Changes in mean systemic filling pressure as an estimate of hemodynamic response to anesthesia induction using propofol.
Ontology highlight
ABSTRACT: Background
Even a small change in the pressure gradient between the venous system and the right atrium can have significant hemodynamic effects. Mean systemic filling pressure (MSFP) is the driving force of the venous system. As a result, MSFP has a significant effect on cardiac output. We aimed to test the hypothesis that the hemodynamic instability during induction of general anesthesia by intravenous propofol administration is caused by changes in MSFP.Methods
We prospectively collected data from 15 patients undergoing major surgery requiring invasive hemodynamic monitoring. Hemodynamic parameters, including MSFP, were measured before and after propofol administration and following intubation, using venous return curves at a no-flow state induced by a pneumatic tourniquet.Results
A significant decrease in MSFP was observed in all study patients after propofol administration (median (IQR) pressure 17 (9) mmHg compared with 25 (7) before propofol administration, p = 0.001). The pressure gradient for venous return (MSFP - central venous pressure; CVP) also decreased following propofol administration from 19 (8) to 12 (6) mmHg, p = 0.001. Central venous pressure did not change.Conclusions
These results support the hypothesis that induction of anesthesia with propofol causes a marked reduction in MSFP. A possible mechanism of propofol-induced hypotension is reduction in preload due to a decrease in the venous vasomotor tone.
SUBMITTER: Zucker M
PROVIDER: S-EPMC9306094 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Background: A decade ago, it became possible to derive mean systemic filling pressure (MSFP) at the bedside using the inspiratory hold maneuver. MSFP has the potential to help guide hemodynamic care, but the estimation is not yet implemented in common clinical practice. In this study, we assessed the ability of MSFP, vascular compliance (Csys), and stressed volume (Vs) to track fluid boluses. Second, we assessed the feasibility of implementation of MSFP in the intensive care unit (ICU). Exploratory, a potential difference in MSFP response between colloids and crystalloids was assessed. Methods: This was a prospective cohort study in adult patients admitted to the ICU after cardiac surgery. The MSFP was determined using 3-4 inspiratory holds with incremental pressures (maximum 35 cm H2O) to construct a venous return curve. Two fluid boluses were administered: 100 and 500 ml, enabling to calculate Vs and Csys. Patients were randomized to crystalloid or colloid fluid administration. Trained ICU consultants acted as study supervisors, and protocol deviations were recorded. Results: A total of 20 patients completed the trial. MSFP was able to track the 500 ml bolus (p < 0.001). In 16 patients (80%), Vs and Csys could be determined. Vs had a median of 2029 ml (IQR 1605-3164), and Csys had a median of 73 ml mmHg-1 (IQR 56-133). A difference in response between crystalloids and colloids was present for the 100 ml fluid bolus (p = 0.019) and in a post hoc analysis, also for the 500 ml bolus (p = 0.010). Conclusion: MSFP can be measured at the bedside and provides insights into the hemodynamic status of a patient that are currently missing. The clinical feasibility of Vs and Csys was judged ambiguously based on the lack of required hemodynamic stability. Future studies should address the clinical obstacles found in this study, and less-invasive alternatives to determine MSFP should be further explored. Clinical Trial Registration: ClinicalTrials.gov Identifier NCT03139929.
| S-EPMC9745184 | biostudies-literature
Project description:Mean systemic filling pressure (Pms) is a promising parameter in determining intravascular fluid status. Pms derived from venous return curves during inspiratory holds with incremental airway pressures (Pms-Insp) estimates Pms reliably but is labor-intensive. A computerized algorithm to calculate Pms (Pmsa) at the bedside has been proposed. In previous studies Pmsa and Pms-Insp correlated well but with considerable bias. This observational study was performed to validate Pmsa with Pms-Insp in cardiac surgery patients. Cardiac output, right atrial pressure and mean arterial pressure were prospectively recorded to calculate Pmsa using a bedside monitor. Pms-Insp was calculated offline after performing inspiratory holds. Intraclass-correlation coefficient (ICC) and assessment of agreement were used to compare Pmsa with Pms-Insp. Bias, coefficient of variance (COV), precision and limits of agreement (LOA) were calculated. Proportional bias was assessed with linear regression. A high degree of inter-method reliability was found between Pmsa and Pms-Insp (ICC 0.89; 95%CI 0.72-0.96, p = 0.01) in 18 patients. Pmsa and Pms-Insp differed not significantly (11.9 mmHg, IQR 9.8-13.4 vs. 12.7 mmHg, IQR 10.5-14.4, p = 0.38). Bias was -0.502 ± 1.90 mmHg (p = 0.277). COV was 4% with LOA -4.22 - 3.22 mmHg without proportional bias. Conversion coefficient Pmsa ➔ Pms-Insp was 0.94. This assessment of agreement demonstrates that the measures Pms-Insp and the computerized Pmsa-algorithm are interchangeable (bias -0.502 ± 1.90 mmHg with conversion coefficient 0.94). The choice of Pmsa is straightforward, it is non-interventional and available continuously at the bedside in contrast to Pms-Insp which is interventional and calculated off-line. Further studies should be performed to determine the place of Pmsa in the circulatory management of critically ill patients. ( www.clinicaltrials.gov ; TRN NCT04202432, release date 16-12-2019; retrospectively registered).Clinical Trial Registration www.ClinicalTrials.gov , TRN: NCT04202432, initial release date 16-12-2019 (retrospectively registered).
| S-EPMC8011774 | biostudies-literature
Project description:Background and objectiveAnesthesia induction can produce severe propofol dose-dependent hypotension. Fentanyl coadministration reduces the catecholaminergic response to orotracheal intubation allowing propofol dose reduction. The aim of this study is to determine whether the hemodynamic response is improved by increasing the time between fentanyl and propofol administration and reducing the dose of the latter without increasing the time to achieve optimal hypnosis.MethodsAfter approval by the Research Ethics Committee, patients undergoing non-cardiac surgery with endotracheal intubation were randomized by a computer-generated table into six time-dose groups (1 or 2...minutes/1, 1.5, or 2...mg.kg-1 of propofol). Patients with high bronchoaspiration risk, a difficult airway, hemodynamic instability, or anesthetic allergies were excluded. After giving intravenous fentanyl (2.....g.kg-1), each group received different doses of propofol after 1 or 2...minutes. Noninvasive blood pressure (BP) and heart rate (HR) were measured at pre-induction, pre-intubation, and post-intubation. Time to hypnosis (bispectral index < 60) was also recorded.ResultsOf the 192 recruited patients, 186 completed the study (1...min group n...=...94; 2...min group n...=...92). It was observed that HR and BP decreased after propofol administration and increased after intubation in all groups (p...<...0.0001). In patients over 55 years, the 2 min ... 2 mg.kg-1 group showed the greatest systolic BP reduction (36........12%) at pre-intubation, while the 1...min.........1.5...mg.kg-1 group showed the least hemodynamic alteration between pre- and post-intubation (-4........13%). No significant differences were found in younger patients or in the time to reach hypnosis between the six groups. While no cases of severe bradycardia were recorded, 5,4% of the sample required vasopressors.ConclusionIncreasing the time between the administration of fentanyl and propofol by up to two minutes results in greater hypotension in patients over 55 years.
| S-EPMC10877358 | biostudies-literature
Project description:We developed a method for measuring in vivo venular volumes and the mean systemic filling pressure in the limbs using near-infrared spectroscopy (NIRS). We aimed to validate the NIRS methodology by comparing two independent methods of calculation based on different physiological approaches. Pressure-volumes (P-V) curves were recorded following graded venous occlusion on the forearm. Values from a P-V curves analysis model (method 1) were compared with data derived from a resistor-capacitance calculation model (method 2) based on arterial pressure and venous compliance. We tested these methods on 10 healthy participants at rest and during exercise and on 6 severely ill patients. Results from method 1 were comparable with those calculated by method 2. Venular volumes calculated using method 1 correlated linearly with those calculated using method 2 both in participants (R2 = 0.98) and in patients (R2 = 0.94). A good agreement between methods was shown with few values out of the range of ± 1.96 standard deviation. Our findings added mathematical consistency for the NIRS methodology validation in the venular P-V assessment with no flow interruption. Further research will be required to confirm the relevance of the methodology in the clinical setting.
| S-EPMC8338930 | biostudies-literature
Project description:The mechanism(s) by which anesthetics reversibly suppress consciousness are incompletely understood. Previous functional imaging studies demonstrated dynamic changes in thalamic and cortical metabolic activity, as well as the maintained presence of metabolically defined functional networks despite the loss of consciousness. However, the invasive electrophysiology associated with these observations has yet to be studied. By recording electrical activity directly from the cortical surface, electrocorticography (ECoG) provides a powerful method to integrate spatial, temporal, and spectral features of cortical electrophysiology not possible with noninvasive approaches. In this study, we report a unique comprehensive recording of invasive human cortical physiology during both induction and emergence from propofol anesthesia. Propofol-induced transitions in and out of consciousness (defined here as responsiveness) were characterized by maintained large-scale functional networks defined by correlated fluctuations of the slow cortical potential (<0.5 Hz) over the somatomotor cortex, present even in the deeply anesthetized state of burst suppression. Similarly, phase-power coupling between ?- and ?-range frequencies persisted throughout the induction and emergence from anesthesia. Superimposed on this preserved functional architecture were alterations in frequency band power, variance, covariance, and phase-power interactions that were distinct to different frequency ranges and occurred in separable phases. These data support that dynamic alterations in cortical and thalamocortical circuit activity occur in the context of a larger stable architecture that is maintained despite anesthetic-induced alterations in consciousness.
| S-EPMC3000270 | biostudies-literature
Project description:Background: Diastolic function in patients with heart failure is usually impaired, resulting in increased left ventricular (LV) filling pressures, whose gold standard assessment is right heart catheterization (RHC). Hemodynamic force (HDF) analysis is a novel echocardiographic tool, providing an original approach to cardiac function assessment through the speckle-tracking technology. The aim of our study was to evaluate the use of HDFs, both alone and included in a new predictive model, as a potential novel diagnostic tool of the diastolic function. Methods: HDF analysis was retrospectively performed in 67 patients enrolled in the "Right1 study." All patients underwent RHC and echocardiography up to 2 h apart. Increased LV filling pressure (ILFP) was defined as pulmonary capillary wedge pressure (PCWP) ≥ 15 mmHg. Results: Out of 67 patients, 33 (49.2%) showed ILFP at RHC. Diastolic longitudinal force (DLF), the mean amplitude of longitudinal forces during diastole, was associated with the presence of ILFP (OR = 0.84 [0.70; 0.99], p = 0.046). The PCWP prediction score we built including DLF, ejection fraction, left atrial enlargement, and e' septal showed an AUC of 0.83 [0.76-0.89], with an optimal internal validation. When applied to our population, the score showed a sensitivity of 72.7% and a specificity of 85.3%, which became 66.7 and 94.4%, respectively, when applied to patients classified with "indeterminate diastolic function" according to the current recommendations. Conclusion: HDF analysis could be an additional useful tool in diastolic function assessment. A scoring system including HDFs might improve echocardiographic accuracy in estimating LV filling pressures. Further carefully designed studies could be useful to clarify the additional value of this new technology.
| S-EPMC8455914 | biostudies-literature
Project description:AimsEchocardiographic assessment of left ventricular filling pressures is performed using a multi-parametric algorithm. Unselected sample of patients with heart failure with reduced ejection fraction (HFrEF) patients may demonstrate an indeterminate status of diastolic indices making interpretation challenging. We sought to test improvement in the diagnostic accuracy of standard and strain echocardiography of the left ventricle and left atrium (LA) to estimate a pulmonary capillary wedge pressure (PCWP) > 15 mmHg in patients with HFrEF.Methods and resultsOut of 82 consecutive patients, 78 patients were included in the final analysis and right heat catheterization, and echocardiogram was performed simultaneously. According to the univariable analysis, E wave velocity, the ratio between E-wave/A-wave (E/A, area under the curve [AUC] = 0.81, respectively), isovolumic relaxation time (AUC = 0.83), pulmonary vein D wave (AUC = 0.84), pulmonary vein S/D Ratio (AUC = 0.85), early pulmonary regurgitation velocity (AUC = 0.80), and accelerationa time at right ventricular out-flow tract (RVOT AT, AUC = 0.84) identified with the highest accuracy PCWP > 15 mmHg. They were all tested in multivariate analysis, and they were not independently correlated with PCWP. Tricuspid regurgitation (TR) velocity was measurement with the highest predictive value in identifying PCWP > 15 mmHg (AUC = 0.89), compared with other established parameters such as the ratio between e-wave velocity divided by mitral annular e' velocity (E/e'), deceleration time, or LA indexed volume (LAVi), which all reached a lower accuracy level (AUC = 0.75; 0.78; 0.76). Among strain measures, global longitudinal strain in four chamber view (GLS 4ch), the ratio between e-wave velocity divided by mitral annular e' strain rate (E/e'sr), and LA longitudinal strain at the reservoir phase were helpful in estimating elevated PCWP (AUC = 0.77; 0.76; 0.75). According to multivariable analysis, the following two models had the greatest accuracy in detecting PCWP > 15 mmHg: (i) TR velocity, LAVi, and E wave velocity (receiver operating characteristic [ROC]-AUC = 0.98), (ii) AT RVOT, LAVi and GLS 4ch (ROC-AUC = 0.96). Neither E/A (ROC-AUC = 0.81) nor E/e' (ROC-AUC = 0.75) was an independent predictor when included in the model. The two MODELS were applicable to the entire population and demonstrated better agreement with the invasive reference (91% and 88%) than the guidelines algorithm (77%) regardless of the type of rhythm.ConclusionsOur suggested echocardiographic approach could be used to potentially reduce the frequency of "doubtful" classification and increase the accuracy in predicting elevated left ventricular filling pressure leading to a decrease in the number of invasive assessment made by right heart catheterization.
| S-EPMC7524233 | biostudies-literature
Project description:Rats are commonly used animals for laboratory experiments and many experiments require general anesthesia. However, the lack of published and reproducible intravenous anesthesia protocols for rats results in unnecessary animal use to establish new anesthesia techniques across institutions. We therefore developed an anesthesia protocol with propofol, ketamine, and rocuronium for mechanically ventilated rats, and evaluated vital parameters and plasma concentrations. 15 male Sprague-Dawley rats underwent inhalation induction with sevoflurane and tracheal, venous and arterial cannulation. After established venous access, sevoflurane was substituted by propofol and ketamine (ketofol). Rocuronium was added under mechanical ventilation for 7 h. Drug dosages were stepwise reduced to prevent accumulation. All animals survived the observation period and showed adequate depth of anesthesia. Mean arterial pressure and heart rate remained within normal ranges. Median propofol plasma concentrations remained stable: 1, 4, 7 h: 2.0 (interquartile range (IQR): 1.8-2.2), 2.1 (1.8-2.2), 1.8 (1.6-2.1) µg/ml, whereas median ketamine concentrations slightly differed after 7 h compared to 1 h: 1, 4, 7 h: 3.7 (IQR: 3.5-4.5), 3.8 (3.3-4.1), 3.8 (3.0-4.1) µg/ml. Median rocuronium plasma concentrations were lower after 4 and 7 h compared to 1 h: 1, 4, 7 h: 3.9 (IQR: 3.5-4.9), 3.2 (2.7-3.3), 3.0 (2.4-3.4) µg/ml. Our anesthesia protocol provides stable and reliable anesthesia in mechanically ventilated rats for several hours.
| S-EPMC9130037 | biostudies-literature
Project description:Propofol is a new anesthetic agent in clinical practice, but randomized double-blinded prospective studies on its role in pediatric anesthesia remain limited. We aimed to compare the preventive effects of pre-injected lidocaine or ketamine and its pre-mixture on the anesthesia-induced injection pain of propofol using a randomized double-blinded prospective method, and to compare the outcomes with those of medium-/long-chain propofol (M/LCT).A total of 360 pediatric patients (aged 5-12 years old) who received elective surgery were randomly divided into six groups (n= 60) as follows. S group: control group; L group: lidocaine group; L + P group: lidocaine + propofol group; K group: ketamine group; K + P group: ketamine + propofol group; M group: M/LCT group. After the drug fluid completely entered the cubital vein, the venous access was closed. During propofol injection, the injection pain was scored using the VRS 4-point scale. Meanwhile, the heart rates before and during injection were recorded, the adverse reactions during and after injection were observed, and the incidence rate and degree of pain were evaluated.The VRS 4-point scale showed that the incidence rates of injection pain of S group, L group, L + P group, K group, K + P group and M group were 78.3%, 66.67%, 51.66%, 43.33%, 48.33% and 45% respectively. The incidence rates of injection pain of all experimental groups were significantly lower than that of S group (P<0.01). The incidence rates of injection pain of L + P group, K group, K + P group and M group were significantly lower than that of L group (P<0.05). The differences among the other groups were not statistically significant.Intravenous pre-injection of lidocaine, ketamine or those mixed with propofol can all significantly reduce the incidence rate of injection pain of propofol.
| S-EPMC5510140 | biostudies-other
Project description:Background:Target-controlled infusion (TCI) propofol and sevoflurane are common agents for general anesthesia, including for kidney transplantation procedure. This study compared the effect of TCI propofol and sevoflurane on intraoperative hemodynamic profile in kidney transplant patients. Methods:A single-blinded prospective study was performed in 46 kidney transplant recipients who were randomized into receiving TCI propofol or sevoflurane as anesthetics maintenance. Hemodynamic parameters such as mean arterial pressure (MAP), cardiac index (CI), stroke volume index (SVI), and systemic vascular resistance index (SVRI) were measured at baseline before induction, postintubation, first surgical incision, every 15 minutes after the first incision, reperfusion, and 15 minutes after reperfusion. Data were analyzed using unpaired t-test, paired t-test, and general linear model. Results:Intraoperative MAP, CI, SVI, and SVRI changes were similar in both groups (p?=?0.480, 0.216, 0.086, and 0.054). In comparison to the baseline value, TCI propofol and sevoflurane groups showed significant reductions of MAP at postintubation (p=0.010; p < 0.001) and during the first surgical incision (p=0.009; p < 0.001); significant reduction of CI at postintubation (p=0.003; p < 0.001) and during the first surgical incision (p < 0.001; p < 0.001); significant reduction of SVI at postintubation (p=0.013; p=0.008), during the first surgical incision (p=0.008; p=0.003), and 15 minutes after reperfusion (p=0.010; p=0.005); and significant increasing of SVRI during the first surgical incision (p=0.007; p=0.005). The TCI propofol group showed significantly lower SVRI compared to the sevoflurane group postintubation (p=0.029) and during the first surgical incision (p=0.026). Conclusion:Intraoperative hemodynamic profile was similar between the TCI propofol and sevoflurane group during kidney transplant surgery. The TCI propofol group had higher CI and SVI but showed significantly lower SVRI as compared to the sevoflurane group. The incidence of postanesthesia agitation, postoperative outcome, and complication were not significantly different between the two groups.
| S-EPMC6925739 | biostudies-literature