Toshiya Shiga

Endoscopic Thoracic Sympathectomy for Primary Erythromelalgia in the Upper Extremities

rythromelalgia, a rare syndrome of unknowncause, is characterized by burning pain, redness,edema, and increased skin temperature in thelower, upper, or both extremities (1,2). In addition todrug therapies (2–5), sympathetic blockade is effectivein improving the symptoms (6–8). We report the suc-cessful outcome of treating primary erythromelalgiaof the upper extremities with bilateral thoracic sym-pathectomy using a video-assisted thoracic surgical(VATS) technique.

Nitrous oxide produces minimal hemodynamic changes in patients receiving a propofol-based anesthetic: an esophageal Doppler ultrasound study

PurposeNitrous oxide (N2O) is a frequently used adjunct to propofol anesthesia. Although N2O reduces the requirement of propofol for induction and maintenance, the effects of both drugs on overall hemodynamics remain controversial. We tested the hypothesis that the addition of N2O to therapeutic doses of propofol alters hemodynamics and Doppler-derived variables evaluated with the esophageal Doppler monitor in a randomized, doubleblinded, placebo-controlled design.MethodsThirty ASA I–II patients (aged 30–66 yr) were randomly assigned to receive propofol with oxygen-enriched air (FIO2 =0.3; air group) or propofol with 70% N2O (N2O group). Following intubation, a computerized target-controlled infusion technique was used to administer propofol from 0 μg·mL−1 (baseline) to 5 μg·mL−1 in 1 μg·mL−1 increments.ResultsMean arterial pressure (MAP) decreased more in the N2O group than in the air group only at 5 μg·mL−1. Aortic blood flow (ABF) showed a similar dose-dependent decrease in both groups. Peak aortic flow acceleration, as a myocardial contractility index, decreased significantly and similarly in both groups in a dosedependent manner whereas peak velocity of ABF, as another measure of myocardial contractility, remained unchanged. Heart rate-corrected left ventricular ejection time, as a measure of preload, remained constant in both groups at any target plasma concentration.ConclusionPropofol causes dose-dependent decreases in ABF and MAP; however, 70% N2O produces minimal hemodynamic and Doppler-derived variable changes under target-controlled propofol infusion at therapeutic concentrations.RésuméObjectifLe protoxyde d’azote (N2O) complète souvent l’anesthésie au propofol. Quoique le N2O réduise la quantité de propofol nécessaire à l’induction et au maintien de l’anesthésie, les effets des deux médicaments sur l’hémodynamique générale demeurent controversés. Nous avons testé l’hypothèse voulant que l’ajout de N2O à des doses thérapeutiques de propofol modifie l’hémodynamique et les variables dérivées de l’examen Doppler évaluées avec un moniteur Doppler œsophagien dans une étude randomisée, à double insu et contrôlée par placebo.MéthodeTrente patients d’état physique ASA I– II (de 30 à 66 ans), répartis de façon aléatoire, ont reçu du propofol avec de l’air enrichi d’oxygène (FIO2 = 0,3; groupe air) ou du propofol avec 70 % de N2O (groupe N2O). Après l’intubation, une technique informatisée de perfusion cible contrôlée a été utilisée pour administrer du propofol de 0 μg·mL− 1 (mesure de base) à 5 μg·mL− 1 en paliers de 1 μg·mL− 1.RésultatsLa tension artérielle moyenne (TAM) a baissé davantage avec le N2O qu’avec l’air, seulement à 5 μg·mL− 1. Le débit sanguin aortique (DSA) a montré une baisse dosedépendante similaire dans les deux groupes. L’accélération du débit de pointe aortique, comme index de contractilité myocardique, a diminué de façon significative et semblable dans les deux groupes, de manière dépendante de la dose, tandis que la vélocité maximale du DSA, une autre mesure de la contractilité myocardique, est demeurée stable. Le temps d’éjection ventriculaire de la fréquence cardiaque corrigée, comme mesure de précharge, est demeuré constant dans les deux groupes pour toutes les concentrations plasmatiques cibles.ConclusionLe propofol cause une baisse dosedépendante du DSA et de la TAM; mais avec 70 % de N2O, il produit des changements minimes de l’hémodynamique et des variables dérivées du Doppler avec une perfusion cible contrôlée à concentrations thérapeutiques de propofol.

Survey of observer variation in transesophageal echocardiography: comparison of anesthesiology and cardiology literature.

OBJECTIVE Transesophageal echocardiographic examination tends to be somewhat observer and experience dependent, and observer bias can arise easily when data are calculated and interpreted by unskilled, nonblinded, or single observers. The study plan was to see whether authors have adequately described how observer bias is minimized in their studies. Thus, a study was conducted systematically reviewing methods reported in transesophageal echocardio graphy articles in peer-reviewed anesthesiology journals versus those reported in peer-reviewed cardiology journals. INTERVENTIONS After MEDLINE searches of the literature published from 1997 through 1999, the authors investigated 56 anesthesiology reports and 56 randomly selected, year-matched cardiology reports. An 8-item questionnaire was developed that examined several factors: the number of observers and their experience levels, whether observers were blind to clinical data, whether low-quality images were excluded, the use of on-line or off-line analysis, and observer variability. MAIN RESULTS The analysis revealed inadequacies in reporting of important information that relates to bias and quality in 91.1% of anesthesiology and 98.2% of cardiology articles. Observer variability was not reported in 50.0% of the anesthesiology reports and 67.9% of the cardiology reports; however, difference between the 2 bodies of literature was not significant. The journal impact factor was significantly higher for the cardiology literature than for the anesthesiology literature (2.42 [0.386-10.893] v 1.07 [0.664-3.439]; median [range], p < 0.001). CONCLUSION Articles reviewed had at least some inadequacies in reporting the methods to minimize observer bias in both the anesthesiology and cardiology literature. Reporting methodology standards in TEE examinations remain to be established.

Minor Cardiac Troponin T Release in Patients Undergoing Coronary Artery Bypass Graft Surgery on a Beating Heart

OBJECTIVES To determine whether and to what extent coronary artery bypass graft (CABG) surgery without extracorporeal circulation is associated with cardiac troponin T (TnT) release. DESIGN Prospective study. SETTING A single university hospital. PARTICIPANTS Twenty-three patients scheduled for minimally invasive CABG surgery. Sixteen patients received one coronary anastomosis, and seven received two. INTERVENTIONS TnT and creatine kinase-MB (CK-MB) levels were determined immediately before induction of anesthesia (baseline) and at 0, 12, and 24 hours after surgery. Hemodynamic measurements were made, and 5-lead electrocardiograms with continuous automated ST-segment trends were analyzed. MEASUREMENTS AND MAIN RESULTS All patients had a good cardiac outcome. Median cumulative coronary artery occlusion time was 27 minutes (range, 10 to 49 minutes). TnT levels were undetectable in 91.3% of patients at baseline when a detection limit of 0.01 ng/mL was employed. TnT and CK-MB showed significant elevations at 12 and 24 hours versus baseline. Postoperatively, TnT was detectable in 91.3% of patients, and 17.4% suffered minor myocardial damage, as evidenced by an abnormal increase in TnT greater than 0.2 ng/mL, excluding those exhibiting myocardial infarction. ST segment changes developed in seven patients, persisting for 13.0 minutes (range, 9.5 to 15.8 minutes) and disappearing immediately after coronary artery clamp release. There were no significant correlations between cumulative coronary occlusion time and peak TnT or CK-MB levels. CONCLUSIONS TnT was detected after surgery in most patients, and significant TnT levels indicative of myocardial injury (>0.2 ng/mL) were detected in only 17% of patients, probably as a result of brief periods of coronary artery occlusion.

Transesophageal echocardiographic evaluation during negative-pressure ventilation using the Hayek oscillator

OBJECTIVES To evaluate the effects of negative-pressure ventilation (NPV) on hemodynamics using the Hayek oscillator (Breasy Medical Equipment, London, UK) and to determine whether the oscillation frequency can modify the hemodynamics, assessed by transesophageal echocardiography (TEE). DESIGN A prospective study. SETTING A university hospital. PARTICIPANTS Eleven American Society of Anesthesiologists class I patients undergoing orolaryngeal surgery. INTERVENTIONS The ultrasound probe was inserted under general anesthesia. After baseline measurements were determined during spontaneous breathing, the frequency was changed from 30 to 60 to 120 cycles/min, consecutively. The left ventricular end-diastolic area (LVEDA), end-systolic area (LVESA), fractional area change (LVFAC), and end-systolic wall stress (ESWS) were determined. The velocities of the pulmonary artery (PA) flow, pulmonary venous (PV) flow, and transmitral flow were measured by pulsed Doppler techniques. MEASUREMENTS AND MAIN RESULTS PaO2 increased and PaCO2 decreased significantly. NPV caused a significant increase in the LVEDA, whereas it did not significantly change the PA velocity. ESWS, an index of afterload, remained unchanged. CONCLUSION The authors conclude that NPV using the Hayek oscillator induces an increase in the LVEDA without any changes in PA velocity, suggesting increased transmural pressure rather than increased preload, and that the three different frequencies do not modify the effects on the hemodynamics.

Local Cardiac Wall Stabilization Influences the Reproducibility of Regional Wall Motion during Off-Pump Coronary Artery Bypass Surgery

Objective.Myocardial ischemia is a risk factor during off-pumpcoronary artery bypass procedures. The development of new regional wall motionabnormalities assessed by transesophageal echocardiography (TEE) is a verysensitive sign of myocardial ischemia. To facilitate anastomosis, theepicardial area of the anastomosis site is often immobilized by a“stabilizer.” This study was designed to investigate whethercardiac wall stabilization with an epicardial stabilizer could affect theinterpretation of wall motion during coronary anastomosis withoutcardiopulmonary bypass. Methods.The TEE videotapes of 15 adultpatients were investigated. Left ventricular (LV) transgastric short and longaxis views were divided according to a modified 16-segment method. LV wallmotion was scored using a 5-grade scale by two independent blindedinvestigators during pre-occlusion, occlusion, and reperfusion of anastomosedcoronary arteries. The wall motion scores of a stabilized segment combinedwith two adjacent segments were compared with those of non-stabilizedsegments. Interobserver agreement was assessed using the weighted kappastatistic. Results.A total of 216 segments were analyzed by twoinvestigators. The interobserver kappa coefficient in pre-occlusion andreperfusion periods was 0.87, 0.87 and 0.86, 0.87, respectively, indicatinghigh agreements without stabilizer. During the occlusion period in stabilizedand non-stabilized segments, it was 0.59 and 0.76, respectively, showingsignificantly less reproducibility in the presence of stabilizer.Conclusion.Cardiac wall stabilization affects the reproducibility inthe interpretation of regional wall motion during off-pump coronary arterybypass surgery. Caution should be used when monitoring for myocardial ischemiausing TEE during coronary artery bypass surgery with epicardial stabilizer.

Thoracic epidural blockade preserves left ventricular early diastolic filling assessed by transesophageal echocardiography

PurposeThe objective of this study was to examine the effect of thoracic epidural anesthesia (TEA) on left ventricular systolic and diastolic function assessed by transesophageal echocardiography under general anesthesia.MethodsSixteen patients were allocated to control (n=8) and TEA (n=8) groups. We administered 1% mepivacaine (8.9±1.2 ml) into the thoracic epidural space in the TEA group.ResultsThe concomitant decline of the left vertricular systolic functional parameters, such as end-systolic diameter and fractional shortening, was observed, whereas preload, as measured by end-diastolic diameter, and afterload, as measured by end-systolic wall stress, were unchanged. No significant alteration was observed in early peak velocity or deceleration rate. The deceleration time was independent of heart rate and was unchanged.ConclusionHigh TEA reduces fractional shortening without any changes in preload and afterload, indicating impairment of systolic function, but early peak velocity, deceleration rate, and deceleration time, which are the indices of diastolic function, are not changed during high TEA combined with general anesthesia.