrite during hemodialysis (parameter estimate +0.16 nM, p=0.02) (Table 1). CONCLUSIONS: Patients who received the low dialysate-to-serum Na+ gradient before the high dialysate-to-serum Na+ gradient had higher levels of nitrite and lower levels of ET-1 throughout the three week study period compared to patients who received the high dialysate-to-serum Na+ gradient before the low dialysate-to-serum Na+ gradient. This suggests that the dialysate Na+ concentration may have longer-term effects on endothelial cell function.Item Atrial function and its clinical implications(1964-04-09) Mitchell, Jere H.Item Blood pressure management in hemodialysis patients(2016-06-03) Van Buren, PeterItem The highs and lows of blood pressure regulation in older adults(2021-04-09) Lipsitz, Lewis A.Item Hypertension in pregnancy: an internist's perspective(1989-05-04) Ram, C. Venkata S.Item The Incidence of Post-Intubation Hypotension in Trauma Patients after Etomidate Administration(2015-01-26) Glidewell, Ryan; Cooper, Benjamin; Kendall, Brian; Knepper, Scott; Kim, Jaehyun; Hynan, Linda; Roppolo, Lynn P.BACKGROUND: Post-intubation hypotension (PIH) is found in up to 44% of patients emergently intubated in the ED. Etomidate is a popular agent used in rapid sequence induction (RSI) for emergency intubations due to its stable hemodynamic profile. The purpose of this study was to prospectively investigate the incidence of PIH in trauma patients requiring emergent intubation using etomidate as the induction agent. METHODS: All patients intubated in the emergency department (ED) who were induced using etomidate were prospectively recruited for this study. Serial vital signs were recorded just prior to RSI drug administration and every 5 minutes after for 20 minutes. RESULTS: 20 adult patients were recruited for this study over an 8-week period, 12 (80%) medical and 8 (89%) trauma. Each patient received an average dose of 22 mg. See Table 1 and Figure 1 a comparison of MAP changes observed in medical patients verses trauma patients just prior to the administration of RSI medications and at 5, 10, 15, and 20 minutes intervals. CONCLUSION: Etomidate can significantly reduce the MAP in trauma patients. One plausible explanation in the immediate post-intubation period is the reduced sympathetic stimulation that results once unconsciousness is induced. Critically ill trauma patients who require emergent intubation are likely to have concomitant injuries and are at risk for hemorrhagic shock or worsening cerebral injury from precipitous decreases in blood pressure. Resuscitative measures should be cautiously instituted to mitigate any adverse effects of hypoperfusion from PIH in these critically ill patients.Item Nonpharmacologic aspects of blood pressure management: what's the data?(2010-01-22) Hedayati, SusanItem Orthostatic hypotension(1981-11-05) Gaffney, F. AndrewItem Quality Assessment of Fiber Optic Pressure Sensors(2014-02-04) Rosenblatt, Anna; Purdy, Phillip D.; King, KevinBACKGROUND: Since the functional features of an artery can correlate to the risk of cardiovascular events, intra-arterial pressures can be utilized as a tool to gain more information about the condition of a vessel or even downstream structural features in the vasculature. Pressure waveforms contain information regarding peak systolic and diastolic pressures, as well as the elasticity and possibly sites of reflection. Similarly, the pulse wave velocity can be indicative of the mechanical properties of the arterial system. Intravascular fiber optic pressure sensors are one tool that can be used to record continuous pressure readings. OBJECTIVE: In order to effectively maximize the capabilities of the RJC fiber optic pressure sensors, they must be tested to fully understand the magnitude of their capabilities. Specific tests were performed to analyze the behavior, precision, and accuracy in different scenarios. METHOD: In vitro, four RJC fiber optic pressure sensors were immersed into known depths of water systematically. The pressures ranged from 0 mm H2O to 500 mmH2O. The pressure measurements included 6 measurements at low pressures (under 100 mmH2O) and 1 measurement at 500 mmH2O. Each pressure reading was approximately 10 seconds and the sensor recorded pressure measurements at a frequency of 1000 Hz. At each pressure reading, the variation and behavior of each individual sensor, the discrepancies between two sensors, as well as the accuracy compared to the theoretical pressure value were evaluated. In addition, the pressure receiver box and various methods of calibration were tested to ensure that there were not other factors causing a bias on the sensors' measurements. RESULTS: The sensors were found to have the capability of giving instantaneous pressure values with a precision of 0.03 mm Hg. The standard deviation of one pressure sensor at a constant pressure for 10 seconds was 0.15mmHg. The average difference between two sensors' pressure values that were calibrated simultaneously was 0.66 mmHg. Lastly, the accuracy of the sensors decreased at higher pressures. Specifically, at a pressure of 37 mmHg, the accuracy of the sensors was approximately 1.9%. CONCLUSION: This data will be important for all future experiments and measurements that involve the RJC fiber optic pressure sensors. With a complete understanding of quantitatively how the sensors behave, it will be feasible to analyze results of future pressure measurements.Item [Southwestern News](2002-03-05) Shields, AmyItem [Southwestern News](2005-06-07) Morales, KatherineItem [Southwestern News](2001-06-19) Shields, AmyItem Uremic autonomic neuropathy: the ups and downs of blood pressure in patients with chronic renal failure(1992-10-22) Victor, Ronald G.Item [UT Southwestern Medical Center News](2010-10-07) Ladson, LaKishaItem [UT Southwestern Medical Center News](2011-03-01) Ladson, LaKishaItem [UT Southwestern Medical Center News](2008-09-04) Stafford, Erin Prather