Differences In Hemodynamic Parameters Research Articles

CARDIAC SYMPATHETIC ACTIVITY, MYOCARDIAL PERFUSION AND HEART CONTRACTILITY IN PATIENTS WITH ISCHAEMIC AND NON-ISCHAEMIC HEART FAILURE

Purpose:to assess the cardiac sympathetic activity, perfusion and contractility in ischemic and nonischemic chronic heart failure patients by using a radionuclide methods.Material and Methods.The study included 33 heart failure patients with NYHA class III and ischemic (n=13.39%) and non-ischemic (n=20.61%) heart failure. All patients underwent123I-MIBG imaging, myocardial perfusion imaging with 99mTc-MIBI and gated blood-pool single-photon emission computed tomography. Based on123I-MIBG study heart to mediastinum ratio as well as123I-MIBG washout rate were calculated. According to the myocardial perfusion imaging, Summed Rest Score was evaluated. Systolic and diastolic functions and ejection fraction as well as mechanical intraventricular dyssynchrony of both ventricles were analyzed by gated blood-pool single-photon emission computed tomography.Results.There was no statistically significant difference of hemodynamic parameters between the groups. In the first group, which include patients with ischemic heart failure, there were found the following correlations: washout rate and left ventricular end-diastolic volume (0.75; p<0.05), washout rate and left ventricular end-systolic volume (0.68; p<0.05), heart to mediastinum ratio and right ventricular ejection fraction (–0.57; p<0.05). In the group of patients with non-ischemic heart failure there were the following correlation: heart to mediastinum ratio and left ventricular end-systolic volume (–0.77; p<0.05), heart to mediastinum ratio and left ventricular ejection fraction (0.77, p<0.05), heart to mediastinum ratio and right ventricular ejection fraction (0.62, p<0.05), washout rate and left ventricular interventricular dyssynchrony (0.6; p<0.05).Conclusion.It was found out that heart failure patients were characterized by a correlation between sympathetic activity and volumes, hemodynamics and contractility of heart ventricles. The relationship between the cardiac sympathetic activity and myocardial perfusion as well as contractility depend on the etiology of chronic heart failure.

Midazolam increases preload dependency during endotoxic shock in rabbits by affecting venous vascular tone

BackgroundSeptic patients often require sedation in intensive care unit, and midazolam is one of the most frequently used sedatives among them. But the interaction between midazolam and septic shock is not known. The aim of this study is to investigate the effects of midazolam on preload dependency in an endotoxic shock model by evaluating systemic vascular tone and cardiac function.MethodsEighteen rabbits were randomly divided into three groups: Control group, MID1 group and MID2 group. Rabbits underwent ketamine anaesthesia and mechanical ventilation, and haemodynamic assessments were recorded in three groups (T0). Endotoxic shock was induced by lipopolysaccharide intravenously, and fluid resuscitation and norepinephrine were administered to obtain the baseline mean arterial pressure (MAP) (T1). Rabbits received equivalent normal saline (Control) and two consecutive dosages of midazolam: 0.3 mg kg−1 h−1 (MID1) and 3 mg kg−1 h−1 (MID2) (T2). Rabbits received another round of fluid challenge and norepinephrine infusion to return the MAP to normal (T3).ResultsNo significant differences in haemodynamic parameters were observed in three groups at T0, T1 or T3. Midazolam infusion significantly increased pulse pressure variation (PPV) and stroke volume variation (SVV) compared to the values in Control group, and MAP, central venous pressure (CVP), mean systemic filling pressure (Pmsf) and cardiac output (CO) decreased at T2. Same effects were observed with increasing doses of midazolam, and resistance for venous return (Rvr) decreased (MID1 vs. MID2) at T2. PPV and SVV increased significantly at T2 compared to the values at T1. MAP, CVP, Pmsf and CO decreased in MID1 and MID2 groups. Rvr also decreased in MID2 group (T2 vs. T1). Midazolam did not affect cardiac function index, systemic vascular resistance or artery resistance (T2 vs. T1).ConclusionsMidazolam administration promoted preload dependency in septic shock models via decreased venous vascular tone without affecting cardiac function.

Abstract 721: The Exercise Pressor Response to Lower Extremity Dynamic Exercise is Accompanied by an Abnormal Change in Total Peripheral Resistance in Peripheral Arterial Disease Subjects

Patients with peripheral arterial disease (PAD) have an exaggerated pressor response to dynamic exercise of the affected limb. We tested the hypothesis that this response is mediated by an increase in total peripheral resistance (TPR). We measured heart rate, blood pressure, stroke volume, cardiac output (CO), and total peripheral resistance (TPR) during exercise in 9 subjects with PAD and 9 age matched controls using continuous finger arterial pressure monitoring (Finometer). Finometer derived values were adjusted to values obtained by echocardiography, and brachial pressure at baseline. The average age and ABI was 65 ± 7 and 1.06 ± 0.07 in controls, and 66 ± 7 and 0.64 ± 0.08 in PAD. Participants performed dynamic plantar flexion at progressive workloads of 2 to 12kg (increased by 1kg/min until onset of fatigue/pain) using their symptomatic leg or leg with lower ABI. Those who reached 12kg continued exercise at a constant load until onset of fatigue/pain or a maximum of 4 minutes. Participants were then asked to perform an isometric handgrip exercise at 30% of maximum voluntary contraction (MVC) until fatigue. Results are shown in Table 1. There were no differences in hemodynamic parameters at baseline. The average weight at end of plantar flexion was 12.0 ± 0.2 and 9.2 ± 2.5 kg (p<0.0001) for control and PAD. Perceived exertion (Borg scale) and pain (NPRS scale) at end of exercise was 15 ± 2 and 0, and 15 ± 2 and 6 ± 3 in control and PAD. Plantar flexion elicited a significantly higher rise in blood pressure in PAD compared to control. TPR decreased in controls, but slightly increased in PAD. In contrast, isometric handgrip elicited a similar pressor response, as well as changes in CO and TPR in both groups. We conclude that the exaggerated pressor response in PAD is mediated by an abnormal response in TPR, which counteracts the normal vasodilatory response to dynamic leg exercise seen in controls. This response appears to be specific to dynamic plantar flexion exercise in PAD.

3:18 PM Abstract No. 53 Changes in two-dimensional perfusion angiography before and after inferior vena cava filter retrieval

To investigate differences in hemodynamic flow parameters acquired in two-dimension (2D) perfusion angiography before and after inferior vena cava (IVC) filter retrieval. IVC filter retrievals at a single institution were retrospectively reviewed. Standardized breath-hold, digital subtraction angiography was performed at 2-3 frames per second before and after removal, and 2D-perfusion images were reconstructed on a dedicated workstation (Philips Allura Xper FD20, Philips Medical Systems, Best, Netherlands). Changes in the density per pixel per second within a region of interest (ROI) were used to calculate contrast arrival time, time-to-peak (TTP), wash-in-rate (WIR), area under the curve (AUC), and mean transit time (MTT). Measurements were obtained inferior, superior, and at the level of the filter. Differences in the hemodynamic parameters before and after filter removal were assessed with Mann-Whitney U analysis. A p-value of <0.05 was considered statistically significant. At the level of the filter, the TTP was significantly longer before filter removal when compared to after, with mean times of 1.28 and 0.78 seconds, respectively (p = 0.042). The MTT inferior to the filter was longer before filter removal when compared to after, with mean times of 0.8 and 0.5 seconds, respectively. The WIR inferior to the filter was longer before filter removal when compared to after, with mean of 435 and 250 HU/second, respectively. Preliminary data evaluating differences in flow parameters acquired in 2D-perfusion angiography before and after IVC filter retrieval demonstrate a significantly longer TTP when filters are in place, suggesting a functional hemodynamic delay secondary to filter presence.

The Effect of Inhalation Anesthesia with Hyperventilation and Total Intravenous Anesthesia on Intracranial Pressure Control in Pediatrics with Craniosynostosis Surgery: A Randomized Clinical Trial

Background: Intracranial pressure (ICP) control is one of the anesthesiologist challenges in craniosynostosis repair surgery, especially in multiple sutures involvement. The aim of this study was comparing the effect of two anesthesia methods including inhalation with hyperventilation and total intravenous anesthesia (TIVA) on ICP control and surgeon satisfaction in pediatrics with craniosynostosis surgery. Materials and Methods: In this randomized clinical trial study, 40 pediatric patients with American society of anesthesiologists (ASA) І-ІІ, 6 months to 2 years old were included. All of the patients were scheduled for craniosynostosis repair at Mofid Children Hospital, Tehran, Iran, in May 2016 to January 2017. The patients were randomly divided into two groups. In hyperventilation group, patients received isoflurane for maintenance of anesthesia and hyperventilation (Paco2=25-30 mmHg) established during surgery. The total intravenous anesthesia (TIVA) group received propofol infusion for anesthesia maintenance and Paco2 was maintained 35 mmHg. Intra cranial pressure (ICP) was assessed by surgeon using a 4-point scale. Hemodynamic (mean arterial pressure and heart rate) changes and blood loss were compared between hyperventilation and TIVA groups. Results: The mean age of patients in hyperventilation group was 10.9±3.25 months and in TIVA group was 8.7 ± 2063 months (p=0.11). Fourteen (70%) patients in hyperventilation group and 6 (30%) patients in TIVA group were male (p=0.74). A significant difference was seen in ICP control and surgical condition between hyperventilation and TIVA groups (p=0.032). ICP was controlled better in hyperventilation group. There was no difference in hemodynamic parameters and blood loss between hyperventilation and TIVA groups (p>0.05). Conclusion: This study showed inhalation anesthesia with hyperventilation was more effective than TIVA on ICP control in craniosynostosis surgery.

Comparison the Effects of Oral Tizanidine and Tramadol on Intra- and Post-operative Shivering in Patients Underwent Spinal Anesthesia.

Background:Heat loss and core-to-peripheral redistribution of body heat occur in patients undergoing neuraxial anesthesia resulted to decrease of core temperature and early reach of shivering threshold. Because shivering has deleterious metabolic and cardiovascular effects, it should ideally be prevented by pharmacologic or other means. Tizanidine is an alpha-2 agonist. We evaluated the usefulness of oral tizanidine (TI) and tramadol in preventing of shivering in patients undergoing spinal anesthesia for transurethral resection of the prostate (TURP).Materials and Methods:Ninety patients, scheduled for TURP with spinal anesthesia, were prospectively enrolled. Patients were randomly assigned to 1 of 3 groups. 90 min before spinal anesthesia, 30 patients received 4 mg oral TI, 30 patients received 50 mg tramadol, and 30 patients received placebo as control group. Spinal anesthesia was induced at the L3–L4 or L4–L5 interspaces with 12.5 mg bupivacaine. An investigator blinded to the drugs recorded the frequency and degree of shivering.Results:The overall frequency and severity of shivering were significantly lower in patients treated with TI and tramadol compared to placebo (P = 0.04) (P = 0.001). There was not much difference in the nausea and vomiting of both the drugs (P = 026) (P = 011). There was no difference in hemodynamic parameters between three groups (P = 0.08) (P = 013).Conclusions:Oral TI and tramadol were comparable in respect to their effect in decreasing the incidence, intensity shivering when used prophylactically in patients who underwent TURP with spinal anesthesia.

Comparison of the Effects of Dexmedetomidine on the Induction of Anaesthesia Using Marsh and Schnider Pharmacokinetic Models of Propofol Target-Controlled Infusion.

The study aimed to determine the effects of dexmedetomidine on the induction of anaesthesia using different models (Marsh and Schnider) of propofol target-controlled infusion (TCI). Sixty-four patients aged 18-60 years, American Society of Anaesthesiologists (ASA) class I-II who underwent elective surgery were randomised to a Marsh group (n = 32) or Schnider group (n = 32). All the patients received a 1 μg/kg loading dose of dexmedetomidine, followed by TCI anaesthesia with remifentanil at 2 ng/mL. After the effect-site concentration (Ce) of remifentanil reached 2 ng/mL, propofol TCI induction was started. Anaesthesia induction commenced in the Marsh group at a target plasma concentration (Cpt) of 2 μg/mL, whereas it started in the Schnider group at a target effect-site concentration (Cet) of 2 μg/mL. If induction was delayed after 3 min, the target concentration (Ct) was gradually increased to 0.5 μg/mL every 30 sec until successful induction. The Ct at successful induction, induction time, Ce at successful induction and haemodynamic parameters were recorded. The Ct for successful induction in the Schnider group was significantly lower than in the Marsh group (3.48 [0.90] versus 4.02 [0.67] μg/mL; P = 0.01). The induction time was also shorter in the Schnider group as compared with the Marsh group (134.96 [50.91] versus 161.59 [39.64]) sec; P = 0.02). There were no significant differences in haemodynamic parameters and Ce at successful induction. In the between-group comparison, dexmedetomidine reduced the Ct requirement for induction and shortened the induction time in the Schnider group. The inclusion of baseline groups without dexmedetomidine in a four-arm comparison of the two models would enhance the validity of the findings.

Sexual dysfunction as a determinant of cardiovascular outcome in patients undergoing chronic hemodialysis.

Sexual dysfunction (SD) is common in men and women with chronic kidney disease (CKD) and is considered as an early marker for cardiovascular (CV) disease. We hypothesized that patients with SD have higher risk for vascular damage of the large arteries, accelerated vascular aging, and consequently higher CV mortality than other end-stage renal disease (ESRD) patients. In this study, the International Index of Erectile Function (IIEF) questionnaire and the Female Sexual Function Index (FSFI) questionnaire were applied in men and women, respectively. Ambulatory blood pressure monitoring (ABPM), arterial stiffness, and ankle-brachial index (ABI) were performed in all patients. Pulse wave velocity (PWV) was significantly slower in non-SD patients (10.5 vs. 8.8 m/s; p < 0.001) with significantly lower number of non-SD patients with PWV > 10 m/s compared to SD patients (p < 0.001). Only 57% of the patients with prior CV event had PWV > 10 m/s. No difference in AIx was observed. Non-SD patients had better values of ABI (0.83 vs. 1.09; p < 0.05) with significantly lower number of non-SD patients with ABI < 0.9 compared to SD patients (p = 0.001) as well as smaller percentage of LVH (57.5% vs. 80.7%; p = 0.01). There were no differences in hemodynamic parameters when patients with SD were divided by sex. Pulse wave velocity was the strongest predictor of lower IIEF and FSFI scores. Mean survival time was longer in non-SD patients than in SD patients (11.6 vs. 10.5 months, p = 0.019). The higher incidence of prior CV events and CV mortality found in SD patients on hemodialysis (HD) is a consequence of accelerated vascular aging. Sexual dysfunction in HD patients should also be considered a marker of subclinical organ damage and future CV events. Our study confirms the predictive role of PWV in HD patients.

Impaired Central Pulsatile Hemodynamics in Children and Adolescents With Marfan Syndrome

BackgroundMarfan syndrome is characterized by aortic root dilation, beginning in childhood. Data about aortic pulsatile hemodynamics and stiffness in pediatric age are currently lacking.Methods and ResultsIn 51 young patients with Marfan syndrome (12.0±3.3 years), carotid tonometry was performed for the measurement of central pulse pressure, pulse pressure amplification, and aortic stiffness (carotid‐femoral pulse wave velocity). Patients underwent an echocardiogram at baseline and at 1 year follow‐up and a genetic evaluation. Pathogenetic fibrillin‐1 mutations were classified between “dominant negative” and “haploinsufficient.” The hemodynamic parameters of patients were compared with those of 80 sex, age, blood pressure, and heart‐rate matched controls. Central pulse pressure was significantly higher (38.3±12.3 versus 33.6±7.8 mm Hg; P=0.009), and pulse pressure amplification was significantly reduced in Marfan than controls (17.9±15.3% versus 32.3±17.4%; P<0.0001). Pulse wave velocity was not significantly different between Marfan and controls (4.98±1.00 versus 4.75±0.67 m/s). In the Marfan group, central pulse pressure and pulse pressure amplification were independently associated with aortic diameter at the sinuses of Valsalva (respectively, β=0.371, P=0.010; β=−0.271, P=0.026). No significant difference in hemodynamic parameters was found according to fibrillin‐1 genotype. Patients who increased aortic Z‐scores at 1‐year follow‐up presented a higher central pulse pressure than the remaining (42.7±14.2 versus 32.3±5.9 mm Hg; P=0.004).ConclusionsCentral pulse pressure and pulse pressure amplification were impaired in pediatric Marfan syndrome, and associated with aortic root diameters, whereas aortic pulse wave velocity was similar to that of a general pediatric population. An increased central pulse pressure was present among patients whose aortic dilatation worsened at 1‐year follow‐up.

Comparison of Customized Cutting Block and Conventional Cutting Instrument in Total Knee Arthroplasty: A Randomized Controlled Trial

BackgroundCustomized cutting block (CCB) was designed to ensure the accurate alignment of knee prostheses during total knee arthroplasty. Given the paucity of CCB efficacy data, we compare CCB with conventional cutting guide using a randomized controlled trial. MethodsOne hundred eight osteoarthritic knee patients underwent total knee arthroplasty by one experienced surgeon were randomized to receive CCB (n = 54) or conventional cutting instrument (CCI) surgery (n = 54). The primary outcomes were limb alignment, prostheses position, and operative time. The secondary outcomes were hemodynamic alteration after surgery, functional outcomes (modified Western Ontario and McMaster University Osteoarthritis Index) and range of motion at 2 years after surgery. ResultsMean hip-knee-ankle angle in the CCB group was 179.4° ± 1.8° vs 179.1° ± 2.4° in the CCI group, Δ = 0 (95% confidence interval [CI] −0.6 to 1.1, P = .55). Mean operative time was faster in the CCB arm: 93 ± 12 vs 104 ± 12 minutes, Δ = 11 (95% CI −16.7 to −7.2, P < .0001). There were no differences in hemodynamic parameters, mean blood loss (446 [CCB] vs 514 mL [CCI], Δ = −68 [95% CI −138 to 31 mL, P = .21]), postoperative hemoglobin changes, incidence of hypotension (systolic <90 mm Hg), oliguria, and rates of blood transfusion. Functional outcomes and range of motion were also similar. ConclusionThere was no improvement in alignment, hemodynamic changes, blood loss, and knee functional outcomes. CCB reduced surgical time by 11 minutes in our population. CCB cost-effectiveness should be further investigated.

Effect of esmolol on hemodynamics and clinical outcomes in patients with septic shock

To evaluate the effect of heart rate control with esmolol on hemodynamics, inflammatory cytokines and clinical outcomes in patients with septic shock. A prospective randomized controlled trial was conducted. The patients with septic shock admitted to Department of Critical Care Medicine of China-Japan Friendship Hospital from August 2014 to October 2016 were enrolled. After 24 hours of resuscitation and other therapy, they were randomly divided into two groups by sealed envelope. The patients in experimental group was treated with continuous intravenous esmolol infusion for 24 hours, initial dose was 0.05 mg×kg-1×h-1, and was titrated to decrease the heart rate by 20% as compared with the value at the time of enrollment or below 95 bpm, while isotonic saline was given to control group through intravenous line at 3 mL/h for 24 hours. The differences in hemodynamic parameters at 0, 1, 4, 8, 12, 24 and 48 hours, as well as serum inflammatory cytokines and blood lactate (Lac) at 0, 12, and 24 hours, 28-day mortality were compared between the two groups. Seventy-six septic shock patients were admitted during the study, 12 were excluded for suspicious acute myocardial infraction (AMI) or acute left heart failure or for the history of chronic obstructive pulmonary disease (COPD), 4 were quitted the study for being unable to tolerate the lowest dose of esmolol, giving up treatment, or death within 24 hours. Finally, 60 patients completed the study, 30 patients in experimental group, and 30 in control group. There were no differences in gender, age, acute physiology and chronic health evaluation II (APACHE II) score and infection source between two groups, indicating the general data between the two groups were balanced and comparable. The decrease in heart rate was more markedly in experimental group than that of control group at 1, 4, 48 hours after esmolol administration (bpm: 97.4±16.5 vs. 110.9±19.6, 95.2±15.3 vs. 105.1±17.9, 86.4±12.1 vs. 97.2±22.6, all P < 0.05), cardiac index (CI) at 8, 24, 48 hours was significantly increased (mL×s-1×m-2: 57.2±13.5 vs. 46.5±11.0, 57.7±15.7 vs. 48.7±14.7, 61.2±16.5 vs. 51.5±14.7, all P < 0.05), and stroke volume index (SVI) at 4, 8, 24 hours was significantly increased (mL/m2: 34.1±6.9 vs. 29.0±8.7, 35.0±6.1 vs. 28.8±9.6, 38.3±10.1 vs. 31.9±13.2, all P < 0.05). Interleukin-1β (IL-1β) at 24 hours in experimental group was significantly higher than that of control group (ng/L: 0.15±0.06 vs. 0.13±0.05, P < 0.01). There were no differences in mean arterial pressure (MAP), Lac, white blood cell (WBC), IL-6, IL-10, and tumor necrosis factor-α (TNF-α) between the two groups, and no difference in 28-day mortality between experimental group and control group was found (30.0% vs. 36.7%,χ 2 = 0.300, P = 0.583). It is efficient and safe to use esmolol for heart rate control in patients with septic shock after resuscitation. Esmolol can improve cardiac performance without affecting blood pressure and Lac, but has no effect on inflammatory cytokines and prognosis.

Hemodynamics and gas exchange during chest compressions in neonatal resuscitation.

PurposeCurrent knowledge about pulmonary/systemic hemodynamics and gas exchange during neonatal resuscitation in a model of transitioning fetal circulation with fetal shunts and fluid-filled alveoli is limited. Using a fetal lamb asphyxia model, we sought to determine whether hemodynamic or gas-exchange parameters predicted successful return of spontaneous circulation (ROSC).MethodsThe umbilical cord was occluded in 22 lambs to induce asphyxial cardiac arrest. Following five minutes of asystole, resuscitation as per AHA-Neonatal Resuscitation Program guidelines was initiated. Hemodynamic parameters and serial arterial blood gases were assessed during resuscitation.ResultsROSC occurred in 18 lambs (82%) at a median (IQR) time of 120 (105–180) seconds. There were no differences in hemodynamic parameters at baseline and at any given time point during resuscitation between the lambs that achieved ROSC and those that did not. Blood gases at arrest prior to resuscitation were comparable between groups. However, lambs that achieved ROSC had lower PaO2, higher PaCO2, and lower lactate during resuscitation. Increase in diastolic blood pressures induced by epinephrine in lambs that achieved ROSC (11 ±4 mmHg) did not differ from those that were not resuscitated (10 ±6 mmHg). Low diastolic blood pressures were adequate to achieve ROSC.ConclusionsHemodynamic parameters in a neonatal lamb asphyxia model with transitioning circulation did not predict success of ROSC. Lactic acidosis, higher PaO2 and lower PaCO2 observed in the lambs that did not achieve ROSC may represent a state of inadequate tissue perfusion and/or mitochondrial dysfunction.

Effects of video work on the ocular vascular hemodynamic and visual of the operators

Objective: To investigate the effects of long time video display terminal (VDT) operation on the ocular vascular hemodynamic and visual acuity. Methods: During March and October 2015, 120 cases of video monitoring warriors were selected as study group, another 155 cases of logistics personnel as the control group. The low vision of the two groups was calculated and compared, and the color Doppler flow imaging was used to measure the central retinal artery (CRA) , short posterior ciliary artery (SPCA) , anterior ciliary artery (ACA) , (peak systolic velocity, PSV) , end diastolic velocity (EDV) and (resistance index (RI) . The differences of hemodynamic parameters between these two groups were evaluated, and the relationship between the visual acuity and each hemodynamic parameter was analyzed. Results: The visual acuity of the study group was[0.8 (0.4-1.2) ], much lower than the control group, and the rate of low version in the study group was 40.00%, much higher than that of the control group. Compared with the control group, both of ACA and CRA of SPCA, PSV and EDV in the study group were decreased, while RI of CRA, ACA were increased (P<0.05) ; Compared with the control group, no statistical significance was found in the RI of SPCA in the study group (P>0.05) . The PSV and EDV were negatively correlated with visual acuity (r value of PSV and visual acuity were -0.352, -0.265 and -0.304; r value of EDV and visual acuity were -0.324, -0.348 and -0.365, while RI was positively correlated with visual acuity (r value were 0.363, 0.326 and 0.344) . Conclusion: Our data suggest that long time video operation may be associated with changes of ocular vascular hemodynamic parameters and raise the incidence of low vision.

Total intravenous anesthesia produces outcomes superior to those with combined intravenous-inhalation anesthesia for laparoscopic gynecological surgery at high altitude.

ObjectiveWe compared efficacy and adverse outcomes following totally intravenous anesthesia (TIVA) versus combined intravenous–inhalation anesthesia (CIVIA) on hemodynamics and postoperative recovery following laparoscopic gynecological (LG) surgery at high altitudes.MethodsWe enrolled 80 ASA I or II patients scheduled for LG surgery and randomly assigned them to TIVA with propofol (group P, n = 40) or CIVIA with isoflurane (group I, n = 40). Mean arterial pressure, heart rate, pulse oxygen saturation, and partial pressure of end-tidal carbon dioxide were measured at various time points. Outcome measures were interval to spontaneous ventilation, eye opening, return to consciousness, extubation, operating room duration. Intraoperative awareness and postoperative nausea/vomiting were assessed at follow-up.ResultsNo differences in hemodynamic parameters were detected in either group. Group P had a significantly shorter postoperative anesthetic recovery time and lower incidence of postoperative nausea/vomiting.ConclusionTIVA is superior to CIVIA for GL surgery at high altitudes.

Comparison of haemodynamic parameters between the high and low spinal block in young healthy patients

Background. For some surgical proce-dures a higher sensory block is needed. However, it is complicated by a higher in-cidence of hypotension, more bradycardia and nausea and a higher use of vasoactive drugs. In elderly and obstetric population complications have been attributed to the decrease in cardiac output and systemic vascular resistance, especially in a high block (above Th6). The aim of our study was to find the incidence of hypotension and bradycardia after a spinal anaesthesia in young, healthy patients. As young pa-tients compensate more, we aimed to find the difference in haemodynamic variables between the group with a high and the group with a low spinal block and the un-derlying mechanisms of hypotension. Methods. In a prospective, randomized study 44 American Society of Anaesthe-siologists (ASA) 1 patients scheduled for knee arthroscopy under spinal anaesthe-sia were randomly distributed to a high (group H) and a low (group L) spinal block group. In a group H patients were placed into horizontal, whereas in a group L in 15-degree anti-Trendelenburg posi-tion immediately after the spinal block. Haemodynamic parameters were meas-ured continuously noninvasively from 10 min before to 25 min after the spinal block using the CNAPTM device with the LiD-CORapid monitor.Results. The differences in haemodynamic parameters between the groups were not statistically significant at all measured times despite a significant difference in the spinal block level (18.5 vs 13.3 dermato-mes above S5, p<0.001) and a significant difference in haemodynamic variables inside each group compared to the base-line value. With cardiac index (CI) as a dependent variable, a significant correla-tion between CI and stroke volume in-dex (SVI) was found (β=0.849, p<0.001) and also between CI and heart rate (HR) (β=0.573, p<0.001). In group H the inci-dence of hypotension was 35%, whereas in group L it was 10%. The same difference was seen in the use of phenylephrine be-tween the groups, however the difference was not significant.Conclusion. In our study it was found that in young, healthy patients there are no significant differences in haemodynamic parameters and in incidence of hypoten-sion between a high and low spinal block. Young, healthy patients compensate a decrease in systemic vascular resistance caused by the spinal anaesthesia with a compensatory increase in CI resulting from an increase in SVI and HR. How-ever, a trend towards less hypotension, less bradycardia and less frequent phenyle-phrine use in a low spinal block was noted.

A pilot study of perioperative esmolol for myocardial protection during on-pump cardiac surgery.

The protective effects of preprocedural esmolol on myocardial injury and hemodynamics have not, to date, been investigated in patients who were scheduled for cardiac surgeries under a cardiopulmonary bypass (CPB). A pilot randomized controlled trial was performed at The First Affiliated Hospital of Dalian Medical University (Dalian, China). Patients scheduled for elective open-heart surgeries under CBP were included, and were randomized to esmolol and control groups. For patients in the esmolol groups, intravenous esmolol (70 µg/kg/min) was administered at the time of incision until CPB was performed. For patients assigned to the control group, equal volumes of 0.9% saline were administered. Markers of myocardial injury and hemodynamic parameters were observed until 12 h post surgery. A total of 24 patients were included in the present study. No significant differences in hemodynamic parameters, including the central venous pressure and heart rate, were detected between patients in the two groups during the perioperative period or within the first 12 h post-surgery (P>0.05), except for the mean arterial pressure, which was higher in the esmolol group compared with the control group at 5 and 12 h post-surgery (P<0.05). However, the serum level of cardiac troponin I was higher in patients of the control group compared with those of the esmolol group during the preoperative period (P<0.05). Although creatinine kinase was significantly different at T2 between the two groups, its MB isoenzyme was not significantly different between the groups (P>0.05). In addition, administration of esmolol was not associated with an increased risk for severe complications and adverse events in these patients. In conclusion, preoperative esmolol may be an effective and safe measure of myocardial protection for patients who undergo elective cardiac surgeries under CBP.

Abstract PR275

Background & Objectives: Dexmedetomidine is α2 adrenergic agonist, used for sedation and analgesia.1,2 This study compares the effect of intra-nasal dexamedetomidine and oral midazolam for premedication by comparing vital parameters, preoperative anxiolysis, sedation and onset of sedation in children before induction of anaesthesia. Materials & Methods: It was a one year double blinded randomized controlled trial, conducted in a tertiary care hospital, after ethics approval. 60 children undergoing elective minor surgery were divided into two groups on the basis of premedicant drug, namely Group A (intranasal dexmedetomidine, 0.5 µg/kg) and Group B (Oral midazolam 0.5 mg/kg). Outcome variables (vitals, anxiety and sedation) were monitored at baseline (just prior to administration of drug), 15, 30 and 45 minutes after drug administration. Sedation status was assessed using Five-Point Sedation Scale and anxiety by Four-Point Anxiety Score.3 Statistical analysis included chi-square test and student ‘t’ test. Results: Mean age, heart rate, systolic blood pressure, diastolic blood pressure, mean arterial pressure and oxygen saturation at all intervals including baseline, were comparable in both the groups. Time (in minutes) required for onset of sedation was significantly less in Group A than Group B (p=0.013). Mean sedation score was significantly low in Group A compared to Group B at 15 minutes interval (1.63 ± 0.67 versus 2.10 ± 0.80; p=0.018). Mean anxiety score was significantly low in Group A compared to Group B at 15 and 30 minutes interval (1.10 ± 0.31 versus 1.70 ± 0.53; p<0.001 and 1.50 ± 0.57 versus 1.83 ± 0.59; p=0.031 respectively). Conclusion: Intranasal dexmedetomidine is a better premedicant in terms of sedation and anxiolysis, however difference in hemodynamic parameters was not significant.

Hemodynamic determinants and ventriculo-arterial coupling are sex-associated in heart failure patients.

End-systolic volume (ESV) and end-diastolic volume (EDV) are key parameters in the analysis of left ventricular (LV) function, and the study of cardiac remodeling. The volume regulation graph (VRG) relates these fundamental determinants, and permits convenient stratification for clinically relevant covariates. This contribution analyzes sex-associated differences in hemodynamic parameters for 197 heart failure (HF) patients, evaluated by biplane ventriculography, in combination with arterial pressure. We calculated LV parameters such as stroke volume (SV), cardiac output (CO), ESV, EDV, ejection fraction (EF), end-systolic elastance (Emax), besides arterial parameters: effective arterial elastance (Ea), elastance ratio (the coupling index k), peripheral resistance (Rs), pulse pressure (PP), and arterial compliance (C), all normalized for body surface area when appropriate. Average values for heart rate, SV, CO, Ea, C, Rs are similar between the sexes, as are the VRG regression lines. However, ESV and EDV are significantly (P<;0.034 and P<;0.016, respectively) smaller in women (N=67), whereas EF, Emax, mean arterial pressure, PP, and k are higher (P<;0.008 or less). We conclude that the various sex-associated differences observed in these HF patients are striking, and thus require due attention when evaluating the clinical status of HF patients. Formulation of distinct cut-off values for male and female patients with HF seems warranted, when considering specific HF phenotypes.

Half dose protamine sulphate, does it work in valvular replacement cardiac surgery? A prospective, double-blinded randomized study

IntroductionCardiac surgery of valvular replacement carries multiple complications, the commonest of which is bleeding. Effective anti-coagulation during valvular replacement is necessary to prevent excessive activation of the hemostatic system; protamine sulfate is used to neutralize the effect of circulating heparin. The Aim of the work was to determine the effectiveness of half dose Protamine in reversing the action of heparin in valvular replacement cardiac surgery without the appearance the side effect of protamine.Method40 patients undergoing valvular replacement divided into two groups. Group A: received 1mg of protamine per 100 unit heparin (common ratio 1:1, protamine: heparin). Group B: received 0.5 mg of protamine per100 unit of heparin (our ratio 1:2, protamine: heparin). Following data were detected in each patients (1) blood loss, 2 Activated clotting Time, (3) Hemoglobin, (4) unites of FFP requirements, (5) Clotting Time, and Maximum Clot Firmness (MCF) test.ResultsWe found that the administration of half (1/2) of Total Calculated Dose of protamine sulphate was always able to reverse the anticoagulant effect of heparin .with insignificant difference in hemodynamic parameters, and in the amount of blood loss and insignificant difference in unites of FFP requirement, on other hand there was mild significant results in MCF test between both groups.DiscussionOur present study suggests that the commonly applied ratio equal to 1:1 (ratio of protamine to heparin) could be higher than needed with potential and hazardous impacts and lowering it to be 1:2 ratio is similarly effective. Our results are in line with the findings obtained by Salvatore et al., who observed that reversal of heparin administered in patients undergoing cardiac surgery could be effectively achieved with 2/3 of the usual dose of Protamine and that the additional administration of protamine seems to induce an elongation of the clotting time with no impact on clot firmness. (1) While the impact of a high protamine to heparin ratio was even studied by Kahn et al., who studied blood samples of 46 patients undergoing cardiac surgery using CABG and found a significant worsening of the coagulation parameters using protamine to heparin ratio of more than 2:12.

Characteristic analysis of hemodynamics for trunk aneurysm of posterior communicating artery

Objective To study the hemodynamic characteristics of the difference between the trunk aneurysm of posterior communicating artery (PCoA) and the internal carotid artery (ICA)-PCoA aneurysm. Methods A total of 15 patients with trunk aneurysm of PCoA (11 ruptured aneurysms, 4 unruptured aneurysms, for short PCoA trunk group) treated at the Department of Interventional Neuroradiology, Beijing Tiantan Hospital, Capital Medical University from January 2014 to June 2015 were studied retrospectively. The 15 patients with ICA-PCoA aneurysm with approximately the same size and the same rupture state at the same time were used as a matched control group. A numerical simulation analysis was conducted for individual three-dimensional digital subtraction angiography (DSA) images of the patients using the method of computational fluid dynamics. The differences of hemodynamic parameters of the aneurysms were compared between the 2 groups. Results The PCoA trunk aneurysms were in accordance with the blood flow pattern of the lateral aneurysms, and the ICA-PCoA aneurysms were in accordance with the flow blood pattern of the aneurysms at the bifurcations. The hemodynamic parameters in the PCoA trunk group vs. the control group: The wall shear stress (WSS) of the PCoA trunk group and the control group was 0.48±0.08 and 0.63±0.07 respectively. The percentage of the low WSS area (LSA) was 23.20±6.94% and 4.50±2.29% respectively. There were significant differences (P=0.022, P=0.008). The oscillatory shear index (OSI) of the two groups was 0.0233±0.0071 and 0.0158±0.0044 respectively. There was no significant difference (P=0.411). The WSS of the ruptured group (n=22) and the unruptured group (n=8) was 0.45±0.05 and 0.84±0.08 respectively, and LSA was 18.22±5.11% and 1.84±1.76% respectively. There was significant difference (P<0.001, P=0.006). The OSI of the two groups was 0.0234±0.0054 and 0.0091±0.0027 respectively. There was no significant difference (P=0.132). Conclusion The low WSS may be one of the reasons for the high risk of PCoA trunk aneurysm rupture. Key words: Intracranial aneurysms; Aneurysm, ruptured; Hemodynamics; Posterior communicating artery; Computational fluid dynamics