Thromboelastographic study of thrombosis in the implantable central venous access device.

BACKGROUND: In the present study thromboelastography (TEG) was to study whether or not hypercoagulopathy might contribute to the thrombosis of implantable central venous access device (Port-A-Cath, Pharmacia) in cancer patients. METHODS: All 76 oncological patients who were enrolled in this study had their R time, alpha angle and MA value measured before Port-A-Cath implantation, of whom 11 patients received re-implantation because of thrombotic device. We compared the measurements of these 11 patients (thrombotic group) with that of 65 patients (control group) who received Port-A-Cath implantation for the first time. According to TEG values the hemostatic status in these patients was classified as hypercoagulable, normal or hypocoagulable for comparison. All patients in the control group were followed up for 3 months for occurrence of thrombosis. RESULTS: It was found that no patient in the thrombotic group was associated with hypercoagulopathy. Five patients (7.5%) in the control group was found in hypercoagulable status at the time of catheter insertion but none of them developed clinical thrombosis during three months of observation. There was no significant difference between the two groups for R time, alpha angle but a higher MA value was found in the control group (p < 0.05). Furthermore, the hypercoagulability (7.5% for the control vs. none for the thrombotic group), hypocoagulability (1.5% vs. 9.1%) and normocoagulability (91.0% vs. 90.9%) were not statistically different between the two groups (Fisher exact test, P = 0.229). CONCLUSIONS: We conclude that hypercoagulopathy in cancer patients has little, if any, contribution in thrombosis of the implantable central venous access device.

A child of suspected malignant hyperthermia during general anesthesia for dental surgery.

Malignant hyperthermia is clinically an uncommon disorder characterized by acute hypercatabolic reactions in muscles in response to the triggering effects of certain drugs mainly used during anesthesia or to physical or emotional stress. We present a pediatric patient with multiple caries who was suspected to contract malignant hyperthermia while underwent the operative procedure of comprehensive restoration. Sinus tachycardia, hyperthermia, hypercapnia, metabolic acidosis, hyperkalemia and hypercalcemia developed unexpectedly during the operation. Fortunately, the patient survived the episode with early recognition and prompt management.

A comparison of lidocaine, fentanyl, and esmolol for attenuation of cardiovascular response to laryngoscopy and tracheal intubation.

BACKGROUND: Laryngoscopy and tracheal intubation are known to increase sympathetic activity that may be detrimental to patients with pre-existing ischemic or hypertensive heart diseases. In order to alter the hyperdynamic consequences resulting from intubation during induction of general anesthesia, we chose esmolol, an ultra-short acting cardioselective beta-adrenergic blocker, to attenuate the cardiovascular responses during tracheal intubation in patients undergoing elective surgery. The efficacy of esmolol in this regard was carefully evaluated. METHODS: Eighty ASA physical status class I or II patients undergoing elective, non-cardiac procedures were included in a randomized, single-blinded study consisting of 4 groups with each group receiving a designated drug: group A received normal saline as control, while group B, group C and group D received lidocaine 2 mg/kg, fentanyl 3 micrograms/kg and esmolol 2 mg/kg, respectively. Monitoring included EKG, pulse oximetry, capnometry and arterial pressure. All patients were premedicated with diazepam 0.1 mg/kg 30 min before induction of general anesthesia. Each designated drug was given upon induction of anesthesia (time zero). Anesthesia was induced with thiopental 5 mg/kg and succinylcholine 1.5 mg/kg, and maintained with N2O, 1% isoflurane in 50% O2 and vecuronium. Intubation was carried out 3 min after the designated drug was given. Heart rate (HR) and systolic arterial blood pressure (SBP) were obtained every min for 10 min after induction. Either chi-square test or analysis of variances (ANOVA) was used for statistical comparison. A p value less than 0.05 was considered statistically significant. RESULTS: There was no difference in the demographic data among the four groups. After intubation, the incidence of tachycardia (HR > 100/min) was found in 3 of 20 (15%) patients in esmolol group, significantly lower than 17 of 20 (85%) patients in the control group, 15 of 20 (75%) patients in lidocaine group, and 11 of 20 (55%) patients in fentanyl group, respectively (p < 0.05). The incidence of hypertension (SBP > 180 mmHg) was found in 4 of 20 (20%) patients in esmolol group, significantly lower than 16 of 20 (80%) patients in control group and 14 of 20 (70%) patients in lidocaine group, respectively (p < 0.05), but not in 8 of 20 (40%) patients in fentanyl group. Besides, the incidence of hypertension in fentanyl group (40%) was significantly lower than control group (80%; p < 0.05), but not in lidocaine group (70%). CONCLUSIONS: Results of this study showed that only esmolol could reliably offer protection against the increase in both HR and SBP, low dose of fentanyl (3 micrograms/kg) prevented hypertension but not tachycardia, and 2 mg/kg lidocaine had no effect to blunt adverse hemodynamic responses during laryngoscopy and tracheal intubation.