Albrecht Gauss

Incidence and prognostic impact of new-onset atrial fibrillation in patients with septic shock: a prospective observational study

IntroductionSince data regarding new-onset atrial fibrillation (AF) in septic shock patients are scarce, the purpose of the present study was to evaluate the incidence and prognostic impact of new-onset AF in this patient group.MethodsWe prospectively studied all patients with new-onset AF and all patients suffering from septic shock in a non-cardiac surgical intensive care unit (ICU) during a 13 month period.ResultsDuring the study period, 687 patients were admitted to the ICU, of which 58 patients were excluded from further analysis due to pre-existing chronic or intermittent AF. In 49 out of the remaining 629 patients (7.8%) new-onset AF occurred and 50 out of the 629 patients suffered from septic shock. 23 out of the 50 patients with septic shock (46%) developed new-onset AF. There was a steady, significant increase in C-reactive protein (CRP) levels before onset of AF in septic shock patients. ICU mortality in septic shock patients with new-onset AF was 10/23 (44%) compared with 6/27 (22%) in septic shock patients with maintained sinus rhythm (SR) (P = 0.14). During a 2-year follow-up there was a trend towards an increased mortality in septic shock patients with new-onset AF, but the difference did not reach statistical significance (P = 0.075). The median length of ICU stay among surviving patients was longer in patients with new-onset AF compared to those with maintained SR (30 versus 17 days, P = 0.017). The success rate to restore SR was 86%. Failure to restore SR was associated with increased ICU mortality (71.4% versus 21.4%, P = 0.015).ConclusionsAF is a common complication in septic shock patients and is associated with an increased length of ICU stay among surviving patients. The increase in CRP levels before onset of AF may support the hypothesis that systemic inflammation is an important trigger for AF.

Electrocardiographic exercise stress testing for cardiac risk assessment in patients undergoing noncardiac surgery.

BackgroundThe value of exercise electrocardiography in the prediction of perioperative cardiac risk has yet to be defined. This study was performed to determine the predictive value of exercise electrocardiography as compared with clinical parameters and resting electrocardiography. MethodsA total of 204 patients at intermediate risk for cardiac complications prospectively underwent exercise electrocardiography before noncardiac surgery. Of these, 185 were included in the final evaluation. All patients underwent follow-up evaluation postoperatively by Holter monitoring for 2 days, daily 12-lead electrocardiogram, and creatine kinase, creatine kinase MB, and troponin-T measurements for 5 days. Cardiac events were defined as cardiac death, myocardial infarction, minor myocardial cell injury, unstable angina pectoris, congestive heart failure, and ventricular tachyarrhythmia. Potential risk factors for an adverse event were identified by univariate and multivariate logistic regression analysis. ResultsPerioperative cardiac events were observed in 16 patients. There were 6 cases of myocardial infarction and 10 cases of myocardial cell injury. The multivariate correlates of adverse cardiac events were definite coronary artery disease (odds ratio, 8.8; 95% confidence interval [CI], 1.1–73.1;P = 0.04), major surgery (odds ratio, 4.7; 95% CI, 1.3–16.3;P = 0.02), reduced left ventricular performance (odds ratio, 2.0; 95% CI, 1.1–3.8;P = 0.03), and ST-segment depression of 0.1 mV or more in the exercise electrocardiogram (odds ratio, 5.2; 95% CI, 1.5–18.5;P = 0.01). A combination of clinical variables and exercise electrocardiography improved preoperative risk stratification. ConclusionsThis prospective study shows that a ST-segment depression of 0.1 mV or more in the exercise electrocardio-gram is an independent predictor of perioperative cardiac complications.

The effects of intraabdominally insufflated carbon dioxide on hepatic blood flow during laparoscopic surgery assessed by transesophageal echocardiography.

Conflicting results have been published about the effects of carbon dioxide (CO2) pneumoperitoneum on splanchnic and liver perfusion. Several experimental studies described a pressure-related reduction in hepatic blood flow, whereas other investigators reported an increase as long as the intraabdominal pressure (IAP) remained less than 16 mm Hg. Our goal in the present study was to investigate the effects of insufflated CO2 on hepatic blood flow during laparoscopic surgery in healthy adults. Blood flow in the right and middle hepatic veins was assessed in 24 patients undergoing laparoscopic surgery by use of transesophageal Doppler echocardiography. Hepatic venous blood flow was recorded before and after 5, 10, 20, 30, and 40 min of pneumoperitoneum, as well as 1 and 5 min after deflation. Twelve patients undergoing conventional hernia repair served as the control group. The induction of pneumoperitoneum produced a significant increase in blood flow of the right and middle hepatic veins. Five minutes after insufflation of CO2 the median right hepatic blood flow index increased from 196 mL/min/m2 (95% confidence interval (CI), 140–261 mL/min/m2) to 392 mL/min/m2 (CI, 263–551 mL/min/m2) (P < 0.05) and persisted during maintenance of pneumoperitoneum. In the middle hepatic vein the blood flow index increased from 105 mL/min/m2 (CI, 71–136 mL/min/m2) to 159 mL/min/m2 (CI, 103–236 mL/min/m2) 20 min after insufflation of CO2. After deflation blood flow returned to baseline values in both hepatic veins. Conversely, in the control group hepatic blood flow remained unchanged over the entire study period. We conclude that induction of CO2 pneumoperitoneum with an IAP of 12 mm Hg is associated with an increase in hepatic perfusion in healthy adults.

The effects of thoracic epidural anesthesia on hepatic blood flow in patients under general anesthesia.

BACKGROUND: Hepatic hypoperfusion is regarded as an important factor in the pathophysiology of perioperative liver injury. Although epidural anesthesia (EDA) is a widely used technique, no data are available about the effects on hepatic blood flow of thoracic EDA with blockade restricted to thoracic segments in humans. METHODS: In 20 patients under general anesthesia, we assessed hepatic blood flow index in the right and middle hepatic vein by use of multiplane transesophageal echocardiography before and after induction of EDA. The epidural catheter was inserted at TH7-9, and mepivacaine 1% with a median (range) dose of 10 (8–16) mL was injected. Norepinephrine (NE) was continuously administered to patients who demonstrated a decrease in mean arterial blood pressure below 60 mm Hg after induction of EDA (EDA-NE group). The other patients did not receive any catecholamine during the study period (EDA group). A further 10 patients without EDA served as controls (control group). RESULTS: In five patients, administration of NE was necessary to avoid a decrease in mean arterial blood pressure below 60 mm Hg. Thus, the EDA-NE group consisted of five patients and the EDA group of 15. In the EDA group, EDA was associated with a median decrease in hepatic blood flow index of 24% in both hepatic veins (P < 0.01). In the EDA-NE group, all five patients showed a decrease in the blood flow index of the right (median decrease 39 [11–45] %) and middle hepatic vein (median decrease 32 [7–49] %). Patients in the control group showed a constant blood flow index in both hepatic veins. Reduction in blood flow index in the EDA group and the EDA-NE group was significant in comparison with the control group (P < 0.05). In contrast to hepatic blood flow, cardiac output was not affected by EDA. CONCLUSIONS: We conclude that, in humans, thoracic EDA is associated with a decrease in hepatic blood flow. Thoracic EDA combined with continuous infusion of NE seems to result in a further decrease in hepatic blood flow.

Transesophageal Echocardiographic Guidance of Thoracic Aortic Stent-Graft Implantation

Purpose: To evaluate the efficacy of intraoperative transesophageal echocardiography (TEE) as an adjunctive measure in guiding the implantation of endoluminal stent-grafts in the thoracic aorta. Methods: TEE was used in 21 of 30 patients (27 men; median age 70 years; range 19–77) undergoing implantation of Excluder or Talent stent-grafts for management of 11 type B aortic dissections, 7 thoracic aortic aneurysms, 2 traumatic thoracic aortic ruptures, and an aortic coarctation. We evaluated the ability of TEE to provide evidence of (1) correct placement of the guidewire within the true lumen, (2) reduction in blood flow in the false lumen following stent deployment, and (3) early complications. Results: Definite identification of the true lumen and a reliable evaluation of the position of the stent-graft guidewire during advancement were possible in all patients. Reduction of blood flow within the false lumen following deployment of the stent-graft was visualized in >70% of patients with aortic dissection. In the patient with aortic coarctation, TEE recognized the acute onset of aortic dissection following stent dilation, which resulted in immediate management with an additional stent. Conclusions: The intraoperative use of TEE in the implantation of stent-grafts in the thoracic aorta is not significantly invasive and is easily employed. It permits excellent evaluation of the correct placement of the stent guidewire and, in patients with aortic dissection, intraoperatively visualizes effective blood flow reduction in the false lumen following stent-graft deployment. Its ability to recognize early complications may indicate the need for additional maneuvers during the surgical procedure.

perioperative Risk of Bradyarrhythmias in Patients with Asymptomatic Chronic Bifascicular Block or Left Bundle Branch Block : does an Additional First-degree Atrioventricular Block Make Any Difference?

Background The incidence of perioperative bradyarrhythmias in patients with bifascicular or left bundle branch block (LBBB) and the influence of an additional first‐degree atrioventricular (A‐V) block has not been evaluated with 24‐h Holter electrocardiographic monitoring. Therefore the authors assessed the rate of block progression and bradyarrhythmia in these patients. Methods Patients (n = 106) with asymptomatic bifascicular block or LBBB with or without an additional first‐degree A‐V block scheduled for surgery under general or regional anesthesia were enrolled prospectively. Three patients were excluded. Of the 103 remaining, 56 had a normal P‐R interval and 47 had a prolonged one. Holter monitoring (CM2, CM5) was applied to each patient just before induction of anesthesia and was performed for 24 h. The primary endpoint of the study was the occurrence of block progression. As secondary endpoints, bradycardias < 40 beats/min with hemodynamic compromise (systolic blood pressure < 90 mmHg) or asystoles > 5 s were defined. Results Block progression to second‐degree A‐V block and consecutive cardiac arrest occurred in one case of LBBB without a prolonged P‐R interval. Severe bradyarrhythmias with hypotension developed in another eight patients: asystoles > 5 s occurred in two cases and six patients had bradycardias < 40/min. Pharmacotherapy was successful in these eight patients. There was no significant difference for severe bradyarrhythmias associated with hemodynamic compromise between patients with and without P‐R prolongation (P = 1.00). Conclusions In patients with chronic bifascicular block or LBBB, perioperative progression to complete heart block is rare. However, the rate of bradyarrhythmias with hemodynamic compromise proved to be relevant. Because an additional first‐degree A‐V block did not increase the incidence of severe bradyarrhythmias and pharmacotherapy by itself was successful in nearly all cases, routine prophylactic insertion of a temporary pacemaker in such patients should be questioned.

Perioperative transcutaneous pacemaker in patients with chronic bifascicular block or left bundle branch block and additional first-degree atrioventricular block

Background: Complete heart block is dreaded perioperatively in patients with chronic bifascicular or left bundle branch block (LBBB) and additional first‐degree A‐V block. Our aim was to investigate the necessity as well as the efficacy and safety of transcutaneous pacing in the perioperative setting.

The effect of i. v. enalaprilat in chronically treated hypertensive patients during cardiac surgery

Background: Angiotensin‐converting enzyme (ACE) inhibitors are well established as long‐term antihypertensives and have also been proved useful in hypertensive emergencies. Therefore, we investigated whether intraoperative i. v. enalaprilat may reduce the incidence of perioperative hypertensive reactions in coronary artery bypass grafting (CABG).

Cardiac function in patients with treated hypertension during aortic aneurysm repair

OBJECTIVES To investigate the impact of arterial hypertension on cardiac function during aortic cross-clamping and declamping. DESIGN Prospective study. SETTING University hospital. PARTICIPANTS Twenty treated hypertensive males with slight left ventricular hypertrophy and 10 normotensive controls undergoing elective repair of an abdominal aortic aneurysm. INTERVENTIONS Using transesophageal echocardiography, the mitral inflow profile was evaluated during aortic cross-clamping and declamping. MEASUREMENTS AND MAIN RESULTS During the clamping period, the ratio of peak atrial to peak early filling velocity (PA/PE) was significantly higher in the hypertensive patients. One minute after aortic cross-clamping, mean arterial pressure (MAP) and pulmonary artery occlusion pressure significantly increased in the hypertensive patients, whereas they did not change in the normotensive group. Cardiac index and heart rate significantly decreased after cross-clamping, and increased after clamp release in both groups. PA/PE significantly dropped in both groups after aortic declamping, and returned to baseline values thereafter. MAP also decreased significantly in both groups after clamp release, but the fall of MAP tended to be more pronounced in the hypertensive patients. CONCLUSIONS In the treated hypertensive patients, more pronounced hemodynamic and echocardiographic responses to aortic cross-clamping probably mirror the altered diastolic left ventricular function in these patients. With respect to intraoperative management, however, the treated hypertensive patients did not react grossly differently from the normotensive controls.

Therapie bradykarder und tachykarder Herzrhythmusstörungen in der Notfallmedizin

ZusammenfassungDie Diagnose und adäquate Therapie von Herzrhythmusstörrungen in der Notfallmedizin sind von grundlegender Bedeutung. Herzrhythmusstörungen und insbesondere ventrikuläre Tachykardien gelten als wichtigste Ursache für den plötzlichen Herztod. Herzrhythmusstörungen sind präklinisch nur dann zwingend behandlungsbedürftig, wenn sie zur klinischen Instabilität führen oder ein hohes Potenzial der Progredienz in eine lebensbedrohliche Rhythmusstörung haben. So sind bradykarde Rhythmusstörungen selten interventionsbedürftig. Während supraventrikuläre Tachykardien von Herzgesunden zumeist gut toleriert werden, können sie beim kardial Vorerkrankten häufig eine kritische Instabilität verursachen, welche bereits eine präklinische Therapie erfordert. Ventrikuläre Tachykardien benötigen zwingend das notärztliche Eingreifen. Sie entstehen meist auf dem Boden gravierender kardialer Vorerkrankungen und sind häufig mit kritischen Perfusionszuständen assoziiert. Damit steigt das Risiko für den Übergang in Kammerflimmern weiter. Die Indikation für einen medikamentösen Therapieversuch oder eine frühzeitige elektrische Therapie sollte bei allen Rhythmusstörungen immer in Abhängigkeit von der Kreislaufstabilität und dem klinischen Gesamtzustand des Patienten gestellt werden.AbstractDiagnosis and adequate therapy of cardiac arrhythmias are of essential significance in emergency medicine. Cardiac arrhythmias and especially ventricular tachycardia are considered to be key triggers for sudden cardiac death. Preclinical therapy for cardiac arrhythmias is only mandatory in the presence of clinical instability or a high potential for progression to life-threatening arrhythmias. Therefore bradycardia rarely needs intervention outside the clinic. While supraventricular tachycardia is usually well tolerated by the healthy patient, it commonly causes vital instability in patients with a cardiac history needing preclinical therapy. In general, ventricular tachycardia needs preclinical intervention. Usually it is caused by preexisting severe cardiac disease and is associated with critically imbalanced perfusion. Therefore it bears a high risk of progression to ventricular fibrillation. The decision to initiate drug therapy versus early cardioversion/defibrillation should depend on the cardiovascular stability and clinical condition of the patient.