Celite-activated thrombelastography in children.

STUDY OBJECTIVE: To quantify global coagulation and establish normal ranges for the celite-activated thrombelastograph (TEG) in healthy pediatric patients. DESIGN: Prospective observational study. SETTING: Operating suite of a university-based hospital. PATIENTS: 110 healthy pediatric patients in four age groups and 25 healthy adult patients. INTERVENTIONS: Blood sampling for the celite-activated TEG was carried out after anesthetic induction. MEASUREMENTS: TEG indices: R time (reflecting time to fibrin formation), K time and alpha angle (fibrinogen-platelet interaction), maximum amplitude (reflecting maximal clot strength, platelet and fibrinogen function), TEG index (mathematical incorporation of the prior four measurements), and percent fibrinolysis at 30 minutes, were all recorded. MAIN RESULTS: Statistically significant differences between <12-month group in angle (compared to 25-48 month group) and % fibrinolysis (compared to all other pediatric groups). Significant differences in angle between two pediatric groups and adult group, and in the TEG index between three pediatric groups and adult group (all differences p < 0.05). CONCLUSIONS: These data identify changes of small magnitude in three celite-TEG parameters in healthy children compared to adults, without implication of abnormal coagulation between groups. Changes do not seem to be consistently related to age and will be useful for clinicians using the TEG to monitor (ab) normal coagulation in pediatric patients.

Sonoclot analysis in healthy children.

UNLABELLED: Although use of the Sonoclot device (Sienco, Inc., Morrison, CO) has been reported in isolated pediatric cases and in small reports in neonates, there are no published data for normal pediatric patients. As the device is used in situations of abnormal coagulation, such as cardiac and liver transplantation surgery, our aim was to determine normal data ranges in healthy pediatric surgical patients. Blood was withdrawn after anesthetic induction, and the Sonoclot activated clotting time, rate of clot formation, time to peak amplitude, and peak amplitude was compared among four pediatric groups (< 12 mo, 13-24 mo, 25-48 mo, 49 mo-9 yr) and an adult group. The Sonoclot activated clotting time in the < 12-mo and the Adult groups were shorter than the oldest group of children (P < 0.05), although all were within the anticipated normal range, and there were no significant differences in clot rate, peak amplitude, and time to peak amplitude among groups without apparent trends with increasing age. These Sonoclot variables quantify adequate global clot formation in pediatric patients and will facilitate clinical coagulation management with appropriate pediatric normal ranges, avoiding the application of extrapolated adult data to children. IMPLICATIONS: Sonoclot variables are presented for 95 healthy pediatric surgical patients in four age groups, with small differences found in the Sonoclot (Sienco, Inc., Morrison, CO) activated clotting time between two groups and no significant differences in three other variables among groups.

Thromboelastography with heparinase in orthotopic liver transplantation.

OBJECTIVE: To investigate the role of heparin in the postreperfusion coagulopathy during liver transplantation with heparinase-guided thromboelastography. DESIGN: A prospective, interventional study. SETTING: A university-affiliated hospital. PARTICIPANTS: Twenty-six patients undergoing orthotopic liver transplantation (OLT). INTERVENTIONS: Blood drawn at five intervals for thromboelastography assessment with native (12 patients) or celite blood (14 patients) compared with simultaneous thromboelastography traces with added heparinase. MAIN RESULTS: In the native samples, the prolonged R (reaction) and K (coagulation) time and decreased alpha angle were corrected in heparinase thromboelastograph traces immediately before reperfusion and 10 minutes postreperfusion. In the celite-accelerated samples, the heparinase traces showed correction of the R and K times and alpha angle only at the 10-minute postreperfusion stage. In seven patients who had thromboelastography performed after protamine administration, there were no differences between celite and heparinase-celite traces. CONCLUSIONS: Heparinase-treated thromboelastography offered compelling evidence for the presence of heparin-like activity after liver graft reperfusion. The objective evidence provided by this modification of thromboelastography-guided protamine administration and was useful in identifying one of the many potential causes of postreperfusion bleeding in patients undergoing OLT.

Perioperative hypercoagulability in uremic patients: a viscoelastic study.

STUDY OBJECTIVE: To examine whole blood coagulation in uremic patients presenting for surgery with the thromboelastogram and the Sonoclot analyzer. DESIGN: Prospective, observational study. SETTING: Operating rooms of a university-affiliated hospital. PATIENTS: 30 ASA physical status II and III patients with chronic renal failure, and 30 age-matched and gender-matched patients with normal renal function, presenting for elective surgery. INTERVENTIONS: Blood sampling for thromboelastograph and Sonoclot analysis immediately after anesthetic induction, prior to surgical incision. MEASUREMENTS AND MAIN RESULTS: Thromboelastographic indices of coagulation, reflecting coagulation factor function (R time), fibrinogen-platelet interaction (K time and alpha angle), and qualitative platelet function (maximum amplitude) were hypercoagulable in the uremic group compared with the control group (p < 0.05). Fibrinolysis (%) was decreased in the uremic group (p < 0.05). Fibrin formation (initial slope) and platelet function (time to peak) of the Sonoclot trace also were hypercoagulable in the uremic group (p < 0.05). CONCLUSIONS: The high incidence of arteriovenous graft and fistulae thromboses in uremic patients belies in vitro laboratory evidence of platelet dysfunction. We have demonstrated perioperative hypercoagulability in uremic patients with viscoelastic measures of whole blood coagulation. These data suggest that traditional concern for coagulopathy and platelet dysfunction in uremic patients may require re-assessment in light of this "pro-thrombotic" state.

Heparinase-guided thrombelastography in an anticoagulated parturient.

We describe the use of heparinase-guided thrombelastography in the assessment of a parturient who had been anticoagulated with heparin for suspected thromboembolic disease. Reversal of the heparin effect in the heparinase-treated sample facilitated administration of protamine and successful subarachnoid analgesia for delivery.

Bronchoscopic findings in post-obstructive pulmonary oedema.

PURPOSE: To present the first photographed bronchoscopic findings associated with negative pressure pulmonary oedema (NPPE). CLINICAL FEATURES: A previously healthy patient underwent anterior C3-C4 disc removal and arthrodesis. Following tracheal extubation he developed acute respiratory distress manifested as stridor, tachypnoea, restlessness, and desaturation. Once the trachea was reintubated, he displayed the classic findings of pulmonary oedema. Bronchoscopy was performed to confirm tracheal tube position and to rule out tracheal injury secondary to surgical manipulation. Diffuse punctate haemorrhages were noted throughout the visualised tracheobronchial tree. CONCLUSION: We believe that these haemorrhages represent disruption of the bronchial vasculature and may contribute to the clinical presentation of NPPE.

Sudden unexpected sneezing during the insertion of peribulbar block under propofol sedation.

The author presents a case report where, following propofol sedation for a peribulbar block, sneezing was induced once the local anaesthetic needle was placed in the orbital cavity. The physiology of sneezing is discussed, as well as the pathophysiology of the ACHOO (Autosomal Dominant Compelling Helio-Ophthalmic Outburst) syndrome, an autosomal dominant condition, present in approximately 25% of the population, where sneezing is provoked upon exposure to bright light. It is suggested that the anaesthesia induced by propofol may have sensitized patients with this condition to sneeze, since there appeared to be no other excitatory sequelae which have previously been described with propofol.