Arterial Pressure Values Research Articles

Influence of perioperative blood pressure regulation on postoperative delirium in patients undergoing head and neck free flap reconstruction

BackgroundPostoperative delirium (POD) is a serious complication in patients undergoing microvascular head and neck reconstruction. Whether intraoperative and postoperative blood pressure regulation are risk factors for POD remains unclear. This study aimed to highlight the relationships between intraoperative and postoperative blood pressure regulation and POD in microvascular head and neck reconstruction.MethodsData from 433 patients who underwent microvascular head and neck reconstruction at our department of oral and maxillofacial surgery between 2011 and 2019 were retrospectively analyzed. The 55 patients with POD were matched with 55 patients without POD in terms of tracheotomy, flap type, and flap location, and the intraoperative and postoperative systolic and mean blood pressure values were compared between the two groups.ResultsPatients with POD showed lower intraoperative and postoperative minimum mean arterial pressure (MAP) values than patients without POD (60.0 mmHg vs. 65.0 mmHg, p < 0.001; and 56.0 mmHg vs. 62.0 mmHg, p < 0.001; respectively). A lower intraoperative minimum MAP value was identified as predictor for POD (odds ratio [OR] 1.246, 95% confidence interval [CI] 1.057–1.472, p = 0.009). The cut-off value for intraoperative MAP for predicting POD was ≤ 62.5 mmHg (area under the curve [AUC] 0.822, 95% CI 0.744–0.900, p < 0.001).ConclusionsMaintaining a stable intraoperative minimum MAP of > 62.5 mmHg could help to reduce the incidence of POD in microvascular head and neck reconstruction.

Evaluation of Mean Platelet Volume in Children with Hypertension.

Childhood hypertension, a disease with increasing prevalence, can lead to severe health problems. With the increased pressure on the vascular endothelium in hypertension, lesions in the endothelium result in endothelial activation and a process of inflammation, which causes platelet activation and in the bone marrow the release of platelet precursor cells into the peripheral blood stream. During inflammation, changes in the number and size of platelets are observed. With the release of platelet precursors into the peripheral blood stream due to platelet activation, an increase in mean platelet volume (MPV) is also seen. Our aim in this study is the evaluation of MPV changes in the hemogram of children suffering from hypertension, a condition causing severe cardiovascular problems. Material and Methods. This research is a descriptive retrospective cross-sectional study. It consists of a patient group diagnosed with hypertension and a control group of children presenting for routine check-ups with no diagnosed hypertension. Demographic characteristics, arterial pressure values, and hemogram parameters have been evaluated. A total of 90 cases were enrolled in the study, including a patient group of 45 cases with hypertension (19 females, 26 males) and a control group of 45 cases (27 females, 18 males). The median age was 15 years in the hypertension group and 13 years in the control group. In the hypertension cases, the thickness of the carotis intima media was statistically significantly greater than in the control group (p < 0.001). Echocardiographic findings (IVSd, LVDd, LVPWd, IVSs, LVDs, LVPWs, and LV mass) were significantly higher in the hypertension group compared to the control group (p < 0.001). A statistically significant difference in platelet count and MPV values between the groups was not found (p = 0.151, p = 0.405, respectively). While MPV is hypothesized to be higher in hypertensive individuals, there was no statistically significant difference between the hypertensive and non-hypertensive groups in this study.

Evaluation of Pre and Post-operative Pulmonary Artery Pressures in Children with Adenotonsillar Hypertrophy and Correlation with Chronicity: A Prospective Study on 50 Children.

Children with grade III or IV of adenotonsillar hypertrophy especially of a longer duration, may show cardiovascular changes due to mouth breathing. These changes can be detected on doppler echocardiocardiography which can be used as a screening tool. Fifty paediatric patients of grade 3 and 4 adenotonsillar hypertrophy underwent adenotonsillar resection after a pre-operative work up which included doppler echocardiography to measure pulmonary artery pressures. A post-operative doppler echocardiography was done after three months. 11 children (22%) showed deranged pulmonary artery pressure values with increased mean pulmonary artery pressure (MPAP) and pulmonary artery systolic pressure (PSAP) on preoperative doppler echocardiography, and 2 out of these 11 children had Pulmonary Artery Hypertension. A significant (p < 0.001) improvement was noted in pulmonary artery pressure values (MPAP and PSAP returned to normal) after adenotonsillectomy in 3-month postoperative echocardiography. Also, a statistically significant correlation was obtained between chronicity of symptoms and raised pulmonary artery pressures. Our study concluded that these children with chronic untreated upper airway obstructive symptoms get predisposed to potential cardiac complications. And these grave consequences can be easily prevented by a timely intervention.

THRIVE combined with i-gel laryngeal mask for prolonging apneic oxygenation time in retrograde intrarenal surgery

To explore the effect of THRIVE combined with i-gel laryngeal mask on the safety of oxygen therapy in apnea and surgical precision of retrograde intrarenal surgery. A total of 120 patients undergoing retrograde intrarenal surgery under general anesthesia with laryngeal mask were randomized into 3 groups (n=40), and after the flexible ureteroscope entered the renal pelvis and located the stones, the patients received assisted ventilation in APPV mode (control group), ventilation with small tidal volume and high respiratory rate (group H), or THRIVE combined with laryngeal mask for oxygen supply without using the ventilator (THRIVE group). The time for lithotripsy by the surgeons, surgeons' satisfaction, diaphragm mobility, and times of urinary tract mucosal injury were recorded, and arterial blood pressure, heart rate, SpO2, PaO2, PaCO2, and pH value were measured before, during and after lithotripsy. Among the 3 groups, THRIVE group had the shortest time for lithotripsy, best satisfaction of the surgeons, the lowest diaphragmatic mobility of the patients, and the smallest number of mucosal injuries. The arterial blood pressure, heart rate, and SpO2 of the patients did not differ significantly among the 3 groups. At 20 min and 30 min after the start of lithotripsy, PaO2 decreased significantly in group H and THRIVE group; in THRIVE group, PaCO2 increased and pH decreased significantly at 10, 20 and 30 min after the start of lithotripsy. No significant difference was found in oxygenation indicators among the 3 groups upon discharge from the PACU. In retrograde intrarenal surgery, THRIVE combined with i- gel laryngeal mask for oxygen therapy during the anaerobic period can improve the surgical accuracy and maintain the patient's oxygenation index in a controllable range within 30 min.

The Effect of Biogel Using Biomagnetic Energy in the Treatment of Acute Pain in the Upper Extremity and Spine: A Randomized Controlled Trial

Objective: Pain is a public health problem, which is caused by various etiological factors and leads to diminished quality of life and decreased workforce. The aim of this study was to determine whether Biogel has an effect in the treatment of pain. Methods: Patients due to acute pain in the upper extremity and/or trunk were divided into two groups as treatment and placebo by randomization method. For the patients in the treatment group,the non-interventional Biogel was applied for 10 minutes. For the control group, a non-interventional placebo was applied for 10 mins. A record was made of patient demographic data,the region of the pain, and mean arterial pressure (MAP) values before and after the application. All the patients in both groups were administered a Visual Analogue Scale (VAS) to evaluate pain severity,and the Nottingham Health Profile (NHP) before and after the applications. The data obtained were compared. Results: In the biogel group, a statistically significant decrease was determined in the NHP-P values after treatment compared to before treatment (P&lt;0.001). In the placebo group,no statistically significant difference was determined in the NHP-P values before and after treatment (P=0.104). In the Biogel group,a statistically significant decrease was determined in the VAS values after treatment compared to before treatment (P&lt;0.001). In the placebo group,no statistically significant difference was determined in the VAS values before and after treatment (P=0.157). Conclusion: These types of complementary medicine applications focussed on pain treatment can reduce the disease burden and can probably reduce costs.

Gut Dysbiosis and Hemodynamic Changes as Links of the Pathogenesis of Complications of Cirrhosis.

The aim was to evaluate the relationship between gut dysbiosis and hemodynamic changes (hyperdynamic circulation) in cirrhosis, and between hemodynamic changes and complications of this disease. This study included 47 patients with cirrhosis. Stool microbiome was assessed using 16S rRNA gene sequencing. Echocardiography with a simultaneous assessment of blood pressure and heart rate was performed to assess systemic hemodynamics. Patients with hyperdynamic circulation had more severe cirrhosis, lower albumin, sodium and prothrombin levels, higher C-reactive protein, aspartate aminotransferase and total bilirubin levels, and higher incidences of portopulmonary hypertension, ascites, overt hepatic encephalopathy, hypoalbuminemia, hypoprothrombinemia, systemic inflammation, and severe hyperbilirubinemia than patients with normodynamic circulation. Patients with hyperdynamic circulation compared with those with normodynamic circulation had increased abundance of Proteobacteria, Enterobacteriaceae, Bacilli, Streptococcaceae, Lactobacillaceae, Fusobacteria, Micrococcaceae, Intestinobacter, Clostridium sensu stricto, Proteus and Rumicoccus, and decreased abundance of Bacteroidetes, Bacteroidaceae, Holdemanella, and Butyrivibrio. The systemic vascular resistance and cardiac output values correlated with the abundance of Proteobacteria, Enterobacteriaceae, Bacilli, Streptococcaceae, Lactobacillaceae, Micrococcaceae, and Fusobacteria. Heart rate and cardiac output value were negatively correlated with the abundance of Bacteroidetes. The mean pulmonary artery pressure value was positively correlated with the abundance of Proteobacteria and Micrococcaceae, and negatively with the abundance of Holdemanella.

Haemodynamic and Haemato-Biochemical Changes with Ketamine, Propofol and Ketofol as Constant Rate Infusion Anesthesia for Elective Ovariectomy in Dogs

Background: Combination of glycopyrrolate, butorphanol, xylazine as premedication and induction with propofol and maintenance with ketamine, propofol and propofol mixtures (Ketofol 1:1) as constant rate infusion (CRI) would have the ability to maintain better hemodynamic and reduce the dose of general anesthesia for maintenance. This technique once gets standardized; it may transfer to field veterinarians for elective ovariectomy under a routine animal birth control programme (ABC) for safe handling of canines. Therefore, the present study was designed to evaluate haemodynamic and haemato-biochemical changes with Ketamine, Propofol and Ketofol as CRI anesthesia in dogs. Methods: The study was conducted on 18 female dogs during 2019-2021 and these animals were randomly divided into three experimental groups, each group (I, II and III) containing six animals. All animals were pre-medicated with glycopyrrolate @ 0.01 mg/kg b.wt I/M followed by inj. butorphanol 0.2 mg/kg b.wt and xylazine 1mg/kg b.wt I/M after 5 minutes by using different syringes. After 10 minutes of xylazine, animals were induced (till effect) with propofol and immediately just after induction animals were maintained with constant rate infusion of ketamine, propofol and ketofol 1:1 along with normal saline @ 10 ml/kg/hr. Result: Cardiovascular parameters showed that the value of systolic arterial pressure increased significantly (P less than 0.05) after pre-medication in all three groups in comparisons to respective base values. Value of diastolic arterial pressure increased significantly (P less than 0.05) after pre-medication in groups I and II, whereas non-significantly (p greater than 0.05) in group III in comparisons to respective base values. Hemoglobin and PCV values decreased non-significantly after pre-medication and remained non-significantly lower at various intervals in comparison to respective base values during observation periods except at recovery in group II. Changes in TLC did not show a definite pattern and values of TEC in all groups changed non-significantly (p greater than 0.05) at various time intervals in comparison to respective base values during the observation period.

Acute fetal cardiovascular adaptation to artificial placenta in sheep model.

To describe the acute cardiovascular adaptation of the fetus after connection to an artificial placenta (AP) in a sheep model, using ultrasound and invasive and non-invasive hemodynamic assessment. This was an experimental study of 12 fetal sheep that were transferred to an AP system, consisting of a pumpless circuit with umbilical cord connection, at 109-117 days' gestation. The study was designed to collect in-utero and postcannulation measurements in all the animals. The first six consecutive fetuses were fitted with intravascular catheters and perivascular probes to obtain invasive physiological data, including arterial and venous intravascular pressures and perivascular blood flows, with measurements taken in utero and at 5 and 30 min after cannulation. These experiments were designed with a survival goal of 1-3 h. The second set of six fetuses were not fitted with catheters, and experiments were aimed at 3-24 h of survival. Echocardiographic assessment of cardiac anatomy and function, as well as measurements of blood flow and pre- and postmembrane pressures recorded by circuit sensors in the AP system, were available for most of the fetuses. These data were acquired in utero and at 30 and 180 min after cannulation. Compared with in-utero conditions, the pulsatility index at 30 and 180 min after connection to the AP system was reduced in the umbilical artery (median, 1.36 (interquartile range (IQR), 1.06-1.50) vs 0.38 (IQR, 0.31-0.50) vs 0.36 (IQR, 0.29-0.41); P < 0.001 for extreme timepoints) and the ductus venosus (median, 0.50 (IQR, 0.41-0.67) vs 0.29 (IQR, 0.22-0.33) vs 0.36 (IQR, 0.22-0.41); P = 0.011 for extreme timepoints), whereas umbilical venous peak velocity increased (median, 20 cm/s (IQR, 18-22 cm/s) vs 39 cm/s (IQR, 31-43 cm/s) vs 43 cm/s (IQR, 34-54 cm/s); P < 0.001 for extreme timepoints) and flow became more pulsatile. Intravascular monitoring showed that arterial and venous pressures increased transiently after connection, with median values for mean arterial pressure at baseline, 5 min and 30 min of 43 mmHg (IQR, 35-54 mmHg), 72 mmHg (IQR, 61-77 mmHg) and 58 mmHg (IQR, 50-64 mmHg), respectively (P = 0.02 for baseline vs 5 min). Echocardiography showed a similar transient elevation of fetal heart rate at 30 and 180 min after connection compared with in utero (median, 145 bpm (IQR, 142-156 bpm) vs 188 bpm (IQR, 171-209 bpm) vs 175 bpm (IQR, 165-190 bpm); P = 0.001 for extreme timepoints). Fetal cardiac structure and function were mainly preserved; median values for right fractional area change were 36% (IQR, 34-41%) in utero, 38% (IQR, 30-40%) at 30 min and 37% (IQR, 33-40%) at 180 min (P = 0.807 for extreme timepoints). Connection to an AP system resulted in a transient fetal hemodynamic response that tended to normalize over hours. In this short-term evaluation, cardiac structure and function were preserved. However, the system resulted in non-physiologically elevated venous pressure and pulsatile flow, which should be corrected to avoid later impairment of cardiac function. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Comparison of the Efficacy of Opioid-Free Anesthesia With Conventional Opioid-Based Anesthesia for Nasal Surgeries - A Prospective Randomized Parallel Arm Triple-Blinded Study.

Introduction In the setting of nasal surgeries, the use of opioid-free anesthesia involving the use ofdexmedetomidine,and lignocaine is being investigated as a potential alternative to opioids. This combination of drugs provides sympatholysis, pain relief, and sedative properties, thereby aiming at reducing the negative effects commonly associated with opioid usage. The objective of this study is to evaluate and compare the effectiveness of opioid-free anesthesia using dexmedetomidineand lignocaineversus conventional opioid anesthesia with fentanylfor nasal surgeries. The comparison will be based on the primary outcome of postoperative visual analog scale(VAS) scores. Secondary outcomes assessed were the amount of rescue analgesic consumption, intraoperative sevoflurane usage, intraoperative blood loss, hemodynamic stability, postoperative nausea and vomiting (PONV) scores, and postoperative Ramsay Sedation Scores. Methods A triple-blind, prospective, randomized, parallel arm study in which 48 patients planned for elective nasal surgery were allocated randomly to one of two groups. In the study, the population labeled as Group D, comprising 24 participants, received dexmedetomidine at a dosage of 1 mcg.kg-1 via intravenous infusion lasting for a duration of 10 minutes prior to the induction of anesthesia. This was followed by a continuous infusion of 0.6 mcg.kg-1 h-1 throughout the intraoperative period, and intravenous Lignocaine 1.5 mg.kg-1 was administered three minutes prior to induction, subsequently an intraoperative infusion of 1.5 mg.kg-1 h-1. In Group F, consisting of 24 participants,intravenous fentanyl of 2 mcg.kg-1was administered three minutes before the induction. This was subsequently followed by a fentanyl infusion of 0.5 mcg.kg-1h-1in the intraoperative period. Results The study findings indicate that Group D had considerably lower postoperative VAS scores from 30 minutes to two hours compared to Group F (p<0.05). The utilization of sevoflurane during the intraoperative period was comparatively reduced in Group D in order to achieve the desired bispectral index (BIS) range of 40-60 (p<0.01). Mean intraoperative blood loss was also lower in Group D (85 ml) compared to Group F (115 ml )(p<0.01). Additionally, Group D had significantly lower rescue analgesic consumption and lower incidence of PONV up to 60 minutes compared to Group F (P-value <0.01).A statistically significant difference was observed between Group D and Group F in terms of lower mean values of both mean arterial pressure (MAP) and heart rate in Group D(p<0.01). The results indicate that the postoperative sedation scores within the first two hours were significantly greater in Group D compared to Group F(p<0.01). Conclusion The usage of opioid-free anesthesia has been found to be superior to a traditional opioid-based approach in various aspects, including the provision of sufficient pain relief after surgery, maintenance of stable hemodynamics during the operation, and reduction in occurrences of postoperative nausea and vomiting.

Prevalence and clinical significance of right ventricular pulmonary arterial uncoupling in cardiac amyloidosis

BackgroundThis study aims to evaluate the prevalence and the clinical significance of the right ventricular pulmonary arterial (RV-PA) uncoupling in patients with cardiac amyloidosis (CA). MethodsThe study population consisted in 92 consecutive patients with CA (age 71.1 ± 12.2 years, 71% males; 47% with immunoglobulin light chain (AL), 53% with transthyretin [ATTR]). A pre-specified tricuspid anulus plane systolic excursion on pulmonary arterial systolic pressure (TAPSE/PASP) value <0.31 mm/mmHg was used to define RV-PA uncoupling and to dichotomize the study population. ResultsThirty-two patients (35%) showed RV-PA uncoupling at baseline evaluation (15/44 [34%] AL and 17/48 [35%] ATTR). Patients with RV-PA uncoupling, in both AL and ATTR, showed worse NYHA functional class, lower systemic blood pressure, and more pronounced left ventricular and RV systolic dysfunction than those with RV-PA coupling.During a median follow-up of 8 months (IQR 4–13), 26 patients (28%) experienced cardiovascular death. Patients with RV-PA uncoupling showed lower survival at 12 months follow-up than those with RV-PA coupling (42.7% [95%CI 21.7–63.7%] vs. 87.3% [95%CI 78.3–96.3%], p-value<0.001). Multivariate analysis identified high-sensitivity troponin I values (HR 1.01 [95%CI 1.00–1.02] per 1 pg/mL increase; p-value 0.013) and TAPSE/PASP (HR 1.07 [95%CI 1.03–1.11] per 0.01 mm/mmHg decrease; p-value 0.002) as independent predictors of cardiovascular death. ConclusionsRV-PA uncoupling is common among patient with CA, and it is a marker of advanced disease and worse outcome. This study suggest that TAPSE/PASP ratio has the potential to improve risk stratification and guide management strategies in patients with CA of different etiology and advanced disease.

Effects of pneumoperitoneum and Trendelenburg position on intracranial pressure and cerebral blood flow assessed using transcranial doppler: A prospective observational study.

Laparoscopic lower abdominal surgeries involve carbon dioxide (CO2) insufflation and Trendelenburg position. The raised intra-abdominal pressure can increase intracranial pressure (ICP) and alter cerebral blood flow. This study was conducted to determine the effect of pneumoperitoneum and Trendelenburg position on ICP and cerebral perfusion pressure (CPP) measured using transcranial Doppler (TCD). A prospective observational study was conducted in 43 patients of either sex, aged between 18 and 60 years with American Society of Anesthesiologists physical status I and II, undergoing elective laparoscopic surgery in Trendelenburg position. After standard anesthesia induction, pneumoperitoneum was created to facilitate surgery, maintaining an intra-abdominal pressure of 10-15 mmHg and Trendelenburg position of 25°-30°. End-tidal carbon dioxide (EtCO2) was maintained between 30 and 35 mmHg. The ICP was assessed non-invasively using TCD-based diastolic flow velocities (FVd) and pulsatility index (PI) of middle cerebral artery. Data was represented as mean ± standard deviation and compared using paired t test. A P value of < 0.05 was considered significant. Mean ICPPI at baseline was 14.02 ± 0.89 mmHg which increased to 14.54 ± 1.21 mmHg at pneumoperitoneum and Trendelenburg position (P = 0.005). Mean ICPFVd at baseline was 6.25 ± 2.47 mmHg which increased to 8.64 ± 3.79 mmHg at pneumoperitoneum and Trendelenburg position (P < 0.001). There was no statistically significant change in the CPP or mean arterial pressure values intraoperatively. Laparoscopic procedures with CO2 pneumoperitoneum in Trendelenburg position increase ICP as measured using TCD ultrasonography. The CPP was not significantly altered when EtCO2 was maintained in the range of 30-35 mmHg.

A prospective comparison of invasive and non-invasive blood pressure in children undergoing cardiac catheterization.

Blood pressure measurement is a standard of monitoring during general anesthesia. Invasive measurement is considered the gold standard but is less commonly used than non-invasive. Automated oscillometric blood pressure devices measure the mean arterial pressure (MAP) and use an algorithm to determine the systolic and diastolic pressures. Few devices have been validated in children, particularly during anesthesia. Few studies have assessed the agreement between invasive and non-invasive blood pressure measurements in children. This was a multi-center prospective observational study of children under 16 years undergoing cardiac catheterization with general anesthesia. Paired invasive and non-invasive blood pressure measurements were recorded for each patient during stable periods of the procedure. Correlation within and between sites was assessed with Pearson's correlation coefficient, and agreement was examined using Bland-Altman methodology to determine bias. Agreement during episodes of hypotension and for age and weight was also determined. Bias greater than 5 mmHg and standard deviation greater than 8 mmHg was considered clinically significant. The primary end point was agreement of MAP measurements. A total of 683 paired blood pressure values were collected from 254 children in three pediatric hospitals. Median [IQR] age and weight were 3 [1-7] years and 13.9 [8-23] Kg. The overall bias (SD) for mean arterial pressure values was 7.2 (11.4) mmHg. During hypotension (190 readings), the bias (SD) was 15 (11.0) mmHg. The non-invasive MAP was frequently higher than invasive MAP during infancy, and lower in older children. Automated oscillometric blood pressure measurement is unreliable in anesthetized children during cardiac catheterization. Invasive pressure measurement should be considered for high-risk cases.

The average value of mean arterial pressure among children aged 3-10 years as per age, gender and height centiles: A cross sectional study

Background: Objective of the study was to find out the average MAP among children aged between 3-10 years based on age, gender and height centiles and to study the correlation of MAP with weight, height and BMI. Methods: A total of 502 children were included in the study. First the demographic details of the children was collected. Then anthropometric parameters were measured. Systolic BP, Diastolic BP and MAP were recorded. SPSS version 20 was used for statistical analysis. Results: MAP has got a positive correlation with weight, height and BMI. Conclusions: The mean MAP of male children, 3-4 years 75±9 mmHg, 5-6 years 75±8 mmHg, 7-8 years 76±7 mmHg, 9-10 years, 79±11 mmHg. The mean MAP of female children, 3-4 years 77±7 mmHg, 5-6 years 77±8 mmHg, 7-8 years 78±9 mmHg, 9-10 years, 79±8 mmHg. MAP was found to be highly correlated with weight, height and BMI.

“The peripheral perfusion index discriminates haemodynamic responses to induction of general anaesthesia”

Induction of general anaesthesia is often accompanied by hypotension. Standard haemodynamic monitoring during anaesthesia relies on intermittent blood pressure and heart rate. Continuous monitoring systemic blood pressure requires invasive or advanced modalities creating a barrier for obtaining important information of the circulation. The Peripheral Perfusion Index (PPI) is obtained non-invasively and continuously by standard photoplethysmography. We hypothesized that different patterns of changes in systemic haemodynamics during induction of general anaesthesia would be reflected in the PPI. Continuous values of PPI, stroke volume (SV), cardiac output (CO), and mean arterial pressure (MAP) were evaluated in 107 patients by either minimally invasive or non-invasive means in a mixed population of surgical patients. 2 min after induction of general anaesthesia relative changes of SV, CO, and MAP was compared to the relative changes of PPI. After induction total cohort mean(± st.dev.) MAP, SV, and CO decreased to 65(± 16)%, 74(± 18)%, and 63(± 16)% of baseline values. In the 38 patients where PPI decreased MAP was 57(± 14)%, SV was 63(± 18)%, and CO was 55(± 18)% of baseline values 2 min after induction. In the 69 patients where PPI increased the corresponding values were MAP 70(± 15)%, SV 80(± 16)%, and CO 68(± 17)% (all differences: p < 0,001). During induction of general anaesthesia changes in PPI discriminated between the degrees of reduction in blood pressure and algorithm derived cardiac stroke volume and -output. As such, the PPI has potential to be a simple and non-invasive indicator of the degree of post-induction haemodynamic changes.

TOP2: Miniature Extravascular Aortic Sensor for Continuous Blood Pressure Measurement: In-vivo Validation Under Pathological Conditions

Purpose of the Study: In individuals suffering from cardiovascular diseases, and especially in heart failure patients supported with left ventricular assist devices (VADs), the long-term monitoring of arterial blood pressure (ABP) holds significant value for assessing the disease progression, monitoring patient compliance, and evaluating the treatment efficacy. Hence, it is imperative to advance and extensively validate new, accurate and robust sensory technologies for this purpose. Methods: The present study aimed to evaluate the performance of a newly developed hall-based magnetic aortic sensor (HBSD) in monitoring arterial blood pressure (ABP) in conditions of low pulse pressures that simulate the hemodynamic conditions of VAD supported patients (Magkoutas et al, JACC: Basic to Translational Science, 2023). To this end, twelve acute in-vivo experiments were performed using pigs that were connected to a cardiopulmonary bypass circuit, and their hemodynamic state was regulated through adjustments to the support rate and pharmacological stimulation. In each experiment, two HBSDs were implanted, one in the ascending and one in the descending aorta. The reference ABP measurements were obtained using an intravascular fluid-filled catheter. Results: The pressure signal provided by the HBSD accurately captured the highly varying pressure profiles, regardless of the pressure level, CPB support level, and effective pulse pressure. The analysis of the difference between the end-diastolic (EDP), systolic (SP), and mean arterial (MAP) pressure values measured with the HBSDs and the reference sensors (Figure 1B) demonstrates that the HBSDs provide highly accurate measurements with a mean absolute error less than 5 mm Hg, except for two cases. Furthermore, the comparison of the entire dataset of the HBSD and the reference sensor during one of the in-vivo experiments reveals a high linear association between the two methods, confirmed by an intraclass coefficient higher than 0.95 (Figure 1C). The results of the Bland-Altman plot in Figure 1D also indicate that the developed HBSD has a mean bias of 0 mmHg, with limits of agreement approximately equal to 8.5 mmHg, compared to the reference pressure sensor. Conclusion: This study provides evidence supporting the accuracy of the proposed HBSD in measuring the ABP waveform in pathological and varying hemodynamic conditions. This constitutes a crucial preliminary stage in advancing the HBSD towards clinical utilization, thereby unlocking the valuable information contained in the ABP waveform and enhancing patient surveillance and therapeutic intervention in individuals supported by VADs.Figure 1. A) Implantation procedure and components of the hall-based aortic sensor. B) Boxplots of the difference between the end-diastolic (EDP), systolic (SP), and mean arterial (MAP) pressure values measured with the HBSDs and the reference sensors. C) The intraclass coefficient (ICC) with 95% confidence intervals for the ABP measured with the HBSD and the reference ABP. D) Bland-Altman plot with the representation of the mean difference, the limits of agreement (LoA) (dashed line) from −1.96s to +1.96s, and 95% confidence intervals (CI).

Correlation between blood pressure indexes and prognosis in sepsis patients: a cohort study based on MIMIC-III database

To investigate the correlation between early-stage blood pressure indexes and prognosis in sepsis patients. A retrospective cohort study was conducted on the medical records of patients diagnosed with sepsis from 2001 to 2012 in the Medical Information Mart for Intensive Care-III (MIMIC-III) database. Patients were divided into survival group and death group according to the 28-day prognosis. General data of patients and heart rate (HR) and blood pressure at admission to ICU and within 24 hours after admission were collected. The blood pressure indexes including the maximum, median and mean value of systolic index, diastolic index and mean arterial pressure (MAP) index were calculated. The data were randomly divided into training set and validation set (4 : 1). Univariate Logistic regression analysis was used to screen covariates, and multivariate Logistic stepwise regression models were further developed. Model 1 (including HR, blood pressure, and blood pressure index related variables with P < 0.1 and other variables with P < 0.05) and Model 2 (including HR, blood pressure, and blood pressure index related variables with P < 0.1) were developed respectively. The receiver operator characteristic curve (ROC curve), precision recall curve (PRC) and decision curve analysis (DCA) curve were used to evaluate the quality of the two models, and the influencing factors of the prognosis of sepsis patients were analyzed. Finally, nomogram model was developed according to the better model and effectiveness of it was evaluated. A total of 11 559 sepsis patients were included in the study, with 10 012 patients in the survival group and 1 547 patients in the death group. There were significant differences in age, survival time, Elixhauser comorbidity score and other 46 variables between the two groups (all P < 0.05). Thirty-seven variables were preliminarily screened by univariate Logistic regression analysis. After multivariate Logistic stepwise regression model screening, among the indicators related to HR, blood pressure and blood pressure index, the HR at admission to ICU [odds ratio (OR) = 0.992, 95% confidence interval (95%CI) was 0.988-0.997] and the maximum HR (OR = 1.006, 95%CI was 1.001-1.011), maximum MAP index (OR = 1.620, 95%CI was 1.244-2.126), mean diastolic index (OR = 0.283, 95%CI was 0.091-0.856), median systolic index (OR = 2.149, 95%CI was 0.805-4.461), median diastolic index (OR = 3.986, 95%CI was 1.376-11.758) were selected (all P < 0.1). There were 14 other variables with P < 0.05, including age, Elixhauser comorbidity score, continuous renal replacement therapy (CRRT), use of ventilator, sedation and analgesia, norepinephrine, norepinephrine, highest serum creatinine (SCr), maximum blood urea nitrogen (BUN), highest prothrombin time (PT), highest activated partial thromboplastin time (APTT), lowest platelet count (PLT), highest white blood cell count (WBC), minimum hemoglobin (Hb). The ROC curve showed that the area under the curve (AUC) of Model 1 and Model 2 were 0.769 and 0.637, respectively, indicating that model 1 had higher prediction accuracy. The PRC curve showed that the AUC of Model 1 and Model 2 were 0.381 and 0.240, respectively, indicating that Model 1 had a better effect. The DCA curve showed that when the threshold was 0-0.8 (the probability of death was 0-80%), the net benefit rate of Model 1 was higher than that of Model 2. The calibration curve showed that the prediction effect of the nomogram model developed according to Model 1 was in good agreement with the actual outcome. The Bootstrap verification results showed that the nomogram model was consistent with the above results and had good prediction effects. The nomogram model constructed has good prediction effects on the 28-day prognosis in sepsis patients, and the blood pressure indexes are important predictors in the model.

Hemodynamic effects of intraoperative 30% versus 80% oxygen concentrations: an exploratory analysis.

Supplemental oxygen leads to an increase in peripheral vascular resistance which finally increases systemic blood pressure in healthy subjects and patients with coronary artery disease, heart failure, undergoing heart surgery, and with sepsis. However, it is unknown whether this effect can also be observed in anesthetized patients having surgery. Thus, we evaluated in this exploratory analysis of a randomized controlled trial the effect of 80% versus 30% oxygen on intraoperative blood pressure and heart rate. We present data from a previous study including 258 patients, who were randomized to a perioperative inspiratory FiO2 of 0.8 (128 patients) versus 0.3 (130 patients) for major abdominal surgery. Continuous arterial blood pressure values were recorded every three seconds and were exported from the electronic anesthesia record system. We calculated time-weighted average (TWA) and Average Real Variability (ARV) of mean arterial blood pressure and of heart rate. There was no significant difference in TWA of mean arterial pressure between the 80% (80 mmHg [76, 85]) and 30% (81 mmHg [77, 86]) oxygen group (effect estimate -0.16 mmHg, CI -1.83 to 1.51; p = 0.85). There was also no significant difference in TWA of heart rate between the 80 and 30% oxygen group (median TWA of heart rate in the 80% oxygen group: 65 beats.min-1 [58, 72], and in the 30% oxygen group: 64 beats.min-1 [58; 70]; effect estimate: 0.12 beats.min-1, CI -2.55 to 2.8, p = 0.94). Also for ARV values, no significant differences between groups could be detected. In contrast to previous results, we did not observe a significant increase in blood pressure or a significant decrease in heart rate in patients, who received 80% oxygen as compared to patients, who received 30% oxygen during surgery and for the first two postoperative hours. Thus, hemodynamic effects of supplemental oxygen might play a negligible role in anesthetized patients. https://clinicaltrials.gov/ct2/show/NCT03366857?term=vienna&cond=oxygen&draw=2&rank=1.

C63 PREVALENCE AND CLINICAL SIGNIFICANCE OF RIGHT VENTRICULAR PULMONARY ARTERIAL UNCOUPLING IN CARDIAC AMYLOIDOSIS

Abstract Background This study aims to evaluate the prevalence and clinical significance of the right ventricular pulmonary arterial (RV–PA) uncoupling in patients with cardiac amyloidosis (CA). Methods The study population consisted in 92 consecutive patients with CA (age 71.1±12.2 years, 71% males; 47% with immunoglobulin light chain (AL), 53% with transthyretin [ATTR]). All patients underwent a comprehensive evaluation. A pre–specified tricuspid annulus plane systolic excursion on pulmonary arterial systolic pressure (TAPSE/PASP) value &amp;lt;0.31 mm/mmHg was used to define RV–PA uncoupling and to dichotomize the study population. Results Thirty–two patients (35%) showed RV–PA uncoupling at baseline evaluation (15/44 [34%] AL and 17/48 [35%] ATTR). Patients with RV–PA uncoupling in both AL and ATTR showed worse NYHA functional class, lower systemic blood pressure, and more pronounced left and right ventricular systolic dysfunction than those with RV–PA coupling. During a median follow–up of 8 months (IQR 4–13), 26 patients (28%) experienced cardiovascular death. Patients with RV–PA uncoupling showed lower survival at 12 months follow–up than those with RV–PA coupling (42.7% [95%CI 21.7–63.7%] vs. 87.3% [95%CI 78.3–96.3%], p–value&amp;lt;0.001). Multivariate analysis identified high–sensitivity troponin I values (HR 1.01 [95%CI 1.00–1.02] per 1 pg/mL increase; p–value 0.013) and TAPSE/PASP (HR 1.07 [95%CI 1.03–1.11] per 0.01 mm/mmHg decrease; p–value 0.002) as independent predictors of cardiovascular death. Conclusions RV–PA uncoupling is common among patients with CA, and it is a marker of advanced disease and worse outcomes. This study suggest that TAPSE/PASP ratio has the potential to improve risk stratification and guide management strategies in patients with CA.

A Perfusion Index-Based Evaluation and Comparison of Peripheral Perfusion in Sevoflurane and Isoflurane Anaesthesia: A Prospective Randomised Controlled Trial.

Perfusion index has shown to be helpful in the operative and critical care settings to monitor peripheral tissue perfusion. Randomised controlled trials quantifying different agents' vasodilatory properties using perfusion index has been limited. Therefore, we undertook this study to compare the vasodilatory effects of isoflurane and sevoflurane using perfusion index. This is a pre-specified sub-analysis of a prospective randomised controlled trial on the effects of inhalational agents at equipotent concentration. We randomly allocated patients scheduled for lumbar spine surgery to either isoflurane or sevoflurane groups. We recorded values of perfusion index at age-corrected 1 Minimum Alveolar Concentration (MAC) concentration at baseline, pre- and post-application of a noxious stimulus. The primary outcome of interest was the measure of vasomotor tone with perfusion index, and the secondary outcomes which were analysed were mean arterial pressure and heart rate. At age-corrected 1.0 MAC, there was no significant difference in the pre-stimulus haemodynamic variables and perfusion index between both groups. During the post-stimulus period, there was a significant increase in heart rate in the isoflurane group compared to the sevoflurane group, with no significant difference in the mean arterial pressure values between both groups. Though the perfusion index decreased during the post-stimulus period in both groups, there was no statistically significant difference between the 2 groups (P = .526, repeated-measures analysis of variance). In a steady state of age-corrected 1.0 MAC, isoflurane and sevoflurane had a similar perfusion index before and after a standardised nociceptive stimulus, which suggests that both of these agents have similar effect on peripheral perfusion and vasomotor tone.

Prophylactic Use of Ondansetron for Hypotension Prevention in Cases Undergoing Cesarean Section Post-Spinal Anesthesia

Background: Ondansetron is being administrated to prevent post spinal hypotension and its affects are promising. Globally, researches being conducted to identify the prophylactic effects of ondansetron. Aim: To determine the frequency of maternal hypotension with or without intravenous administration of ondansetron in cases undergoing cesarean section post-spinal anesthesia. Study design: Randomized controlled trial Place and duration of study: Jinnah Postgraduate Medical Centre, Karachi from 1st February 2017 to 1st August 2017. Methodology: Eighty four pregnant females between 18-35 years of age enrolled for cesarean-section under spinal anesthesia were included. Patients having a history of cardiorespiratory or renal disorders, as well as bradycardia or tachycardia, hypo/hypertension and or hyperglycemia were excluded. The patients were randomly divided into Group A (ondansetron) and Group B (control) by using codes placed in sealed, sequentially numbered envelopes. The mean value of arterial blood pressure and of the heart rate was documented at 3 min interval for 10 minutes and then every 5 minutes till 30 minutes after spinal anesthesia. Results: The mean age of patients in group A was 26.57±5.28 years and in group B was 26.88±4.62 years. Thirty two (38.10%) were ASA I and 52 (61.90%) were ASA II. The mean age of patients in group A was 39.36±1.65 weeks and in group B was 39.79±1.47 weeks. Mean arterial pressure was 138.44±13.59mmHg. Frequency of maternal hypotension in Group A was seen in 08 (19.05%) while in Group B was seen in 22 (52.38%) patients (p=0.001). Conclusion: There is less maternal hypotension with intravenous administration of ondansetron in patients undergoing cesarean section under spinal anesthesia. Keywords: Spinal anesthesia, Hypotension, Ondansetrone