The Duration of Intrathecal Bupivacaine Mixed with Lidocaine

Transient neurological symptoms (TNS) following spinal anaesthesia with lidocaine versus other local anaesthetics in adult surgical patients: a network meta-analysis

BACKGROUND

Spinal anaesthesia has been implicated as one of the possible causes of neurological complications following surgical procedures. This painful condition, occurring during the immediate postoperative period, is termed transient neurological symptoms (TNS) and is typically observed after the use of spinal lidocaine. Alternatives to lidocaine that can provide high-quality anaesthesia without TNS development are needed. This review was originally published in 2005, and last updated in 2009.

OBJECTIVES

To determine the frequency of TNS after spinal anaesthesia with lidocaine and compare it with other types of local anaesthetics by performing a meta-analysis for all pair-wise comparisons, and conducting network meta-analysis (NMA) to rank interventions.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Elsevier Embase, and LILACS on 25 November 2018. We searched clinical trial registries and handsearched the reference lists of trials and review articles.

SELECTION CRITERIA

We included randomized and quasi-randomized controlled trials comparing the frequency of TNS after spinal anaesthesia with lidocaine to other local anaesthetics. Studies had to have two or more arms that used distinct local anaesthetics (irrespective of the concentration and baricity of the solution) for spinal anaesthesia in preparation for surgery. We included adults who received spinal anaesthesia and considered all pregnant participants as a subgroup. The follow-up period for TNS was at least 24 hours.

DATA COLLECTION AND ANALYSIS

Four review authors independently assessed studies for inclusion. Three review authors independently evaluated the quality of the relevant studies and extracted the data from the included studies. We performed meta-analysis for all pair-wise comparisons of local anaesthetics, as well as NMA. We used an inverse variance weighting for summary statistics and a random-effects model as we expected methodological and clinical heterogeneity across the included studies resulting in varying effect sizes between studies of pair-wise comparisons. The NMA used all included studies based on a graph theoretical approach within a frequentist framework. Finally, we ranked the competing treatments by P scores.

MAIN RESULTS

The analysis included 24 trials reporting on 2226 participants of whom 239 developed TNS. Two studies are awaiting classification and one is ongoing. Included studies mostly had unclear to high risk of bias. The NMA included 24 studies and eight different local anaesthetics; the number of pair-wise comparisons was 32 and the number of different pair-wise comparisons was 11. This analysis showed that, compared to lidocaine, the risk ratio (RR) of TNS was lower for bupivacaine, levobupivacaine, prilocaine, procaine, and ropivacaine with RRs in the range of 0.10 to 0.23 while 2-chloroprocaine and mepivacaine did not differ in terms of RR of TNS development compared to lidocaine. Pair-wise meta-analysis showed that compared with lidocaine, most local anaesthetics were associated with a reduced risk of TNS development (except 2-chloroprocaine and mepivacaine) (bupivacaine: RR 0.16, 95% confidence interval (CI) 0.09 to 0.28; 12 studies; moderate-quality evidence; 2-chloroprocaine: RR 0.09, 95% CI 0.01 to 1.51; 2 studies; low-quality evidence; levobupivacaine: RR 0.13, 95% CI 0.02 to 0.69; 2 studies; low-quality evidence; mepivacaine: RR 1.01, 95% CI 0.18 to 5.82; 4 studies; very low-quality evidence; prilocaine: RR 0.18, 95% CI 0.07 to 0.49; 4 studies; moderate-quality evidence; procaine: RR 0.14, 95% CI 0.04 to 0.52; 2 studies; moderate-quality evidence; ropivacaine: RR 0.10, 95% CI 0.01 to 0.78; 2 studies; low-quality evidence). We were unable to perform any of our planned subgroup analyses due to the low number of TNS events.

AUTHORS' CONCLUSIONS

Results from both NMA and pair-wise meta-analysis indicate that the risk of developing TNS after spinal anaesthesia is lower when bupivacaine, levobupivacaine, prilocaine, procaine, and ropivacaine are used compared to lidocaine. The use of 2-chloroprocaine and mepivacaine had a similar risk to lidocaine in terms of TNS development after spinal anaesthesia. Patients should be informed of TNS as a possible adverse effect of local anaesthesia with lidocaine and the choice of anaesthetic agent should be based on the specific clinical context and parameters such as the expected duration of the procedure and the quality of anaesthesia. Due to the very low- to moderate-quality evidence (GRADE), future research efforts in this field are required to assess alternatives to lidocaine that would be able to provide high-quality anaesthesia without TNS development. The two studies awaiting classification and one ongoing study may alter the conclusions of the review once assessed.

Comparing the Duration of Spinal Anesthesia Induced With Bupivacaine and a Bupivacaince-Lidocaine Combination in Trans-Urethral Resection of the Prostate (TURP)

Background:

Spinal anesthesia is a safe anesthetic mode for transurethral prostate resection (TUPR). There are several studies assessing the effect of bupivacaine, lonely or accompanied by other drugs, on short duration operations. However, there is controversy regarding the exact combination.

Objectives:

The aim of the study was to compare the effects of spinal anesthesia with bupivacaine and low dose lidocaine with bupivacaine alone on postoperative pain in those undergoing transurethral resection of prostate (TURP).

Materials and Methods:

This was a randomized clinical trial performed in Shiraz university of medical sciences during one year. Eighty men scheduled for TURP were randomly assigned to receive spinal anesthesia with 1.5 mL bupivacaine 0.6% and 0.6 mL Lidocaine 1% or spinal anesthesia with 1.5 mL bupivacaine 0.5% in combination with 0.6 mL normal saline. The primary endpoint was the time lag between induction of spinal anesthesia and reaching the highest spinal block level. We also recorded the duration of spinal block declining to L1 level, operation duration and the admission duration.

Results:

Both study groups were comparable regarding the baseline characteristics. We did not find any difference between the two study groups regarding the duration of anesthetic block reaching the maximum level (P = 0.433) and duration of decreasing it to L1 (P = 0.189). The course of postoperative recovery and duration of hospital admission were also comparable between the groups (P = 0.661).

Conclusions:

Lidocaine does not have additive effects on duration and quality of spinal anesthesia with bupivacaine in those undergoing TURP.

Chronic toxicity study of neosaxitoxin in rats

Neosaxitoxin (NeoSTX) is a specific reversible blocker of voltage gated sodium channels on excitable cells. In the last decade, it has been tested in a number of interesting clinical trials, however there is still little information available on mammalian toxicity. Rats were treated for 12 weeks with doses of 1, 3 or 6 μg/kg of subcutaneous NeoSTX. At weeks 12 and 17, animals were sacrificed and blood samples collected for hematological and biochemical analysis. Organs were harvested for weight determination and histopathological assessments. The lowest acute toxicity via the intraperitoneal (ip) route was (30.35 μg/kg) and there was no significant difference between intramuscular and subcutaneous routes (11.4 and 12.41 μg/kg). The NeoSTX adiministration did not produce lethality at week 12 and after five weeks of suspension. NeoSTX 6 μg/kg ip produced reductions (p < 0.05) in body weight and food intake, and increased blood level of total and direct bilirubin, GGT and SGOT at week 12; all of these were reversed in the recovery period. NeoSTX 1 and 3 μg/kg ip did not show significant changes with the control group. Histopathological presentations were normal in all groups. This study revealed that NeoSTX is safe in vivo, giving a reliable security margin for its use like a local anesthetic.

Addition of lidocaine to levobupivacaine reduces intrathecal block duration: randomized controlled trial

BACKGROUND

The duration of the spinal block is a concern for anesthetists. Low dose intrathecal lidocaine has vasodilatory effects and increases the local anesthetic clearance from the intrathecal space. The aim was to investigate whether this effect of lidocaine can be used to increase the resolution of levobupivacaine spinal anesthesia.

METHOD

After obtaining ethical approval and informed patient consent, 40 patients underwent transurethral prostate resection were studied. Patients were randomized into two groups and patients received either levobupivacaine 6.75 mg + 0.3 mL 2% lidocaine (Group L) or levobupivacaine 6.75 mg + saline (Group C). The main outcome measures were the difference between groups regarding the duration of the spinal block and PACU stay. Secondary outcome measures were the difference between groups in onset and resolution of the spinal block, adverse events and treatments were also investigated.

RESULTS

Spinal block resolved faster in Group L than Group C; 162.43±39.4 min vs 219.73 ± 37.3 min (p = 0.000). PACU time was shorter in Group L (109 ± 49.9 min in Group L vs 148 ± 56.8 min in Group C) (p = 0.036). There was no difference between groups with respect to the incidence of adverse events and treatments. Groups were also similar regarding complications. PDPH and TNS were not observed in any group.

CONCLUSION

Addition of low dose lidocaine to hyperbaric levobupivacaine reduces the duration of the intrathecal block provided by hyperbaric levobupivacaine. This technique can be used to reduce the spinal block duration for relatively short procedures like TUR-P.

Fluid therapy in critical illness: a special focus on indication, the use of hydroxyethyl starch and its different raw materials

PURPOSE OF REVIEW

Fluid therapy is a complex intervention with insufficient resuscitation, as well as overinfusion and fluid accumulation being associated with adverse outcomes. Early goal-directed therapy with later conservative fluid management (i.e. prevention of positive fluid balance and weight gain) appears to markedly improve the survival of patients with severe sepsis. The impact of colloids in resuscitation of patients with sepsis has been the topic of several recently published studies. The purpose of the present review is to outline the indication of fluid administration in critically ill patients, discuss the recent findings of trials involving hydroxyethyl starch (HES) solutions and highlight the impact of different raw materials for HES synthesis.

RECENT FINDINGS

Pragmatic trials of modern HES solutions versus crystalloids in critically ill patients show either no difference or adverse outcomes associated with HES infusion. However, fluid therapy was not protocolized in most of these studies and probably associated with overinfusion and hemodilution. Data on the use of waxy maize-derived 6% HES 130/0.4 during early goal-directed therapy show no evidence for harm and an improvement in microvascular blood flow. In addition, experimental data suggest that waxy maize-derived 6% HES 130/0.4 may have different biological effects compared to potato-derived 6% HES 130/0.42 with potentially reduced pulmonary inflammation.

SUMMARY

Adverse effects of fluid resuscitation in critically ill patients appear to be a consequence of dose and timing rather than the type of fluid itself. Modern waxy maize-derived 6% HES 130/0.4 may have advantages over crystalloids in the very early course of the disease. Clinical trials of early, goal-directed and protocolized therapy with innovative endpoints of resuscitation comparing balanced crystalloids and balanced, waxy maize-derived 6% HES 130/0.4 as the initial resuscitation fluid are warranted.

Addition of lidocaine to bupivacaine for spinal anaesthesia compared with bupivacaine spinal anaesthesia and local infiltration anaesthesia

BACKGROUND

Two spinal anaesthesia techniques were compared with local infiltration anaesthesia (LIA) to test the hypothesis that the addition of lidocaine to bupivacaine would decrease the spinal block's duration and provide shorter recovery to discharge.

METHODS

Ninety-three patients undergoing outpatient herniorrhaphy were randomised into three groups. Spinal anaesthesia: the BL Group (bupivacaine-lidocaine) received 2 ml hyperbaric bupivacaine (10 mg) + 0.6 ml 1% lidocaine (6 mg), the BS Group (bupivacaine-saline) received 2 ml hyperbaric bupivacaine (10 mg) + 0.6 ml saline. LIA: the LIA group received plain bupivacaine + lidocaine. Resolution of the nerve blocks were compared between spinal anaesthesia groups, and post-operative pain scores, analgesic requirements, post-anaesthesia care unit (PACU) time, and discharge time were compared among all groups.

RESULTS

Spinal block resolved faster in the BL group vs. the BS group: 194.8 [standard deviation (SD) 29.2] min vs. 236.8 (SD 36.5) min (P = 0.000). PACU and discharge time were shortest in the LIA group [PACU time: 108.7 (SD 27.6) min vs. 113.0 (SD 39.4) min and 151.9 (SD 43.7) min in the BL and BS groups (P = 0.000), and discharge time 108.5 (SD 29.5) min vs. 145.8 (SD 37.3) min and 177.1 (SD 32.0) min in the BL and BS groups, respectively (P = 0.000)]. Pain scores and analgesic consumption were lower, with the time to first analgesic intake being longer in the LIA group.

CONCLUSION

Addition of lidocaine to bupivacaine reduced the duration of the spinal block and was associated with shorter recovery times. However, LIA provided the fastest recovery to discharge after outpatient inguinal herniorrhaphy.

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