Jan Svennevig

Association between intraoperative cerebral microembolic signals and postoperative neuropsychological deficit: comparison between patients with cardiac valve replacement and patients with coronary artery bypass grafting

OBJECTIVES To examine the association between intraoperative cerebral microembolic signals (MES) and postoperative neuropsychological deficit in patients with valve replacement (VR) and patients with coronary artery bypass grafting (CABG). METHODS Neuropsychological examination (10 tests) was performed 1–2 days before and 2 months after surgery (VR (n=26) and CABG (n=14)). The intraoperative number of cerebral MES were monitored from the right middle cerebral artery using transcranial Doppler. RESULTS A higher number of cerebral MES were detected in VR patients with neurological deficit (6/26) compared with those without deficit (20/26) (MES median number 2083 v645, p=0.04). No such difference was found in patients with CABG (2/14v 12/14) (MES median number 50 v 112, p=0.2). CONCLUSION A high number of MES were detected in patients with VR with neuropsychological deficit. In patients with CABG with such a deficit, a low number of MES were detected. This difference in number may be explained by relatively more gaseous emboli in the first and more solid in the second. However, the results in the patients with CABG should be interpreted with caution due to the few patients in this subgroup.

Mediastinitis After Coronary Artery Bypass Grafting Risk Factors and Long-Term Survival

BACKGROUND Mediastinitis is a severe complication of coronary artery bypass grafting. The aim of the present study was to determine incidence of mediastinitis, its risk factors, and its effect on early and long-term survival. METHODS The study has a dual design, a case-control, and a retrospective cohort, using a source population of 18,532 consecutive patients who underwent coronary artery bypass grafting from January 1989 to December 2000. The closing date was February 1, 2008. Median follow-up was 10.3 (range 8.1 to 18.9) years. Patients with mediastinitis were compared with a random control group without mediastinitis issued from the same source population in a ratio 1:4. The crude effect of mediastinitis was estimated using rate ratio and 95% confidence limits. Adjustment for multiconfounders was done with the Cox model. A logistic model was used to pinpoint risk factors of mediastinitis. Calibration and discrimination of a prognostic model was done. RESULTS One hundred seven patients (0.6%) developed mediastinitis. Diagnosis was made 12 (9 to 19) days postoperatively. Independent risk factors of mediastinitis using the logistic model were advanced age, male gender, left main stenosis, body mass index 30 kg/m(2) or greater, chronic obstructive pulmonary disease, diabetes, and increased amount of blood transfusion. There was no increased risk of early mortality (odds ratio = 0.58; 95% confidence interval 0.13 to 2.61) (p = 0.48) but there was increased risk of morbidity (intraaortic balloon pump, ventricular and supraventricular arrhythmia, stroke, inotrope, and myocardial infarction). Follow-up had a median observation time of 10.3 years. Survival for patients with mediastinitis was 49.5 +/- 5.0% versus 71.0 +/- 2.2% for controls (p < 0.01). Analysis of specific death causes documented that cardiac deaths were significantly more frequent in mediastinitis patients than in control patients. When controlling for the confounding effect of the other variables (age, cardiopulmonary bypass time, body mass index, chronic obstructive pulmonary disease), the hazard ratio associated with mediastinitis on long-term mortality was 1.59, 95% confidence limits (1.16 and 2.70) (p = 0.003). CONCLUSIONS The incidence of mediastinitis in 18,532 patients undergoing coronary artery bypass grafting surgery was low. The major preventable risk factor of mediastinitis was amount of blood transfusion. Mediastinitis had an excess risk of early morbidity and was associated with a significant reduced long-term survival. Most deaths were considered to be cardiac.

Meeting Talk An Introduction

This special issue of Journal of Business Communication focuses on an area of major interest at the workplace, namely meetings. In specific, the special issue investigates how meetings as complex social events can be understood as an interactional joint achievement of all involved participants. Hence, the special issue focuses on researching social relations, emotions, identity construction, decision making, and the social organization of meeting talk. It does so by both investigating meetings in public and private organizations and studying traditional face-to-face meetings and virtual team meetings. The special issue explores these topics by approaching them from empirical studies of meetings based on transcripts of authentic interaction. This microanalytical approach contributes to understanding the interactive and dynamic nature of workplace interaction. Thereby, the different articles in this special issue shed light on questions of efficiency, leadership, and group dynamics in meetings. The current introduction presents some of the main characteristics of meetings as described in previous research and the main approaches to meeting interaction used in this issue. After a short overview of traditions that have dealt with meetings (first section), the qualitative, microanalytical approach adopted in the special issue is presented in more detail (second section). In the third section, the main characteristics of meeting talk as described in previous studies within this tradition are presented in detail. The introduction ends by shortly presenting the six contributions to this special issue on “meeting talk.”

Cerebral Microembolic Signals During Cardiopulmonary Bypass Surgery Frequency, Time of Occurrence, and Association With Patient and Surgical Characteristics

BACKGROUND AND PURPOSE We sought to determine the number of cerebral microembolic signals (MES) and their time of occurrence during the two most frequent types of cardiopulmonary bypass (CPB) surgery: coronary artery bypass grafting (CABG) and cardiac valve replacement (VR). Furthermore, we sought to examine the association between MES, patient characteristics, and intraoperative parameters. METHODS Forty-two patients were studied, 15 of whom had CABG and 27 VR. Cerebral MES were detected with the use of transcranial Doppler monitoring of the right middle cerebral artery. RESULTS Cerebral MES were detected in all patients. The number was significantly higher during VR (median, 1048) than during CABG (median, 82) (P < .001). In VR patients, 85% of the MES were detected when the heart regained effective ejection. During CABG, the highest number was detected when the aorta was cross-clamped (18%) and on release of the side clamp (13%). The numbers of MES during the period when the aorta was cross-clamped and in association with surgical procedures were not significantly different in the two patient groups. The total number of MES was inversely correlated to nasopharyngeal temperature (P < .01). CONCLUSIONS A significantly higher number of cerebral MES were detected during VR than during CABG. The highest number occurred in VR patients when effective heart ejection was regained and in CABG patients when the aorta was cross-clamped and on release of the side clamp. The total number of MES increased at lower nasopharyngeal temperatures. Transcranial Doppler monitoring may alert the surgical team when emboli enter the cerebral circulation during CPB surgery, thus allowing preventive measures to be taken.

Incidence and Frequency of Cerebral Embolic Signals in Patients With a Similar Bileaflet Mechanical Heart Valve

BACKGROUND AND PURPOSE The aim of this study was to determine the incidence and frequency of cerebral embolic signals in a patient population with the same mechanical heart valve using transcranial Doppler examination. Furthermore, it aimed to identify patient and valve characteristics that correlated with the occurrence of these signals. METHODS Ninety-two patients with Carbomedics valves and 15 healthy control subjects took part in the study. Thirty-six patients were examined before and immediately after valve implantation (group 1), 34 patients 1 year after surgery (group 2), and 22 patients 5 years after surgery (group 3). Cerebral embolic signals were detected using transcranial Doppler monitoring of the right middle cerebral artery. RESULTS Asymptomatic cerebral embolic signals were detected in 87% of the total 92 patients, in 77.8% of group 1 patients, in 91.2% of group 2 patients, and in 95.5% of group 3 patients. No cerebral embolic signals were detected in group 1 patients before surgery or in control subjects. The incidence (P = .04) and frequency (P = .002) of cerebral embolic signals increased significantly with longer duration of valve implantation. A significant positive correlation was also found between frequency of cerebral embolic signals and valve size (r = .4326, P = .00001). Median frequency of embolic signals in patients with a history suggestive of cerebrovascular events (n = 14) was 60 signals per hour compared with 11 signals per hour in those with no such history (n = 42; P = .04). CONCLUSIONS The incidence and frequency of cerebral embolic signals increased with the duration of valve implantation. The frequency of these signals also was dependent on valve size. Patients who had experienced cerebrovascular symptoms had a higher frequency of cerebral embolic signals compared with those with no such signals. These results should be interpreted with caution but suggest that this method could be of help in assessing the risk of stroke in prosthetic heart valve patients and that prospective clinical studies should now be carried out.

Heparin-coated cardiopulmonary bypass equipment. II. Mechanisms for reduced complement activation in vivo

OBJECTIVE Our objective was to study mechanisms for reduced complement activation by heparin coating of cardiopulmonary bypass equipment in clinical heart surgery. METHODS Adults undergoing elective coronary artery bypass grafting were randomized to cardiopulmonary bypass with Duraflo II heparin-coated (n = 15) or uncoated (n = 14) sets (Duraflo coating surface; Baxter International, Inc, Deerfield, Ill). Blood samples were analyzed with the use of enzyme immunoassays for C1rs-C1 inhibitor complexes and the activation products Bb, C4bc, C3bc, C5a-desArg, and the terminal complement complex. Data were compared by repeated-measures analysis of variance. RESULTS C1 was activated during bypass, and increases in C1rs-C1 inhibitor complexes were larger with heparin coating (P =.03). C4bc increased after administration of protamine, without intergroup differences (P =.69). Bb (P =.22) and C5a-desArg (P =.13) tended to increase less with heparin coating. Formation of C3bc (P =.03) and the terminal complement complex (P <.01) was significantly reduced with heparin coating. C5a-desArg increased 2-fold during bypass, whereas the terminal complement complex increased 10- to 20-fold. Maximal terminal complement complex concentrations were significantly correlated to maximal Bb and C3bc (R = 0.6, P <.001), but not to C1rs-C1 inhibitor complexes or C4bc (R < 0.05, P >.8). CONCLUSIONS C1 activation during bypass was increased by heparin coating, but further classical pathway activation was held in check until administration of protamine. Heparin coating significantly inhibited C3bc and terminal complement complex formation. Terminal complement complex concentrations were related to alternative pathway activation and may be useful for evaluation of differences in bypass circuitry. Increases and intergroup differences in terminal complement complex concentrations were much larger than those in C5a-desArg.

Other-repetition as display of hearing, understanding and emotional stance

In this article, other-repetition after informing statements is investigated in a corpus of institutional encounters between native Norwegian clerks and non-native clients. Such repetition is used to display receipt of information. A plain repeat with falling intonation is described as a display of hearing, whereas a repeat plus a final response particle, ‘ja’ (yes), constitutes a claim of understanding. Repeats with high-tone response particles (rising intonation) in addition display emotional stance, such as surprise or interest, and these are primarily exploited for the purposes of topic organization. In the cross-linguistic context of the current encounters, the native speakers are shown to use receipts as embedded corrections of the non-native speaker’s utterances. The repeats also have certain formal features that are characteristic of the situation, such as less pronominalization and ellipsis, and this is explained as a procedure to ensure the joint construal of linguistic form.

Intraaortic balloon pumping for predominantly right ventricular failure after heart transplantation.

BACKGROUND Right ventricular failure from elevated pulmonary vascular resistance in the recipient is a main cause of early mortality after heart transplantation. When pharmacologic treatment is insufficient, mechanical circulatory assistance has been used to support the failing right ventricle. Considering right and left ventricular interdependence, we investigated whether intraaortic balloon counterpulsation (IABP) might also alleviate predominantly right ventricular dysfunction after heart transplantation. METHODS Among 278 cardiac recipients, 12 adult patients underwent mechanical circulatory support for cardiac allograft dysfunction. Five patients were treated with percutaneous IABP for early postoperative low cardiac output syndrome characterized by predominantly right ventricular failure. Clinical data and hemodynamic variables were recorded before and during IABP treatment. RESULTS Cardiac index (CI) and mean arterial pressure (MAP) increased (CI 1.7 +/- 0.1 to 2.5 +/- 0.2, MAP 53 +/- 12 to 71 +/- 7, p < 0.05) within 1 hour after IABP, whereas central venous pressure (CVP) and pulmonary artery wedge pressure (PAWP) decreased (CVP 21.6 +/- 1.7 to 13.8 +/- 3.1, p < .05; PAWP 14.8 +/- 4.9 to 12.4 +/- 3.7, nonsignificant). Within the next 12 hours, CI and mixed venous oxygen saturation increased (p < 0.05) and pulmonary artery pressure decreased (p < 0.05). All 5 patients were weaned successfully and 4 are long-term survivors with adequate cardiac performance at 1 year follow-up. CONCLUSIONS Intraaortic balloon pumping is a minimally invasive circulatory assist device with proved efficiency in low cardiac output syndromes. This report shows that low output syndrome caused by predominantly right ventricular allograft failure may be an additional indication for IABP.

Intraaortic Balloon Pump in Open Heart Operations: 10-Year Follow-up With Risk Analysis

BACKGROUND The intraaortic balloon pump (IABP) is the primary mechanical device used for perioperative cardiac failure. METHODS We analyzed the prognostic predictors and long-term survival of 344 patients undergoing cardiac operations who required the perioperative use of an IABP at our institution from January 1980 to December 1989. Hospital survivors (163 patients) were followed up for a mean of 7.45 years (range, 1 month to 15.3 years); cumulative follow-up included 1,167 patient-years. RESULTS The early mortality rate was 52.6% (181 patients). From parameters available at the time of IABP insertion, logistic regression analysis identified preoperative serum creatinine level, left ventricular ejection fraction, perioperative myocardial infarction, timing of IABP insertion, and indication for operation as independent predictors of early (30-day) death (p < 0.05). Cox regression analysis of hospital survivors identified timing of IABP insertion, perfusion time, and preoperative serum creatinine level as independent prognostic factors for late death (p < 0.05), whereas patient age was only marginally significant (p < 0.06). There was no association between IABP-related complications and death. Survival analysis demonstrated a 10-year actual survival rate of 22.04% +/- 0.023%, with 57 patients still at risk and significantly improved survival among those who received an IABP before operation (p < 0.02). CONCLUSIONS The early mortality rate in patients who received an IABP was high. Hospital survivors had a relatively good long-term prognosis. The significantly better short- and long-term survival of patients who received an IABP before operation may justify more liberal preoperative use of the IABP in high-risk patients.

Viral safety of solvent/detergent-treated plasma

BACKGROUND: Pooling of plasma donations increases the risk for blood‐borne infections. In solvent/detergent (SD)‐treated plasma, lipid‐enveloped viruses are efficiently inactivated. This method, however, does not affect non‐lipid‐enveloped viruses. The current study investigated the viral safety of SD‐treated plasma (Octaplas) and paid particular attention to the transmission of non‐lipid‐enveloped viruses.