Blood Pressure and Heart Rate Variability in Patients on Conventional or Sodium-Profiling Hemodialysis

Background. Autonomic nervous system dysfunction and dialysate sodium (Na) concentration are believed to play a role in the pathogenesis of hemodialysis-related hypertension. The present study was undertaken to determine whether increases in blood pressure in hemodialysis patients are associated with changes in heart rate variability (HRV), a measure of the autonomic nervous system function, and long-term exposure to increased dialysate Na concentration. Methods. Baseline clinical, biochemical data and HRV of patients undergoing increased Na profiling dialysis (High-Na, n?=?9) and on conventional treatment (Control, n?=?11) were compared with those obtained after one year of study. Results. After one year, the mean predialysis systolic blood pressure (SBP) increased in seven patients of the High-Na and in five of the Control group, and decreased or remained unchanged in the remaining subjects. Initial HRV was significantly higher in patients with increased SBP, and it increased further in these patients after one year. At the end of the study, post-dialysis plasma Na, osmolality, and weight gains were significantly higher in the High-Na group. No significant correlation, however, was found between individual changes in intradialytic sodium elimination and the alterations in blood pressure. Conclusion. These data suggest that the dialysate sodium concentration, a most important determinant of interdialytic weight gain and fluid balance, is only partly correlated with long-term changes in blood pressure. An increased blood pressure over time may develop in a subset of hemodialysis patients with higher HRV, suggestive of increased sympathetic activity.     

Salt and Fluid Intake in the Development of Hypertension in Peritoneal Dialysis Patients

Background. Although fluid overload contributes to hypertension in CAPD patients, less attention has been paid to the role of excess salt and fluid intake. Therefore, we investigated the role of salt and fluid intake in the development of hypertension in CAPD patients. Methods. A total of 165 stable CAPD patients were included into this study. Based on the blood pressure in three consecutive months, they were divided into three groups: persistent hypertensive (PH; n = 33), intercurrent hypertensive (IH; n = 58) and persistent normotensive (PN; n = 74). The IH group was further divided into two phases: normotensive and hypertensive. Fluid status was evaluated by clinical assessment and bioimpedance analysis (BIA). Results. There were no differences in age, gender, and duration of dialysis among groups. Patients were more fluid overloaded in the PH group. Extracellular water (ECW), total body water (TBW), and normalized extracellular water by height (NECW) were higher in the PH group than the PN group (16.77 ± 3.62 L vs. 14.61 ± 2.92 L for ECW, p < 0.01; 32.22 ± 8.23 L vs. 28.98 ± 6.00 L for TBW, p < 0.05; and 10.28 ± 1.86 L/m vs. 9.08 ± 1.63L/m for NECW, p < 0.01). However, patients in the PH group also had more total fluid removal (TFR) and total sodium removal (TSR) compared with the PN group (1346.82 ± 431.27 mL/d vs. 1139.28 ± 412.65 mL/d for TFR, p < 0.05; and 141.52 ± 61.57 mmol/d vs. 102.42 ± 62.51 mmol/d for TSR, p < 0.01). The same trend was demonstrated when compared values of hypertensive and normotensive phase in IH group; patients had higher ECW, TBW, NECW, TSR, and PNa when they were in hypertensive phase than in the normotensive phase. Conclusions. This study confirmed that fluid overload was closely associated with the development of hypertension in CAPD patients. It also showed that hypertensive patients were in general more fluid overloaded despite a higher fluid and sodium removal as compared with normotensive patients.     

Transcutaneous Monitoring of Blood Gas Tensions in Patients on Intermittent Peritoneal Dialysis

A relative contraindication to intermittent peritoneal dialysis (IPD) is chronic lung disease. To evaluate whether the instillation of 2 L of fluid into the peritoneal cavity affects respiratory function, five IPD patients were studied in the supine position during the first 4 h of a routine IPD session. Blood gas tensions were monitored transcutaneously throughout the study period. At the onset of dialysis, mean transcutaneous blood oxygen tension (PtcO2) was 70.6 +/- 9.1 mm Hg. It decreased to 55 +/- 9.9 mm Hg (22% change from basal values) during the instillation of dialysate. Upon drainage, PtcO2 returned to baseline. This sequence of events repeated itself on subsequent exchanges, although with decreasing decrements of PtcO2 with each consecutive exchange (decrease to 58.6 +/- 7.05, 61 +/- 6.5, 63.8 +/- 5.2 mm Hg corresponding to 16%, 12.7%, and 9.6%, respectively, during the second to fourth exchanges). Transcutaneous blood carbon dioxide tension, PtcCO2, showed a very mild increase during the study (33 +/- 7.1 to 38 +/- 6.0 mm Hg). In two patients, the same study protocol was performed during the last 4 h of an IPD session. In these two patients, there was only a 5% variation of PtcO2 from baseline values. These results suggest that an adaptive response to the hypoxemia induced by dialysate instillation rapidly occurs in IPD patients.     

Heart rate variability predicts mortality in peritoneal dialysis patients

Abstract

Background: The predictive value of heart rate variability (HRV) in peritoneal dialysis (PD) has never been tested. Methods: In this study, the associations between HRV measures and the mortality in 81 PD patients were analyzed. HRV was measured by using 5-min recordings of a stationary system by a standardized method. Both time domain and frequency domain parameters were analyzed. Results: During a follow-up period of 43.78?±?14.77 months, 25 patients died, four patients were transferred to hemodialysis. Of the 81 patients, the time domain parameters, such as the standard deviation of differences between adjacent normal sinus to normal sinus (NN) intervals (SDSD) and the square root of the mean of the squared differences between adjacent normal NN intervals (RMSSD), were higher; the frequency domain parameters, such as the ratio of low-frequency power to high-frequency power (LF/HF) and the normalized LF, were lower, and the normalized HF was higher in the non-survived group as compared with the survived group. A Cox proportional hazards model analysis revealed that, of the HRV measures, decrease of the normalized LF, LF/HF and increase of rMSSD, SDSD, normalized HF had significant predictive value for mortality. After adjustment for other univariate predictors including age, urine volume, renal Kt/V, high-sensitivity C-reactive protein (hs-CRP), the predictive value of decreased LF/HF remained significant. Kaplan–Meier survival analysis showed mortality rate was much higher in patients with a low LF/HF (median value of 1.56). Conclusion: The decreases of LF/HF which reflects impaired sympathetic nerve regulation is an independent predictor of mortality in PD patients.     

Twenty-Four-Hour Ambulatory Assessment of Heart Rate and Blood Pressure in Chronic PTSD and Non-PTSD Veterans

This study examined 24-hr levels of ambulatory heart rate (HR) and blood pressure (BP) in 2 groups of male veterans: 19 with chronic posttraumatic stress disorder (PTSD) and 17 who never met criteria for PTSD. The relationships between diagnostic status, basal cardiovascular activity, and cardiovascular reactivity to stress were examined. Hierarchical linear modeling analyses revealed that the PTSD group had higher resting HR than the non-PTSD group. Moreover, the PTSD group showed greater BP reactivity during times of affective distress than the non-PTSD group. The health care implications of these findings are discussed, as are directions for future research.     

Twenty-Four-Hour Ambulatory Blood Pressure and Heart Rate Monitoring in Combat-Related Posttraumatic Stress Disorder

This study examined the cardiovascular correlates of posttraumatic stress disorder (PTSD) in Vietnam combat veterans using 24-hr ambulatory blood pressure and heart rate monitoring. Veterans with PTSD (n = 11) exhibited significantly higher heart rate and diastolic blood pressure across the 24 hr than veterans without PTSD (n = 7) (80.8 vs. 71.9 bpm, and 80.1 vs. 71.5 mm Hg, respectively). Heart rate during sleep was also significantly higher among veterans with PTSD, compared to veterans without PTSD (71.0 vs. 62.7 bpm). These results, based on a more naturalistic measurement methodology used outside the laboratory, support an association between PTSD and increased chronic cardiovascular arousal.     

放松训练对术前患者血压心率的影响

目的探讨保持患者术前血压、心率平稳的方法。方法将100例择期手术患者随机分为观察组和对照组,各50例。两组均行术前健康教育,观察组在此基础上行放松训练,即采用深吸静息式全身肌肉放松的方法进行训练。两组均于入院后及手术前1d晚临睡前(术前晚)、入手术室后麻醉前(麻醉前)分别测量其血压和心率。结果两组术前晚血压均有下降(均P<0.05),而观察组较对照组更为显著(均P<0.05);观察组心率较对照组平稳(P<0.05),两组心率麻醉前加快,对照组较观察组更为显著(P<0.05)。结论知识教育配合放松训练能使术前患者血压、心率平稳。     

Early Initiation of Peritoneal Dialysis after Arterial Switch Operations in Newborn Patients

Background and aim: We investigated the clinical outcome of early initiated peritoneal dialysis (PD) use in our newborn patients who underwent arterial switch operation (ASO) for transposition of the great arteries (TGA) and had routine intraoperative PD catheter implantation. We determined the risk factors for PD, factors associated with prolonged PD, morbidity, and mortality. The aim of the present study was to describe our experience of using PD in this patient cohort. Materials and Methods: Eighty two patients who were diagnosed with TGA and TGA-ventricular septal defect (VSD) and who had undergone TGA correction operation in Ba?kent University, Istanbul Medical Research and Training Hospital between 2007 and 2012 were retrospectively investigated. All the patients were under 30 days old. PD catheters were routinely implanted intraoperatively at the end of the operation. PD was initiated in transient renal insufficiency. In the absence of oliguria and increased creatinine level, PD was established in the presence of one of the following: clinical signs of fluid overload, hyperkalemia (>5 mEq/L), persistent metabolic acidosis, lactate level above 8 mmol/L or low cardiac output syndrome. The patients were divided into two groups according to the need for postoperative PD (PD group and non-PD group). PD was initiated in 32 (39%) patients after the operation, whereas 50 (61%) patients did not need dialysis. The clinical outcomes and perioperative data of the two groups were compared. Results: The demographics in the two groups were similar. Cardiopulmonary bypass time was longer in the PD group [non-PD group, 175.24 ± 32.39 min; PD group, 196.22 ± 44.04 min (p < 0.05)]. Coronary anomaly was found to be higher in the PD group [non-PD group, n = 2 patients (4.0%); PD group, n = 7 patients (21.9%); p < 0.05]. There was more need for PD in TGA + VSD patients [simple TGA patients, n = 14; TGA + VSD patients, n = 18 (p < 0.05)]. PD rate was higher in patients whose sterna were left open at the end of the operation (p < 0.05). The ventilator time [non-PD group, 4.04 ± 1.51 days; PD group, 8.12 ± 5.21 days (p < 0.01)], intensive care unit stay time [non-PD group, 7.98 ± 5.80 days; PD group, 15.93 ± 18.31 days (p < 0.01)], and hospital stay time were significantly longer in the PD group [non-PD group, 14.98 ± 10.14 days; PD group, 22.84 ± 20.87 days (p < 0.01)]. Conclusion: We advocate routine implantation of PD catheters to patients with TGA-VSD, coronary artery anomaly, and open sternum in which we have determined high rate of postoperative PD need.     

高血压病人无创血压值与有创血压值的对比研究

目的探讨临床常用汞柱式血压计测量高血压病人血压的误差及其原因。方法选取高血压病人及正常血压者各 2 0例 ,用有创法及无创法分别测量同一上肢肱动脉血压 ,每例均于 7:0 0～ 8:0 0空腹状态用两种方法测血压 6次。结果汞柱式血压计测量血压的结果与实际血压相比 ,在高血压病人中收缩压约低 10mmHg(P <0 .0 1) ,舒张压差异无显著性意义 (P >0 .0 5 ) ;在血压正常者中 ,收缩压低 6mmHg左右 (P <0 .0 1) ,舒张压约高 9mmHg(P<0 .0 5 )。造成这种误差的原因与臂围大小无明显关系。结论用汞柱式血压计测量肱动脉血压的值与实际值有一定差异 ,对于高血压病人 ,收缩压误差较大 ,而舒张压则较准确 ;对于正常人收缩压易低估 ,舒张压易高估。高血压病人的血压较高且有明显动脉硬化者 ,临床表现与血压不符时 ,可考虑采用有创法测量血压 ,以便准确了解病情。     

盐酸右美托咪定对老年冠心患者全麻气管插管期心率变异性的影响

目的：研究盐酸右美托咪定（dexmedetomidine．Dex）在全麻诱导气管插管期间对老年冠心病患者自主神经系统功能的影响。方法：98例择期腹部手术老年冠心病患者．随机分成盐酸右美托咪定（D组n=49,诱导前给予负荷剂量右美托咪定0．7ug,／0g．注射泵缓慢静脉注射．输注时间超过10rain．维持剂量以0．4ug/（kg·h）持续静脉注射）和安慰剂组（P组n=49．诱导前静脉注射等容量氯化钠溶液）．分别于麻醉前（To）．麻醉诱导后（T1）及气管插管后（T2）用心率变异功率谱分析（heart rate Power spectrum analysis．HRPSA）技术观察患者的心率变异性（heart rate variability．HRV）改变。结果：麻醉诱导后．两组HRV总功率频段（TP）和其中低频段（LF）、高频段（HF）．LF／HF（低频／高频比）均显著降低（P〈O．05）．组问比较D组LF低于P组（P〈O．05）;气管插管后,两组LF、HF及TP均显著升高（P〈O．05）,而D组的LF／HF较麻醉前（T0）差异无统计意义,P组的LF／HF较麻醉前（T0）显著升高（P〈O．05）：组间比较D组LF、TP升高程度显著低于P组（P〈0．05）．HF组间差异无统计学意义。结论：盐酸右美托咪定能明显抑制插管操作引起的对植物神经功能的干扰,有利于维护老年冠心病患者围插管期心脏的自主神经调节功能。     

耳穴贴压法对围术期患者焦虑及心率、血压的影响

目的寻找减轻或改善围术期患者焦虑、保证患者生命体征稳定的方法。方法将200例住院择期手术患者随机分为常规护理组（A组）和耳穴贴压护理组（B组）。两组均予常规围术期护理；B组在此基础上加用耳穴贴压法，即在耳穴板上将带有王不留行籽的小方块胶布贴于耳穴位，使用时间为术前3d至术后3d；采用焦虑自评量表（SAS）和心电监护仪对患者焦虑程度和心率、血压进行评定与监测。结果两组术前1d、术后3d焦虑程度变化比较，差异有显著性意义（P〈0．01）；入手术室后20rainA组心率、收缩压较术前1d显著增加（均P〈0．01），B组差异无显著性意义（均P〉0．05）；两组入手术室后20min心率、收缩压比较，差异有显著性意义（均P〈0．01）。结论围术期行耳穴贴压法配合常规护理可缓解患者焦虑情绪，稳定心率和血压，利于手术的顺利进行。     

The Relationship of Visfatin Levels with Insulin Resistance and Left Ventricular Hypertrophy in Peritoneal Dialysis Patients

Background/objectives: Cardiovascular abnormalities are common in patients with chronic kidney disease. Visfatin influences lipid metabolism, insulin sensitivity, and cardiovascular health. The aim of this study was to explore the relation of serum visfatin to cardiovascular risk factors in nondiabetic peritoneal dialysis (PD) patients. Patients and methods: Eighty-seven nondiabetic patients (mean age 48 ± 15 years, 39 males) under PD were enrolled. Weight, anthropometric measurements, blood pressure, biochemical parameters, and insulin resistance (homeostatic model assessment-insulin resistance—HOMA-IR) were measured. Visfatin was measured and left ventricular mass index (LVMI) was calculated by echocardiography. Results: LVMI was correlated with body mass index (BMI; r = 0.47, p = 0.01), systolic blood pressure (SBP; r = 0.62, p = 0.04), and serum visfatin levels (r = 0.49, p = 0.03). According to HOMA-IR levels patients were grouped as insulin-resistant (IR) (HOMA-IR ≥2.0, n = 35) and noninsulin-resistant (non-IR) (HOMA-IR <2.0, n = 52) groups. The IR group had longer PD duration and higher BMI, total cholesterol, uric acid, and serum visfatin levels (p < 0.05). The study patients were divided into three groups according to their serum visfatin levels. Group 1 (≤34 ng/mL, n = 22) was considered as the lowest tertile of low visfatin and group 2 (35–42 ng/mL, n = 43) and group 3 (≥43 ng/mL, n = 22) in the upper tertile. Considering the visfatin groups, group 3 patients had significantly higher BMI (p = 0.00), total cholesterol (p = 0.03), C-reactive protein (CRP) (p = 0.03), HOMA-IR (p = 0.03), and LVMI (p = 0.02). In regression analysis, SBP (β = 0.19, p < 0.05) and serum visfatin levels (β = 0.74, p < 0.05) were independent variables affecting LVMI. Conclusion: Serum visfatin might be a sensitive marker than HOMA-IR evaluations for cardiac performance in nondiabetic PD patients.     

Assessment of autonomic cardiovascular changes associated with recovery from anaesthesia in children: a study using spectral analysis of blood pressure and heart rate variability

Recovery from anaesthesia is associated with large changes in cardiovascular autonomic activity, which are poorly documented in children. This study was undertaken to investigate the cardiovascular autonomic activity in anaesthetized and recovering children, using a noninvasive approach based on spectral analysis of heart rate (HR) and blood pressure (BP) variability. Ten children (aged 5-13 years) undergoing major surgery were studied. Continuous HR and BP were recorded using a noninvasive device during deep anaesthesia and recovery. Spectral analysis was used to determine the main oscillatory components of HR and BP signals. For each power spectrum, the frequency components were identified as follows (i): the low frequency (LF) component (0.04-0.14 Hz) both parasympathetically and sympathetically mediated for HR and corresponding to vasomotor sympathetic modulation for BP; and (ii) the high frequency (HF) component (0.2-0.6 Hz) parasympathetically mediated for HR, and reflecting mechanical influence of ventilation on cardiac output for BP. In addition, the LF : HF ratio for HR, reflecting the cardiac sympathovagal balance, was calculated. Under deep anaesthesia, HR variability and BP variability were very low and mainly due to mechanical influence of intermittent positive pressure ventilation. Conversely, the recovery period was associated with a marked increase of HR and BP overall variability. Compared to anaesthesia, spectral analysis of HR and BP revealed that the LF component of BP and HR spectra increased 40-fold during recovery; the LF : HF ratio of HR was also increased during recovery (0.1 +/- 0.1 versus 1.3 +/- 1.2, P=0.008). The results of this study demonstrate that the recovery period is associated with an increase of cardiovascular sympathetic drive in children after major surgery.     

静脉注射利多卡因对老年冠心病非心脏手术围插管期心率变异性的影响

目的：研究静脉注射利多卡因在全麻诱导气管插管期间对老年冠心病自主神经系统功能的影响。方法：选择90例择期腹部手术老年冠心病患者．随机分成利多卡因组（L组n=45）和安慰剂组（P组n=45）．分别于麻醉前（T0）,麻醉诱导后（T1）及气管插管后（T2）用心率变异功率谱分析（HRPSA）技术观察患者的心率变异性（HRV）改变。结果：麻醉诱导后．两组HRV总功率频段（TP）和其中低频段（LF）,高频段（HF）．LF／HF（低频／高频比）均显著降低（P〈0．05）．组间比较L组LF低于C组（P〈0．05）;气管插管后,两组LF、HF、LF／HF及TP均显著升高（P〈0．05）．组间比较L组LF与LF／HF升高程度显著低于P组（P〈0．05）,HF组间差异无统计意义。结论：静注利多卡因能明显抑制插管操作引起植物神经功能的干扰．有利于维护老年冠心病患围插管期心脏自主神经调节功能。     

Volume Status in Patients on Peritoneal Dialysis: The Role of Apelin and Bio-Impedance Spectroscopy

One of the main factors determining the survival of peritoneal dialysis (PD) patients is volume status. We aimed to investigate hydration status of PD patients by bio-impedance spectroscopy (BIS) and echocardiography and to study the relation of them with apelin, which has effects related with volume status like vasodilation, positive inotropism, and inhibition of ADH release and RAS antagonism. Chronic PD patients without active cardiac disease or clinically prominent hypervolemia were included. Besides the demographic, clinical, and laboratory data, BIS and echocardiographic findings together with apelin levels were recorded. The study included 21 patients. Of them, eight patients were euvolemic, one patient was hypovolemic, and others have some degree of overhydration (1.1–6.8 L) with BIS, although all were euvolemic clinically. Mean apelin level was 1.49 ± 0.49 ng/mL. Apelin level was positively correlated with ejection fraction and negatively with total body water (TBW), intracellular and extracellular water, lean tissue mass, and left atrium diameter. On linear regression model, TBW was the major determinant of apelin. Although apelin is expected to increase in hypervolemic patients, the negative correlation with body water in this study may be related with yet unknown role of apelin in dialyzed patients. They may have important roles in volume status in future.     

The Prevalence of Left Ventricular Hypertrophy in Chinese Hemodialysis Patients Is Higher Than That in Peritoneal Dialysis Patients

Background. Left ventricular hypertrophy (LVH) is common in dialysis patients, and an independent predictor of mortality. While recent studies have shown no differences in mortality between the two most common dialysis modalities, hemodialysis (HD) and peritoneal dialysis (PD), their impact on LVH is controversial. We thus performed cardiac ultrasound studies in prevalent dialysis patients receiving either HD or PD and compared LVH. Methods. We included 48 HD and 62 PD patients receiving treatment for at least three months in our dialysis center. All patients underwent echocardiographic examination and blood pressure measurements immediately following therapy. Volume status was assessed by bioelectrical impedance analysis. Results. There was no baseline difference in demographics or comorbidities between HD and PD patients. As expected, extracellular water (ECW) in post-HD patients was significantly lower than that in pre-HD and PD patients, while cardiac output (CO) and systolic blood pressure (SBP) were higher in pre-HD than that in post-HD or PD patients. There was no significant difference in CO or SBP between post-HD and PD patients. Left ventricular mass index (LVMI) was markedly higher in HD patients as compared to PD patients. Thus, the prevalence of LVH according to the Framingham criteria was 68.8% in HD patients and 45.2% in PD patients. Subgroup analysis showed similar results in the patients who had been on single-modality dialysis for at least two years and in the anuric patients. Finally, in a linear regression model (r² = 0.364, p < 0.001), SBP, treatment modality (to be in HD), and ECW were all independent predictors of LVMI. Conclusions. In a cross-sectional analysis of prevalent Chinese patients, we found a higher LVMI and a higher prevalence of LVH in HD than in PD patients. As LVMI was associated with high blood pressure and volume overload, we suggest that in these patients, PD may preserve more physiological hemodynamics even during long-term therapy.     

The Affecting Factors and Comparison of Tuberculin Skin Test in Peritoneal Dialysis and Hemodialysis Patients

Compared with the general population, patients with chronic renal failure have increased tuberculosis (TB) prevalence and mortality rates. In this study, we aimed to investigate tuberculin skin test (TST) positivity rates in hemodialysis (HD) and peritoneal dialysis (PD) patients and the factors influencing TST positivity. Ninety-two HD patients and 44 PD patients who had been on HD and PD treatment for at least 3 months were recruited into the study. TST was administered in all patients. Positivity was defined as an induration diameter >10 mm. At least 5 mm of induration following skin testing together with a chest radiography indicating previous infection was defined as latent TB infection. TST positivity rates, diameter of TST indurations, and serum albumin levels in HD patients were higher than the PD patients. TST induration size was not correlated with any other parameters in both HD and PD groups. TST-positive patients had higher albumin levels and lower leukocyte count than the TST-negative patients. In TST-positive patients, albumin level was correlated with the duration of dialysis but TST induration size was not correlated with the lymphocyte count and albumin level. In our study, TST positivity of patients was found in 30.4% of HD patients, 9% of PD patients, and 23.5% of total patients. It is still recommended to use TST for the screening test of TB. We found a significant relationship between TST and albumin level. It should be remembered that TST response may be lower in PD patients, especially in cases in which TB is suspected.     

Heart Rate and Blood Pressure Resting Levels and Responses to Generic Stressors in Vietnam Veterans with Posttraumatic Stress Disorder

Resting heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure (DBF) were measured on 3 successive mornings in the homes of drug-free Vietnam combat veterans, classified on the basis of DSM-III-R criteria into current posttraumatic stress disorder (PTSD; n = 20) or non-PTSD (n = 15). Responses to three generic stressor challenges (orthostatic, mental arithmetic, and cold pressor) were also measured. In the orthostatic stressor condition, DBP increased over time in the non-PTSD, but not in the PTSD, veterans, suggesting a paradoxically reduced autonomic response in PTSD. There were no other significant group differences in resting levels or responses to any of the challenges for any measure.