Immediate and delayed neuroendocrine responses to social exclusion in males and females

Social exclusion is a complex phenomenon, with wide-ranging immediate and delayed effects on well-being, hormone levels, brain activation and motivational behavior. Building upon previous work, the current fMRI study investigated affective, endocrine and neural responses to social exclusion in a more naturalistic Cyberball task in 40 males and 40 females. As expected, social exclusion elicited well-documented affective and neural responses, i.e., increased anger and distress, as well as increased exclusion-related activation of the anterior insula, the posterior-medial frontal cortex and the orbitofrontal cortex. Cortisol and testosterone decreased over the course of the experiment, whereas progesterone showed no changes. Hormone levels were not correlated with subjective affect, but they were related to exclusion-induced neural responses. Exclusion-related activation in frontal areas was associated with decreases in cortisol and increases in testosterone until recovery. Given that results were largely independent of sex, the current findings have important implications regarding between-sex vs. within-sex variations and the conceptualization of state vs. trait neuroendocrine functions in social neuroscience.

The impact of social exclusion vs. inclusion on subjective and hormonal reactions in females and males

BACKGROUND

The experience of social exclusion represents an extremely aversive and threatening situation in daily life. The present study examined the impact of social exclusion compared to inclusion on steroid hormone concentrations as well as on subjective affect ratings.

METHODS

Eighty subjects (40 females) participated in two independent behavioral experiments. They engaged in a computerized ball tossing game in which they ostensibly played with two other players who deliberately excluded or included them, respectively. Hormone samples as well as mood ratings were taken before and after the game.

RESULTS

Social exclusion led to a decrease in positive mood ratings and increased anger ratings. In contrast, social inclusion did not affect positive mood ratings, but decreased sadness ratings. Both conditions did not affect cortisol levels. Testosterone significantly decreased after being excluded in both genders, and increased after inclusion, but only in males. Interestingly, progesterone showed an increase after both conditions only in females.

DISCUSSION

Our results suggest that social exclusion does not trigger a classical stress response but gender-specific changes in sex hormone levels. The testosterone decrease after being excluded in both genders, as well as the increase after inclusion in males can be interpreted within the framework of the biosocial status hypothesis. The progesterone increase might reflect a generalized affiliative response during social interaction in females.

Bilateral Bispectral Index (BIS)-Vista as a measure of physiologic sleep in sleep-deprived anesthesiologists

BACKGROUND

Anesthesiologists who work extended hours exhibit acute and chronic sleep deprivation. The newest bilateral Bispectral Index (BIS)-Vista monitor offers new advantages over earlier models, which include a new algorithm (version 1.4). One possible useful application for BIS monitoring of physiological sleep would be in critically ill patients who almost uniformly suffer from sleep disruption and deprivation because they loose their circadian rhythm due to the harsh noisy environment of critical care units. Previous studies, which used earlier versions of the BIS monitor to depict normal physiologic sleep, produced widely conflicting results. The aim of our study was to assess whether the new BIS-Vista monitor would exhibit a temporal decline that corresponds to natural physiologic sleep stages in healthy sleep-deprived, post-call anesthesiologists.

METHODS

BIS-Vista sensors were bilaterally mounted, according to the manufacturer guidelines, onto the forehead of 10 healthy sleep-deprived volunteer anesthesiologists. Using the conventional Rechtschaffen and Kales criteria, BIS values during the awake, S1, S2, S3, S4, and rapid eye movement (REM) sleep stages were recorded.

RESULTS

Mean±SD BIS values during the awake, S1, S2, S3, S4, and REM sleep stages significantly declined for the left (96±2, 82±11, 73±10, 53±13, 43±11, 66±9) and right (97±2, 78±11, 69±9, 50±10, 39±13, 61±14) hemispheres respectively. There were no significant interhemispheric differences in BIS values over time (two-way ANOVA). However, in one subject, the left and right BIS values were mostly discordant throughout the recordings.

CONCLUSION

We demonstrated that although the BIS-Vista monitor was neither designed nor validated for monitoring normal physiologic sleep, it depicted a temporal decline that corresponds to normal physiologic sleep stages in sleep-deprived anesthesiologists.

Bispectral index (BIS) monitoring of acute encephalitis with refractory, repetitive partial seizures (AERRPS)

Diagnosis of ictal discharges during epileptic activity should be based on raw electroencephalography (EEG). The apparatus necessary for such a diagnosis would typically require time to properly set up and operate. The bispectral index (BIS), an EEG-derived parameter that is easy to establish and easy to use, has been shown to correlate with numerous EEG conditions and may represent a useful tool. Acute encephalitis with refractory, repetitive, partial seizures (AERRPS) is an epileptic syndrome first described by Sakuma in Japan in 2001. We assessed the utility of using BIS monitoring as a diagnostic tool and as a monitor of anticonvulsive therapy in a 14-year-old patient admitted to the intensive care unit with AERRPS. After BIS monitor montage, BIS, electromyography (EMG) and raw EEG data were continuously recorded. Epileptic seizures lasting 1-2 min were repeated every 3-4 min. Using paired t-test analysis, mean +/- SD BIS and EMG peak values at the start of epileptic seizures (94.5+/-3.6, 55.8+/-2.5 dB) were significantly higher than values measured at the end of seizures (55.1+/-12.5, 34.5+/-2.8 dB), respectively. Real-time EEG revealed bursts of epileptiform discharges replaced by slow d and q waves with ictal remissions. During induced pharmacologic barbiturate/diazepam coma, BIS decreased to near isoelectricity (11.9+/-2.5) with a steady increase in suppression ratio (65.5+/-9.7). The characteristic BIS profile of repetitive 1-2 min high EEG/EMG activity could serve as an indicator of a global increase in cerebral activity with seizures. Our report suggests that BIS, an easy-to-use device, might be helpful in monitoring clinical trends after EEG confirmation of diagnosis as well as in successfully depicting the efficacy of therapy.

Procalcitonin's role in the sepsis cascade. Is procalcitonin a sepsis marker or mediator?

PCT is a 116-amino acid polypeptide glycoprotein that is ubiquitously expressed from various extrathyroid neuroendocrine tissues during bacterial infection. PCT was shown to closely correlate with the severity of sepsis. PCT synthesis is probably induced by tumor necrosis factor-alpha (TNFalpha) or interleukin-6 (IL-6), the primary cytokines in the inflammatory cascade, as they always peak before PCT. In healthy and septic animals, PCT injection did not initiate or enhance the production of TNFalpha, while TNFalpha injection induced a 25-fold massive and sustained PCT increase. This indicates that PCT release is not a ''proximal'' but rather an ''intermediary'' event in the sepsis cascade that requires a ''primed'' inflammatory background to exert its effect. PCT, a prohormone that follows a cytokine-like expression pathway, was coined a ''hormokine'' to signify its cytokine-like host-response. In our center, over a period of 2 years, we investigated subsets of postoperative ICU patients with sepsis. The area under the Receiver Operating Characteristic curve for PCT's prediction of survival outcome demonstrated a very high discriminative power of 0.90 from day 6, with a cut-off value of 3.2 ng mL(-1) PCT concentration. Interestingly, in our study, PCT declined a few days before a lethal outcome. This ominous sign clearly demonstrates that patients with poor prognosis would manifest, at a certain stage, a decrease in their ability to mount an effective response to sepsis.

Influence of acute normovolaemic haemodilution on bispectral index monitoring and propofol dose requirements

BACKGROUND

Numerous medical and physiological conditions that might alter electroencephalography (EEG), such as hypoglycaemia, hypothermia or hypovolaemia, were shown to result in the bispectral Index (BIS) indicating an incorrect hypnotic state. Recently, acute normovolaemic haemodilution (ANH) was shown to be associated with significant impairment of cognitive functions that could alter EEG and consequently BIS monitoring, an EEG derived parameter.

METHODS

In a randomised clinical study, we assessed the effect of ANH on BIS monitoring before induction and after propofol target controlled infusion (TCI) anaesthesia in 45 unmedicated patients randomly allocated to ANH with oxygen insufflation (oxygen group), ANH with air insufflation (air group), or control group.

RESULTS

With ANH, mean BIS values briefly declined in the oxygen group (82+/-4) and air group (84+/-3) before returning to baseline values. The loss of consciousness time was significantly shorter, with fewer propofol TCI dose requirements, and BIS was significantly higher in the oxygen group (1.3+/-0.5 min, 2.41+/-0.15 microg/ml, 73+/-7) and air group (1.2+/-0.6 min, 2.44+/-0.17 microg/ml, 75+/-5), compared with the control group (1.7+/-0.4 min, 2.75+/-0.17 microg/ml, 61+/-5), respectively. Whereas, there was no significant difference in BIS values between the oxygen group (38+/-7), air group (36+/-5) and control group (40+/-6) at propofol TCI 4 microg/ml anaesthesia maintenance.

CONCLUSIONS

BIS values briefly declined with ANH before returning to baseline values before anaesthesia induction. Despite transient ANH enhancement of propofol effect during induction, there was no significant difference in BIS values with or without ANH during propofol maintenance of anaesthesia.

[Adverse events and adverse event reporting systems]

Knowledge about the incidence of errors in anaesthesia and intensive care is only rudimentary but it appears justified to assume that errors occur much more often than we all expect. One reason is most likely the complexity of our work. Errors may alter our patients' health and healing process, imply financial and legal personal and institutional threats and may reduce health workers' performances. The article summarizes several methods to identify errors within a health care system and strengthens the importance of error analysis to reduce its incidence. Results of an analysis should be published if they are of general interest.

Sensitivity and specificity of bispectral index for classification of overt hepatic encephalopathy: a multicentre, observer blinded, validation study

BACKGROUND

The severity of hepatic encephalopathy is currently graded clinically using West Haven criteria and psychometric tests.

OBJECTIVE

To assess the discriminative power of the bispectral index (BIS) monitor to classify the degree and progression of hepatic encephalopathy.

DESIGN

A consecutive, multicentre, observer blinded validation study.

SETTING

Medical University of Graz (Graz, Austria), Zhejiang University First Affiliated Hospital (Hang Zhou, China), and Cairo University (Cairo, Egypt).

PATIENTS

28 consecutive patients with hepatic encephalopathy were first enrolled at Medical University of Graz as a test set. The estimated BIS cut off values were subsequently tested in a validation set of 31 patients at Zhejiang University First Affiliated Hospital and 26 patients at Cairo University; 18 patients were reassessed later in a longitudinal study. Fifteen of 85 patients (18%) were excluded from the final analysis (11 became too agitated with high electromyographic activity; four fell asleep during the recording).

RESULTS

Applying the Austrian BIS cut off values of 85, 70, and 55 for discriminating West Haven grades 1 to 4 yielded agreement between BIS classification and West Haven grades in 40 of the 46 validation patients (87%), and in 16 of the 18 follow up patients (89%). Mean (SD) BIS values differed significantly between patients with West Haven grade 1 (90.2 (2.5)), grade 2 (78.4 (6.6)), grade 3 (63.2 (4.8)), and grade 4 (45.4 (5.0)).

CONCLUSIONS

BIS is a useful measure for grading and monitoring the degree of involvement of the central nervous system in patients with chronic liver disease.

Koronare Stents, duale Antiplättchentherapie und die perioperative Problematik

Up to 90% of all percutaneous coronary interventions include coronary artery stenting. Dual antiplatelet therapy, usually involving acetylsalicyl acid combined with clopidogrel, is mandatory for patients with coronary artery stents. The duration of antiplatelet therapy for bare metal stents is 3-4 weeks, for drug eluting stents 6-12 months. Preoperative discontinuation of both drugs increases the risk of stent thrombosis, continuation the risk of relevant bleeding. According to the recommendations of anaesthesiological and cardiological societies, perioperative management has to balance the risk of bleeding vs stent thrombosis. Surgery involving a high risk of bleeding can require the discontinuance of both substances. In cases of high thrombosis risk, at least the acetylsalicyl acid should be continued until the day of surgery. For patients under antiplatelet therapy scheduled for local anaesthesia, national recommendations exist. A close collaboration between the anaesthesiologist, cardiologist and surgeon is essential for appropriate pre-, intra- and postoperative management.

Influence of acute normovolaemic haemodilution on the dose-response relationship and time course of action of cisatracurium besylate

BACKGROUND

Acute normovolaemic haemodilution (ANH) is an efficacious blood conservation strategy aiming at avoiding allogeneic blood transfusion. ANH was shown to increase the potency of vecuronium, atracurium, and rocuronium. The aim of our study was to investigate whether cisatracurium potency is altered with ANH.

METHODS

Using the Relaxometer mechanomyograph, we compared cisatracurium dose-response relationship and time course of action in 60 patients randomly allocated to the ANH or control groups. Patients in each group were randomly allocated to receive one of three cisatracurium doses (30, 40, 50 microg kg(-1)) followed by a second supplemental dose to reach a total of 100 microg kg(-1).

RESULTS

ANH did not result in a significant shift in cisatracurium log dose-probit dose-response curve. There was no significant difference in mean (95% confidence intervals) ED(50), ED(90), and ED(95) (effective doses required for 50, 90, and 95% first twitch depression) between the ANH group [29.5 (27-32), 50.4 (47.4-53.4), 58.7 (55.3-62) microg kg(-1)] and the control group [28.2 (25.3-31), 47.6 (44.9-50.3), 55.3 (52.5-58.1) microg kg(-1)], whereas there was no difference in mean (SD) Dur(25) and Dur(0.8) (time until 25% first twitch and 0.8 train-of-four ratio recoveries) between the ANH group [40.8 (5.9), 64.7 (8.4) min] and the control group [42.2 (7.6), 66.5 (10.7) min].

CONCLUSIONS

Our results demonstrated that unlike other previously reported neuromuscular blocking drugs, ANH did not alter cisatracurium potency. Thus, cisatracurium would be the neuromuscular blocking drug of choice in patients who undergo surgery with ANH, as no dose adjustments are required.

Influence of acute normovolaemic haemodilution on the dose-response relationship, time-course of action and pharmacokinetics of rocuronium bromide

BACKGROUND

Acute normovolaemic haemodilution (ANH) is an effective strategy for avoiding or reducing allogeneic blood transfusion. We aimed to study its effect on the pharmacological profile of rocuronium.

METHODS

In two study centres, 28 patients undergoing major surgery with ANH were matched with 28 control patients. In the dose-response groups, using the mechanomyograph, neuromuscular block of six consecutive incremental doses of rocuronium 50 microg kg(-1), followed by 300 microg kg(-1), was evaluated. In the pharmacokinetics groups, serial arterial blood samples were withdrawn for rocuronium assay after a single dose of rocuronium 600 microg kg(-1).

RESULTS

ANH resulted in a shift to the left of rocuronium dose-response curve. Rocuronium effective dose(95) (ED(95)) was 26% lower (P<0.05) in the ANH group [283.4 (92.0) microg kg(-1)] compared with the control group [383.5 (127.3) microg kg(-1)]. Times from administration of last incremental dose until 25% of first response of train-of-four (TOF) recovery (Dur(25)) and 0.8 TOF ratio recovery (Dur(0.8)) were 28% longer in the ANH group [39.9 (8.4), 66.7 (14.2) min] compared with the control group [31.1 (6.6), 52.1 (15.8) min] (P<0.01, P<0.05), respectively. Volume of distribution was higher (P<0.01), central clearance was lower (P<0.05) and terminal elimination half-life was longer (P<0.0001) in the ANH group [234.97 (47.11) ml kg(-1), 4.70 (0.94) ml kg(-1) min(-1), 77.29 (12.25) min] compared with the control group [181.22 (35.73) ml kg(-1), 5.71 (1.29) ml kg(-1) min(-1), 56.86 (10.05) min, respectively].

CONCLUSION

ANH resulted in prolongation of rocuronium time-course of action, thus careful monitoring of neuromuscular block is recommended in patients who undergo ANH.

Procalcitonin for early prediction of survival outcome in postoperative critically ill patients with severe sepsis

BACKGROUND

Identification of postoperative patients at high risk of dying early after intensive care unit (ICU) admission through a fast and readily available parameter may help in determining therapeutic interventions or further diagnostic procedures that could have an impact on patients' outcome. The aim of our study was to assess the utility of procalcitonin (PCT) and other readily available parameters, as useful early (days 1-3) predictors of mortality in postoperative patients diagnosed with severe sepsis within 24 h preceding their operation.

METHODS

More than a period of 2 yr, subsets of 69 postoperative patients admitted with severe sepsis and 890 non-septic ICU patients were investigated. PCT, C-reactive protein (CRP) and sequential organ failure assessment (SOFA) score were recorded over the duration of ICU stay.

RESULTS

PCT area under receiver operating characteristic (ROC) curve was 0.78 on day 3 and was highly predictive of fatal outcome (0.90) at day 6. Area under ROC curve of SOFA score was 0.85 on day 3 and remained in this range until day 6. Area under ROC curves on day 3 of CRP (0.61) was non-predictive and remained non-predictive over the duration of ICU stay.

CONCLUSIONS

PCT exhibited no discriminative power early after ICU admission for prediction of mortality in critically ill patients with severe sepsis, compared with a high predictive power of SOFA score on day 3. However, using PCT could still serve as a useful complementary comparator for prediction of survival outcome using the SOFA score.

Beneficial outcome after prostaglandin-induced post-partum cardiac arrest using levosimendan and extracorporeal membrane oxygenation

BACKGROUND

Administration of high doses of prostaglandins is a frequently performed and effective method for the treatment of atonic uterine haemorrhage in order to increase uterine muscle tone. Rarely, however, these drugs may cause life-threatening complications including bronchospasm, acute pulmonary oedema and myocardial infarction caused by coronary spasms.

METHODS

We discuss the management of a patient suffering post-partum atonic uterine bleeding, catecholamine-resistant cardiac arrest and fulminant pulmonary failure due to deleterious side-effects of treatment with prostaglandins.

RESULTS

During therapy resistant cardiopulmonary resuscitation, the addition of levosimendan to standard medications resulted in a prompt stabilization of haemodynamics. Subsequent treatment of pulmonary failure was successfully managed with ECMO.

CONCLUSION

Although levosimendan is not approved for pharmacological treatment of cardiopulmonary arrest, the beneficial effects in this patient suggest an important role of calcium sensitization and vasodilation during prostaglandin-induced cardiac arrest.

Coronary artery stenting and non-cardiac surgery--a prospective outcome study

BACKGROUND

A 45% complication rate and a mortality of 20% were reported previously in patients undergoing non-cardiac surgery after coronary artery stenting. Discontinuation of antiplatelet drugs appeared to be of major influence on outcome. Therefore we undertook a prospective, observational multicentre study with predefined heparin therapy and antiplatelet medication in patients undergoing non-cardiac procedures after coronary artery stenting.

METHODS

One hundred and three patients from three medical institutions were enrolled prospectively. Patients received coronary artery stents within 1 yr before non-cardiac surgery (urgent, semi-urgent or elective). Antiplatelet drug therapy was not, or only briefly, interrupted. Heparin was administered to all patients. All patients were on an intensive/intermediate care unit after surgery. Main outcome was the combined (cardiac, bleeding, surgical, sepsis) complication rate.

RESULTS

Of 103 patients, 44.7% (95% CI 34.9-54.8) suffered complications after surgery; 4.9% (95% CI 1.6-11.0) of the patients died. All but two (bleeding only) adverse events were of cardiac nature. The majority of complications occurred early after surgery. The risk of suffering an event was 2.11-fold greater in patients with recent stents (<35 days before surgery) as compared with percutaneous cardiac intervention more than 90 days before surgery.

CONCLUSIONS

Despite heparin and despite having all patients on intensive/intermediate care units, cardiac events are the major cause for new perioperative morbidity/mortality in patients undergoing non-cardiac surgery after coronary artery stenting. The complication rate exceeds the re-occlusion rate of stents in patients without surgery (usually <1% annually). Patients with coronary artery stenting less than 35 days before surgery are at the greatest risk.

Haemodynamic and catecholamine stress responses to the Laryngeal Tube-Suction Airway and the Proseal Laryngeal Mask Airway

Supraglottic airway devices such as the ProSeal Laryngeal Mask Airway (PLMA) and Laryngeal Tube-Suction Airway (LTS) that provoke the least stress responses could be beneficial in many situations, especially in patients with cardiovascular disease. We compared the haemodynamic and catecholamine stress response of the LTS and PLMA in a randomised study of 36 patients. Mean arterial pressure, heart rate, epinephrine and norepinephrine levels were all reduced following induction of anaesthesia with no significant differences between the two groups. Following insertion of LTS, mean arterial pressure, heart rate, epinephrine and norepinephrine levels increased to pre-induction levels. However, following the insertion of the PLMA, mean arterial pressure, heart rate, epinephrine and norepinephrine levels remained significantly lower than pre-induction values. Mean arterial pressure, heart rate and epinephrine were significantly greater in the LTS group than in the PLMA group. We conclude that the LTS produces a greater and more sustained haemodynamic and catecholamine stress response than does the PLMA.

Endotoxin pretreatment modifies peristalsis and attenuates the antipropulsive action of adrenoceptor agonists in the guinea-pig small intestine

The action of endotoxin to alter gastrointestinal motility in vivo may reflect a direct effect on the gut or result from vascular and other systemic manifestations of this sepsis model. Here we examined whether in vivo pretreatment of guinea-pigs with endotoxin modifies peristalsis in the isolated gut and influences the antipropulsive action of adrenoceptor agonists. Distension-induced peristalsis was recorded in fluid-perfused segments of the small intestine taken from animals pretreated intraperitoneally with endotoxin (1 mg kg(-1)Escherichia coli lipopolysaccharide) or vehicle 4 or 20 h before. Clonidine, adrenaline, noradrenaline, dopamine and dobutamine inhibited peristalsis with differential potency. Endotoxin pretreatment lowered the peristaltic pressure threshold and altered other parameters of baseline peristalsis in a time-related manner. The potency and efficacy of clonidine to inhibit peristalsis were markedly decreased after endotoxin administration, while the potency of the other test drugs was less attenuated. The antipropulsive action of clonidine in control segments was reduced by yohimbine and prazosin, whereas in segments from endotoxin-pretreated animals it was antagonized by yohimbine but not prazosin. We conclude that systemic endotoxin pretreatment of guinea-pigs modifies baseline peristalsis by an action on the gut and inhibits the antipropulsive action of adrenoceptor agonists through changes in adrenoceptor activity.

Different effects of abciximab and cytochalasin D on clot strength in thrombelastography

Maximum amplitude (MA) in thrombelastography (TEG) consists of a plasmatic and a platelet component. To assess the magnitude of the plasmatic component, pharmacological approaches have been proposed to eliminate the platelet component. We evaluated the individual and combined effects of abciximab and cytochalasin D on the MA of TEG. Whole blood, platelet-rich plasma (PRP) and homologous platelet-poor plasma (PPP) from 20 healthy volunteers were spiked with abciximab or cytochalasin D or a combination of both and TEGs performed. Abciximab and cytochalasin D decreased MA in all samples. MA of whole blood (18.6 +/- 3.1 mm) and PRP (33.7 +/- 3.5 mm) spiked with abciximab or cytochalasin D alone (15.0 +/- 2.9 mm and 25.0 +/- 4.0 mm) were significantly higher when compared with abciximab and cytochalasin D combined (10.4 +/- 3.0 and 20.2 +/- 3.5 mm). While MA of PRP and homologous PPP were significantly (P < 0.001) different after individual administration of abciximab and cytochalasin D, combination of both abolished this difference (20.2 +/- 3.5 mm and 20.4 +/- 3.7 mm, P = 0.372). In whole blood of critically ill patients or patients undergoing major surgery there was also a significant difference of MA between abciximab alone and in combination with cytochalasin D (16.5 +/- 11.3 mm and 11.3 +/- 7.7 mm, P < 0.001). This indicates that in contrast to individual administration of abciximab or cytochalasin D, a combination of both compounds eliminates the platelet-specific effect on MA of TEG tracings.

Lowering cardiac risk by preoperative interventions

Postoperative myocardial infarction still represents a serious complication in patients with coronary artery disease, after the first 48 hours following non cardiac surgery (NCS). To reduce the incidence, patient's status should be optimised, including CABG, PTCA and stenting, before the NCS. Indications for CABG, PTCA and stenting suggested by ACC/AHA are in general applicable also for NCS. Patients undergoing low and intermediate risk procedures would not benefit from extensive testing and CABG, while a potential benefit exists for high risk surgery in severe CAD patients. Revascularisation by means of PTCA seems to decrease the risk only if it is performed more than 90 days before the NCS. By the contrary, the combination of PTCA and stenting reduces incidence of coronary re-stenosis, but it increases bleeding, thrombosis and distal embolisation, especially if not supported by an anti-platelet or combined pharmacological schedule; therefore, perioperative stenting is not recommended to increase safety. Moreover, if NCS is urgent, despite a recent stenting, the patient should be included in a high risk group.

First clinical experience with the rapid-, short-acting amiodarone derivative E 047/1 after cardiac surgery

BACKGROUND AND OBJECTIVE

Amiodarone is very effective against a variety of dysrhythmias but has poor pharmacodynamic properties and many undesired side-effects. Its short- and rapid-acting derivative E 047/1 may circumvent some of these drawbacks. It is easier to titrate while retaining the high efficacy of amiodarone and may have acceptable influences on haemodynamics and cardiac conduction in patients who develop serious, destabilizing ventricular tachydysrhythmias after cardiac surgery.

METHODS

Testing E 047/1 was performed prospectively in two consecutive phase II open, clinical studies. Out of 504 patients scheduled for surgery using cardiopulmonary bypass for coronary artery grafting and/or valve repair, 35 developed serious, haemodynamically destabilizing ventricular dysrhythmias (Lown 2-Lown 4b) after surgery and were treated with a 1 mg kg(-1) (pilot study, n = 15) or randomized to a 2 or 3 mg kg(-1) bolus of E 047/1, followed by a 1 mg kg(-1) h(-1) continuous infusion for 2 h (n = 10 in each group). Dysrhythmias, PQ, QTc intervals and haemodynamics using the thermodilution technique were evaluated for up to 24 h after drug initiation.

RESULTS

At the time of final inclusion the patients had between 6 and 12 (or more) ventricular ectopics per minute. Within the first 2-3 min of application in the pilot trial E 047/1 induced a decrease of ventricular dysrhythmias to between 0 and 4 per min, a decrease that held for the duration of treatment. The area under the curve decreased from 434 (322, 855; median, quartiles) to 114 (9, 477, P < 0.01) events per hour. In the randomized trial, E 047/1 administered in either dose rapidly reduced ventricular dysrhythmias at least as effectively as in the pilot trial 565 (478, 701) to 33 (8, 238, P < 0.05) after a 2 mg bolus; 482 (339, 482) to 95 (13, 540, P < 0.01) events per hour after a 3 mg bolus. Approximately 4-6 h after drug termination, dysrhythmias reappeared in the majority of patients. In only three patients did the incidence of dysrhythmias return to inclusion criteria levels. In contrast to the pilot trial, in the randomized trial there was a slight increase of mean pulmonary artery pressure, central venous pressure and pulmonary arterial wedge pressure and a slight decrease of LCWI in both groups. E 047/1 did not cause QTc prolongation.

CONCLUSIONS

E 047/1 appears to be a safe alternative to amiodarone in the perioperative setting of cardiac surgery when serious, destabilizing dysrhythmias occur.

Sufentanil potentiates the inhibitory effect of epinephrine on intestinal motility

OBJECTIVE

The aim of our study was to evaluate the effect of the combination of different catecholamines and sufentanil on peristalsis of the isolated guinea pig small bowel in vitro.

DESIGN

In vitro study on excised guinea pig small-bowel segments (8-10 segments per substance tested).

SETTING

Laboratory for experimental studies at the University.

SUBJECTS

Isolated guinea pig small-bowel segments.

INTERVENTIONS

Excised segments of guinea pig small bowel were mounted in a tissue bath (37 degrees C) in Tyrode's solution and bubbled with carbogen (95% O2/5% CO2). The lumina were perfused with Tyrode's solution at 0.5 ml/min. The test drugs (epinephrine, norepinephrine, dobutamine, sufentanil, and a combination of these catecholamines with sufentanil) were added to the tissue bath and peristalsis recorded via changes in the intraluminal pressure. One-way and two-way ANOVA were used for statistical analysis.

MEASUREMENTS AND RESULTS

All the tested substances, both individually and in combination, inhibited intestinal peristalsis in a dose-dependent manner. High doses resulted in a complete blockade of peristalsis. Preexposure of the segments to sufentanil at 0.1 nM barely influenced the effects of the catecholamines on peristalsis. However, sufentanil at 0.3 nM enhanced the antiperistaltic activity of epinephrine in a supraadditive manner, whereas the effect on norepinephrine and dobutamine was less pronounced.

CONCLUSIONS

Our experimental data suggest that the combination of epinephrine and sufentanil might be the worst choice for the intensive care setting. This is due to its pronounced inhibitory effect on peristalsis in vitro at moderate and higher concentrations.

[Coronary arterial stent implantation proceeding noncardiac surgical procedures. Is it safe; can we recommend it?]

Patients undergoing non-cardiac surgical procedures who carry coronary artery stents have to be classified as high risk patients. Perioperative myocardial infarction and severe bleeding are possible. Therefore, anaesthetic management directed by invasive monitoring, ECG ST analysis, transesophageal echocardiography and referral to an intensive care unit are absolutely justified. The urgency of the surgical procedure, perioperative risk and an antiplatelet regimen have to be discussed with the patient and the surgeon in advance. In the case of cardiac complications, rapid therapy by an interventional cardiologist must be available.

Coronary artery plaque burden and perioperative cardiac risk

BACKGROUND

Electron-beam computed tomography-derived coronary calcium score correlates with the morphologic severity of coronary artery disease, reflecting both global atherosclerotic plaque formation and coronary artery luminal narrowing. The current study examines the impact of coronary atherosclerotic plaque burden, measured by coronary calcium score, on the potential for perioperative myocardial cell injury, as assessed by cardiac troponin T elevations in patients undergoing elective vascular surgery. The authors further investigated whether perioperative myocardial cell injury in those patients adversely affects noninvasive measures of left ventricular systolic function, such as ejection fraction and wall motion score.

METHODS

Fifty-one consecutive patients scheduled for vascular surgery were enrolled in this prospective study. In addition to standard preoperative evaluation, including patient history and physical examination, electron-beam computed tomography scan, 12-lead electrocardiography, and transthoracic echocardiography were performed on the day before surgery. Subsequent evaluations on postoperative days 2 and 7 included transthoracic echocardiography and 12-lead electrocardiography. Cardiac troponin T determinations were performed on the day before surgery, immediately preoperatively, and on postoperative days 1, 2, 3, and 7.

RESULTS

The median coronary calcium score of the 51 patients was 997.0 (25th percentile, 202.5; 75th percentile, 1,949.5). Cardiac troponin T elevations exclusively occurred in patients with a coronary calcium score greater than 1,000. The six patients (12%) with perioperative cardiac troponin T elevations had a 2.5-fold higher coronary calcium score than those without cardiac troponin T elevation (P = 0.021). In these patients, the ejection fraction decreased from 61 +/- 10% to 52 +/- 13% (mean +/- SD) on postoperative day 2 and was 54 +/- 16% on postoperative day 7 (P = 0.022).

CONCLUSION

A high electron-beam computed tomography coronary calcium score, reflecting substantial coronary plaque burden, carries an increased risk for myocardial cell injury after vascular surgery. In these patients, myocardial damage may result in deterioration of global systolic left ventricular function.

Thromboelastography for monitoring prolonged hypercoagulability after major abdominal surgery

Despite clinical and laboratory evidence of perioperative hypercoagulability, there are no consistent data evaluating the extent, duration, and specific contribution of platelets and procoagulatory proteins by in vitro testing. We tested the hypothesis that the parallel use of standard and abciximab-cytochalasin D-modified thromboelastography (TEG) can assess 7 days' postoperative hypercoagulability and can estimate the independent contribution of procoagulatory proteins and platelets. Thromboelastograms were performed before surgery, at the end of surgery, 6 h after surgery, and on postoperative days 1, 2, 3, and 7; they were analyzed for the reaction time and the maximal amplitude (MA). We calculated the elastic shear modulus of standard MA (G(t)) and modified MA (G(c)), which reflect total clot strength and procoagulatory protein component, respectively. The difference was an estimate of the platelet component (G(p)). There was a 10% perioperative increase of standard MA, corresponding to a 50% increase of G(t) (P < 0.0001) and an 86%-90% contribution of the calculated G(p) to G(t). We conclude that serial standard and modified thromboelastography may reveal prolonged postoperative hypercoagulability and the independent contribution of platelets and procoagulatory proteins to clot strength.

IMPLICATIONS

Postoperative hypercoagulability, occurring for at least 1 wk after major abdominal surgery, may be demonstrated by standard and modified thromboelastography. This hypercoagulability is not reflected by standard coagulation monitoring and seems to be predominantly caused by increased platelet reactivity.

Low potential of dobutamine and dopexamine to block intestinal peristalsis as compared with other catecholamines

OBJECTIVE

Catecholamines are frequently used in critically ill patients to restore stable hemodynamics and to improve organ perfusion. One effect of short-term or long-term administration of catecholamines may be inhibition of propulsive motility in the intestine. We therefore analyzed the effect of dopexamine, dobutamine, and dopamine on ileal peristalsis and compared their action with that of epinephrine and norepinephrine, which have long been known to suppress intestinal peristalsis.

DESIGN

In vitro study on excised guinea pig ileum segments.

SETTING

Laboratory for experimental studies at the University.

SUBJECTS

Isolated guinea pig ileum.

INTERVENTIONS

Segments of ileum excised from guinea pigs were mounted in a tissue bath in Krebs-Henseleit solution and bubbled with 95% oxygen/5% CO2. Luminal perfusion with the same solution was performed at a rate of 0.35 mL/min. The bath temperature was kept at 36.5 degrees C. Peristalsis was recorded via changes in the intraluminal pressure. The drugs under investigation (dopamine, epinephrine, norepinephrine, dobutamine, and dopexamine) were added to the tissue bath.

MEASUREMENTS AND MAIN RESULTS

Low concentrations of each catecholamine, except epinephrine, caused a decrease in the pressure threshold, which reflects a stimulatory effect on peristalsis. Higher catecholamine concentrations caused a concentration-related increase in the threshold, cumulating in a complete block of peristalsis. The rank order of inhibitory potency was epinephrine > norepinephrine > dopamine > dobutamine approximately dopexamine. Dobutamine and dopexamine were about 500-fold less active than epinephrine in suppressing peristalsis.

CONCLUSIONS

This study shows that dobutamine and dopexamine have the least potential to block propulsive motility in the intestine, whereas epinephrine demonstrates the most adverse inhibitory effect. Because at low concentrations dobutamine and dopexamine even stimulate peristalsis, these drugs appear to be superior compared with other catecholamines with regard to their direct effects on intestinal motility.

Perioperative myocardial cell injury: the relationship between troponin T and cortisol

STUDY OBJECTIVE

To investigate whether there is an association between Troponin T (TnT), reflecting myocardial cell injury, and cortisol, reflecting the degree of surgical trauma and associated stress, in light of our recent evaluation of TnT as a marker of perioperative myocardial cell injury.

DESIGN

Prospective, cohort study.

PATIENTS

70 patients (67.4 +/- 8.7 yrs) with definite or at-risk coronary artery disease (CAD) undergoing elective noncardiac surgery (vascular n = 38, abdominal n = 21, orthopedic n = 8) with general (n = 63) or regional (n = 4) anesthesia with postoperative on-demand analgesia.

MEASUREMENTS AND MAIN RESULTS

Morning blood samples for TnT (upper limit of normal: <0.2 ng/mL), CK-MB (reference range </=12 U/L), and cortisol (normal morning range 7-25 mcg/dL) were taken on the day before surgery, on the morning of surgery before induction of anesthesia, and on the first 5 postoperative days. Data were compared by analysis of variance. Three patients were excluded from the study because of incomplete blood samples of TnT or cortisol. Preoperative mean cortisol levels (mcg/dL +/- SD) were within the normal range and equal in TnT positive (n = 13) and negative (n = 54) patients (16.1 +/- 4.5 vs. 15.6 +/- 5.8). On the 1st postoperative day, there was a substantial increase of cortisol in the TnT positive group (35.7 +/- 26.9). Cortisol remained high until the 5th postoperative day (24.7 +/- 9. 4). There was a significant difference in the cortisol concentration in TnT-positive compared to TnT-negative patients (p < 0.001), a significant difference in the perioperative cortisol concentration over time (p < 0.05), and a significant interaction (p < 0.001). But there was no consistent temporal relationship between the increase of TnT and the increase of cortisol.

CONCLUSIONS

The significant relationship between a highly sensitive and specific marker of myocardial cell injury and a marker of stress suggests that cardiac-risk patients undergoing stressful surgical procedures might benefit from close perioperative TnT monitoring with early recognition of myocardial cell injury.

Successful treatment of massive arterial air embolism during open heart surgery

We report a case of a 5-year-old girl who suffered a massive arterial air embolism during surgical closure of an atrial septal defect. The risk of permanent neurologic deficits or even fatal outcome is significant (mortality rate, 31%). We successfully treated a proven arterial air embolism with intraoperative (retrograde cerebral perfusion) combined with postoperative procedures (deep barbiturate anesthesia and hyperbaric oxygenation). At discharge the girl had fully recovered from the initial neurologic defects.

[Anesthesia monitoring: degree of compliance with guidelines in Austria]

PURPOSE

For the first time an evaluation of standard anesthetic monitoring was performed according to the guidelines of the Austrian Society for Anesthesiology, Resuscitation und Intensive Care Medicine (OGARI).

METHODS

A questionnaire was delivered to all medical institutions performing anesthesia in Austria. A descriptive statistical evaluation was performed on all returned and completed questionnaires.

RESULTS

Generally, there is a high standard in compulsory monitoring and in PACU (actual compliance > 99%/85.8%). Supplemental equipment is required for disconnection alarm and measurement of inspired oxygen concentration (actual compliance: 98.3%/98.9%). Furthermore, measurement for inspired concentration of volatile anesthetics and relaxometry (actual compliance 68.7%/47.3%) has yet to be completed. University departments and regional hospitals have comparable standards (82.2% vs. 79.6%).

CONCLUSIONS

For the first time an Austrian-wide evaluation of anesthetic monitoring investigated the compliance with the 1992 recommendations of the Austrian Society of Anesthesiology, Resuscitation and Intensive Care Medicine. The data demonstrate that these recommendations including the anesthetic monitoring equipment have already been implemented to a high degree.

Perioperative catecholamine changes in cardiac risk patients

BACKGROUND

It has previously been found that in cardiac risk patients undergoing non-cardiac surgery post-operative cardiac complications are correlated with high post-operative serum levels of troponin T (TNT) and troponin I (TNI). We investigated whether perioperative changes in the release of free (fCAs) and conjugated catecholamines (cCAs) correlate with the increased serum level of TN (TN upward arrow).

MATERIALS AND METHODS

Plasma levels of CAs were determined in 28 patients at risk for or with definite coronary artery disease. Blood sampling was performed in the morning on the day before surgery, on the day of surgery before induction of anaesthesia and until the fifth post-operative day for measurement of CAs by high-performance liquid chromatography.

RESULTS

The plasma concentrations of free and conjugated noradrenaline (fNA and cNA) as well as of free and conjugated adrenaline (fA and cA) were increased significantly in TN upward arrow patients post-operatively. The plasma levels of free as well as of conjugated NA and A in TN upward arrow patients were significantly higher than in TN0 patients over the whole post-operative period.

CONCLUSION

This study demonstrates that increased post-operative release of fNA and fA as well as of cNA and cA correlates with high post-operative serum levels of troponins in cardiac risk patients undergoing non-cardiac surgery.

The influence of different strategies on clinical outcome in patients undergoing total cavopulmonary connection

BACKGROUND

We report on results of a prospective clinical trial designed to demonstrate the influence of various strategies in "Total Cavopulmonary Connection" (TCPC) for palliative therapy of patients with "single ventricle" physiology.

METHODS

From 1989 to 1997, a total of 47 patients (mean age 4.8 +/- 3.6 years) underwent definitive TCPC at our unit. 31 patients (66%) underwent one-stage TCPC, in 16 patients (34%) we performed a two-stage modified Fontan operation; 21 patients had central fenestration (4 mm). Inhalative NO therapy in the immediate postoperative period was adopted in 1993.

RESULTS

Overall 5-year survival was 76.4%, after two-stage TCPC 87.5%, and 81.3% in patients undergoing fenestrated procedures. Two of three patients survived perioperative Fontan take-down. We lost 11 patients (nine early and two late deaths): three patients died primarily because of neurologic dysfunction and eight patients because of cardiac failures. Under perioperative NO therapy there was no early death. After a mean follow-up of 35.9 +/- 23.3 months, 76% of all patients were in NYHA I and 21 % in NYHA I-II. 89.7% had sinus rhythm. 42% of our patients suffered from temporary pleuropericardial effusions.

CONCLUSIONS

Definitive palliation with TCPC achieves acceptable clinical results. Two-stage repair, fenestration, and postoperative inhalative NO therapy - each have a positive influence on early and long-term survival.

[Amalgam--a question of belief? A review and assessment of the current literature]

Several hundred written sources have been researched regarding old and new findings. Forgotten and new facts are covered in four chapters. One of the authors is a retired industrial chemist, and the other a dental surgeon. In the first section the natural and synthetic sources of mercury are explained. In every scientific study the ubiquity of mercury for billions of years must be taken into consideration. The second chapter looks at the toxicology of mercury and its compounds. Well known catastrophies in Japan and Iraq are depicted. Individual intoxications are hardly mentioned in literature. The third chapter is devoted to the dental amalgam, a silver alloy with both physical-chemical properties, and corrosive and thermal behaviour. An attempt is made to define the mercury balance. The forth paragraph deals with the disposal and recycling of mercury. Many dental associations are currently discussing the possibility of recycling amalgam, which is rather a stable silver alloy than a volatile mercury compound. A controlled landfill disposal of dental amalgam will absorb a certain quantity of mercury during its life cycle, and is positive. Recycling is expensive, energy consuming and causes additional exposure. Unless silver and mercury become rare metals, recycling should not be considered. As yet no worldwide regulatory procedures exist.

DA1-receptor stimulation by fenoldopam in the treatment of postcardiac surgical hypertension

BACKGROUND

Besides adequate analgesia, sedation and ventilation, postcardiac surgical hypertension has to be treated frequently with vasoactive drugs to avoid possible complications. In this study the hemodynamic effects of the DA1-receptor agonist fenoldopam (F) are compared to those of the Ca-channel antagonist nifedipine (N).

METHODS

Postoperatively, 64 CABG-patients with a mean arterial pressure (MAP) of more than 105 mmHg over 10 min were investigated. Patients with compromised ventricular function, insufficient surgical repair, arrhythmia or an ECG unable to detect myocardial ischemia were excluded. The study drugs (initial dosage: F: 0.8; N: 0.3 micrograms.kg-1.min-1) were given continuously via a central venous catheter to reduce and to maintain the MAP between 80 and 95 mmHg. Hemodynamic parameters were determined using thermodilution technique.

RESULTS

A significant reduction of the MAP (F: from 121 +/- 11 to 83 +/- 4, N: from 119 +/- 8 to 82 +/- 9 mmHg) and of the calculated systemic vascular resistance (SVR) (F: 2110 +/- 500 to 970 +/- 200, N:1980 +/- 660 to 1020 +/- 300 dyn.s.cm-5) were noted in both groups, whereby in the F group the therapeutic goal could be achieved more quickly with the dosage regimen chosen. As a result, a marked increase of heart rate, cardiac index and stroke volume index could be observed, which was more pronounced due to the initially stronger decrease of SVR with F. There was also a stronger decrease of pulmonary vascular resistance in the F group, but the indices of right ventricular function did not differ between the groups.

CONCLUSION

Fenoldopam seems to be an efficient alternative to nifedipine, especially because of its more rapid onset of action.

Inhaled nitric oxide in infants and children after open heart surgery

OBJECTIVE

To assess the effects of inhaled nitric oxide (NO) on oxygenation and pulmonary circulation in infants and children with critical pulmonary perfusion and/or hypoxemia after open heart surgery.

STUDY

A prospective case series report.

SETTING

A multidisciplinary pediatric intensive care unit in a University hospital

PATIENTS

From June 1993 to March 1996 37 pediatric patients after open heart surgery were treated with inhaled NO. Their mean age was 2.9+/-0.6 years, their mean body weight 12.6+/-1.8 kg.

METHODS

Inhaled NO was applied using a microprocessor controlled delivery system which continuously measured NO and NO2 by the chemilumniscence method. Monitoring included ECG, continuous pulse oximetry (SaO2), arterial (AP), central venous (CVP) and left atrial (LAP) pressures and in 8 patients a pulmonary artery (PAP) pressure. Inhaled NO was started at an SaO2 <90% with a fraction of inspired oxygen concentration (FiO2) >0.7, at a mean pulmonary artery pressure (MPAP) >50% of the mean arterial pressure (MAP), and in patients after Fontan-procedure at a CVP-LAP pressure gradient >10 mmHg.

RESULTS

The mean dose of inhaled NO was 3.7+/-0.3 ppm and the mean duration was 112+/-14.7 hours. For the whole group SaO2 increased from 79.6+/-2.3 to 90.1+/-1.5% (p<0.01) within 20 minutes of NO-inhalation. Inhaled NO significantly decreased the MPAP from 47.8+/-4 to 27.5+/-2.3 mmHg (p<0.01) in 8 patients with postoperative pulmonary hypertension and significantly decreased the transpulmonary pressure (CVP-LAP) from 14.3+/-0.8 to 7.3+/-0.9 mmHg (p<0.01) in 16 patients after Glenn- or Fontan-procedure.

CONCLUSIONS

Inhaled NO is very effective to decrease pulmonary artery pressure, to improve oxygenation, and to improve Fontan-circulation in infants and children after open heart surgery.