Risk Of Transient Neurologic Symptoms Research Articles

Single-dose lidocaine spinal anesthesia in hip and knee arthroplasty.

BackgroundWith the increasing interest in fast recovery and outpatient joint arthroplasty, short-acting local anesthetic agents and minimal narcotic use are preferred. Lidocaine is a fast-onset, short-duration local anesthetic that has been used for many years in spinal anesthesia. However, lidocaine spinal anesthesia has been reported to have a risk of transient neurologic symptoms (TNSs). The purpose of this study is to determine the safety and efficacy of single-dose lidocaine spinal anesthesia in the setting of outpatient joint arthroplasty.MethodsWe performed a prospective study on 50 patients who received lidocaine spinal anesthesia in the setting of outpatient hip and knee arthroplasty. All patients received a single-shot spinal injection, with 2% isobaric lidocaine along with titrated propofol sedation. We evaluated demographic data, length of motor blockage, time to ambulation, time to discharge readiness, patient-reported symptoms of TNS.ResultsOf the 50 patients studied, 11 had total hip arthroplasty, 33 total knee arthroplasty, 5 unicompartmental knee arthroplasty, and 1 underwent isolated polyethylene liner exchange in a total knee arthroplasty. The average total duration of motor blockade was 2.89 hours (range 1.73-5.17, standard deviation 0.65). Average time from postanesthesia care unit to return of motor function was 0.58 hours (range 0-1.5, standard deviation 0.48). None of the patients reported TNS.ConclusionsIsobaric lidocaine spinal anesthesia appears to be a safe and effective regimen for outpatient hip and knee arthroplasty. All patients were discharged on the day of surgery with isobaric lidocaine spinal injection. There were no reports of TNSs.

Spinal anesthesia revisited: toxicity of new and old drugs and compounds.

Neural toxicity of substances injected into the intrathecal space has been a matter of debate since the introduction of spinal anesthesia in clinical practice. In recent years, new local anesthetics and adjuvants have been proposed for intrathecal use, and new techniques such as the use of ultrasound have been propagated. The present review summarizes recent clinical and experimental data on the neurotoxic effects of drugs and substances used for or in conjunction with spinal anesthesia. Chloroprocaine has been demonstrated to be associated with a lower risk of transient neurologic symptoms compared with lidocaine. However, despite extensive research, the issue of chloroprocaine or bisulfite neurotoxicity has not yet been resolved.Recent experimental data have identified a smaller neurotoxic potential for ropivacaine compared to levobupivacaine, procaine and bupivacaine. The addition of epinephrine has not been shown to increase lidocaine neurotoxicity. In-vivo experimental data suggest that lidocaine and bupivacaine neurotoxicity is not enhanced in diabetic patients.Furthermore, intrathecal introduction of aqueous ultrasound gel has been demonstrated to cause a distinct neuroinflammatory reaction. Finally, a large cohort study did not find the use of chlorhexidine gluconate for skin disinfection before neuraxial block to be associated with the risk of adhesive arachnoiditis. Clinical data suggest a high safety profile for intrathecal drugs and substances used for or in conjunction with spinal anesthesia. Recent experimental models for toxicity have provided further insight into the mechanisms and demonstrated possible, albeit clinically small differences in the relative neurotoxic potential of intrathecal drugs. This may contribute to a further increase in the safe use of spinal anesthesia in the clinical setting.

Practical use of local anesthetics in regional anesthesia.

The choice of local anesthetics in regional anesthesia depends on desired onset, intensity, and duration of block, as well as possible adverse effects. This review highlights recent advances in day-case spinal anesthesia; considerations in selecting local anesthetic volume, concentration, and mass in peripheral nerve blockade; and the pharmacokinetics of ropivacaine. Spinal anesthesia using 2-chloroprocaine offers fast onset and rapid recovery, whereas mepivacaine and lidocaine are suitable for longer procedures. Intrathecal lidocaine in the lithotomy position carries a significant risk of transient neurologic symptoms and should be avoided. Dosing studies of local anesthetics in peripheral nerve blockade suggest that mass of drug, not volume or concentration, primarily determines block onset, success, and duration. Commonly used doses of ropivacaine for Transversus Abdominis Plane blocks can result in high plasma concentrations and local anesthetic systemic toxicity. There are effective alternatives to bupivacaine in day-case spinal anesthesia but more safety and outcome data are required, particularly for 2-chloroprocaine. The trend toward smaller doses of local anesthetics in ultrasound-guided regional anesthesia improves safety but should be weighed against possible reductions in speed of onset and analgesic duration. Strategies to reduce the risk of local anesthetic systemic toxicity should be employed when performing large-volume fascial plane blocks with ropivacaine.

The Effect of Needle Type, Duration of Surgery and Position of the Patient on the Risk of Transient Neurologic Symptoms

BackgroundThe incidence of transient neurologic symptoms (TNS) after spinal anesthesia with lidocaine is reported as high as 40%.ObjectivesThis prospective clinical trial was designed to determine the incidence of TNS in patients who underwent spinal anesthesia with two different needles, in two different surgical positions.Patients and MethodsThe present randomized clinical trial was conducted on 250 patients (ASA I-II), who were candidates for surgery in supine or lithotomy positions. According to the needle type (Sprotte or Quincke) and local anesthetics (lidocaine and bupivacaine) all patients were randomly divided into four groups. After performing spinal anesthesia in sitting position, the position was changed into supine or lithotomy, according to surgical procedure. The patients were observed for complications of spinal anesthesia during the first five post-operative days. The primary end-point for this trial was to recognize the incidence of TNS among the four groups. Our secondary objective was to evaluate the effect of patient's position, needle type, and duration of surgery on the development of TNS following spinal anesthesia.ResultsTNS was most commonly observed when lidocaine was used as anesthetic drug (P = 0.003). The impact of needle type, was not significant (P = 0.7). According to multivariate analysis, the duration of surgery was significantly lower in cases suffering from TNS (P = 0.04). Also, the risk of TNS increased following surgeries performed in lithotomy position (P = 0.00).ConclusionsAccording to the results of this clinical study, spinal anesthesia with lidocaine, and the lithotomy position in surgery increased the risk of TNS.

Current issues in spinal anesthesia.

Spinal anesthesia is an old, simple, and popular anesthetic technique, yet much remains unknown regarding pertinent anatomy, physiology, and pharmacology. Investigations into physiologic effects of spinal anesthesia reveal complex actions on multiple organ systems. New local anesthetics, analgesic additives, and techniques are being investigated for different applications as the practice of medicine focuses on outpatient care. Safety of spinal agents and complications from spinal anesthesia continue to be examined and re-examined to improve safety. Further study will be needed to fully resolve these issues and to further understand and improve the clinical use of spinal anesthesia.

Transient neurologic symptoms after spinal anesthesia: an epidemiologic study of 1,863 patients.

Recent evidence suggests that transient neurologic symptoms commonly follow lidocaine spinal anesthesia. However, information concerning factors that affect their occurrence is limited. Accordingly, to evaluate many potential risk factors, the authors undertook a prospective, multicenter, epidemiologic study. On a voluntary basis, anesthetists at 15 participating centers forwarded a data sheet on patients who had spinal anesthesia to a research nurse blinded to the details of anesthesia and surgery. A subset was randomly selected for follow-up. The pressure [corrected] of transient neurologic symptoms, defined as leg or buttock pain, was the principal outcome variable. Logistic regression was used to control for potential confounders, and adjusted odds ratios and confidence intervals were used to estimate relative risk. During a 14-month period, 1,863 patients were studied, of whom 47% received lidocaine, 40% bupivacaine, and 13% tetracaine. Patients given lidocaine were at higher risk for symptoms compared with those receiving bupivacaine (relative risk, 5.1; 95% CI, 2.5 to 10.2) or tetracaine (relative risk, 3.2; 95% CI, 1.04 to 9.84). For patients who received lidocaine, the relative risk of transient neurologic symptoms was 2.6 (95% CI, 1.5 to 4.5) with the lithotomy position compared with other positions, 3.6 (95% CI, 1.9 to 6.8), for outpatients compared with inpatients, and 1.6 (95% CI, 1 to 2.5) for obese (body mass index >30) compared with nonobese patients. These results indicate that transient neurologic symptoms commonly follow lidocaine spinal anesthesia but are relatively uncommon with bupivacaine or tetracaine. The data identify lithotomy position and outpatient status as important risk factors in patients who receive lidocaine. Among other factors postulated to increase risk, obesity had an effect of borderline statistical significance, whereas age, sex, history of back pain, needle type, and lidocaine dose and concentration failed to affect risk.