EFFECTS OF PROPOFOL ON CARDIOVASCULAR DYNAMICS, MYOCARDIAL BLOOD FLOW AND MYOCARDIAL METABOLISM IN PATIENTS WITH CORONARY ARTERY DISEASE

The effects of propofol {emulsion formulation) on cardiovasculardynamics, myocardial blood flow and myocardial metabolism werestudied in 12 patients scheduled for elective coronary arterybypass surgery. Measurements were performed with the patientawake, during steady-state maintenance anaesthesia with propofol200 µ kg^–1 min^–1 at rest, and during sternotomywhen the propofol was supplemented with fentanyl 10µgkg^–1. Propofol alone decreased mean arterial pressureand cardiac index; heart rate was increased. Myocardial bloodflow and myocardial oxygen consumption were decreased by 26%and 31%, respectively. Myocardial lactate production was seenin one patient during this period. Surgical stimulation, underpropofol-fentanyl anaesthesia, led to the return of arterialpressure and heart rate towards baseline; cardiac index decreasedfurther. Myocardial blood flow and oxygen consumption increasedsuch that they almost achieved their baseline values. Myocardiallactate production was seen in one patient. These results suggestthat propofol may on occasions, lead to myocardial ischaemiain patients with coronary artery disease, but that it is ableto block the sympathetic responses to surgical stimulation whencombined with a suitable analgesic.     

HEPATIC AND EXTRAHEPATIC DISPOSITION OF PROPOFOL IN PATIENTS UNDERGOING CORONARY BYPASS SURGERY

In order to clarify the relative contribution of the liver tothe short term disposition of propofol, hepatic blood flow wasmeasured during induction of anaesthesia with an i.v. bolusdose of propofol 2 mg kg^–1. Total clearance of the drugwas 2390 (SD 340) ml min^–1, hepatic extraction 82% andhepatic clearance 1060 (260) ml min^–1. During the 60-minperiod of observation, hepatic extraction of propofol increasedfrom 79% to 92%. It is concluded that, within 1 h, only 44%of the administered dose is removed by the liver. Consequently,drug accumulation may occur with repeated dosing or infusionof propofol. The increase in extraction results presumably fromslow release of propofol from the soy-bean emulsion. Results presented in part at the 29th Spring Meeting of theGerman Association of Pharmacology, March 8–11, Mainz,FRG. (Abstract (No. 490) in Naunyn-Schmiedebergs Archives ofPharmacology 1988; 337 (Suppl.): R123.)     

A Multicenter, Randomized Trial Comparing Calcium Hydroxylapatite to Two Hyaluronic Acids for Treatment of Nasolabial Folds

INTRODUCTION In this study, we examined Radiesse (calcium hydroxylapatite; CaHA), Juvederm 24 (hyaluronic acid; HA-1A), Juvederm 24HV (HA-1B), and Perlane (HA-2) for patient satisfaction, likelihood to return, immediate efficacy, and duration of correction.
OBJECTIVE This multicenter, blinded, randomized study compares patient satisfaction variables, efficacy, and durability of CaHA gel and HA for correction of nasolabial folds (NLFs) through 12 months after 4-month touch-up.
METHODOLOGY A total of 205 randomized patients received either CaHA gel or HA for NLF treatment at initial visit and 4-month touch-up. Patients returned at 4, 8, and 12 months after the second injection for evaluation. Surveys measured patient satisfaction; effectiveness measures included the Global Aesthetic Improvement Scale (GAIS).
RESULTS More CaHA gel patients were satisfied or extremely satisfied than each HA tested. At 8 months, significantly more CaHA gel–treated NLFs were improved on the GAIS than any HA. The volumes of CaHA gel and three HA materials injected through 4 months were 2.2, 2.9, 4.8, and 2.9 mL, respectively ( p <.005). No serious adverse events were observed.
CONCLUSIONS In this controlled study, CaHA gel ranked highest in patient satisfaction and likelihood to return. The material was more effective and longer lasting than each HA in maintaining NLF augmentation.     

Favorable Long‐Term Survival in Patients Undergoing Multivessel‐PCI Compared to Predicted Prognosis of CABG Estimated by EuroSCORE: Procedural and Clinical Determinants of Long‐Term Outcome

Aims/Methods: Treatment of patients with multivessel coronary artery disease (CAD) has been an ongoing focus of recent clinical studies, questioning the ideal treatment. Randomized trials comparing coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) have so far only included a minority of screened patients. Therefore, we analyzed data from 679 consecutive “all‐comer” patients, who underwent PCI in at least two main vessels. Expected in‐hospital mortality for CABG was calculated using the EuroSCORE and compared to the observed mortality rate during in‐hospital as well as long‐term follow‐up. Results: The patients were suffering from 2.5 ± 0.6 diseased vessels, and 2.8 ± 1.0 lesions were stented (32% of patients received at least one drug‐eluting stent [DES]; 20% of lesions were treated with DES). Forty‐seven percent of patients were treated for acute coronary syndrome (ACS) ( N = 176 ST‐elevation myocardial infarction [STEMI]; N = 140 non‐ST‐elevation myocardial infarction [NSTEMI]). The EuroSCORE was significantly higher in ACS patients compared to stable patients (logistic: STEMI 16.3 ± 17.2; NSTEMI 13.6 ± 13.0; stable CAD 3.9 ± 4.2). The observed in‐hospital mortality (STEMI 13.0%; NSTEMI 2.9%; stable CAD 1.7%, P < 0.001) was far lower than the estimated 30‐day mortality. Cox regression analysis identified an elevated logistic EuroSCORE (HR per quartile 2.7, P = 0.003), severely reduced left ventricular ejection fraction (HR 2.7, P < 0.001), elevated C‐reactive protein (HR 1.8, P = 0.012), and chronic renal failure (HR 2.8, P = 0.001) as independent predictors of long‐term mortality. Conclusions: The EuroSCORE, which is routinely used to estimate the perioperative risk of patients undergoing CABG, also predicts short‐ and long‐term prognosis of patients undergoing MV‐PCI. The observed mortality of patients undergoing MV‐PCI seems to be much lower than the estimated mortality of CABG.     

The effect of age on the dose of remifentanil for tracheal intubation in infants and children

Introduction: This study aimed to determine the age‐specific bolus dose of remifentanil (ED₅₀) to facilitate tracheal intubation without the use of neuromuscular blocking agents. Methods: ASA 1–2 subjects were recruited into three groups of 0–3 months (group I), 4–12 months (group II), and 1–3 years (group III) of age. A sequential up‐and‐down design determined the remifentanil bolus dose, which was initially started at 3 mcg·kg^?1 and adjusted in 1 mcg·kg^?1 increments (range 1–6 mcg·kg^?1). Following pretreatment with glycopyrrolate 10 μg·kg^?1 and an induction dose of propofol 5 mg·kg^?1, remifentanil was administered with a blinded study investigator commencing tracheal intubation after 60 s. After tracheal intubation, the time to return of spontaneous ventilation was measured. Logistic regression was used to predict the ED₅₀ and ED₉₅ of remifentanil. Results: Sixty‐four subjects were recruited. Tracheal intubation was successful at first attempt in over 90% of subjects in each age group. Satisfactory intubating conditions were achieved in 85%, 63%, and 75% of subjects in groups I, II, and III, respectively. The logistic regression results for ED₅₀ (95% CI) were 3.1 (2.5–3.8), 3.7 (2.0–5.4), and 3.0 (2.1–3.9) mcg·kg^?1, and ED₉₅ (95% CI) were 5.0 (3.0–7.0), 9.4 (1.5–17.4), and 5.6 (2.9–8.4) mcg·kg^?1 in groups I, II, and III, respectively. Infants aged 4–12 months (group II) showed a marked variability in dose response; however, the mean ED₅₀ and ED₉₅ were not different to groups I and III. Older children had a longer duration of apnea than infants, 331 vs 180 s (P < 0.05). Discussion: The ED₅₀ of remifentanil for tracheal intubation was higher in all age groups than previously reported. Ideal intubating conditions were achieved in 50% of subjects with remifentanil doses of 3.1–3.7 mcg·kg^?1. Higher doses will be required for higher success rates and with anticholinergic pretreatment, doses of up to 6 mcg·kg^?1 were tolerated, without adverse effects, in two patients. Further investigation of the variability in dose response in infants and assessment of the safety this technique is warranted.     

Reduced Fluoroscopy During Atrial Fibrillation Ablation: Benefits of Robotic Guided Navigation

Reduced Fluoroscopy in PVI Using RN.   Background: Recently, a nonmagnetic robotic navigation system (RN, Hansen-Sensei™) has been introduced for remote catheter manipulation.
Objective: To investigate the influence of RN combined with intuitive 3-dimensional mapping on the fluoroscopy exposure to operator and patient during pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (PAF) in a prospective randomized trial.
Methods: Sixty patients were randomly assigned to undergo PVI either using a RN guided (group 1; n = 30, 20 male, 62 ± 7.7 years) or conventional ablation approach (group 2; n = 30, 14 male, 61 ± 7.6 years). A 3-dimensional mapping system (NavX™) was used in both groups.
Results: Electrical disconnection of the ipsilateral pulmonary veins (PVs) was achieved in all patients. Use of RN significantly lowered the overall fluoroscopy time (9 ± 3.4 vs 22 ± 6.5 minutes; P < 0.001) and reduced the operator's fluoroscopy exposure (7 ± 2.1 vs 22 ± 6.5 minutes; P < 0.001). The difference in fluoroscopy duration between both groups was most pronounced during the ablation part of the procedure (3 ± 2.4 vs 17 ± 6.3 minutes; P < 0.001). The overall procedure duration tended to be prolonged using RN without reaching statistical significance (156 ± 44.4 vs 134 ± 12 minutes, P = 0.099). No difference regarding outcome was found during a midterm follow-up of 6 months (AF freedom group 1 = 73% vs 77% in group 2 [P = 0.345]).
Conclusion: The use of RN for PVI seems to be effective and significantly reduces overall fluoroscopy time and operator's fluoroscopy exposure without affecting mid-term outcome after 6-month follow-up. (J Cardiovasc Electrophysiol, Vol. 21, pp. 6–12, January 2010)     

Predicting Recurrence of Vasovagal Syncope: A Simple Risk Score for the Clinical Routine

Background: Predictors for recurrence of syncope are lacking in patients with vasovagal syncope. The aim of this study was to identify risk factors for recurrence of syncope and develop a simple prognostic risk score of clinical value.
Methods: Two hundred seventy-six patients with a history of vasovagal syncope were prospectively followed for 2 years. Diagnosis of vasovagal syncope was based on clinical history and negative standard work-up. Inclusion in the study was independent from the result of the head-up tilt test, which was performed in all cases. Risk factors for syncope recurrence were evaluated by the Cox proportional hazards regression model and implemented in a risk score, which was validated with the log-rank test and an internal cross-validation.
Results: The Cox-regression analysis identified the number of previous syncopal events, history of bronchial asthma, and female gender as predictors for syncope recurrence (all P < 0.05). In contrast, head-up tilt test response had no predictive value (P = 0.881). Developing a risk score, study patients were identified as having high (recurrence rate during 2 years of follow-up: 37.2%), intermediate (24.8%), and low (6.5%) risk for syncope recurrence (receiver operating characteristic [ROC] of score 0.83, P < 0.01; Log-rank test for event-free survival, P < 0.005).
Conclusions: In patients with vasovagal syncope, risk of recurrence can be stratified and is predictable based on a simple risk score.     

The Effects of Ventricular Fibrillation Duration and a Preceding Unsuccessful Shock on the Probability of Defibrillation Success Using Biphasic Waveforms in Pigs

Influence of VF Duration on Defibrillation Efficacy. introduction: While the defibrillation threshold has been reported to increase with ventricular fibrillation (VF) duration for monophasic waveforms, the effect of VF duration for biphasic waveforms is unknown. Methods and Results: The ED 50 requirements (the 50% probability of defibrillation success) for an endocardial lead system, which included a subcutaneous array, were determined by logistic regression using a recursive up-down algorithm for a biphasic waveform ((6/6 msec). The study was performed in two parts, each with eight pigs. In part 1, ED 50 was compared for shocks delivered after 10 seconds of VF and for shocks delivered after 20 seconds of VF following a failed first shock at 10 seconds. Energy at ED 50 decreased from 6.5 ± 0.9, J for shocks delivered after 10 seconds of VF to 4.9 ± 0.8, J (P < 0.01) for shocks delivered after 20 seconds. To determine if improved second shock efficacy was a result of preconditioning by the failed first shock or a function of VF duration, part 2 of the study compared defibrillation efficacy between shocks delivered after 10 seconds of VF with shocks delivered after 20 seconds of VF with and without a failed first shock at 10 seconds. Mean energy at ED 50 decreased from 10.1 ± 2.4, J for shocks delivered after 10 seconds of VF to 7.9 ± 2.4 J (P < 0.01) and 7.5 ± 3.2 J (P < 0.01) for shocks delivered after 20 seconds of VF with and without a failed first shock, respectively. The mean energy at KD 50 for shocks delivered after 20 seconds of VK with and without a failed first shock was not significantly different (P = 0.53). A strong linear correlation for energy at ED 50 was found between shocks delivered after 10 seconds of VF and shocks delivered after 20 seconds of VF following a failed first shock (r = 0.95, P < 0.01). Conclusion: (1) As opposed to monophasic shocks, ED 50 is significantly lower for biphasic shocks delivered after 20 seconds of VF compared with shocks delivered after 10 seconds of VF in pigs. (2) An unsuccessful biphasic shock in pigs does not affect the defibrillation efficacy for a subsequent shock. (3) ED 50 for a biphasic shock delivered after 20 seconds of VK is linearly related to ED 50 for a shock delivered after 10 seconds of VK.