Just Published Spinal Anesthesia Research

Spinal anaesthesia for elective surgery: a comparison of hyperbaric solutions of racemic bupivacaine, levobupivacaine, and ropivacaine.

Spinal anaesthesia for elective surgery: a comparison of hyperbaric solutions of racemic bupivacaine, levobupivacaine, and ropivacaine.

Br J Anaesth. 2008 Nov;101(5):705-10

Authors: Luck JF, Fettes PD, Wildsmith JA

BACKGROUND: The aim of this study was to compare the clinical effects of 'hyperbaric' bupivacaine for spinal anaesthesia with those of similar preparations of levobupivacaine and ropivacaine. METHODS: Sixty ASA grade I-II patients undergoing elective surgery under spinal anaesthesia were randomized to receive 3 ml of bupivacaine, levobupivacaine, or ropivacaine, each at 5 mg ml(-1) and made hyperbaric by the addition of glucose 30 mg ml(-1). A standard protocol was followed after which a blinded observer assessed the sensory and motor blocks. The level and duration of sensory (pinprick) block, intensity and duration of motor block, and time to mobilize and to micturate were also recorded. RESULTS: One patient (ropivacaine group) required general anaesthesia because of technical failure, but all the other blocks were adequate. There were no significant differences between the groups with regard to the mean time to onset of sensory block at T10, the extent of spread, or mean time to maximum spread. Regression of sensory block in the ropivacaine group was more rapid as demonstrated by duration at T10 (P<0.0167) and total duration of sensory block (P<0.0167). Patients in the ropivacaine group had more rapid recovery from motor block (P<0.0167) and shorter times to independent mobilization (P<0.0167). There were no significant differences between the bupivacaine and the levobupivacaine groups. CONCLUSIONS: 'Hyperbaric' ropivacaine provides reliable spinal anaesthesia of shorter duration than bupivacaine or levobupivacaine, both of which are clinically indistinguishable. The recovery profile of ropivacaine may be useful where prompt mobilization is required.

PMID: 18765643 [PubMed - indexed for MEDLINE]

Effect of prewarming on post-induction core temperature and the incidence of inadvertent perioperative hypothermia in patients undergoing general anaesthesia.

Effect of prewarming on post-induction core temperature and the incidence of inadvertent perioperative hypothermia in patients undergoing general anaesthesia.

Br J Anaesth. 2008 Nov;101(5):627-31

Authors: Andrzejowski J, Hoyle J, Eapen G, Turnbull D

BACKGROUND: Inadvertent perioperative hypothermia (IPH) occurs in many patients because warming techniques are insufficient to counteract thermal redistribution resulting from the ablation of thermoregulatory vasoconstriction associated with anaesthesia. We tested the efficiency of a preoperative forced-air warming (FAW) device (Bair Paws) in preventing IPH. METHODS: Sixty-eight adult patients undergoing spinal surgery under general anaesthesia were randomized to receive either normal care or prewarming for 60 min, at 38 degrees C, using the Bair Paws system. All patients received routine FAW intraoperatively. RESULTS: Thirty-one patients were prewarmed and 37 patients were in the control group. There was a 0.3 degrees C smaller decrease in mean core temperature in the prewarmed group at 40, 60, and 80 min post-induction (P< or =0.05). Temperature was maintained above the hypothermic threshold of 36 degrees C in 21 (68%) patients in the prewarmed group, compared with 16 (43%) patients in the control group (P<0.05). CONCLUSIONS: Preoperative warming using the Bair Paws system results in smaller decreases in core temperature intraoperatively and less IPH in patients undergoing spinal surgery under general anaesthesia.

PMID: 18820248 [PubMed - indexed for MEDLINE]

Prophylactic mirtazapine reduces intrathecal morphine-induced pruritus.

Prophylactic mirtazapine reduces intrathecal morphine-induced pruritus.

Br J Anaesth. 2008 Nov;101(5):711-5

Authors: Sheen MJ, Ho ST, Lee CH, Tsung YC, Chang FL, Huang ST

BACKGROUND: Activation of the serotonergic system is an important factor in the pathogenesis of intrathecal morphine-induced pruritus. Mirtazapine is a new antidepressant that selectively blocks 5-HT(2) and 5-HT(3) receptors. We therefore tested the hypothesis that preoperative mirtazapine would reduce the incidence of intrathecal morphine-induced pruritus. METHODS: One hundred and ten ASA I patients undergoing lower limb surgery under spinal anaesthesia were randomly allocated into two equal groups and received either mirtazapine 30 mg or an orally disintegrating placebo tablet 1 h before operation in a prospective, double-blinded trial. All patients received an intrathecal injection of 15 mg of 0.5% isobaric bupivacaine and 0.2 mg preservative-free morphine. The occurrence and the severity of pruritus were assessed at 3, 6, 9, 12, and 24 h after intrathecal morphine. RESULTS: Pruritus was significantly more frequent in the placebo group compared with the mirtazapine group (75% vs 52%, respectively; P=0.0245). The time to onset of pruritus in the two groups was also significantly different. The patients who experienced pruritus in the placebo group had a faster onset time than that in the mirtazapine group [mean (sd): 3.2 (0.8) vs 7.2 (4.1) h, P<0.0001]. CONCLUSIONS: Mirtazapine premedication prevents pruritus induced by intrathecal morphine in patients undergoing lower limb surgery with spinal anaesthesia.

PMID: 18713761 [PubMed - indexed for MEDLINE]

Intrathecal lidocaine elevates prostaglandin E2 levels in cerebrospinal fluid: a microdialysis study in freely moving rats.

Intrathecal lidocaine elevates prostaglandin E2 levels in cerebrospinal fluid: a microdialysis study in freely moving rats.

Br J Anaesth. 2008 Nov;101(5):716-22

Authors: Umbrain V, Shi L, Lauwers MH, Smolders I, Michotte Y, Camu F

BACKGROUND: In this study, we have investigated whether intrathecal (i.t.) lidocaine administration is accompanied with changes of cerebrospinal fluid (CSF) prostaglandin E(2) (PGE(2)) levels. METHODS: Rats were anaesthetized for i.t. implantation of a triple-lumen spinal loop dialysis catheter. CSF changes in PGE(2) after i.t. injection of saline, 400, or 1000 microg of lidocaine were measured. The impact of i.t. pretreatment with 5 microg MK801 (N-methyl-D-aspartate glutamate antagonist) or 10 microg SC76309A (COX-2 inhibitor) was also investigated. CSF dialysates for measurement of PGE(2) were collected for 4 h. During the whole procedure, motor and sensory blocks were evaluated. A separate group receiving i.t. lidocaine 400 microg (without dialysate sampling) was assessed for mechanical (Von Frey) and radiant heat pain. RESULTS: PGE(2) levels increased to 400% of baseline and remained elevated for 90-120 min after i.t. lidocaine at both doses. Pretreatment with SC76309A and MK801 attenuated this increase. A 40 min period of enhanced pain response was observed after Von Frey filament stimulation during and after sensory and motor block recovery. CONCLUSIONS: I.T. lidocaine (400 or 1000 microg) increases PGE(2) levels in the CSF for 90-120 min along with a transient period of mechanical hyperalgesia after sensory and motor block recovery.

PMID: 18716004 [PubMed - indexed for MEDLINE]

A randomized trial of dural puncture epidural technique compared with the standard epidural technique for labor analgesia.

A randomized trial of dural puncture epidural technique compared with the standard epidural technique for labor analgesia.

Anesth Analg. 2008 Nov;107(5):1646-51

Authors: Cappiello E, O'Rourke N, Segal S, Tsen LC

BACKGROUND: We designed this prospective, double-blind, randomized study to examine whether a dural puncture without intrathecal drug administration immediately before epidural drug administration would improve labor analgesia when compared to a traditional epidural technique without prior dural puncture. METHODS: Eighty nulliparous parturients with cervical dilation less than 5 cm were randomly assigned to receive a standardized epidural technique, with or without a single dural puncture with a 25-gauge (G) Whitacre spinal needle. After successful placement of the needle(s) and the epidural catheter, 12 mL of bupivacaine 2.5 mg/mL was administered through the epidural catheter and a patient-controlled epidural infusion of bupivacaine 1.25 mg/mL + fentanyl 2 mug/mL was initiated. The presence of sacral analgesia (S1) and pain scores were compared between groups. RESULTS: In demographically similar groups, parturients with prior dural puncture had more frequent blockade of the S1 dermatome (absolute risk difference [95% confidence interval] 22% [6-39]), more frequent visual analog scale scores <10/100 at 20 min (absolute risk difference 20% [1-38]), and reduced one-sided analgesia (absolute risk difference [95% CI] 17% [2-330]). The highest median sensory level (T10) was no different between groups. CONCLUSIONS: Dural puncture with a 25-G spinal needle immediately before the initiation of epidural analgesia improves the sacral spread, onset, and bilateral pain relief produced by analgesic concentrations of bupivacaine with fentanyl in laboring nulliparous patients.

PMID: 18931227 [PubMed - indexed for MEDLINE]

[Coronary artery bypass grafting in conscious patients : A procedure with a perspective?]

[Coronary artery bypass grafting in conscious patients : A procedure with a perspective?]

Anaesthesist. 2008 Nov 19;

Authors: Byhahn C, Meininger D, Kessler P

Patients undergoing coronary artery bypass grafting increasingly show severe co-morbidities, which can negatively affect the outcome. Recent developments in cardiac surgery have therefore focused on minimizing the invasiveness of the procedure by revascularization on the beating heart without cardiopulmonary bypass, and by reducing surgical trauma using smaller surgical incisions. Progress in minimally invasive cardiac surgery has led to minimally invasive anesthesia, i.e. using high thoracic epidural anesthesia as the sole technique in the conscious patient (awake coronary artery bypass grafting, ACAB). Published data on ACAB procedures in smaller cohorts have demonstrated that the procedure is safe. Significant complications occurred in 7.1% of patients. A particular cause of concern during ACAB surgery is the development of spinal epidural hematoma the risk of which has been estimated to be as high as 1:1,000. A thorough risk-benefit analysis has therefore to be made. Currently, ACAB surgery remains limited to few specialized centers and highly selected patients.

PMID: 19015830 [PubMed - as supplied by publisher]

Tranexamic Acid reduces perioperative blood loss in adult patients having spinal fusion surgery.

Tranexamic Acid reduces perioperative blood loss in adult patients having spinal fusion surgery.

Anesth Analg. 2008 Nov;107(5):1479-86

Authors: Wong J, El Beheiry H, Rampersaud YR, Lewis S, Ahn H, De Silva Y, Abrishami A, Baig N, McBroom RJ, Chung F

BACKGROUND: Spinal reconstructive surgery in adults can be associated with significant blood loss, often requiring allogeneic blood transfusion. The objective of this randomized, prospective, double-blind, multicenter study was to evaluate the efficacy of tranexamic acid (TXA) in reducing perioperative blood loss and transfusion in adult patients having elective posterior thoracic/lumbar instrumented spinal fusion surgery. METHODS: One hundred fifty-one adult patients were randomized to receive either a bolus of 10 mg/kg IV of TXA after induction followed by a maintenance infusion of 1 mg/kg/hr of TXA, or an equivalent volume of placebo (normal saline). The primary outcome was the total perioperative estimated and calculated blood loss intraoperatively and 24 h postoperatively. Secondary outcomes were incidence of allogeneic blood exposure, and duration of hospital stay. RESULTS: Four patients were withdrawn for identifiable surgical bleeding, therefore 147 patients were included in the analysis. The total estimated and calculated perioperative blood loss was approximately 25% and 30% lower in patients given TXA versus placebo (1592 +/- 1315 mL vs 2138 +/- 1607 mL, P = 0.026; 3079 +/- 2558 vs 4363 +/- 3030, P = 0.017), respectively. There was no difference in the amounts of blood products transfused, and length of stay between the two groups. TXA, surgical duration, and number of vertebrae fused were independent factors related to perioperative blood loss. Predictors for the need for allogeneic red blood cell transfusion were ASA classification, surgical duration and number of levels fused. CONCLUSIONS: TXA significantly reduced the estimated and calculated total amount of perioperative blood loss in adult patients having elective posterior thoracic/lumbar instrumented spinal fusion surgery.

PMID: 18931202 [PubMed - indexed for MEDLINE]

Lidocaine inhibits NIH-3T3 cell multiplication by increasing the expression of cyclin-dependent kinase inhibitor 1A (p21).

Lidocaine inhibits NIH-3T3 cell multiplication by increasing the expression of cyclin-dependent kinase inhibitor 1A (p21).

Anesth Analg. 2008 Nov;107(5):1592-7

Authors: Desai SP, Kojima K, Vacanti CA, Kodama S

BACKGROUND: We explored molecular mechanisms by which lidocaine inhibits growth in the murine embryonic fibroblast cell line NIH-3T3. Local anesthetics can adversely affect cell growth in vitro. Their effects on wound healing are controversial. We examined the effects and novel mechanisms by which lidocaine affects in vitro multiplication of the murine fibroblast cell line NIH-3T3. METHODS: NIH-3T3 cells were grown in culture with lidocaine [0, 0.05, 0.5, 1, 2, and 5 mM]. Cell multiplication was assessed by determining cell counts on subsequent days, while mechanisms by which inhibition occurred were evaluated by bromodeoxyuridine uptake, gene expression using polymerase chain reaction array, and Western blot analysis to verify increased levels of affected proteins. RESULTS: Lidocaine caused dose-dependent inhibition of multiplication of NIH-3T3 cells. Effects ranged from no inhibition [0.05 and 0.5 mM] and mild inhibition [1 mM], to severe inhibition [2 and 5 mM] [P = 0.006]. Lidocaine 2 mM inhibited bromodeoxyuridine uptake at day 3.5 [P = 0.02 versus control, and P = 0.0495 vs 1 mM lidocaine]. On day 1.5, lidocaine upregulated expression of cyclin-D1 and cyclin-dependent kinase inhibitor 1A [p21]. On day 2.5, lidocaine increased the levels of p21 protein. CONCLUSIONS: Low concentrations of lidocaine, as would be seen in plasma after spinal, epidural, or plexus anesthesia, do not significantly affect multiplication of fibroblasts. Higher doses of lidocaine arrest cell multiplication at the S-phase of the growth cycle by upregulation of p21, an extremely potent inhibitor of cell multiplication. Higher concentrations, as would be seen after tissue infiltration, severely inhibit fibroblast multiplication and thus may impair wound healing.

PMID: 18931217 [PubMed - indexed for MEDLINE]