Left Atrial Appendage Occlusion on a Beating Heart during Minimally Invasive Valve Surgery Using an Aortic Endoclamp: A Case Report.

Concomitant LAA occlusion has been shown to be an effective and safe treatment for patients with atrial fibrillation during cardiac surgery to prevent embolic stroke. Minimally invasive procedures are challenging due to restricted access to and visibility of the surgical site. Also, aortic endoclamping has been developed as an alternative surgical approach to exoclamping. The aim of this article is to demonstrate the method of beating heart LAA occlusion with the Atriclip® (AtriCure, Mason, OH, USA) device during minimally invasive mitral valve surgery while using the endoclamping alternative for aortic cross-clamping.

A Practical Approach to Systemic Mastocytosis Complications in Cardiac Surgery: A Case Report and Systematic Review of the Literature.

(1) Background: Systemic mastocytosis is a rare, non-curable disease with potential life-threatening complications in patients receiving cardiac surgery. (2) Methods: This systematic review of the literature was prompted by the case of a life-threatening anaphylactic reaction during cardiac surgery related to systemic mastocytosis. The search of all types of studies, using several databases (Pubmed, Scopus and Web of Science), was conducted through September 2022 to identify the relevant studies. (3) Results: Twelve studies were included describing cases of patients undergoing cardiac surgery who were diagnosed with systemic mastocytosis. An adverse effect, namely anaphylaxis, has happened in three cases. Different strategies of premedication, intraoperative and postoperative management were used. In our case, the patient was admitted for elective biological aortic valve replacement due to severe aortic stenosis. Intraoperatively, the patient developed an anaphylactic shock during the administration of protamine after separation from the cardiopulmonary bypass. This anaphylaxis reaction was a complication of the pre-existing systemic mastocytosis and could be successfully managed by the administration of epinephrine, antihistamines and corticosteroids. (4) Conclusions: This systematic literature search and case report highlight the importance of careful preoperative planning, as well as coordination between cardiac surgeons, anesthesiologists and hemato-oncological specialists, in patients with rare but complication-prone diseases such as systemic mastocytosis.

Quantification of Remimazolam Besylate (CNS7056B) and Its Metabolite (CNS7054X) by LC-MS/MS in Human Plasma Using Midazolam-d4 Maleate as Internal Standard.

A new assay was developed to measure the concentration of remimazolam besylate (CNS7056B) and its major carboxylic acid metabolite (CNS7054X) in human plasma. For this new assay method, midazolam-d4 maleate was used as an internal standard. After setting up a previously described assay method, using CNS7056-d4 and CNS7054-d4 as internal standards, analytical results of both methods were compared. For the new analytical method, ultra-high-performance liquid chromatography (UHPLC) with tandem mass spectrometry was applied. A purification method, using solid phase extraction, was developed and validated. The chromatographic separation of the analytes was achieved with a mobile phase gradient using a Water Acquity™ UHPLC-System. The Kinetex™ biphenyl 50 × 2.1 mm UHPLC column was used with a particle diameter of 1.7 µm (Phenomenex, Germany). A measuring range of 0.6-2,000 ng/mL for CNS7056B and of 6-20,000 ng/mL for CNS7054X could be achieved with this new assay. The lower limit of quantification was 0.6 ng/mL for CNS7056B and 6 ng/mL for CNS7054X. The assay was validated according to US Food and Drug Administration guidelines. The new method showed an accuracy of 96.9-110.4% and a precision of 2.1-6.7% for both analytes.

Remimazolam - current knowledge on a new intravenous benzodiazepine anesthetic agent.

Intravenous anesthetic agents such as midazolam, propofol, and ketamine are routinely used to provide anesthesia and sedation. They have been shown to effectively induce and maintain amnesia, sedation, and hypnosis in various patient groups and clinical settings. However, all anesthetic agents have the potential to cause unwanted side effects such as hemodynamic instability, respiratory depression, or slow recovery due to prolonged post-procedural sedation. Remimazolam, a recently approved benzodiazepine for general anesthesia and procedural sedation in Korea, has been successfully used for these purposes. To date, inconclusive knowledge has been obtained regarding the use of remimazolam in different patient populations and under various surgical conditions. With respect to the specific pharmacokinetic and pharmacodynamic characteristics of remimazolam, the use of remimazolam is expected to increase providing safe general anesthesia and sedation. This review aims to provide an overview of the basic and clinical pharmacology of remimazolam and to compare it with midazolam and propofol.

Pharmacokinetics and Pharmacodynamics of Remimazolam (CNS 7056) after Continuous Infusion in Healthy Male Volunteers: Part I. Pharmacokinetics and Clinical Pharmacodynamics.

BACKGROUND: Remimazolam (CNS 7056) is a new ultra-short-acting benzodiazepine for intravenous sedation and anesthesia. Its pharmacokinetics and pharmacodynamics have been reported for bolus administration. This study aimed to investigate the pharmacokinetics and pharmacodynamics of remimazolam after continuous infusion. METHODS: Twenty healthy male volunteers (20 to 38 yr, 64 to 99 kg) received remimazolam as continuous intravenous infusion of 5 mg/min for 5 min, 3 mg/min for the next 15 min, and 1 mg/min for further 15 min. Pharmacokinetics of remimazolam and its metabolite were determined from arterial plasma concentrations. Sedation was assessed using the Modified Observer's Assessment of Alertness and Sedation scale. Pharmacokinetic-pharmacodynamic modeling was performed by population analysis. Hemodynamics and the electrocardiogram were also investigated. RESULTS: Pharmacokinetics was best described by a three-compartment model for remimazolam and a two-compartment model with transit compartment for the metabolite. Remimazolam showed a high clearance (1.15 ± 0.12 l/min, mean ± SD), a small steady-state volume of distribution (35.4 ± 4.2 l) and a short terminal half-life (70 ± 10 min). The simulated context-sensitive halftime after an infusion of 4 h was 6.8 ± 2.4 min. Loss of consciousness was observed 5 ± 1 min after start, and full alertness was regained 19 ± 7 min after stop of infusion. Pharmacodynamics of Modified Observer's Assessment of Alertness and Sedation score was best described by a sigmoid probability model with effect site compartment. The half-maximum effect site concentration for a Modified Observer's Assessment of Alertness and Sedation score less than or equal to 1 was 695 ± 239 ng/ml. The equilibration half-time between central and effect compartment was 2.7 ± 0.6 min. Mean arterial blood pressure decreased by 24 ± 6%, and heart rate increased by 28 ± 15%. Spontaneous breathing was maintained throughout the study. There was no significant prolongation of the QT interval of the electrocardiogram observed. CONCLUSIONS: Remimazolam was characterized by a pharmacokinetic-pharmacodynamic profile with fast onset, fast recovery, and moderate hemodynamic side effects.

Accuracy and Trending Ability of the Fourth-Generation FloTrac/EV1000 System in Patients With Severe Aortic Valve Stenosis Before and After Surgical Valve Replacement.

OBJECTIVE: Evaluate the accuracy and trending ability of the fourth-generation FloTrac/EV1000 (Edwards Lifesciences, Irvine, CA) system in patients with severe aortic valve stenosis by comparing FloTrac/EV1000-derived cardiac output (CCO-FT) with continuous thermodilution pulmonary artery catheter (CCO-PAC) measurements before and after surgical valve replacement. DESIGN: Prospective clinical study. SETTING: Anesthesia for cardiac surgery, operating room, single-center university hospital. PARTICIPANTS: Twenty-five patients were included. After exclusion, 20 patients undergoing elective aortic valve replacement were analyzed. INTERVENTIONS: After induction of general anesthesia, CCO-FT and CCO-PAC values were recorded every 30 seconds before and after aortic valve replacement with a bioprosthesis under cardiopulmonary bypass (CPB). MEASUREMENTS AND MAIN RESULTS: Data were analyzed separately from skin incision to last suture and before and after CPB. Regression analyses, Bland-Altman analyses, and trending analyses (4-quadrant plot, polar plot) were performed. The percentage errors of the FloTrac/EV1000 were 69.7% and 59.3% before and after CPB, respectively. The concordance rates (CRs) and angular CRs of the FloTrac/EV1000 were 50.9% and 57.1%, and 48.7% and 61.9% before and after CPB, respectively. CONCLUSION: This study revealed a low level of agreement and poor trending ability of the FloTrac/EV1000 system compared to continuous thermodilution pulmonary artery catheter in patients with severe aortic stenosis. Although there was a slight improvement after surgical valve replacement and CPB, the results were not within acceptable limits to replace CCO-PAC in this patient population.

Patient-controlled Analgesia with Target-controlled Infusion of Hydromorphone in Postoperative Pain Therapy.

BACKGROUND: Patient-controlled analgesia (PCA) is a common method for postoperative pain therapy, but it is characterized by large variation of plasma concentrations. PCA with target-controlled infusion (TCI-PCA) may be an alternative. In a previous analysis, the authors developed a pharmacokinetic model for hydromorphone. In this secondary analysis, the authors investigated the feasibility and efficacy of TCI-PCA for postoperative pain therapy with hydromorphone. METHODS: Fifty adult patients undergoing cardiac surgery were enrolled in this study. Postoperatively, hydromorphone was applied intravenously during three sequential periods: (1) as TCI with plasma target concentrations of 1 to 2 ng/ml until extubation; (2) as TCI-PCA with plasma target concentrations between 0.8 and 10 ng/ml during the following 6 to 8 h; and (3) thereafter as PCA with a bolus dose of 0.2 mg until the next morning. During TCI-PCA, pain was regularly assessed using the 11-point numerical rating scale (NRS). A pharmacokinetic/pharmacodynamic model was developed using ordinal logistic regression based on measured plasma concentrations. RESULTS: Data of 43 patients aged 40 to 81 yr were analyzed. The hydromorphone dose during TCI-PCA was 0.26 mg/h (0.07 to 0.93 mg/h). The maximum plasma target concentration during TCI-PCA was 2.3 ng/ml (0.9 to 7.0 ng/ml). The NRS score under deep inspiration was less than 5 in 83% of the ratings. Nausea was present in 30%, vomiting in 9%, and respiratory insufficiency in 5% of the patients. The EC50 of hydromorphone for NRS of 4 or less was 4.1 ng/ml (0.6 to 12.8 ng/ml). CONCLUSION: TCI-PCA with hydromorphone offered satisfactory postoperative pain therapy with moderate side effects.

Population pharmacokinetic modeling of hydromorphone in cardiac surgery patients during postoperative pain therapy.

BACKGROUND: Hydromorphone is a µ-selective opioid agonist used in postoperative pain therapy. This study aimed to evaluate the pharmacokinetics of hydromorphone in cardiac surgery patients during postoperative analgesia with target-controlled infusion and patient-controlled analgesia. METHODS: In this study, 50 adult patients were enrolled to receive intravenous hydromorphone during postoperative pain therapy. Arterial plasma samples were collected for measurements of drug concentration. Population pharmacokinetic parameters were estimated using nonlinear mixed-effects modeling. Results were validated and simulations were carried out to evaluate results. RESULTS: Data from 49 patients (age range, 40-81 yr) were analyzed. The pharmacokinetics of hydromorphone were best described by a three-compartment model. Age was incorporated as a significant covariate for elimination clearance and central volume of distribution. Scaling all parameters with body weight improved the model significantly. The final estimates of the model parameters for the typical adult patient (67 yr old, weighing 70 kg) undergoing cardiac surgery were as follows: CL1 = 1.01 l/min, V1 = 3.35 l, CL2 = 1.47 l/min, V2 = 13.9 l, CL3 = 1.41 l/min, and V3 = 145 l. The elimination clearance decreased by 43% between the age of 40 and 80 yr, and simulations demonstrated that context-sensitive half-time increased from 26 to 84 min in 40- and 80-yr-old subjects, respectively. CONCLUSIONS: The final pharmacokinetic model gave a robust representation of hydromorphone pharmacokinetics. Inclusion of age and body weight to the model demonstrated a significant influence of these covariates on hydromorphone pharmacokinetics. The application of this patient-derived population model in individualized pain therapy should improve the dosing of hydromorphone in patients undergoing cardiac surgery.

A randomized open-label phase I pilot study of the safety and efficacy of total intravenous anesthesia with fospropofol for coronary artery bypass graft surgery.

OBJECTIVE: To determine safety and efficacy of the water-soluble prodrug fospropofol for anesthesia in cardiac surgery and to compare the pharmacodynamic profiles of fospropofol and propofol. DESIGN: Pilot study and a prospective, phase I, open-label, single-center, randomized clinical trial. SETTING: University hospital; single institution. PARTICIPANTS: Sixteen patients undergoing elective first-time coronary artery bypass surgery. INTERVENTIONS: Patients were randomized to receive total intravenous anesthesia with fospropofol (n = 8) or propofol (n = 8) combined with alfentanil as total intravenous anesthesia. Bispectral index, arterial blood pressure, and heart rate were recorded continuously, and pulmonary artery catheter measurements were obtained. Plasma concentrations of formate, phosphate, and Ca(2+) were monitored closely. Safety and tolerability were assessed by adverse events, neurologic examinations, clinical laboratory tests, and vital signs. MEASUREMENTS AND MAIN RESULTS: The total doses of fospropofol and propofol during anesthesia were 11.3±2.5 and 4.4±1.0 mg/kg/h, respectively. According to the achieved bispectral index (BIS) values, fospropofol was as effective as propofol in providing general anesthesia and sedation. There were no clinical signs of formate toxicity in the fospropofol group. The only treatment-related adverse event after administration of fospropofol was a transient burning sensation in the perineal and perianal region during induction of sedation or anesthesia. CONCLUSIONS: Fospropofol could be used to provide general anesthesia in patients undergoing coronary artery bypass graft surgery. Further larger studies are needed to prove the safety of fospropofol when given to provide general anesthesia for major cardiac surgical procedures.

Analysis of total and unbound hydromorphone in human plasma by ultrafiltration and LC-MS/MS: application to clinical trial in patients undergoing open heart surgery.

A method for a sensitive and specific analysis of hydromorphone total and unbound drug concentrations in human plasma was developed and validated. Sample preparation was preceded with an ultrafiltration step to separate the unbound drug from the protein bound fraction of hydromorphone. Both the ultrafiltrate and plasma samples were extracted with solid-phase extraction and substituted with stable isotope-labeled hydromorphone that was used as internal standard. Chromatographic separation was performed by gradient elution with UPLC-like system and eluates were analyzed by tandem mass spectrometry equipped with an electrospray ionization source. Sample preparation was optimized for good recovery of hydromorphone and the results were consistent. Calibration curves demonstrated linearity in the concentration range of 78-5000pg/ml for analysis of both total and unbound concentrations of hydromorphone. The limit of detection was 1pg and the lower limit of quantification was 78pg/ml for both total and unbound hydromorphone plasma drug concentrations. Intra- and interassay reproducibility and inaccuracy did not exceed 10%. Hydromorphone was on the average 14% bound to plasma proteins, supporting the previously published unreferenced statements that the protein binding of hydromorphone is low. Method was applied to a clinical trial in patients undergoing open heart surgery to generate a target controlled infusion model for the postoperative patient controlled analgesia with hydromorphone.

Determination of total and unbound sufentanil in human plasma by ultrafiltration and LC-MS/MS: application to clinical pharmacokinetic study.

A sensitive and specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the quantification of sufentanil total and unbound drug concentrations. Unbound drug was separated by an ultrafiltration step before sample preparation. Both the ultrafiltrate and plasma samples were extracted with solid-phase extraction and substituted with deuterated sufentanil used as an internal standard. Separation was performed by gradient elution using UPLC-like system and analysed by MS/MS consisting of an electrospray ionization source. Calibration curves showed linearity in the concentration range of 5-2500 pg/ml for analysis of both total and unbound concentrations of sufentanil. The lower limit of quantification was 5 pg/ml for both total and unbound sufentanil plasma drug concentrations. Intra- and interassay precision and accuracy did not exceed 15%. Method was applied to pharmacokinetic study in patients undergoing coronary artery bypass grafting.

Fospropofol disodium, a water-soluble prodrug of the intravenous anesthetic propofol (2,6-diisopropylphenol).

BACKGROUND: Today, propofol or 2,6-diisopropylphenol is the anesthetic mainly used for monitored anesthetic care sedation and during intravenous anesthesia. The formulation, a lipid macroemulsion, shows several disadvantages. Therefore, during the past years considerable scientific effort has been undertaken to find either a better formulation or a prodrug of propofol. Fospropofol is the first propofol prodrug that has been intensively studied in man. It has been licensed in 2008 by the FDA for monitored anesthetic care sedation. OBJECTIVES AND METHODS: This review describes first published study results of fospropofol with regard to its pharmacokinetics/pharmacodynamics, drug safety, tolerability and drug side effects. Using a Medline search all published articles and abstracts containing the words fospropofol or GPI 15715 were included. RESULTS AND CONCLUSION: As the impact of an errorness drug assay for propofol liberated from fospropofol is not exactly defined, no clear conclusions can be drawn from the first published pharmacokinetic/pharmacodynamic studies. Fospropofol was well tolerated in the first two clinical studies and no serious side effects were reported. After characterization of the true pharmacokinetic/pharmacodynamics profile, fospropofol, an aqueous solution, has the potential to favorably compare with benzodiazepines for procedural sedation and also may be used for long-term sedation and intravenous anesthesia.

Electroencephalogram monitoring during anesthesia with propofol and alfentanil: the impact of second order spectral analysis.

Bispectral analysis of the electroencephalogram (EEG) has been used for monitoring anesthesia. The estimation of bicoherence allows us to determine whether a given time series represents a linear random process in cases where the bicoherence is trivial, i.e., a mere constant independent of frequency. In this study, we investigated the proportion of EEG epochs with nontrivial bicoherence during surgical anesthesia with propofol and alfentanil as an indicator for the degree of nonlinearity in the EEG. We reanalyzed 90 h of EEG recorded from 20 patients undergoing abdominal surgery using the Hinich procedure, which provides a statistical test for the following hypothesis: the EEG is a linear random process. In approximately 90% of all artifact-free, stationary EEG epochs, the bicoherence was found to be zero or a mere constant. Under these conditions, the EEG can be considered as a linear random process. Our findings suggest that the spectral information in the frequency domain delivered by the EEG monitoring during anesthesia is largely contained in the power spectrum of the signal. This calls into question the benefit of EEG bispectral analysis for monitoring anesthesia effect.

Sedation with GPI 15715, a water-soluble prodrug of propofol, using target-controlled infusion in volunteers.

GPI 15715 is the first water-soluble propofol prodrug that has been studied in humans. Present propofol lipid formulations have well known undesirable properties, for example, pain on injection and increased triglyceride concentrations. We investigated whether GPI 15715 is suitable to achieve and maintain moderate sedation for 2 h. Six male and six female volunteers received a target-controlled infusion of GPI 15715, with an initial propofol target concentration of 1.8 microg/mL and the possibility to adjust the propofol target once after 1 h. Propofol concentrations, the bispectral index, and modified Observer's Assessment of Alertness/Sedation Scale (MOAA/S) scores were monitored. The median MOAA/S score was 4 during the first hour and was 3 during the second hour of infusion. The propofol target had to be changed to 2.4 microg/mL in seven volunteers and to 3.0 microg/mL in two volunteers. A propofol concentration of 1.9 microg/mL had the highest probability to result in an MOAA/S score of 3, which corresponds with moderate sedation. We observed no serious side effects. We conclude that GPI 15715 produces excellent sedation.

Comparative pharmacokinetics and pharmacodynamics of the new propofol prodrug GPI 15715 and propofol emulsion.

BACKGROUND: GPI 15715 is a new water-soluble prodrug that is hydrolyzed to release propofol. The objectives of this crossover study in volunteers were to investigate the pharmacokinetics and pharmacodynamics of GPI 15715 in comparison with propofol emulsion. METHODS: In two separate sessions, nine healthy male volunteers (19-35 yr, 70-86 kg) received GPI 15715 and propofol emulsion as a target controlled infusion over 60 min. In the first 20 min, the propofol target concentration increased linearly to 5 microg/ml. Subsequently, the targets were reduced to 3 microg/ml and 1.5 microg/ml for 20 min each. The plasma concentrations of GPI 15715 and propofol were measured from arterial and venous blood samples up to 24 h and pharmacokinetics were analyzed. The pharmacodynamic effect was measured by the median frequency of the power spectrum of the electroencephalogram, and a sigmoid model with effect compartment was fitted to the data. RESULTS: Compared with propofol emulsion, propofol from GPI 15715 showed a different disposition function and especially larger volumes of distribution. The propofol effect site concentration for half maximum effect was 2.0 +/- 0.5 microg/ml for GPI 15715 and 3.0 +/- 0.7 microg/ml for propofol emulsion (P < 0.05). Propofol from GPI 15715 did not show a hysteresis between plasma concentration and effect. CONCLUSIONS: Compared with propofol emulsion, propofol from GPI 15715 showed different pharmacokinetics and pharmacodynamics, particularly a higher potency with respect to concentration. These differences may indicate an influence of the formulation.

Pharmacokinetics and clinical pharmacodynamics of the new propofol prodrug GPI 15715 in volunteers.

BACKGROUND: GPI 15715 (AQUAVAN injection) is a new water-soluble prodrug which is hydrolyzed to release propofol. The objectives of this first study in humans were to investigate the safety, tolerability, pharmacokinetics, and clinical pharmacodynamics of GPI 15715. METHODS: Three groups of three healthy male volunteers (aged 19-35 y, 67-102 kg) received 290, 580, and 1,160 mg GPI 15715 as a constant rate infusion over 10 min. The plasma concentrations of GPI 15715 and propofol were measured from arterial and venous blood samples up to 24 h. Pharmacokinetics were analyzed with compartment models. Pharmacodynamics were assessed by clinical signs. RESULTS: GPI 15715 was well tolerated without pain on injection. Two subjects reported a transient unpleasant sensation of burning or tingling at start of infusion. Loss of consciousness was achieved in none with 290 mg and in one subject with 580 mg. After 1,160 mg, all subjects experienced loss of consciousness at propofol concentrations of 2.1 +/- 0.6 microg/ml. A two-compartment model for GPI 15715 (central volume of distribution, 0.07 l/kg; clearance, 7 ml. kg-1 min-1; terminal half-life, 46 min) and a three-compartment model for propofol (half-lives: 2.2, 20, 477 min) best described the data. The maximum decrease of blood pressure was 25%; the heart rate increased by approximately 35%. There were no significant laboratory abnormalities. CONCLUSIONS: Compared with propofol lipid emulsion, the potency seemed to be higher with respect to plasma concentration but was apparently less with respect to dose. Pharmacokinetic simulations showed a longer time to peak propofol concentration after a bolus dose and a longer context-sensitive half-time.