[Introduction of Prehospital Emergency Ultrasound into an Emergency Medical Service Area]. / Einführung der präklinischen Notfallsonographie in einem ländlichen Notarztdienst-Bereich.

BACKGROUND: Emergency ultrasound as part of the provision of emergency medical services using mobile devices offers great benefits regarding to some important questions related to the management of critically ill and injured patients in the prehospital situation where diagnostic resources are limited. The aim of this study is to determine whether the comprehensive introduction of prehospital emergency ultrasound examinations into a German Emergency Medical Services ("rescue services") area is both feasible and beneficial for patients. METHODS: All emergency physicians at a rural emergency physician base were trained in emergency ultrasound scanning techniques (FAST, FEEL, 14 h of instruction), followed by regular weekly training sessions of approximately 30 min. Over a period of 12 months, prehospital ultrasound examinations performed during emergency physician callouts at this base were documented and analysed. RESULTS: A total of 87 emergency ultrasound examinations were performed during 1343 callouts. Among these, focussed assessment with sonography for trauma (FAST) was performed in 35 patients (40.2%) and focused echocardiography in emergency life support (FEEL) in 41 patients (47.1%). In 11 patients (12.6%), ultrasound scans were performed for other indications (e. g. to rule out urinary tract obstruction in a case of flank pain). One trauma patient's life was saved by the decision to transport him to the nearest hospital and once there directly to the operating room, based on the ultrasound finding of significant free intra-abdominal fluid (ruptured spleen and liver). CONCLUSION: Prehospital emergency ultrasound can be introduced into an emergency medical service area as a diagnostic modality that provides benefits to patients. Emergency physicians have to be specifically trained and to participate in continuous education activities. Especially in rural areas with longer transport routes and journey times, the early diagnosis of for example massive intra-abdominal bleeding is critical for the patient's prognosis.

Randomized evaluation of fibrinogen vs placebo in complex cardiovascular surgery (REPLACE): a double-blind phase III study of haemostatic therapy.

BACKGROUND: Single-dose human fibrinogen concentrate (FCH) might have haemostatic benefits in complex cardiovascular surgery. METHODS: Patients undergoing elective aortic surgery requiring cardiopulmonary bypass were randomly assigned to receive FCH or placebo. Study medication was administered to patients with a 5 min bleeding mass of 60-250 g after separation from bypass and surgical haemostasis. A standardized algorithm for allogeneic blood product transfusion was followed if bleeding continued after study medication. RESULTS: 519 patients from 34 centres were randomized, of whom 152 (29%) met inclusion criteria for study medication. Median (IQR) pretreatment 5 min bleeding mass was 107 (76-138) and 91 (71-112) g in the FCH and placebo groups, respectively (P=0.13). More allogeneic blood product units were administered during the first 24 h after FCH, 5.0 (2.0-11.0), when compared with placebo, 3.0 (0.0-7.0), P=0.026. Fewer patients avoided transfusion in the FCH group (15.4%) compared with placebo (28.4%), P=0.047. The FCH immediately increased plasma fibrinogen concentration and fibrin-based clot strength. Adverse event rates were comparable in each group. CONCLUSIONS: Human fibrinogen concentrate was associated with increased allogeneic blood product transfusion, an unexpected finding contrary to previous studies. Human fibrinogen concentrate may not be effective in this setting when administered according to 5-minute bleeding mass. Low bleeding rates and normal-range plasma fibrinogen concentrations before study medication, and variability in adherence to the complex transfusion algorithm, may have contributed to these results. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov identifier no. NCT01475669; EudraCT trial no. 2011-002685-20.

Recovery from prolonged deep rocuronium-induced neuromuscular blockade: A randomized comparison of sugammadex reversal with spontaneous recovery.

BACKGROUND: Deep neuromuscular blockade (NMB) may not always be maintained to the end of surgery and the depth of block may be allowed to gradually diminish over time, particularly if reversal of NMB is not routinely performed. AIM: The current study aimed to assess recovery from deep rocuronium-induced NMB with sugammadex compared with placebo, provide data regarding the extent of residual blockade after deep rocuronium-induced NMB (placebo group), and to determine whether complete and reliable recovery could be provided by sugammadex (sugammadex group). MATERIALS AND METHODS: This was a randomized, placebo-controlled, safety-assessor-blinded study in adult patients of American Society of Anesthesiologists Class I to III. Patients with clinically relevant kidney or liver insufficiency were excluded. Anesthesia was administered as routinely practiced at each study site. Rocuronium 0.6 mg/kg was administered for intubation, with maintenance doses of 0.1-0.2 mg/kg as needed. After the last rocuronium dose, at deep NMB (target depth 1-2 post-tetanic counts), patients received a single dose of sugammadex 4.0 mg/kg or placebo as randomized. The primary endpoint was time from sugammadex or placebo administration to recovery of the train-of-four (TOF) ratio to 0.9. Safety was assessed through monitoring of adverse events, vital signs and physical examination. Patients were also assessed for evidence of residual or recurrence of NMB. With this design, the study will provide data regarding the extent of residual blockade under these conditions (placebo group), and determine whether complete and reliable recovery could be provided by sugammadex (sugammadex group). RESULTS: Recovery to a TOF ratio of ≥ 0.9 with sugammadex was significantly faster (~ 40 times) than spontaneous recovery: geometric mean (95 % confidence interval) times were 2.2 (1.9-2.5) and 89.8 (80.1-100.7) min, respectively (p < 0.0001, N = 134); maximum spontaneous recovery was 289.8 min. Safety was comparable between groups, with no recurrence of blockade. CONCLUSIONS: This study confirms a prolonged residual blockade in patients who did not receive sugammadex, with median time to recovery > 1.5 h in the placebo group and one patient taking 4.8 h to achieve a safe level of neuromuscular function recovery following deep NMB. In contrast, sugammadex provided complete and reliable recovery of neuromuscular function (median time to recovery of 2.0 min). Thus, deep NMB with rocuronium until the end of the operation may be possible in combination with sugammadex reversal.

[Trauma-induced coagulopathy]. / Traumainduzierte Koagulopathie.

The main cause of death in the patient group less than 45 years is trauma. Beside severe traumatic brain injury, bleeding remains a leading cause of death in this group. For a causal therapy, it is necessary to understand the pathophysiology of trauma-induced coagulopathy (TIC). Beside the well-known lethal triad of trauma (hypothermia, acidosis, and coagulopathy), dilution and hypoperfusion with activation of the protein C pathway play a crucial role. TIC is a complex independent syndrome which may be present without initial hypercoagulopathy. A rapid and differentiated diagnosis and goal-directed therapy is crucial for causal therapy.

Time course of haemostatic effects of fibrinogen concentrate administration in aortic surgery.

BACKGROUND: There is currently a contrast between the demonstrated benefits of fibrinogen concentrate in correcting bleeding and reducing transfusion, and its perceived thrombogenic potential. This analysis evaluates the effects of fibrinogen concentrate on coagulation up to 12 days after administration during aortic surgery. METHODS: We performed a post hoc analysis of a prospective, randomized, double-blind, controlled trial of fibrinogen concentrate as first-line haemostatic therapy in aortic surgery. After cardiopulmonary bypass (CPB) and protamine administration, subjects with coagulopathic bleeding received fibrinogen concentrate or placebo. The placebo group received allogeneic blood products, including fresh-frozen plasma (FFP; n=32); the fibrinogen concentrate group received fibrinogen concentrate alone (FC; n=14), or fibrinogen concentrate followed by allogeneic blood products (FC+FFP; n=15). Plasma fibrinogen, fibrin-based clotting (ROTEM(®)-based FIBTEM assay), and peri- and postoperative haematological and coagulation parameters were compared. RESULTS: Plasma fibrinogen and FIBTEM maximum clot firmness (MCF) decreased ∼50% during CPB but were corrected by FC or FC+FFP. At last suture, the highest values for plasma fibrinogen (360 mg dl(-1)) and FIBTEM MCF (22 mm) were within normal ranges--below the acute phase increases observed after surgery. In patients receiving only FFP as a source of fibrinogen, these parameters recovered marginally by last suture (P<0.001 vs FC and FC+FFP). All groups displayed comparable haemostasis at 24 h post-surgery. Fibrinogen concentrate did not cause alterations of other haemostasis parameters. CONCLUSIONS: Fibrinogen concentrate provided specific, significant, short-lived increases in plasma fibrinogen and fibrin-based clot firmness after aortic surgery.

Propofol, remifentanil and mivacurium: fast track surgery with poor intubating conditions.

BACKGROUND: Mivacurium is widespread used because it is the non-depolarizing muscle relaxant with the shortest duration time. Therefore, it seems to be ideal for fast track or ambulatory surgery. However, especially in combination with propofol and remifentanil onset time remains unclear and incidence of poor intubating conditions seems to be higher than in other regimes of anesthesia. METHODS: We included 35 ear, nose and throat (ENT) patients in this study. Muscle relaxation was measured by acceleromyograhpy at the adductor pollicis muscle (a.p.m.) and intubating conditions were evaluated. Anesthesia was induced with 2.5 mg kg-1 propofol and 1 µg kg-1 remifentanil and intubation was performed three minutes after the administration of 0.2 mg kg-1 mivacurium. Open vocal cords conjoined with full relaxation of the a.p.m., easy mouth opening and prevention of coughing and bucking represented the primary endpoint in this study. RESULTS: Only 20% of patients (N.=7) had optimal intubating conditions and achieved the primary endpoint. In 21 patients (60%) a complete block of the a.p.m. could not be achieved and in six patients (17%) the vocal cords were closed. In seven patients (20%) we observed difficult mouth opening and in 11 patients (31%) coughing and bucking. In addition, we found a prolonged onset time of 228±95 seconds (mean±SD). CONCLUSION: In combination with propofol and remifentanil the muscle relaxant agent mivacurium led to uncertain muscle relaxation and to poor intubating conditions. Therefore the study was aborted after 35 patients. Probably mivacurium is not a useful muscle relaxant agent if fast and deep muscle relaxation is needed. The advantage of a short duration time is foiled by intubation complications due to insufficient muscle relaxation.

Acquired type 2A von Willebrand syndrome caused by aortic valve disease corrects during valve surgery.

BACKGROUND: Aortic valve (AV) defects can destroy high molecular weight multimers (HMWM) of von Willebrand factor (VWF), leading to acquired von Willebrand syndrome (aVWS) type IIA. This syndrome is considered a cause for increased perioperative bleeding in AV surgery. If diagnosed before operation, administration of VWF/FVIII concentrates is recommended. However, there is currently no evidence that the VWF HMWM defect persists during surgery long enough to require haemostatic therapy. We hypothesized that the preoperative VWF HMWM defect corrects already during cardiopulmonary bypass (CPB) before any haemostatic therapy. METHODS: This prospective observational study enrolled 17 patients undergoing AV surgery, either isolated or associated with mitral valve or aorta surgery, and also 10 patients undergoing coronary artery bypass surgery (CABG) for comparison. VWF HMWM, VWF antigen (VWF:Ag) concentration, and collagen-binding capacity (VWF:CB) were measured before operation, directly after weaning from CPB, and on the first postoperative day. RESULTS: In 12 of the 17 subjects undergoing AV surgery (71%), VWF HMWM were abnormally absent before operation. At the end of CPB, VWF HMWM were normal in 15 of AV subjects (88%), and was normal in 16 subjects on the first postoperative day. VWF:Ag and VWF:CB were within or above the normal range at all three times. Two out of 10 subjects undergoing CABG (20%) had preoperative deficits of VWF HMWM that normalized after operation. CONCLUSIONS: Preoperative VWF HMWM defects corrected at the end of CPB in the absence of haemostatic therapy in most patients undergoing AV surgery. Diffuse bleeding occurring after CPB is unlikely to be related to persisting type 2A von Willebrand syndrome; other causes of coagulopathy should be suspected. Administration of VWF/FVIII concentrates appears unnecessary in this setting.

Prospective observational study for perioperative volume replacement with 6% HES 130/0,42, 4% gelatin and 6% HES 200/0,5 in cardiac surgery.

BACKGROUND: the constantly growing amount of different kinds of colloid fluids necessitates comparative investigations with regards to the safety and effectivity in clinical use of these preparations. Hence we compared three colloid fluids in an observational study. The objective was the exploration of the influence of these three colloids on blood coagulation, hemodynamics and renal function of the cardiac surgical patient. METHODS: we included 90 patients undergoing an elective open-heart surgery with the use of the heart-lung machine and observed them consecutively. Group 1 [gelatin 4% (n = 30)], Group 2 [HES 200/0,5 (n = 30)] and Group 3 [HES 130/0,42 (n = 30)]. We measured the perioperative volume replacement, the administration of blood- and coagulation-products, the application of catecholamines, the renal function, blood gas and the platelet aggregation using multiplate electrode analyzer (Multiplate, Dynabyte medical, Munich, Germany). RESULTS: the gelatin-group needed significantly more norepinephrine than the HES 130/0.42 group. The responsible surgeon considered the blood coagulation in the HES 200/0.5 group most frequently as impaired. Furthermore we saw a significant decrease in platelet function in the HES 200/0.5 group when performing the multiplate-analysis (ADP-and COL-test). HES 130/0.4 as well as gelatin 4% showed no significant change in platelet function. The gelatin-group and the HES 200/0.5 needed significantly more aprotinine than the HES 130/0.4 group. We saw no significant difference with regards to administration of blood and coagulation products between the three groups. The urinary excretion during the intervention was significantly higher in the HES 200/0.5 group and in the gelatin group than in the HES 130/0.4 group. CONCLUSIONS: our results confirm the lower stabilizing effect of gelatin on circulation during fluid resuscitation. The blood coagulation was mostly impaired due to HES 200/0.5 confirmed by the multiplate®-analysis as well as by different clinical findings.

Impact of platelet count on results obtained from multiple electrode platelet aggregometry (Multiplate).

OBJECTIVES: Use of potent antiplatelet drugs requires evaluation of platelet function. While platelet function in elective cases is usually assessed in a central laboratory environment, there is also an urgent need for rapid perioperative point-of-care assessment. Recently, multiple electrode platelet aggregometry has been developed and assumed to measure platelet function independent from platelet count. We tested the hypothesis that results of multiple electrode platelet aggregometry are affected by platelet count, in particular if platelet count is below normal range. METHODS: Whole blood samples from 20 healthy volunteers were prepared containing platelet concentrations of 50,000, 100,000, 150,000, 200,000, and 250,000 microl(-1) while maintaining hematocrit. Platelet aggregation was induced by collagen, thrombin receptor activating peptide 6 (TRAP-6), adenosine-diphoshate (ADP), and arachidonic acid, respectively, and aggregation was measured by multiple electrode platelet aggregometry (Multiplate). RESULTS: Results of multiple electrode platelet aggregometry significantly decreased in blood samples with platelet count below normal range. Compared to results measured in blood samples with platelet count within normal range, aggregometry results decreased by 18.4 % (p<0.001) and 37.2 % (p<0.001) in blood samples with a platelet count of 100.000 and 50.000 microl(-1), respectively. On the other hand, large interindividual variation has been observed and some blood samples showed normal results even with platelet counts of 50.000 microl(-1). CONCLUSION: The results obtained with Multiplate. Analyzer are influenced by platelet function as well as platelet count thus displaying the overall platelet aggregability within the blood sample rather than platelet function alone.

Effects of desmopressin on platelet function under conditions of hypothermia and acidosis: an in vitro study using multiple electrode aggregometry*.

SUMMARY: Hypothermia and acidosis lead to an impairment of coagulation. It has been demonstrated that desmopressin improves platelet function under hypothermia. We tested platelet function ex vivo during hypothermia and acidosis. Blood samples were taken from 12 healthy subjects and assigned as follows: normal pH, pH 7.2, and pH 7.0, each with and without incubation with desmopressin. Platelet aggregation was assessed by multiple electrode aggregometry. Baseline was normal pH and 36 degrees C. The other samples were incubated for 30 min and measured at 32 degrees C. Acidosis significantly impaired aggregation. Desmopressin significantly increased aggregability during hypothermia and acidosis regardless of pH, but did not return it to normal values at low pH. During acidosis and hypothermia, acidosis should be corrected first; desmopressin can then be administered to improve platelet function as a bridge until normothermia can be achieved.

Prospective study comparing skin impedance with EEG parameters during the induction of anaesthesia with fentanyl and etomidate.

OBJECTIVE: Sympathetic stimulation leads to a change in electrical skin impedance. So far it is unclear whether this effect can be used to measure the effects of anaesthetics during general anaesthesia. The aim of this prospective study is to determine the electrical skin impedance during induction of anaesthesia for coronary artery bypass surgery with fentanyl and etomidate. METHODS: The electrical skin impedance was measured with the help of an electro-sympathicograph (ESG). In 47 patients scheduled for elective cardiac surgery, anaesthesia was induced with intravenous fentanyl 10 mug/kg and etomidate 0.3mg/kg. During induction, the ESG (Electrosympathicograph), BIS (Bispectral IndeX), BP (arterial blood pressure) and HR (heart rate) values of each patient were recorded every 20 seconds.The observation period from administration of fentanyl to intubation for surgery lasted 4 min. - RESULTS: The ESG recorded significant changes in the electrical skin impedance after administration of fentanyl and etomidate(p <0.05). During induction of anaesthesia, significant changes of BIS, HR and blood pressure were observed as well (p <0.05). CONCLUSIONS: The electrical skin impedance measurement may be used to monitor the effects of anesthetics during general anaesthesia.

Recovery of fibrinogen after administration of fibrinogen concentrate to patients with severe bleeding after cardiopulmonary bypass surgery.

BACKGROUND: Normalization of plasma fibrinogen levels may be associated with satisfactory haemostasis and reduced bleeding. The aim of this retrospective study was to assess fibrinogen recovery parameters after administration of fibrinogen concentrate (Haemocomplettan P) to patients with diffuse bleeding in cardiovascular surgery. Data on transfusion and patient outcomes were also collected. METHODS: Patient characteristic and clinical data were obtained from patient records. RESULTS: of the thromboelastometry (FIBTEM)and of the standard coagulation tests, including plasma fibrinogen level, measured before surgery, before and after haemostatic therapy, and on the following day, were retrieved from laboratory records. Results Thirty-nine patients receiving fibrinogen concentrate for diffuse bleeding requiring haemostatic therapy after cardiopulmonary bypass were identified. The mean fibrinogen concentrate dose administered was 6.5 g. The mean fibrinogen level increased from 1.9 to 3.6 g litre(-1) (mean increment of 0.28 g litre(-1) per gram of concentrate administered); maximum clot firmness increased from 10 to 21 mm. The mean fibrinogen increase was 2.29 (sd 0.7) mg dl(-1) per mg kg(-1) bodyweight of concentrate administered. Thirty-five patients received no transfusion of fresh-frozen plasma (FFP) or platelet concentrate after receiving fibrinogen concentrate; the remaining four patients received platelet concentrate intraoperatively. Eleven patients received platelets, FFP, or both during the first postoperative day. No venous thromboses, arterial ischaemic events, or deaths were registered during hospitalization. CONCLUSIONS: In this retrospective study, fibrinogen concentrate was effective in increasing plasma fibrinogen level, and contributed to the correction of bleeding after cardiovascular surgery.

Bicarbonate-buffered ultrafiltration during pediatric cardiac surgery prevents electrolyte and acid-base balance disturbances.

Pediatric cardiopulmonary bypass is still a challenge because of electrolyte disturbances and inflammation. Many investigations deal with different types of hemofiltration to reduce these potentially harmful side effects. We tested the hypothesis of whether bicarbonate-buffered hemofiltration of the priming solution minimizes electrolyte and acid-base disturbances during the initiation of cardiopulmonary bypass and whether bicarbonate-buffered hemofiltration performed during cardiopulmonary bypass could reduce cytokine levels. Twenty children younger than 2 years of age (mean age 166 +/- 191 days; mean weight 6.42 +/- 3.22 kg) scheduled for pediatric cardiac surgery with cardiopulmonary bypass were enrolled in this prospective clinical study. Cardiopulmonary bypass circuits were primed with a bicarbonate-buffered hemofiltration solution, gelatin and 1 unit of packed red blood cells. The priming was hemofiltered using an ultrahemofilter until approximately 1000 mL of ultrafiltrate was restored with the buffered solution. Further hemofiltration was performed throughout the whole bypass time, especially during rewarming. Blood gas analyses and inflammatory mediators were monitored during the operation. Blood gas analysis results after initiation of cardiopulmonary bypass and throughout the entire study remained within the physiologic ranges. Even potassium decreased from 4.0 +/- 0.3 to 3.4 +/- 0.4 mmol l(-1) after initiation of cardiopulmonary bypass. Plasma levels of tumor necrosis factor alpha decreased significantly (47 +/- 44 vs. 24 +/- 21 pg mL(-1)) whereas complement factor C3a (5.0 +/- 2.9 vs. 16.8 +/- 6.6 ng mL(-1)) and interleukin-6 (7.3 +/- 15.2 vs. 110 +/- 173 pg mL(-1)) increased despite hemofiltration. In conclusion, this study shows that bicarbonate-buffered ultrafiltration is an efficient, simple and safe method for performing hemofiltration, both of the priming solution and during the entire bypass time. The use of a physiological restitution solution prevents electrolyte and acid-base balance disturbances. The elimination of inflammatory mediators seems to be as effective as other ultrafiltration methods.

Finding the optimal concentration range for fibrinogen replacement after severe haemodilution: an in vitro model.

BACKGROUND: Replacement of fibrinogen is presumably the key step in managing dilutional coagulopathy. We performed an in vitro study hypothesizing that there is a minimal fibrinogen concentration in diluted whole blood above which the rate of clot formation approaches normal. METHODS: Blood samples from six healthy volunteers were diluted 1:5 v/v with saline keeping haematocrit at 24% using red cell concentrates. We measured coagulation factors and thrombin generation in plasma at baseline and after dilution. Thromboelastometry was used to evaluate (i) speed and quality of clot formation in diluted samples supplemented with fibrinogen 50-300 mg dl(-1) and (ii) clot resistance to fibrinolysis. Diluted and undiluted samples with no added fibrinogen served as controls. RESULTS: Coagulation parameters and platelets were reduced by 74-85% after dilution. Peak thrombin generation was reduced by 56%. Adding fibrinogen led to a concentration-dependent improvement of all thromboelastometric parameters. The half maximal effective concentration (EC50) for fibrinogen replacement in haemodiluted blood was calculated to be 125 mg dl(-1). Adding tissue plasminogen activator, 0.15 microg ml(-1), led to a decrease of clot firmness and lysis time. CONCLUSIONS: The target plasma concentration for fibrinogen replacement was predicted by these in vitro results to be greater than 200 mg dl(-1) as only these concentrations optimized the rate of clot formation. This concentration is twice the level suggested by the current transfusion guidelines. Although improved, clots were prone to fibrinolysis indicating that the efficacy of fibrinogen therapy may be influenced by co-existing fibrinolytic tendency occurring during dilutional coagulopathy.

Comparison of breathing tube connectors during invasive bronchial procedures.

Bronchoscopy and bronchial suctioning during intra-operative artificial ventilation often causes leakage from the ventilation circuit with a decrease in ventilatory parameters and possible workplace contamination with anaesthetic gases. Different connectors have been developed to reduce gas leakage. We evaluated the following connectors : VBM 2 mm, 3 mm and 5 mm, Bodai Suction-Safe, Bodai Bronch-Safe and Bodai Trach-Safe, as well as the BE 105-7, BE 105-8 and SH 7-45. Invasive bronchial instruments (catheters, bronchoscopes and bronchial blockers) with 1.67-7.33 mm diameter were used. Pressure-controlled ventilation was performed on a test lung using a ventilator. Sevoflurane concentration in the room was measured 0.2 and 1.5 m from the connector using a photo-acoustic infrared-spectroscope. The VBM connectors caused the least gas leak and ensured stability of ventilation parameters even at peak pressures when combined with smaller instruments. With instruments > 6 mm, BE 105-7, BE 105-8 and SH 7-45 connectors performed best. The Bodai connectors showed a reduced ability to prevent leakage and to keep ventilatory parameters stable. All connectors, excluding the Bodai Trach-Safe, prevented exposure to anaesthetic gases beyond the current safety recommendations when combined with the fitting instruments. The connectors showed different ranges of tightness, equivalent to different ranges of compatibility with the instruments used.

Bleeding management with fibrinogen concentrate targeting a high-normal plasma fibrinogen level: a pilot study.

BACKGROUND: Bleeding diathesis after aortic valve operation and ascending aorta replacement (AV-AA) is managed with fresh-frozen plasma (FFP) and platelet concentrates. The aim was to compare haemostatic effects of conventional transfusion management and FIBTEM (thromboelastometry test)-guided fibrinogen concentrate administration. METHODS: A blood products transfusion algorithm was developed using retrospective data from 42 elective patients (Group A). Two units of platelet concentrate were transfused after cardiopulmonary bypass, followed by 4 u of FFP if bleeding persisted, if platelet count was < or =100 x 10(3) microl(-1) when removing the aortic clamp, and vice versa if platelet count was >100 x 10(3) microl(-1). The trigger for each therapy step was > or =60 g blood absorbed from the mediastinal wound area by dry swabs in 5 min. Assignment to two prospective groups was neither randomized nor blinded; Group B (n=5) was treated according to the algorithm, Group C (n=10) received fibrinogen concentrate (Haemocomplettan P/Riastap, CSL Behring, Marburg, Germany) before the algorithm-based therapy. RESULTS: A mean of 5.7 (0.7) g fibrinogen concentrate decreased blood loss to below the transfusion trigger level in all Group C patients. Group C had reduced transfusion [mean 0.7 (range 0-4) u vs 8.5 (5.3) in Group A and 8.2 (2.3) in Group B] and reduced postoperative bleeding [366 (199) ml vs 793 (560) in Group A and 716 (219) in Group B]. CONCLUSIONS: In this pilot study, FIBTEM-guided fibrinogen concentrate administration was associated with reduced transfusion requirements and 24 h postoperative bleeding in patients undergoing AV-AA.

Platelet concentrates transfusion in cardiac surgery and platelet function assessment by multiple electrode aggregometry.

BACKGROUND: Platelet dysfunction contributes to the pathophysiology of bleeding complications during and after cardiac surgery. In most surgical institutions, no peri-operative point-of-care monitoring of platelet function is used. We evaluated the usefulness of the Multiplate platelet function analyser based on impedance aggregometry for identifying groups of patients at a high risk of transfusion of platelet concentrates (PC). METHODS: Platelet function parameters were determined in 60 patients before and after routine cardiac surgery. Impedance aggregometry measurements were performed on Multiplate using ADP (ADPtest), collagen (COLtest) and thrombin receptor activating peptide (TRAPtest) as platelet activators. The correlations between the aggregometry results and the transfusion of PC were calculated. The results of the aggregation tests were also divided into tertiles and the differences in PC transfusion between the low and the high tertile were assessed. RESULTS: Low aggregometry delimited groups of patients with significantly higher PC transfusion. In the receiver operating characteristic curve, low pre-operative aggregation in the ADPtest identified patients with high total transfusion of PC (area under the curve 0.74, P=0.001), while the ADPtest performed at the end of the operation identified patients with high PC transfusion on the intensive care unit (ICU) (area under the curve 0.76, P=0.002). CONCLUSIONS: Near-patient platelet aggregation may allow the identification of patients with enhanced risk of PC transfusion, both pre-operatively and upon arrival on the ICU.

Endocrine stress response and inflammatory activation during CABG surgery. A randomized trial comparing remifentanil infusion to intermittent fentanyl.

BACKGROUND AND OBJECTIVE: Our aim was to compare a continuous infusion of remifentanil with intermittent boluses of fentanyl as regards the perioperative hormonal stress response and inflammatory activation in coronary artery bypass graft patients under sevoflurane-based anaesthesia. METHODS: In all, 42 patients undergoing coronary artery bypass grafting with cardiopulmonary bypass were prospectively randomized to a fentanyl group (n = 21, total fentanyl dose 2.6 +/- 0.3 mg), or a remifentanil group (n = 21, infusion rate 0.25 microg kg(-1) min(-1)). Haemodynamics, plasma levels of epinephrine, norepinephrine, antidiuretic hormone, adrenocorticotropic hormone, cortisol, complement activation (C3a, C5b-9), interleukin (IL)-6, IL-8 and tumour necrosis factor-alpha were measured at T1: baseline, T2: intubation, T3: sternotomy, T4: 30 min on cardiopulmonary bypass, T5: end of surgery and T6: 8 h postoperatively. Troponin T and creatine kinase-MB were measured postoperatively. RESULTS: Patients in the remifentanil group were extubated significantly earlier than fentanyl patients (240 +/- 182 min vs. 418 +/- 212 min, P = 0.006). Stress hormones 30 min after start of cardiopulmonary bypass showed higher values in the fentanyl group compared to the remifentanil group (antidiuretic hormone (ADH): 39.94 +/- 30.98 vs. 11.7 +/- 22.8 pg mL(-1), P = 0.002; adrenocorticotropic hormone: 111.5 +/- 116.8 vs. 21.81 +/- 24.71 pg mL(-1), P = 0.01; cortisol 185 +/- 86 vs. 131 +/- 82 ng mL(-1), P = 0.04). The interleukins were significantly higher at some perioperative time points in the fentanyl group compared to the remifentanil group (tumour necrosis factor: T5: 3.57 vs. 2.37; IL-6: T5: 4.62 vs. 3.73; and IL-8: T5: 4.43 vs. 2.65 and T6: 2.61 vs. 1.13). However, cardiopulmonary bypass times and aortic cross-clamp times were longer in the fentanyl group, which may to some extent account for the differences. CONCLUSIONS: The perioperative endocrine stress response was attenuated in patients supplemented with continuous remifentanil infusion as compared to intermittent fentanyl.