title: [Effectiveness of isobaric 0.5% bupivacaine and 5% lidocaine in continuous subarachnoid anesthesia with microcatheters].
abstract: OBJECTIVE
  To study the clinical effect of two isobaric local anesthetics infused through microcatheters for continuous subarachnoid anesthesia.
  
  
  METHODS
  Patients undergoing surgery under continuous subarachnoid anesthesia were enrolled prospectively over 12 months. Twenty-seven-gage catheters were inserted through 22 G Sprotte (Intralong) needles. The two isobaric anesthetics (0.5% bupivacaine and 5% lidocaine) were studied in two successive six-month periods. One milliliter of local anesthetic was administered, followed by incremental doses of 0.5 ml until the required anesthetic level was reached. Hemodynamic variables were recorded, as were levels of anesthetic and motor blockade and complications developing during the surgical and postoperative periods.
  
  
  RESULTS
  Thirty-one patients were anesthetized with isobaric 0.5% bupivacaine and 40 with isobaric 5% lidocaine. A high blockade was observed in three patients in the bupivacaine group and in 15 in the bupivacaine group (p < 0.05). The highest anesthetic level reached was T4. Hypotension occurred in one patient in the bupivacaine group and in 10 in the lidocaine group (p < 0.05). Blockade was difficult to increase to the appropriate level in 11 lidocaine patients and in one bupivacaine patient, whereas blockade of distal roots was difficult in 13 bupivacaine patients and in 7 lidocaine patients (p < 0.005). The total doses infused were 11.0 +/- 3.0 mg of 0.5% bupivacaine and 95.6 +/- 24.6 mg of 5% lidocaine.
  
  
  CONCLUSIONS
  Isobaric 0.5% bupivacaine provides a more predictable anesthetic blockade with greater hemodynamic stability and a lower rate of difficulty in raising the level of blockade than does 5% lidocaine when administered through microcatheters for continuous subarachnoid anesthesia.
authors.affiliation: Servicio de Anestesiología, Reanimación y Terapéutica del Dolor, Hospital Clínic de Barcelona, Universidad de Barcelona.
authors.forename: P
authors.initials: P
authors.lastname: de Santos
authors.forename: C
authors.initials: C
authors.lastname: Gomar
authors.forename: R
authors.initials: R
authors.lastname: Valero
authors.forename: A
authors.initials: A
authors.lastname: Villalonga
mesh_terms: D000775:Anesthesia, Spinal / Q000379:methods*; D000779:Anesthetics, Local; D002045:Bupivacaine; D002404:Catheterization; D005260:Female; D006801:Humans; D008012:Lidocaine; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013346:Subarachnoid Space
chemical_list: D000779:Anesthetics, Local; D008012:Lidocaine; D002045:Bupivacaine