Fibrin sealant: clinical use and the development of the University of Virginia Tissue Adhesive Center.

The utilization of fibrin sealants to augment hemostasis, seal tissues, and facilitate targeted delivery of drugs is increasing. In 1985, a hospital-based program was established to provide autologous and allogeneic cryoprecipitate that serves as a fibrin sealant when combined with bovine thrombin. To date, more than 4,000 patients have been treated with this product at our institution, with an efficacy rate greater than 90%. Collaboration among surgical services and the blood bank fostered multispecialty expertise with this product that led, in 1997, to the establishment of the University of Virginia Tissue Adhesive Center. The Tissue Adhesive Center is a multidisciplinary center whose physician director and nursing and administrative support staff facilitate basic research, laboratory investigation, and preclinical and clinical trials with collaborators throughout the university. The Tissue Adhesive Center also provides educational programs and clinical consultation, and tracks and participates in peer review of sealant use. The licensure of a commercially produced, virally inactivated, pooled-plasma fibrin sealant in May 1998 provided an alternative source of adhesive. Utilization of the commercial product surpassed use of the blood bank product in April 1999. At present, use of the commercial product is approximately 3 times that of the blood bank-produced sealant. This report reviews the clinical uses of fibrin sealant, its regulatory history, the production of fibrin sealants, the evolution of a blood bank fibrin sealant program, the development of the Tissue Adhesive Center, and the utilization of commercial and blood bank-produced sealant at our university hospital.

Autologous fibrin sealant reduces pain after tonsillectomy.

OBJECTIVES/HYPOTHESIS: Pain is a major cause of morbidity after tonsillectomy. Although various efforts have been made to reduce pain, the use of oral analgesics, which can have adverse side effects, remains the standard of care. It is hypothesized that fibrin sealant, used to achieve hemostasis and enhance healing in many surgical procedures, might help decrease pain after this operation. STUDY DESIGN: A prospective, randomized, blinded study was performed on 20 children aged 5 to 17 years who were undergoing tonsillectomy, to evaluate the efficacy of FIBRIN SEALANT in reducing postoperative pain. METHODS: All patients pre-donated 40 mL of blood from which autologous concentrated fibrinogen was prepared by cryoprecipitation. In the fibrin sealant group, fibrinogen and topical bovine thrombin were sprayed onto the surgical site to form fibrin sealant at the conclusion of tonsillectomy. The 10 patients in the control group (C) received no fibrin sealant. Patients rated their level of pain immediately after surgery and at regular intervals for 3 days after surgery using the Wong-Baker Faces Pain Rating Scale (1-6). Emesis, postoperative bleeding, medications, and adverse events were also evaluated. RESULTS: At 7.00 P.M. on postoperative day (POD) 0, the mean +/- SD fibrin sealant group pain score (2.9+/-0.41 units) was significantly lower than for the C group (4.1+/-0.43 units; P < or = .05). There was also a trend in favor of less pain in the fibrin sealant group at 7:00 P.M. on POD 1, with a mean of 3.5+/-0.43 units versus 2.4+/-0.48 units for C (P = .15). The odds of a patient in C experiencing emesis were 8.16 times higher, (P < or = .05) than for patients in the fibrin sealant group. CONCLUSIONS: Fibrin sealant significantly reduced pain the evening after pediatric tonsillectomy and also decreased the chance of experiencing emesis. Thus fibrin sealant may be clinically useful as an adjunct to tonsillectomy.

Intrathoracic fibrin sealant application using computed tomography fluoroscopy.

Persistent intrathoracic airspace and bronchopleural fistula remain a problem following lung resection or in patients with severe bullous disease experiencing a spontaneous pneumothorax. Although fibrin sealant has been used successfully to manage such air-leaks, precise nonoperative intrathoracic application is difficult. This report describes a novel technique using computed tomography fluoroscopy for catheter-directed FS application through a previously placed thoracostomy tube. Continuous computed tomography-fluoroscopy images allowed real-time catheter manipulation for precise placement of fibrin sealant.

Chronically administered progesterone decreases halothane requirements in rabbits.

The MAC for halothane is 25% lower in pregnant than that in nonpregnant ewes. The reason for this is uncertain, but changes in both steroidal and endogenous opiate have been implicated. This study was undertaken to assess the effect of exogenous progesterone on minimal alveolar concentrations (MAC) of halothane in ovariectomized rabbits. Minimal alveolar concentration of halothane was determined in 84 female rabbits, 37 intact (group A), 20 ovariectomized and injected with inert carrier peanut oil (group B), and 27 ovariectomized and injected with progesterone in peanut oil (group C). Minimal alveolar concentration in group A, 1.68 +/- 0.06% (mean +/- SEM), did not differ significantly from that in group B rabbits, 1.77 +/- 0.06%. However, MAC in progesterone-treated rabbits, 1.48 +/- 0.06%, was significantly lower than the MAC of the other two groups (P less than 0.01). Plasma progesterone concentrations in group A, B, and C were 5.28 +/- 0.62 ng/ml, 6.83 +/- 2.00 ng/ml, and 37.33 +/- 4.25 ng/ml, respectively. These results suggest that experimental treatment with progesterone can reduce the amount of halothane required to produce anesthesia and may explain the phenomenon of decreased need of inhalation anesthetic in human parturients.

Incidence and morbidity of extubation failure in surgical intensive care patients.

The rate of extubation failure (reintubation rate) was determined for 700 consecutive extubations in surgical patients admitted to one of two ICUs. Patients were weaned in a standardized fashion and extubated using a standardized gas exchange and mechanics criteria. Of 400 extubations in the general surgical ICU, there were 22 reintubations in 20 patients. Average age was 65 yr, and the major reason for reintubation was need for positive-pressure ventilation. Morbidity (pulmonary edema and/or pneumonia) was 36%, and the inhospital mortality was 40% in this group. The major cause of death was progressive cardiopulmonary failure. There were 10 failures in eight patients, of 300 extubations in the Burn/Trauma unit, where the mean age was 44 yr. Five failures occurred in patients with smoke inhalation and burns, a 13% incidence in this population. The reason for reintubation was airway maintenance and pulmonary toilet. Four failures occurred in head injury patients, a 5% incidence with the major reason for reintubation being airway protection. Morbidity was 60% (new pulmonary infiltrates), while mortality rate was only 10% in this group. Only one failure was noted in a nonhead-injured trauma patient. In no group studied were any predictors of extubation failure detected. We conclude that the incidence, reasons for, and outcome of reintubations in surgical ICU patients varies dramatically depending on the underlying disease process. Overall failure rate was 4%.

Effect of pregnancy on bupivacaine-induced conduction blockade in the isolated rabbit vagus nerve.

Bupivacaine-induced conduction blockade of A, B, and C fibers of the isolated vagus nerve was compared in fourteen pregnant and fourteen nonpregnant rabbits. After a control period in HEPES-Liley solution, the isolated nerves were exposed to bupivacaine concentrations of 0.1 mM to 1.0 mM. After 30 min exposure, the nerves were stimulated supramaximally and the percent reduction in amplitude of A, B, and C fiber compound action potentials was recorded. Linear regressions were fitted by the least squares method. The A fiber conduction blockade was consistently greater in the nerves from pregnant rabbits (P less than 0.001). The slope of the C fiber dose-response curves was also significantly greater in nerves from pregnant rabbits (P less than 0.01). The results indicate that the response of isolated nerves from pregnant animals to local anesthetic-induced conduction blockade differs from that of nerves from nonpregnant animals. However, it is not certain whether the difference is related simply to a more rapid diffusion and shorter onset of block or an enhanced sensitivity of the nerve membrane during pregnancy.