Changes in mean systemic filling pressure as an estimate of hemodynamic response to anesthesia induction using propofol.
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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
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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.
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Project description:Background: Post-induction hypotension frequently occurs and can lead to adverse outcomes. As target-controlled infusion (TCI) obviates the need to calculate the infusion rate manually and helps safer dosing with prompt titration of the drug using complex pharmacokinetic models, the use of TCI may provide a better hemodynamic profile during anesthesia induction. This study aimed to compare TCI versus manual induction and to determine the hemodynamic risk factors for post-induction hypotension. Methods: A total of 200 ASA grade 1–3 patients, aged 24 to 82 years, were recruited and randomly assigned to the TCI (n = 100) or manual induction groups (n = 100). Hemodynamic parameters were monitored with the pressure-recording analytic method. The propofol dosage was adjusted to keep the Bispectral Index between 40 and 60. Results: Post-induction hypotension was significantly higher in the manual induction group than in the TCI group (34% vs. 13%; p < 0.001, respectively). The propofol induction dose did not differ between the groups (TCI: 155 (135–180) mg; manual: 150 (120–200) mg; p = 0.719), but the induction time was significantly longer in the TCI group (47 (35–60) s vs. 150 (105–220) s; p < 0.001, respectively). In the multivariable Cox regression model, the presence of hypertension, stroke volume index (SVI), cardiac power output (CPO), and anesthesia induction method were found to predict post-induction hypotension (p = 0.032, p = 0.013, p = 0.024, and p = 0.015, respectively). Conclusion: TCI induction with propofol provided better hemodynamic stability than manual induction, and the presence of hypertension, a decrease in the pre-induction SVI, and the CPO could predict post-induction hypotension.
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Project description:BackgroundDesflurane is not recommended during anesthesia induction because of its sympathetic stimulation effect, particularly in patients with myocardial ischemic disease. To date, the hemodynamic response to 1 MAC desflurane inhalation in combination with remifentanil infusion during anesthesia induction has rarely been reported.MethodsThis investigation was designed to compare hemodynamic responses to 1 MAC desflurane (group D, n = 200) with sevoflurane (group S, n = 200) during anesthesia induction and endotracheal intubation in adult patients undergoing elective spine surgery. Subgroup analysis of the different age subgroups was also performed. With continuous infusion of remifentanil 0.1 μg/kg/min, anesthesia was induced with propofol bolus, and endotracheal intubation was performed after muscle relaxation. Heart rate (HR) and mean arterial blood pressure (MAP) were measured every minute for 5 min after anesthesia induction (T1-5) and after endotracheal intubation (T6-10).ResultsHR was significantly higher in group D (n = 182) than in group S (n = 173) at T3-10 except at T6 (1 min after intubation) (all P < 0.05). In the age-based subgroup analyses, which subdivided the group D and S into four subgroups based on patient's age, the changes in HR from baseline values were significantly different between the coeval subgroups of patients in their 20-29 years and 30-39 years of age (all P < 0.05). MAP was reduced from baseline value, irrespective of group and age.ConclusionInhalation of 1 MAC desflurane during anesthesia induction with propofol bolus and remifentanil continuous infusion and during endotracheal intubation was more likely to induce elevations in HR more likely than 1 MAC sevoflurane, especially in younger patients.Trial registrationThis study was registered in the Clinical Research Information Service (CRIS, http://cris.nih.go.kr ) of the Republic of Korea on Feb 12, 2016 (Registration No. KCT 0,001,813).
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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.
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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.
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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.
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