Age related hemodynamic changes in the elderly

Systolic blood pressure (SBP) increases by aging. In contrast, diastolic blood pressure (DBP) decreases after age 60 because of lowering aortic compliance. Therefore, isolated systolic hypertension (ISH) is common in the elderly. ISH is a risk for cardiovascular complications, and induces a left ventricular hypertrophy combined with diastolic dysfunction. Diastolic heart failure followed by diastolic dysfunction is more common than systolic heart failure in the elderly. Furthermore, changes in neuroendocrine systems by aging may lead orthostatic hypotension, non-dipping status, large blood pressure variability, and reduced heart rate variability. In the management of elderly hypertension, the understanding for these age-related hemodynamic changes is very important.     

Preventing hypoxemia and hemodynamic compromise related to endotracheal suctioning.

OBJECTIVE: To help the clinician bridge the gap between research and practice in determining ways to minimize side effects of endotracheal suctioning. DATA SOURCES: This article summarizes four previous reviews of research and studies published between 1984 and 1991 related to oxygenation techniques before, during and after endotracheal suctioning, and hemodynamic consequences of the suctioning procedure. STUDY SELECTION: Studies were reviewed by type of subject: animals, human subjects with normal lung function, and human subjects with abnormal lung function. Research of pediatric and head-injured populations was excluded from this review. DATA EXTRACTION: Oxygenation protocol, endotracheal suction characteristics, outcomes and measurement times, sample and setting, and findings were presented. CONCLUSIONS: Conclusions relate to the effectiveness of various endotracheal suction protocols on prevention of hypoxemia and hemodynamic compromise in intubated patients. DATA SYNTHESIS: An algorithm to guide clinical decision making is presented based on the conclusions of this review of the research.     

Correction of hemodynamic changes during aortofemoral bifurcation bypass surgery under combined epidural anesthesia

Assessment of hemodynamic parameters in 50 patients before aortofemoral bifurcation bypass surgery could identify 3 types of baseline central hemodynamics and differentiate methods for correcting its disorders. It was ascertained that the development of the intraoperative reperfusion phenomenon during epidural block might predispose to the low cardiac output syndrome for which correction ganglionic blockers are effective at the stage of aortic ligation and a combination of inotropic agents and venous vasodilators is beneficial at the stage of reperfusion.     

Significant beat-to-beat hemodynamic changes in fetal circulation: a consequence of abrupt intrathoracic pressure variation induced by hiccup.

During routine fetal echocardiographic studies, we incidentally observed abrupt beat-to-beat changes in blood flow velocity and direction during bouts of hiccups in fetuses with a normal heart and regular and synchronized atrioventricular cardiac rhythm. The effect of hiccups on blood flow velocity and direction varied depending on the time of occurrence of hiccups during the cardiac cycle. In systole, a significant transient reduction of peak flow velocity occurred at the aortic and pulmonic valves, and brief tricuspid regurgitation appeared synchronously with each hiccup. In diastole, a transient reversal of flow direction was recorded simultaneously with the hiccup at the aorta and ductus arteriosus, and acceleration of peak flow velocity was observed across the tricuspid and mitral valves. Throughout the entire cardiac cycle, marked blood flow acceleration was observed in the superior vena cava, inferior vena cava, and ostium secundum simultaneously with the hiccup. A direct transmission of briefly augmented, negative intrathoracic pressure to a compliant aorta and systemic veins appears to be a reasonable explanation for most of our observations.     

不同循环模式下冠状动脉搭桥术对患者微循环功能及心肾功能的影响

目的研究不同循环模式下冠状动脉搭桥术(CABG)对患者微循环功能及心肾功能损伤的影响。方法选择在本院行CABG术的冠心病患者150例,按不同循环方式将其分为A组和B组,各75例。A组患者在体外循环模式下行CABG术,B组患者在非体外循环模式下行CABG术。比较两组患者治疗前、后微循环功能和心肾功能指标变化。结果治疗后,A组SvO2、MAP、cTnI、CK-MB、BNP、Cys C和Scr水平均明显高于B组(P<0.05)。结论相比于体外循环模式,非体外循环模式下行CABG术对患者微循环功能和心肾功能损伤更小,更具有优势。     

CD检测评价尿毒症合并心力衰竭时血液动力学改变分析

目的 探讨尿毒症合并心力衰竭时的血液动力学改变并分析其发生原因。方法 使用血液循环动力学信息检测仪(CD)检测23例尿毒症合并心力衰竭及31例尿毒症无心力衰竭。结果 充血性心力衰竭组左室舒张末期压力、左室舒张末期容量、心输出量、射血阻抗、心肌耗氧量、左室有效功率均明显增高，射血分数明显降低。结论 CD检测简单方便，重复性好。心力衰竭根本原因左室收缩乏力、顺应性降低、β受体兴奋而不是有效循环血量增加。     

Acute pain in an emergency clinic: Latency of onset and descriptor patterns related to different injuries

Features of acute pain were examined in patients at an emergency clinic. Patients who had severe, life-threatening injuries or who were agitated, drunk, or ‘in shock’ were excluded from the study. Of 138 patients who were alert, rational and coherent, 51 (37%) stated that they did not feel pain at the time of injury. The majority of these patients reported onset of pain within an hour of injury, although the delays were as long as 9 h or more in some patients. The predominant emotions of the patients were embarrassment at appearing careless or worry about loss of wages. None expressed any pleasure or indicated any prospect of gain as a result of the injury.The occurrence of delays in pain onset was related to the nature of the injury. Of 46 patients whose injuries were limited to skin (lacerations, cuts, abrasions, burns), 53% had a pain-free period. Of 86 patients with deep-tissue injuries (fractures, sprains, bruises, amputation of a finger, stabs and crushes), only 28% had a pain-free period. The McGill Pain Questionnaire was administered to patients who felt pain immediately after injury or after a delay, and revealed a normal distribution of sensory scores but very low affective scores compared to patients with chronic pain. The results indicate that the relationship between injury and pain is highly variable and complex.     

经食道超声观察心肺复苏时胸外心脏按压的血流动力学变化

目的　探讨心肺复苏时胸外心脏按压的血流动力学机制。方法　 6例心搏骤停患者均为2 0 0 0～ 2 0 0 1年心内科患者 ,男性 5例 ,女性 1例。在心肺复苏胸外按压时用变频多平面食道超声及彩色多普勒观察心脏改变。结果　所有 6例病人 ,在胸外按压阶段 ,二尖瓣关闭 ,主动脉瓣开放。主动脉瓣峰值血流速度为 (5 9 0± 13 0 )cm/s。在放松阶段 ,二尖瓣开放 ,主动脉瓣关闭 ,二尖瓣峰值血流速度平均为(6 0 0± 2 0 0 )cm/s。在按压末左室内径明显减小为 (32 1± 7 1)mm ,放松末增大为 (42 1± 12 9)mm (P<0 0 5 )。按压末左室容积为 (39 0± 8 9)ml,放松末 (6 8 8± 2 1 7)ml (P <0 0 5 )。按压频率为 10 0次 /min ,心排血量为 (2 8± 0 8)L/min。按压时有创血压为 6 0～ 80 / 10～ 30mmHg,指端血氧饱和度可达 98%～99 %。结论　在实行心肺复苏胸外心脏按压的过程中 ,食道超声可清楚地显示二尖瓣关闭、主动脉瓣开放 ,左室容积减小 ,产生前向血流 ,支持心泵机制     

Sleep architecture as related to temperature changes in neonates at term

SUMMARY. Sleep architecture was assessed under different environmental temperatures in 10 full-term and 10 preterm infants who reached term. Five 30-min periods of baseline, normothermia heating, peak temperature, cooling and normothermia were analysed. A significant decrease in the proportion of active sleep (AS) and an increase in quiet sleep (QS) was noted among the full-term infants during the heating and peak temperature conditions, whereas, among the preterm infants, a similarly significant difference was noted during the heating and cooling stages of the study, but not during the stage of peak temperature. This differential response to environmental hyperthermia is possibly related to maturational factors. This phenomenon may be related to the increased vulnerability of low birth weight infants to apnoea and sudden infant death syndrome.     

Resource utilization related to atrial fibrillation after coronary artery bypass grafting.

BACKGROUND: Studies of resource utilization by patients with new-onset atrialfibrillation after coronary artery bypass grafting have addressed only length of stay and bed charges. OBJECTIVE: To compare resource utilization between patients with new-onset atrial fibrillation and patients without atrialfibrillation after isolated coronary artery bypass grafting. METHODS: Retrospective review of clinical and administrative electronic databases for 720 subjects who underwent isolated coronary artery bypass grafting with cardiopulmonary bypass in 25 months at one medical center The prevalence of atrial fibrillation was determined, and resource utilization in various hospital cost centers was compared between subjects with and without atrialfibrillation. RESULTS: The prevalence of new-onset atrial fibrillation was 33.1%. Compared with subjects without atrialfibrillation, subjects with atrialfibrillation had a longer stay (5.8 +/- 2.4 vs. 4.4+/-1.2 days, P<.001), more days receiving mechanical ventilation (P =.002) and oxygen therapy (P<.001), and higher rates of readmission to the intensive care unit (4.6% vs. 0.2%, P<.001). Subjects with atrial fibrillation also had more laboratory tests (P<.001) and more days receiving cardiac drugs, heparin, diuretics, and electrolytes. Subjects with atrialfibrillation had higher total postoperative charges ($57261 +/- $17101 vs. $50905 +/- $10062, P = .001), a mean difference of $6356. The mean differences were greatest for bed charges ($1642), laboratory charges ($1215), pharmacy ($989), and respiratory care ($582). CONCLUSION: The economic impact of atrialfibrillation after coronary artery bypass grafting has been underestimated.     

Spinal and supraspinal changes in opioid mRNA expression are related to the onset of pain behaviors following excitotoxic spinal cord injury

Excitotoxic spinal cord injury (SCI) causes anatomic, physiologic and molecular changes within the spinal cord and brain. Intraspinal injection of quisqualic acid (QUIS) produces an excitotoxic injury that leads to the onset of behavioral syndromes, believed to be related to the clinical condition of chronic pain. The opioid system, classically involved in the suppression of pain transmission, has been associated with the onset of pain-related behaviors and changes in spinal opioid peptide expression have been demonstrated in various models of SCI and chronic pain. Recently, changes in opioid peptide expression have been demonstrated in both spinal and supraspinal areas following excitotoxic SCI. Therefore, the purpose of this study was to examine changes in opioid peptide gene expression as they relate to the onset of pain behaviors following excitotoxic SCI. Male, Long-Evans rats were given an intraspinal injection of 1.2 microl of 125 mM QUIS and allowed to survive for 10 days, a duration sufficient for the development of pain-related behaviors. Animals were assessed daily for the presence of excessive grooming behavior, i.e. self-directed biting and scratching resulting in damage to superficial and deeper layers of the skin. Animals were also tested for thermal hypersensitivity using a cold plate apparatus on days 5, 7, and 10 following QUIS injection. After sacrifice, quantitative in situ hybridization was performed on regions of the spinal cord surrounding the lesion site as well as whole brain sections through various levels of the thalamus and cortex. Spinal preproenkephalin (PPE) and preprodynorphin (PPD) expression was significantly increased in animals that developed excessive grooming behaviors vs. those that did not. For PPE, this difference was seen bilaterally, in areas of cord caudal to the site of injury. For PPD, this difference was seen only ipsilateral to the site of injection, rostral to the site of injury. In addition, PPE expression in the anterior cingulate cortex and PPD expression in the contralateral parietal cortex were significantly higher in grooming vs. non-grooming animals. These results support previous conclusions that both spinal and supraspinal regulation of endogenous opioid peptide expression plays a role in the response to or onset of post-SCI pain. These results also suggest that the opioid peptides are regulated independently and serve different functions in response to SCI.     

Doppler changes in the main fetal brain arteries at different stages of hemodynamic adaptation in severe intrauterine growth restriction.

OBJECTIVE: To evaluate changes in the temporal evolution and regional distribution of arterial brain Doppler parameters in relation to different stages of hemodynamic adaptation in fetuses with severe intrauterine growth restriction (IUGR). METHODS: Thirty-six fetuses with severe IUGR ( 2 SD) were evaluated longitudinally with pulsed Doppler ultrasound at four different hemodynamic stages: Stage 1 (n = 36), mean UA-PI > 2 SD or absent UA end-diastolic flow; Stage 2 (n = 34), abnormal middle cerebral artery (MCA) PI (mean < 2 SD); Stage 3 (n = 30), reversed UA end-diastolic flow; Stage 4 (n = 12), absent or reversed atrial flow in the ductus venosus. In addition, 36 normally grown fetuses were studied for comparison. PI and time-averaged maximum velocity (TAMXV) in the MCA and the anterior cerebral (ACA), pericallosal (PER) and posterior cerebral (PCA) arteries were measured. RESULTS: In IUGR fetuses, PI values from all arteries were significantly reduced at Stage 2. At Stages 3 and 4, ACA-PI and PCA-PI did not change further, whereas MCA-PI and PER-PI showed a slight increase. In the ACA, MCA and PER, TAMXV in Stage 2 increased significantly. In Stages 3 and 4, ACA and PER-TAMXV remained unchanged, whereas MCA-TAMXV showed a slight decrease, mirroring the PI values. PCA-TAMXV values were similar to controls at all stages. CONCLUSION: In IUGR fetuses, the brain arteries differ in the magnitude and time sequence of Doppler parameters in relation to systemic hemodynamic adaptation, suggesting the existence of regional brain redistribution processes.     

Doppler sonographic evaluation of hemodynamic changes in colorectal liver metastases relative to liver size.

OBJECTIVE: The mechanisms of hemodynamic alterations in colorectal liver metastases are not clearly understood yet. Considering that an increase in liver size in patients with metastases could also result in an alteration in total liver flow, we aimed to analyze hemodynamic changes relative to the liver volume and to search for the possibility of any intrinsic factors affecting blood flow in patients with metastases. METHODS: Twenty-eight patients with colorectal liver metastases and 20 control subjects with no liver disease were evaluated sonographically. All patients were examined prospectively by Doppler sonography and helical computed tomography. Hepatic hemodynamic parameters, including blood flow in the hepatic artery and portal vein, total blood flow to the liver, and Doppler perfusion index, were calculated, and values relative to liver volume were obtained. Hepatic perfusion changes in liver metastases were then compared with those in a control group. RESULTS: The liver volume of the patients with liver metastases was greater than that of the control group (P=.003). Hepatic arterial blood flow rates were higher, whereas portal flow rates were lower, in patients with liver metastases compared with control subjects (P<.05). Total liver blood flow was not significantly different between the two groups. However, total blood flow relative to liver volume was significantly lower in the metastatic group (P<.001). Doppler perfusion index values in the patients with metastasis were significantly higher than in the control group (P=.000). CONCLUSIONS: Our findings may support the hypothesis that a humoral mediator-induced portal venous flow reduction causes perfusion changes in liver metastases from colorectal disease. However, an additional intrinsic hepatic hemodynamic event should also be present. Doppler perfusion index measurements can provide additional information in the evaluation of patients with colorectal liver metastases.     

Seeing patterns through the hemodynamic veil--the future of pattern-information fMRI

Pattern-information fMRI (pi-fMRI) has become a popular method in neuroscience. The technique is motivated by the idea that spatial patterns of fMRI activity reflect the neuronal population codes of perception, cognition, and action. In this commentary, we discuss three fundamental outstanding questions: (1) What is the relationship between neuronal patterns and fMRI patterns? (2) Does pattern-information fMRI benefit from hyperacuity, enabling the investigation of columnar-level neuronal information, even at low resolution? (3) Do high-resolution and high-field fMRI increase sensitivity to pattern information? The empirical answers will enable us to optimize pi-fMRI data acquisition and to understand the ultimate potential and appropriate interpretation of pi-fMRI results. Furthermore, considering the relationship between neuronal activity and fMRI at the level of spatiotemporal patterns provides a novel and important perspective on the basis of the fMRI signal.     

彩色多普勒超声评价颈内-外动脉侧支循环对颈总动脉血流动力学的影响

目的探讨颈内动脉（ICA）重度狭窄或闭塞时颈内-外动脉侧支循环（IEACC）是否开放对患侧颈总动脉（CCA）血流动力学的影响。方法选择临床及影像资料完整，单侧ICA颅外段狭窄70％～99％（74例）、闭塞（86例），且健侧ICA及双侧CCA正常或狭窄程度〈50％的患者。按IEACC是否开放将患者分为ICA狭窄70％-99％IEACC开放组（42例）和IEACC未开放组（32例），闭塞IEACC开放组（43例）和IEACC未开放组（43例）。采用彩色多普勒超声测量CCA和颈外动脉（ECA）的收缩期峰值流速（PSV）、舒张末期流速（EDV）、平均流速（MV）、阻力指数（RI），计算CCA的血流量（BFV）。分别比较ICA狭窄70％-99％及闭塞时，IEACC是否开放对患侧CCA血流动力学的影响，分析ECA在IEACC开放后患侧、健侧血流动力学的变化特点。结果（1）ICA狭窄70％-99％组与闭塞组IEACC开放者患侧CCA的EDV、BFV高于IEACC未开放者，EDV分别为（15±5）cm／s、（12±5）cm／s（P=0．010）与（14±6）cm／s、（10±6）cm／s（P=0．002），BFV分别为（676±271）ml／min、（557±188）ml／min（P=0．036）与（606±218）ml／min、（488±180）ml／min（P=0．035），而PSV、MV、RI差异均无统计学意义；（2）ICA狭窄70％～99％组与闭塞组IEACC开放者比较，患侧CCA的PSV、EDV、MV、RI、BFV差异均无统计学意义；IEACC未开放患者比较，70％～99％组的EDV及BFV高于闭塞组，分别为（12±5）cm／s、（10±6）cm／s（P=0．014）与（557±188）ml／min、（488±180）ml／min（P=0．047）；（3）ICA狭窄70％～99％组及闭塞组IEACC开放者患侧ECA的PSV、EDV、MV高于健侧，分别为（124±35）cm／s、（107±22）cm／s（P〈0．001），（34±12）cm／s、（22±8）cm／s（P〈0．001）与（64±18）cm／s、（50±11）cm／s（P〈0．001）；RI值患侧低于健侧，分别为0．72±0．07、0．79±0．07（P〈0．001）；IEACC未开放?     

Factors related to the early phase of rehabilitation following aortocoronary bypass surgery

Physical and psychosocial functioning of 30 male patients prior to and 3 months following aortocoronary bypass surgery were compared. Relationships between rehabilitation outcome and selected physical, psychosocial, and health care system variables were examined. Although patients' perceptions of their health improved after surgery, there was little improvement in physical and psychosocial functioning, and vocational functioning declined. When the outcome variables were regressed on their possible explanatory variables, the variance in exercise tolerance and energy expenditure on household activities remained unexplained. Energy expenditure on postoperative leisure activities was related to fear of injury. Preoperative psychosocial functioning, depression, and postoperative perception of health explained postoperative psychosocial functioning. Postoperative perception of health dependent on the number of bypass grafts and spouse's/family's fear of patients' injury.