Clinical Application of Laser Speckle Flowgraphy to Assess Changes in Blood Flow to the Foot After a Lumbar Sympathetic Ganglion Block: A Case Report.

BACKGROUND: The lumbar sympathetic ganglion block (LSGB) has been used as a diagnostic and therapeutic procedure for treating pain conditions such as neuropathic and ischemia-related pain, affecting the lower extremities. In general, an increase in skin temperature is useful in confirming the effectiveness of the sympathetic nerve block in clinical settings. However, the assessment of skin temperature in patients with peripheral arterial disease (PAD) occasionally provides false negatives. CASE PRESENTATION: A novel technology, laser speckle flowgraphy (LSFG) enables noninvasive quantitative and qualitative blood flow assessments. LSFG is a novel neuro-monitor for quantitative blood flow detection in the optic nerve head during cardiac surgery. Herein, we report on measuring foot blood flow using LSFG before and after LSGB in a PAD patient. This research aimed to determine whether LSFG could detect any improvement in the dynamics of foot blood flow after an LSGB in a situation where changes in skin temperature alone could not determine the procedure's outcome. CONCLUSION: LSFG can be used to assess blood flow changes in a foot with PAD, following a LSGB.

Comparison of Right Ventricular Function Between Three-Dimensional Transesophageal Echocardiography and Pulmonary Artery Catheter.

OBJECTIVE: This study aimed to compare measurements of right ventricular function using three-dimensional transesophageal echocardiography (3D TEE), and pulmonary artery catheters (PACs) in patients undergoing cardiac surgery. The authors examined the practicality of using the 3D TEE. DESIGN: Prospective observational. SETTING: Cardiac operating room at a single university hospital. PARTICIPANTS: All adult patients undergoing elective cardiac surgery at a single tertiary care university hospital over two years. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Right ventricular end-diastolic volume (RVEDV), right ventricular end-systolic volume (RVESV), stroke volume (SV), and right ventricular ejection fraction (RVEF) were measured with both 3D TEE and PACs. Assessments were performed using correlation coefficients, paired t tests, and Bland-Altman plots. Thirty-one patients participated in this study. Each measurement showed good agreement. RVEDV and RVESV were slightly lower on 3D TEE than on PAC (205.9 mL v 220.2 mL, p = 0.0018; 143.0 mL v 155.5 mL, p = 0.0143, respectively), whereas no significant differences were observed for SV and RVEF (31.0% v 31.1%, p = 0.0569; 61.6 mL v 66.9 mL, p = 0.92, respectively). Linear regression analysis showed high correlation between 3D TEE and PAC for RVEDV (r = 0.87) and RVESV (r = 0.81), and moderate correlation for SV (r = 0.67) and RVEF (r = 0.67). In the Bland-Altman plot, most patients were within the 95% limits of the agreement throughout all measurements. CONCLUSION: A high correlation was found between measurements made with a PAC and with 3D TEE in the assessment of right ventricular function. Three-dimensional TEE would be a potential alternative to PAC for assessment of right ventricular function during intraoperative periods.

Comparison of intrathecal morphine with continuous patient-controlled epidural anesthesia versus intrathecal morphine alone for post-cesarean section analgesia: a randomized controlled trial.

BACKGROUND: Several neuraxial techniques have demonstrated effective post-cesarean section analgesia. According to previous reports, it is likely that patient-controlled epidural analgesia (PCEA) without opioids is inferior to intrathecal morphine (IM) alone for post-cesarean section analgesia. However, little is known whether adding PCEA to IM is effective or not. The aim of this study was to compare post-cesarean section analgesia between IM with PCEA and IM alone. METHODS: Fifty patients undergoing elective cesarean section were enrolled in this prospective randomized study. Patients were randomized to one of two groups: IM group and IM + PCEA group. All patients received spinal anesthesia with 12 mg of 0.5% hyperbaric bupivacaine, 10 µg of fentanyl, and 150 µg of morphine. Patients in IM + PCEA group received epidural catheterization through Th11-12 or Th12-L1 before spinal anesthesia and PCEA (basal 0.167% levobupivacaine infusion rate of 6 mL/h, bolus dose of 3 mL in lockout interval of 30 min) was commenced at the end of surgery. A numerical rating scale (NRS) at rest and on movement at 4,8,12,24,48 h after the intrathecal administration of morphine were recorded. In addition, we recorded the incidence of delayed ambulation and the number of patients who requested rescue analgesics. We examined NRS using Bonferroni's multiple comparison test following repeated measures analysis of variance; p < 0.05 was considered as statistically significant. RESULTS: Twenty-three patients in each group were finally analyzed. Mean NRS at rest was significantly higher in IM group than in IM + PCEA group at 4 (2.7 vs 0.6), 8 (2.2 vs 0.6), and 12 h (2.5 vs 0.7), and NRS during mobilization was significantly higher in IM group than in IM + PCEA group at 4 (4.9 vs 1.5), 8 (4.8 vs 1.9), 12 (4.9 vs 2), and 24 h (5.7 vs 3.5). The number of patients who required rescue analgesics during the first 24 h was significantly higher in IM group compared to IM + PCEA group. No significant difference was observed between the groups in incidence of delayed ambulation. CONCLUSIONS: The combined use of PCEA with IM provided better post-cesarean section analgesia compared to IM alone. TRIAL REGISTRATION: UMIN-CTR (Registration No. UMIN000032475). Registered 6 May 2018 - Retrospectively registered.

Use of intraoperative neuromuscular monitor reduces the reversal dose of sugammadex: a single-center retrospective study.

PURPOSE: We compared the reversal doses of sugammadex in surgical cases in which intraoperative neuromuscular monitor were used, to cases in which intraoperative neuromuscular monitoring was not used, retrospectively. METHODS: Data were collected by reviewing the electronic medical records of patients who received rocuronium and sugammadex during general anesthesia at Asahikawa Medical University Hospital between May 1, 2017 and April 30, 2018. The primary outcome was the reversal dose of sugammadex per patient actual body weight (mg/kg) between the group in which intraoperative neuromuscular monitoring was used (NM+ group) and the group in which intraoperative neuromuscular monitoring was not used (NM- group). RESULTS: A total of 3496 patients were evaluated, with 2544 patients (73%) included in NM+ group and 952 patients (27%) in NM- group. The reversal doses of sugammadex per actual body weight were significantly higher in NM- group compared to NM+ group. In the NM+ group, 521 patients (20%) received < 2 mg/kg sugammadex, 1377 patients (54%) received 2 ~ 2.5 mg/kg sugammadex, and 646 patients (25%) received > 2.5 mg/kg sugammadex. In contrast, 128 patients (13%) received < 2 mg/kg sugammadex, 362 patients (38%) received 2 ~ 2.5 mg/kg sugammadex and 462 patients (49%) received > 2.5 mg/kg sugammadex in NM- group. CONCLUSION: This single-center retrospective study demonstrated that the use of intraoperative neuromuscular monitor reduced the reversal dose of sugammadex.

Effectiveness and Safety of Ultrasound Guided Lower Extremity Nerve Blockade in Infragenicular Bypass Grafting for High Risk Patients With Chronic Limb Threatening Ischaemia.

OBJECTIVES: Surgical revascularisation to accomplish limb salvage remains preferable in some patients with chronic limb threatening ischaemia (CLTI). The aim of this study was to evaluate the effectiveness and safety of ultrasound guided lower extremity nerve blockade (UGNB) in infragenicular bypass surgery (IGBS). METHODS: This was a single centre, retrospective clinical study. Fifty-nine patients with CLTI (67 limbs) who underwent IGBS under UGNB (femoral and sciatic nerve blockade) at Asahikawa Medical University between January 2012 and December 2017 were compared with patients with CLTI (137 limbs) who underwent IGBS under general anaesthesia (GA) over the same period. Propensity score matching based on pre-operative comorbidities was used to minimise background differences of the two groups. RESULTS: Fifty-six pairs of CLTIs were matched and analysed (55% dialysis dependent). Procedure duration was similar between the two groups, but intraoperative catecholamine index and intravenous fluid volume were lower with UGNB compared with GA (2.9 ± 4.6 vs. 5.9 ± 6.5; p < .01 and 1831 ± 990 vs. 2335 ± 931 mL; p < .01, respectively). The mean arterial blood pressure during induction of anaesthesia was significantly decreased with GA. Post-operatively, the time period to resume a clear liquid and solid food diet was significantly shorter with UGNB (P<0.01 for both outcome measures). Intravenous fluid volume was significanlty lower, while cardiac complications and delirium, based on the NEECHAM confusion scale, occurred significantly less often with UGNB than GA. These significant differences show advantages of UGNB compared to GA. No mortality or major amputations were observed in either group. Early graft thrombosis was observed in five limbs (8.9%) with UGNB and in four limbs with GA (7.1%) (p = .73). CONCLUSIONS: UGNB has advantages for intra- and post-operative management and could be a useful method to prevent peri-operative complications for high risk patients with CLTI. To ensure the effectiveness of UGNB for IGBS for future indications, a randomised study is required.

Cerebral Circulation During Retrograde Cerebral Perfusion: Evaluation Using Laser Speckle Flowgraphy.

BACKGROUND: The cerebroprotective effect of retrograde cerebral perfusion (RCP) and selective antegrade cerebral perfusion (SCP) still remains controversial. Laser speckle flowgraphy has shown much promise for novel perioperative neuromonitoring by assessing blood flow of the optic nerve head. This study aimed to evaluate the cerebral microcirculation in humans using laser speckle flowgraphy during simple circulatory arrest, RCP, and SCP under moderate hypothermia and to investigate whether RCP under moderate hypothermia is a reliable method of cerebral protection. METHODS: A total of 23 consecutive patients who underwent a scheduled aortic arch or hemiarch surgical procedure on thoracic aorta aneurysm were enrolled. The laser speckle flowgraphy measurement that calculates mean blur ratio, a parameter of cerebral circulation, was obtained 6 times: after induction of anesthesia, baseline (T1), after initiation of cardiopulmonary bypass with cardiac arrest (T2), simple circulatory arrest (T3), RCP (T4), SCP (T5), and after the termination of cardiopulmonary bypass (T6). RESULTS: Both mean blur ratios of simple circulatory arrest and RCP were significantly decreased compared with baseline. In contrast, no significant differences were observed between simple circulatory arrest and RCP. The mean blur ratio of SCP was significantly increased compared with both simple circulatory arrest and RCP. CONCLUSIONS: In conclusion, no significant difference was observed in the cerebral circulation between RCP and simple circulatory arrest without adjunctive strategy under moderate hypothermia. In contrast, the cerebral circulation during SCP was significantly higher than simple circulatory arrest and RCP. These results suggest that cerebral microcirculation may not be adequate during RCP compared with SCP under moderate hypothermia.

Phosphorylated CCAAT/Enhancer Binding Protein ß Contributes to Rat HIV-Related Neuropathic Pain: In Vitro and In Vivo Studies.

Chronic pain is increasingly recognized as an important comorbidity of HIV-infected patients, however, the exact molecular mechanisms of HIV-related pain are still elusive. CCAAT/enhancer binding proteins (C/EBPs) are expressed in various tissues, including the CNS. C/EBPß, one of the C/EBPs, is involved in the progression of HIV/AIDS, but the exact role of C/EBPß and its upstream factors are not clear in HIV pain state. Here, we used a neuropathic pain model of perineural HIV envelope glycoprotein gp120 application onto the rat sciatic nerve to test the role of phosphorylated C/EBPß (pC/EBPß) and its upstream pathway in the spinal cord dorsal horn (SCDH). HIV gp120 induced overexpression of pC/EBPß in the ipsilateral SCDH compared with contralateral SCDH. Inhibition of C/EBPß using siRNA against C/EBPß reduced mechanical allodynia. HIV gp120 also increased TNFα, TNFRI, mitochondrial superoxide (mtO2·-), and pCREB in the ipsilateral SCDH. ChIP-qPCR assay showed that pCREB enrichment on the C/EBPß gene promoter regions in rats with gp120 was higher than that in sham rats. Intrathecal TNF soluble receptor I (functionally blocking TNFα bioactivity) or knockdown of TNFRI using antisense oligodeoxynucleotide against TNFRI reduced mechanical allodynia, and decreased mtO2·-, pCREB and pC/EBPß. Intrathecal Mito-tempol (a mitochondria-targeted O2·-scavenger) reduced mechanical allodynia and decreased pCREB and pC/EBPß. Knockdown of CREB with antisense oligodeoxynucleotide against CREB reduced mechanical allodynia and lowered pC/EBPß. These results suggested that the pathway of TNFα/TNFRI-mtO2·--pCREB triggers pC/EBPß in the HIV gp120-induced neuropathic pain state. Furthermore, we confirmed the pathway using both cultured neurons treated with recombinant TNFα in vitro and repeated intrathecal injection of recombinant TNFα in naive rats. This finding provides new insights in the understanding of the HIV neuropathic pain mechanisms and treatment.SIGNIFICANCE STATEMENT Painful HIV-associated sensory neuropathy is a neurological complication of HIV infection. Phosphorylated C/EBPß (pC/EBPß) influences AIDS progression, but it is still not clear about the exact role of pC/EBPß and the detailed upstream factors of pC/EBPß in HIV-related pain. In a neuropathic pain model of perineural HIV gp120 application onto the sciatic nerve, we found that pC/EBPß was triggered by TNFα/TNFRI-mtO2·--pCREB signaling pathway. The pathway was confirmed by using cultured neurons treated with recombinant TNFα in vitro, and by repeated intrathecal injection of recombinant TNFα in naive rats. The present results revealed the functional significance of TNFα/TNFRI-mtO2·--pCREB-pC/EBPß signaling in HIV neuropathic pain, and should help in the development of more specific treatments for neuropathic pain.

Morphologic Evaluation of the Mitral Annulus During Displacement of the Heart in Off-Pump Coronary Artery Bypass Surgery.

OBJECTIVE: To evaluate the morphologic changes of the mitral annulus using 3-dimensional transesophageal echocardiography during heart displacement to expose the anastomosis site in off-pump coronary artery bypass surgery (OPCAB). DESIGN: Prospective case series. SETTING: Single center, university hospital. PARTICIPANTS: The study comprised 34 consecutive patients who underwent OPCAB of the left circumflex artery (LCX) and the right coronary artery (RCA). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Mitral annulus parameters were measured using the Mitral Valve Quantification program after sternotomy (physiologic position) and during displacement of the heart to expose the LCX (LCX position) and the RCA (RCA position). The height of the mitral annulus was significantly lower in the LCX (5.76 ± 0.90 mm) and RCA (5.92 ± 0.97 mm) positions than in the physiologic position (6.96 ± 0.99 mm; both p < 0.0001). The percent change in the height of the mitral annulus was significantly greater in the mitral regurgitation group than in the mitral regurgitation nondeterioration group when in the LCX (-16.3% ± 6.0% v -11.9% ± 3.3%, p = 0.0203) and RCA (-16.9% ± 6.3% v -12.1% ± 3.8%, p = 0.0207) positions. The anteroposterior and intercommissural diameters, annulus perimeter, and surface area of the mitral annulus did not differ significantly among all heart positions. CONCLUSIONS: The mitral annulus flattened and lost its saddle shape without expanding while in the LCX and RCA positions. The greater percent change in the height of the mitral annulus may aggravate mitral regurgitation.

Gene therapy with HSV encoding p55TNFR gene for HIV neuropathic pain: an evidence-based mini-review.

While effective antiretroviral treatment makes human immunodeficiency virus (HIV)-related death decreased dramatically, neuropathic pain becomes one of the most common complications in patients with HIV/acquired immunodeficiency syndrome (AIDS). The exact mechanisms of HIV-related neuropathic pain are not well understood yet, and no effective therapy is for HIV-pain. Evidence has shown that proinflammatory factors (e.g., tumor necrosis factor alpha (TNFα)) released from glia, are critical to contributing to chronic pain. Preclinical studies have demonstrated that non-replicating herpes simplex virus (HSV)-based vector expressing human enkephalin reduces inflammatory pain, neuropathic pain, or cancer pain in animal models. In this review, we describe recent advances in the use of HSV-based gene transfer for the treatment of HIV pain, with a special focus on the use of HSV-mediated soluble TNF receptor I (neutralizing TNFα in function) in HIV neuropathic pain model.

Perioperative Management of Patients With End-Stage Renal Disease.

End-stage renal disease (ESRD) is associated with significant alterations in cardiovascular function; homeostasis of body fluid, electrolytes, and acid-base equilibrium; bone metabolism, erythropoiesis; and blood coagulation. The prevalence of ESRD is increasing rapidly worldwide, as is the number of patients requiring surgery under general anesthesia. Patients with ESRD have significantly higher risks of perioperative morbidity and mortality due to multiple comorbidities. The perioperative management of patients with ESRD under general anesthesia therefore requires special considerations and a careful multidisciplinary approach. In this review, the authors summarize the available literature to address common issues related to patients with ESRD and discuss the best perioperative approach for this patient subgroup.

Comparison of caudal ropivacaine-morphine and paravertebral catheter for major upper abdominal surgery in infants.

BACKGROUND: The caudal epidural block is one of the most commonly used regional anesthetic techniques in children. Administration of morphine via caudal injection enables analgesia, even for upper abdominal surgery. The thoracic paravertebral block has also been successfully used to treat perioperative pain during upper abdominal procedures in pediatric patients. AIM: In the current study, we compared the two regional techniques for upper abdominal surgery in infants to determine whether one of them was preferable to the other. METHODS: Consecutive patients under 12 months of age who underwent upper abdominal surgery were retrospectively divided according to the chosen postoperative analgesia: Group C, caudal ropivacaine-morphine; Group P, paravertebral catheter. We analyzed the following outcomes: requirement for additional analgesics, pain scores, need for mechanical ventilation and oxygen dosage, postoperative blood pressure and heart rate, time to pass first stool, time until first full meal, and complications. RESULTS: Twenty-one consecutive patients were included: 10 in Group C and 11 in Group P. Median age at surgery was 80 (47.5-270.0) and 84.5 (34.3-287.5) days, respectively. No difference was found between the two groups in requirement for additional analgesics at 24 h after surgery (median 1 in Group C vs 1 in Group P, P = 0.288, 95% CI: -2 to 1). BOPS pain scores were only lower in Group P when compared to Group C at 24 h after surgery (median 1 vs 2, P = 0.041, 95% CI: -2 to 0). None of the patients had perioperative complications. CONCLUSIONS: In this small series, there was no significant difference between caudal ropivacaine-morphine and paravertebral catheter for postoperative care in infants undergoing upper abdominal surgery. Further prospective studies are needed to compare the efficacy and incidence of complications of caudal block and paravertebral catheter for postoperative analgesia.

Spinal CPEB-mtROS-CBP signaling pathway contributes to perineural HIV gp120 with ddC-related neuropathic pain in rats.

Human immunodeficiency virus (HIV) patients treated with nucleoside reverse transcriptase inhibitors (NRTIs), have been known to develop neuropathic pain. While there has been a major shift away from some neurotoxic NRTIs in current antiretroviral therapy, a large number of HIV patients alive today have previously received them, and many have developed painful peripheral neuropathy. The exact mechanisms by which HIV with NRTIs contribute to the development of neuropathic pain are not known. Previous studies suggest that cytoplasmic polyadenylation element-binding protein (CPEB), reactive oxygen species (ROS), and cAMP-response element-binding protein (CREB)-binding protein (CBP), are involved in the neuroimmunological diseases including inflammatory/neuropathic pain. In this study, we investigated the role of CPEB, mitochondrial ROS (mtROS), or CBP in neuropathic pain induced by HIV envelope protein gp120 combined with antiretroviral drug. The application of recombinant gp120 into the sciatic nerve plus systemic ddC (one of NRTIs) induced mechanical allodynia. Knockdown of CPEB or CBP using intrathecal antisense oligodeoxynucleotide (AS-ODN) reduced mechanical allodynia. Intrathecal mitochondrial superoxide scavenger mito-tempol (Mito-T) increased mechanical withdrawal threshold. Knockdown of CPEB using intrathecal AS-ODN, reduced the up-regulated mitochondrial superoxide in the spinal dorsal horn in rats with gp120 combined with ddC. Intrathecal Mito-T lowered the increased expression of CBP in the spinal dorsal horn. Immunostaining studies showed that neuronal CPEB positive cells were co-localized with MitoSox positive profiles, and that MitoSox positive profiles were co-localized with neuronal CBP. Our studies suggest that neuronal CPEB-mtROS-CBP pathway in the spinal dorsal horn, plays an important role in the gp120/ddC-induced neuropathic pain in rats.

Inhibition of Mitochondrial Fission Protein Reduced Mechanical Allodynia and Suppressed Spinal Mitochondrial Superoxide Induced by Perineural Human Immunodeficiency Virus gp120 in Rats.

BACKGROUND: Mitochondria play an important role in many cellular and physiologic functions. Mitochondria are dynamic organelles, and their fusion and fission regulate cellular signaling, development, and mitochondrial homeostasis. The most common complaint of human immunodeficiency virus (HIV)-sensory neuropathy is pain on the soles in patients with HIV, but the exact molecular mechanisms of HIV neuropathic pain are not clear. In the present study, we investigated the role of mitochondrial dynamin-related protein 1 (Drp1, a GTPase that mediates mitochondrial fission) in the perineural HIV coat glycoprotein gp120-induced neuropathic pain state. METHODS: Neuropathic pain was induced by the application of recombinant HIV-1 envelope protein gp120 into the sciatic nerve. Mechanical threshold was tested using von Frey filaments. The mechanical threshold response was assessed over time using the area under curves. Intrathecal administration of antisense oligodeoxynucleotide (ODN) against Drp1, mitochondrial division inhibitor-1 (mdivi-1), or phenyl-N-tert-butylnitrone (a reactive oxygen species scavenger) was given. The expression of spinal Drp1 was examined using western blots. The expression of mitochondrial superoxide in the spinal dorsal horn was examined using MitoSox imaging. RESULTS: Intrathecal administration of either antisense ODN against Drp1 or mdivi-1 decreased mechanical allodynia (a sensation of pain evoked by nonpainful stimuli) in the gp120 model. Intrathecal ODN or mdivi-1 did not change basic mechanical threshold in sham surgery rats. Intrathecal Drp1 antisense ODN decreased the spinal expression of increased Drp1 protein induced by peripheral gp120 application. Intrathecal phenyl-N-tert-butylnitrone reduced mechanical allodynia. Furthermore, both intrathecal Drp1 antisense ODN and mdivi-1 reversed the upregulation of mitochondrial superoxide in the spinal dorsal horn in the gp120 neuropathic pain state. CONCLUSIONS: These data suggest that mitochondrial division plays a substantial role in the HIV gp120-related neuropathic pain state through mitochondrial reactive oxygen species and provides evidence for a novel approach to treating chronic pain in patients with HIV.

[The Efficacy of Ultrasound-guided Radial Artery Catheterization.]

BACKGROUND: The goal of this study was to evaluate in patients with peripheral arterial disease (PAD) whether ultrasound-guided radial artery catheterization decreased procedural time and number of attempts compared with the traditional palpation technique. METHODS: Ultrasonography was evaluated for arte- rial catheterization after the traditional palpation tech- nique was unsuccessful in 480 seconds in 10 patients with PAD. The vascular access was performed by a single anesthesiologist. The successful catheterization time and the number of attempts were recorded. We also measured the diameter of the radial artery, the skin-to-artery distance, and the distance between the linear probe and puncture site. RESULTS: The mean overall time per patient for catheter insertion was 220.0?112.6 sec in the ultra- sound group vs. 480 sec in the palpation group (P= 0.0029). The mean number of attempts was 1.30?0.48 in the ultrasound group vs. 4.50?0.53 in the palpation group (P = 0.0024). All catheterizations were success- ful, and no failure was encountered in the ultrasound group. CONCLUSIONS: Ultrasound-guided radial artery cath- eterization took less time to establish the arterial line, and it reduced the number of attempts when com- pared with the palpation technique.

Effect of fluid loading on left ventricular volume and stroke volume variability in patients with end-stage renal disease: a pilot study.

PURPOSE: The aim of this study was to investigate fluid loading-induced changes in left ventricular end-diastolic volume (LVEDV) and stroke volume variability (SVV) in patients with end-stage renal disease (ESRD) using real-time three-dimensional transesophageal echocardiography and the Vigileo-FloTrac system. PATIENTS AND METHODS: After obtaining ethics committee approval and informed consent, 28 patients undergoing peripheral vascular procedures were studied. Fourteen patients with ESRD on hemodialysis (HD) were assigned to the HD group and 14 patients without ESRD were assigned to the control group. Institutional standardized general anesthesia was provided in both groups. SVV was measured using the Vigileo-FloTrac system. Simultaneously, a full-volume three-dimensional transesophageal echocardiography dataset was acquired to measure LVEDV, left ventricular end-systolic volume, and left ventricular ejection fraction. Measurements were obtained before and after loading 500 mL hydroxyethyl starch over 30 minutes in both groups. RESULTS: In the control group, intravenous colloid infusion was associated with a significant decrease in SVV (13.8%±2.6% to 6.5%±2.6%, P<0.001) and a significant increase in LVEDV (83.6±23.4 mL to 96.1±28.8 mL, P<0.001). While SVV significantly decreased after infusion in the HD group (16.2%±6.0% to 6.2%±2.8%, P<0.001), there was no significant change in LVEDV. CONCLUSION: Our preliminary data suggest that fluid responsiveness can be assessed not by LVEDV but also by SVV due to underlying cardiovascular pathophysiology in patients with ESRD.

Effect of fluid loading with normal saline and 6% hydroxyethyl starch on stroke volume variability and left ventricular volume.

PURPOSE: The aim of this clinical trial was to investigate changes in stroke volume variability (SVV) and left ventricular end-diastolic volume (LVEDV) after a fluid bolus of crystalloid or colloid using real-time three-dimensional transesophageal echocardiography (3D-TEE) and the Vigileo-FloTrac™ system. MATERIALS AND METHODS: After obtaining Institutional Review Board approval, and informed consent from the research participants, 22 patients undergoing scheduled peripheral vascular bypass surgery were enrolled in the study. The patients were randomly assigned to receive 500 mL of hydroxyethyl starch (HES; HES group, n=11) or normal saline (Saline group, n=11) for fluid replacement therapy. SVV was measured using the Vigileo-FloTrac system. LVEDV, stroke volume, and cardiac output were measured by 3D-TEE. The measurements were performed over 30 minutes before and after the fluid bolus in both groups. RESULTS: SVV significantly decreased after fluid bolus in both groups (HES group, 14.7%±2.6% to 6.9%±2.7%, P<0.001; Saline group, 14.3%±3.9% to 8.8%±3.1%, P<0.001). LVEDV significantly increased after fluid loading in the HES group (87.1±24.0 mL to 99.9±27.2 mL, P<0.001), whereas no significant change was detected in the Saline group (88.8±17.3 mL to 91.4±17.6 mL, P>0.05). Stroke volume significantly increased after infusion in the HES group (50.6±12.5 mL to 61.6±19.1 mL, P<0.01) but not in the Saline group (51.6±13.4 mL to 54.1±12.8 mL, P>0.05). Cardiac output measured by 3D-TEE significantly increased in the HES group (3.5±1.1 L/min to 3.9±1.3 L/min, P<0.05), whereas no significant change was seen in the Saline group (3.4±1.1 L/min to 3.3±1.0 L/min, P>0.05). CONCLUSION: Administration of colloid and crystalloid induced similar responses in SVV. A higher plasma-expanding effect of HES compared to normal saline was demonstrated by the significant increase in LVEDV.