R. E. Anderson

High Serum S100B Levels for Trauma Patients without Head Injuries

OBJECTIVE Studies of patients with head trauma have demonstrated a correlation between a serum marker of brain tissue damage, namely S100B, and neuroradiological findings. It was recently demonstrated that the increases in serum S100B levels after heart surgery have extracerebral origins, probably surgically traumatized fat, muscle, and bone marrow. The current study examined multitrauma patients without head trauma, to determine whether soft-tissue and bone damage might confound the interpretation of elevated serum S100B concentrations for patients after head trauma. METHODS A commercial assay was used to determine serum S100B concentrations for a normal population (n = 459) and multitrauma patients without head injury (n = 17). Concentrations of the two subtypes of S100B (S100A1B and S100BB) were determined using separate noncommercial assays. RESULTS The mean serum S100B concentration for a normal healthy population was 0.032 microg/L (median, 0.010 microg/L; standard deviation, 0.040 microg/L). The upper 97.5% and 95% reference limits were 0.13 and 0.10 microg/L, respectively. No major age or sex differences were observed. Among trauma patients, serum S100B levels were highest after bone fractures (range, 2-10 microg/L) and thoracic contusions without fractures (range, 0.5-4 microg/L). Burns (range, 0.8-5 microg/L) and minor bruises also produced increased S100B levels. S100A1B and S100BB were detected in all samples. CONCLUSION Trauma, even in the absence of head trauma, results in high serum concentrations of S100B. Interpretation of elevated S100B concentrations immediately after multitrauma may be difficult because of extracerebral contributions. S100B may have a negative predictive value to exclude brain tissue damage after trauma. Similarly, nonacute S100B measurements may be of greater prognostic value than acute measurements.

Increase in serum S100A1-B and S100BB during cardiac surgery arises from extracerebral sources

BACKGROUND Elevated levels of serum S100B after coronary artery bypass grafting may arise from extracerebral contamination. Serum S100B content was analyzed in several tissues, and the two dimers S100A1-B and S100BB were analyzed separately in blood. METHODS Serum, shed blood, marrow, fat, and muscle were studied in patients undergoing coronary artery bypass grafting with cardiopulmonary bypass using suction either to the cardiotomy reservoir (group 1, n = 10) or to a cell-saving device (group 2, n = 10), or operated on off-pump (group 3, n = 10). RESULTS Serum S100B was sixfold higher in group 1 than in groups 2 and 3, which were identical. The same ratio between S100A1-B and S100BB was found in all groups. When compared with serum, S100B was 10(2) to 10(4) times higher in marrow, fat, muscle tissue, and shed blood. CONCLUSIONS Separate analysis of S100A1-B and S100BB did not distinguish between S100B of cerebral and extracerebral origin. The concept that S100B only originates in astroglial and Schwann cells is wrong. Fat, muscle, and marrow in mediastinal blood contain high levels of S100B. Cardiopulmonary bypass caused no increase in S100B.

The effect of cardiotomy suction on the brain injury marker S100β after cardiopulmonary bypass

BACKGROUND An increase of S100beta in serum during cardiopulmonary bypass (CPB) has been interpreted as a sign of brain injury. Cardiotomy suction may cause fat embolization, and its role in the S100beta increase was examined. METHODS Twenty coronary artery operation patients were randomly assigned to two groups, 10 with suction during CPB to cardiotomy reservoir (CR), 10 to cell saving device (CS). S100beta was measured (immunoassay) in blood from the patients and from cell saving device after processing. In 7 additional patients S100beta was measured in the cell saving device before processing and directly from the wound at sternotomy. RESULTS Before anesthesia, serum S100beta was 0.03+/-0.06 microg/L. At the end of CPB it was 2.47+/-1.31 microg/L and 0.44+/-0.27 microg/L (CR vs CS; p < 0.001). S100beta was 33+/-12 microg/L in CS reservoir and 42+/-18 microg/L in blood from the wound. CONCLUSIONS Most serum S100beta after CPB with cardiotomy suction may be of extracerebral origin. S100beta after CPB with cell saving device was the same as after off-pump operation. The interpretation that an increase in S100beta during CPB in patients reflects cerebral injury must be questioned.

Effects on the bispectral index during medium‐high dose fentanyl induction with or without propofol supplement

Background: The search for a drug‐independent monitor to determine depth of anaesthesia and hypnosis continues. The bispectral analysis (BIS) of the EEG correlates well with the clinical dose–response of hypnotic drugs during induction, but the effect on BIS of an opiate induction, as for coronary bypass surgery, is not known.

Release of S100B during coronary artery bypass grafting is reduced by off-pump surgery.

BACKGROUND S100B, a plasma marker of brain injury, was compared after coronary artery bypass grafting with and without cardiopulmonary bypass (CPB). METHODS Fourteen patients with off-pump operations and 18 patients with CPB were compared. Seven patients in the off-pump group underwent a minithoracotomy and received only an arterial graft, whereas 7 patients underwent sternotomy and received both an arterial and one or two vein grafts. S100B was measured in arterial plasma using an immunoassay with enhanced sensitivity. RESULTS S100B before the operation was 0.03 microg/L. At wound closure, S100B in patients of the off-pump and CPB groups reached a maximum level of 0.22 +/- 0.07 and 2.4 +/- 1.5 microg/L, respectively (p < 0.001). No strokes occurred. Patients without CPB receiving arterial and vein grafts released slightly more S100B (p < 0.05) than patients with only arterial grafting. In patients undergoing CPB, S100B increased slightly before aortic cannulation (p < 0.001), to the same level as the maximum reached for the non-CPB group. CONCLUSIONS Coronary artery bypass grafting with CPB caused a 10-fold greater increase in S100B than off-pump grafting. S100B release after off-pump sternotomy with vein grafting was slightly greater than in arterial grafting through a minithoracotomy.

Increased extracellular brain water after coronary artery bypass grafting is avoided by off-pump surgery

OBJECTIVE To determine if coronary artery bypass graft (CABG) surgery without cardiopulmonary bypass (CPB) avoids the brain swelling known to occur after CPB, to quantify these brain water compartment changes, and to identify the water shifts as due to intracellular or extracellular water. DESIGN Prospective, controlled, and blinded. SETTING Cardiac surgical unit in a university teaching hospital. SUBJECTS Patients scheduled for CABG who were assigned to conventional (n = 10) or off-pump (n = 7) surgery according to their coronary anatomy. INTERVENTIONS Magnetic resonance imaging (MRI) examinations were performed 1 day before surgery and 1 hour and 1 week after CABG surgery. MAIN OUTCOME MEASURES Extracellular and intracellular water homeostasis was described quantitatively by calculating the averaged apparent diffusion coefficient of brain water using diffusion-weighted MRI. Blinded visual ordering of the images from the three examinations was performed according to brain size using conventional MRI. RESULTS The average diffusion coefficient of brain water increased 4.7%+/-1.5% immediately after CABG with CPB and normalized after 1 week but did not change after CABG without CPB. No focal ischemic changes were seen in either group, and no gross neurologic deficits were observed. Visual analysis showed consistent brain swelling after CPB and variable changes in those operated without CPB. CONCLUSION Changes consistent with increased extracellular brain water seen after CABG with CPB were not observed in patients undergoing CABG without CPB. The clinical significance of brain water changes and increased brain water content after surgery with CPB remains undefined.

Cerebral state index during anaesthetic induction: a comparative study with propofol or nitrous oxide.

Background:  Confidently predicting the depth of anaesthesia for the individual patient and independently of drug(s) type using EEG‐based monitors has proven difficult. This open, randomized, explorative study of day surgical patients evaluates the ability of the Cerebral State Monitor™ (Danmeter AB, Odense, Denmark) of anaesthetic depth to identify loss of response (LOR) using either propofol or N20 for induction.

Elevated glycosylated haemoglobin (HbA1c) is a risk marker in coronary artery bypass surgery

Objective. To evaluate if glycosylated haemoglobin 1 (HbA1c) was associated with increased risk of infection and mortality after coronary artery bypass grafting (CABG). Design. Prospective observational study. Preoperative HbA1c concentrations were correlated to outcome in patients followed for an average of 3.5 years after CABG. Results. HbA1c was ≥6% in 68% of 161 patients with diabetes mellitus (DM) and in 3% of 444 patients without DM. Superficial sternal wound infection was observed in 13.9% if HbA1c ≥6% versus in 5.5% if <6% (p=0.007). Mediastinitis occurred in 4.9% if HbA1c≥6% and in 2.1% if HbA1c<6% (p=0.20) (Hazard ratio (HR) 1.9, 95% CI 0.6-5.9). Follow-up mortality was 18.9% in patients with HbA1c≥6% compared to 4.1% if HbA1c<6% (p<0.001) with HR 5.4, (95% CI 3.0-10.0) after multivariable adjustment. The risk of death was similar regardless of DM diagnosis. Conclusions. HbA1c ≥6% was associated with an increased risk of postoperative superficial sternal wound infections and a trend for higher mediastinitis rate and significantly higher mortality three years after CABG.

Biochemical markers of cerebrospinal ischemia after repair of aneurysms of the descending and thoracoabdominal aorta.

OBJECTIVE To investigate the clinical potential of several markers of spinal cord ischemia in cerebrospinal fluid (CSF) and serum during aneurysm repair of the descending thoracic or thoracoabdominal aorta. DESIGN Observational study of consecutive patients. Nonblinded, nonrandomized. SETTING University hospital thoracic surgical unit. PARTICIPANTS Eleven consecutive elective patients. INTERVENTIONS Distal extracorporeal circulation and maintenance of CSF pressure <10 mmHg until intrathecal catheter removal. MEASUREMENTS AND MAIN RESULTS CSF and serum levels of S100B (and its isoforms S100A1B and S100BB), neuronal-specific enolase (NSE), and the CSF levels of glial fibrillary acidic protein (GFAp) and lactate were determined. Two patients had postoperative neurologic deficit. One with a stroke showed a 540-fold increased GFAp, a 6-fold NSE, and S100B increase in CSF. One with paraplegia had a 270-fold increase in GFAp, a 2-fold increase in NSE, and 5-fold increased S100B in CSF. One patient without deficit increased GFAp 10-fold, NSE 4-fold, and S100B 23-fold in CSF. CSF lactate increased >50% in 6 of 9 patients without neurologic deficit. Serum S100B increased within 1 hour of surgery in all patients without any concomitant increase in CSF. S100A1B was about 70% of total S100B in both serum and CSF in patients with or without neurologic defects. S100B in CSF increased 3-fold in 3 of 9 asymptomatic patients. CONCLUSIONS In patients with neurologic deficit, GFAp in CSF showed the most pronounced increase. Biochemical markers in CSF may increase without neurologic symptoms. There is a significant increase in serum S100B from surgical trauma alone without any increase in CSF.

Auditory evoked potential monitoring with the AAITM‐index during spinal surgery: decreased desflurane consumption

Background: The auditory evoked potential (AEP) is sensitive to the depth of anesthesia. The A‐line monitor is a novel device that processes the amplitude and latency of the AEP during the mid‐latency time window to provide a simple numerical index, the AAI™‐index. The hypothesis of the present study was that titration of anesthetic depth (desflurane) by means of the AAI™‐index could decrease the consumption of the main anesthetic and shorten emergence times.