Stable Systolic Blood Pressure Research Articles

Development of operationalized intravenous to oral antibiotic switch criteria.

Despite huge overlap in suggested criteria for a safe intravenous (iv)-to-oral antibiotic switch, there is considerable variation in their operationalization. The objective of this study was to develop a set of measurable conditions that should be met in adult hospitalized patients for a safe iv-to-oral switch. A RAND-modified Delphi procedure was performed to develop a set of operationalized iv-to-oral switch criteria. Switch criteria and their accompanying suggested measurable conditions were extracted from the literature and appraised by a multidisciplinary expert panel during two questionnaire rounds with a face-to-face meeting between these two rounds. In a final step, the experts could approve the set of developed operationalized switch criteria. Seven switch criteria and 41 accompanying measurable conditions extracted from the literature were appraised. Sixteen measurable conditions that operationalize six switch criteria were selected: (i) stable systolic blood pressure; and the absence of (ii) fever, (iii) temperature <36°C, (iv) malabsorption syndrome, (v) short bowel syndrome, (vi) severe gastroparesis, (vii) ileus, (viii) continuous nasogastric suction, (ix) vomiting, (x) (severe) sepsis, (xi) fasciitis necroticans, (xii) CNS infection, (xiii) Staphylococcus aureus bacteraemia, and (xiv) endovascular infection. In addition, (xv) the patient should be cooperative and (xvi) adequate antimicrobial concentration should be achievable at the site of infection by oral administration. These operationalized criteria can be used in daily clinical practice. Future use of these criteria in audits and as rules in clinical decision support systems will facilitate the performance and evaluation of iv-oral switch programmes.

Abstract 12489: Association of Longitudinal Blood Pressure Changes and Kidney Function Decline: Findings From the Multi-Ethnic Study of Atherosclerosis

Background: Few studies have examined the association of blood pressure (BP) change over time with kidney function decline. We hypothesized that increasing systolic blood pressure (SBP), decreasing diastolic blood pressure (DBP), and widening pulse pressure (PP) trajectory would be associated with worsening renal function, independent of baseline BP, among persons with relatively preserved estimated glomerular filtration rate (eGFR) and free from cardiovascular disease at baseline. Methods: We used data from 4,156 participants in the MESA Study who had at least two BP measurements from study year 0 to year 5 and eGFR measurements at year 5 and 10. Participants were then grouped into one of three groups based on the distribution of change (top 20% = increasers, middle 21-79% = stable, bottom 20% = decreasers). We calculated eGFR from cystatin C and defined rapid decline as a &gt;30% decrease in eGFR. We used multivariable logistic regression adjusting for demographics, baseline eGFR and BP to determine associations of BP change category with later renal function decline. We also estimated the association of change in BP with annual change in eGFR using adjusted linear regression. Results: The stable SBP group had a mean age of 59, was 50% male, 41% white, and had 29% of participants on an anti-hypertensive medication. The increasing SBP group was similar except for having fewer men (43%). Median year 0 and year 5 SBP for increasing SBP was 110 and 131, for stable 119 and 118, for decreasing 145 and 119 mmHg respectively. Increasing SBP and widening PP trajectory were associated with higher odds of rapid renal function decline compared to stable groups after adjusting for all covariates including baseline BP. Decreasing SBP was not associated with rapid renal function decline after adjusting for baseline BP. Similar findings were seen with annual renal function decline. Implication: Increasing SBP and widening PP appears to increase the risk for accelerated kidney function decline.

Effect of orthostatic hypotension on sustained attention in patients with autonomic failure

IntroductionOrthostatic hypotension has been associated with impaired cognitive function, but cognitive function during orthostatic hypotension has hardly been studied. We studied the effect of orthostatic hypotension, induced by head-up tilt...

Usefulness of bioimpedance spectroscopy for detection of hypotensive episode during dialysis.

Using statistical methods, this study investigates whether bioimpedance spectroscopy (BIS) and plasma electrolytes can be used to identify risk of intradialytic hypotension (IDH) based on information obtained during the first half of the dialysis treatment only. Data obtained from 40 patients included information on blood pressure, parameters defined from BIS, plasma electrolytes, and relevant clinical data. Patients were divided into three groups based on their intradialytic decrease in systolic blood pressure (SysBP) and associated symptoms and interventions: (1) Stable SysBP, (2) Asymptomatic unstable SysBP, and (3) symptomatic unstable SysBP. Retrospective analysis showed a significant reduction in extracellular fluid of 0.64 ± 0.62 L and potassium (K) concentration of 0.24 ± 1.67 mM in parallel with a decrease in SysBP of ≥25 mm Hg/hr. Data analysis using mixed-model procedure revealed that unstable patients compared with stable patients were characterized by higher extracellular resistance (p = 0.014) and K concentration (p = 0.009). Discriminant analysis using relative changes in extracellular resistance, potassium, and pH resulted in correct identification of 85% of the patients at risk. This study indicates that combining BIS and plasma electrolytes analysis may be a promising method to provide more accurate monitoring of IDH.

Characteristics of sleep in patients with stable heart failure versus a comparison group

Sleep disturbance seems to be common among patients with heart failure (HF). However, little is known about the objective and subjective characteristics of sleep in these patients during daily life or the extent to which the sleep of patients with HF differs from the sleep of other adults. We examined the extent to which self-reported and objective characteristics of sleep differ between patients with HF with stable systolic blood pressure (n = 59) and a comparison group of adults who did not have HF (n = 59). The patients with HF had a significantly lower percentage of wake after sleep onset and more frequent wake bouts, as measured with wrist actigraphs. There were no group-related differences in sleep duration. Sixty-seven percent of the patients with HF compared with 51% of the comparison group had poor global sleep quality, and 44% of the patients with HF versus 18.6% of the comparison group reported excessive daytime sleepiness. Future research is needed to examine the causes and consequences of disturbed sleep continuity and poor sleep quality and the effects of sleep-promotion strategies designed for patients with HF.

Can Ketamine Substitute for Fentanyl in Gynecologic Cone Biopsy Anesthesia?

Background: In a gynecologic cone biopsy, fentanyl is commonly used with propofol for its analgesic effect, but it has many side effects, such as bradycardia, respiratory depression and hypotension. A subanesthetic dose of ketamine has an analgesic effect and minimal cardiovascular effects. We wanted to know whether ketamine can be safely used with propofol in a gynecologic cone biopsy instead of fentanyl. Methods: Forty woman patients were randomly allocated to two groups. All patients were anesthesized with a propofol infusion. Fentanyl 1/kg IV was injected 2 minutes before LMA (laryngeal mask airway) insertion in group I, ketamine 0.25 mg/kg IV was injected also in group II. Blood pressure and heart rate were measured before fentanyl or ketamine injection, 1 minute, 3 minutes and 5 minutes after LMA insertion, and during the operation. A numerical rating scale (NRS) for pain and other side effects were checked for 24 hours after the operation. Results: There were no significant differences between the two groups in blood pressure, heart rate, NRS and side effects, but a more stable systolic blood pressure in the ketamine group occurred. Conclusions: For a gynecologic cone biopsy, propofol anesthesia combined with fentanyl or ketamine was not different for stable cardiovascular results, postoperative pain relief and side effects. Therefore, ketamine as an analgesic combined with propofol could replace fentanyl in gynecologic cone biopsy anesthesia.

Increase in Functional Ca 2+ Channels in Cerebral Smooth Muscle With Renal Hypertension

The hypothesis that availability of functional Ca2+ channels in vascular smooth muscle is augmented in hypertension was tested in basilar artery cells from Wistar rats exhibiting stable systolic blood pressure (BPsys) for 2 to 11 weeks after partial renal artery ligation (Goldblatt 2-kidney 1-clip [2K1C] model). Cells were freshly isolated and patch-clamped using a nystatin-perforated patch method. BPsys ranged from 110 to 280 mm Hg and correlated with normalized kidney mass. Macroscopic current-voltage curves were fit to a Boltzmann function to obtain maximum conductance (gmax), steepness and midpoint potential for the voltage dependence of activation (k and E1/2, respectively), and extrapolated reversal potential for the chord conductance (Erev). Linear regression of normalized conductance (ng(max)=g(max)/cell capacitance) versus BPsys for 103 cells indicated a strong relationship, with a slope of 0.0019 nS x pF(-1) x mm Hg(-1) (P<0.0001). Similar analysis of data from 35 other cells exposed to 500 nmol/L Bay K 8644 gave a slope of 0.0041 nS x pF(-1) x mm Hg(-1) (P=0.001). Voltage-dependent parameters, k, E1/2, and Erev, were not significantly related to BPsys. Single-channel measurements in cell-attached patches revealed that the number of channels in 32 patches was significantly related to BPsys (P=0.0024) but that slope conductance, open dwell times at 0 mV, and distribution between 2 open states were not. Finally, in a subgroup of 61 cells from animals made hypertensive (180 mm Hg<BPsys<200 mm Hg) for approximately 1/2 to 6 weeks, we found that elevation of ngmax depended on duration of hypertension (P=0.003), with no elevation at approximately 1/2 week. We conclude that in the 2K1C model, availability of functional Ca2+ channels increases with BPsys with no change in channel properties and that measurable BPsys elevation occurs before the increase in functional channels.