Anesthetic and recovery profiles of lidocaine versus mepivacaine for spinal anesthesia in patients undergoing outpatient orthopedic arthroscopic procedures

Study ObjectiveTo compare isobaric lidocaine and mepivacaine in outpatient arthroscopic surgery.DesignProspective, randomized, double-blinded study.SettingAmbulatory surgery center affiliated with an academic tertiary-care hospital.Patients84 adult, ASA physical status 1, 2, and 3 ambulatory patients, age 18-70 years, undergoing arthroscopic knee surgery.InterventionPatients were randomized to receive a combination spinal-epidural anesthetic using 80 mg of either isobaric 2% mepivacaine or isobaric 2% lidocaine. Patients also received a femoral 3-in-1 block with 0.5% bupivacaine applied to the affected extremity.MeasurementsDemographic data and level and duration of the block were recorded. The use of supplemental epidural anesthesia was noted along with frequency of bradycardia, hypotension, and episodes of nausea and vomiting. Duration of block and times to ambulation and voiding were recorded. Delayed variables, including fatigue, difficulty urinating, back pain, and transient neurologic symptoms (TNS) were obtained.Main ResultsNo demographic differences were noted between groups, and surgical duration was similar. Satisfactory anesthesia was achieved in all cases, with no differences noted in hypotension, bradycardia, nausea, or vomiting. Onset of sensory and motor block was similar. Duration of block before epidural supplementation was 94 ± 21 minutes with lidocaine versus 122 ± 23 minutes for mepivacaine (P < 0.011). Times to ambulation and voiding were longer in patients receiving mepivacaine but did not affect PACU stay. Twenty-four and 48-hour recovery was similar with no TNS symptoms reported.ConclusionNo major differences were noted between lidocaine and mepivacaine spinal anesthesia. Time to ambulation and voiding were longer in patients who received mepivacaine as was time to first dose of epidural catheter. Neither group had TNS symptoms. Lidocaine and mepivacaine are both appropriate spinal anesthetics for ambulatory orthopedic lower extremity procedures.     

Safety of total hip replacement following an intra-articular steroid hip injection--an audit

The aim of this study was to determine the deep infection rates in patients who underwent a total hip replacement after having had a prior diagnostic steroid injection into the same hip. We identified and reviewed the case notes, relevant radiographs and microbiology reports of all patients who underwent a total hip replacement after a diagnostic steroid hip injection in our unit from 1 January 2007 to 31 April 2009. There were 40 patients. (10 males and 30 females) Their mean age was 68.4 (52-82) years. The mean time interval from the injection to the joint replacement was 6.2 (2-23) months. The mean follow-up was 23.2 (11-37) months. None of the patients in the study group developed a deep infection during this followup period. Diagnostic intra articular steroid and local anaesthetic injection prior to total hip replacement appears to be safe.     

In Vitro and In Vivo Efficacy of β-Lactams against Replicating and Slowly Growing/Nonreplicating Mycobacterium tuberculosis

Beta-lactams, in combination with beta-lactamase inhibitors, are reported to have activity against Mycobacterium tuberculosis bacteria growing in broth, as well as inside the human macrophage. We tested representative beta-lactams belonging to 3 different classes for activity against replicating M. tuberculosis in broth and nonreplicating M. tuberculosis under hypoxia, as well as against streptomycin-starved M. tuberculosis strain 18b (ss18b) in the presence or absence of clavulanate. Most of the combinations showed bactericidal activity against replicating M. tuberculosis, with up to 200-fold improvement in potency in the presence of clavulanate. None of the combinations, including those containing meropenem, imipenem, and faropenem, killed M. tuberculosis under hypoxia. However, faropenem- and meropenem-containing combinations killed strain ss18b moderately. We tested the bactericidal activities of meropenem-clavulanate and amoxicillin-clavulanate combinations in the acute and chronic aerosol infection models of tuberculosis in BALB/c mice. Based on pharmacokinetic/pharmacodynamic indexes reported for beta-lactams against other bacterial pathogens, a cumulative percentage of a 24-h period that the drug concentration exceeds the MIC under steady-state pharmacokinetic conditions (%T_MIC) of 20 to 40% was achieved in mice using a suitable dosing regimen. Both combinations showed marginal reduction in lung CFU compared to the late controls in the acute model, whereas both were inactive in the chronic model.     

Laparoscopic removal of an artery forceps.

Numerous foreign bodies, such as surgical gauze, pads and instruments, and other items, have been left behind in the abdominal cavity during open surgeries. These have been traditionally removed at redo open surgeries. Here we describe a case of an artery forceps left behind at a previous surgery (open cholecystectomy and appendicectomy) performed 5 years earlier that was removed by laparoscopy.     

Abnormalities of the auditory brainstem response in post-meningitic infants and children

The auditory brainstem response (ABR) was recorded in 86 infants and children from 1 month to 14 years of age following episodes of bacterial or viral meningitis. Thirty-two demonstrated some degree of cochlear impairment There was a high incidence of neurological sequellae in these children. Eight children exhibited abnormal changes suggestive of brainstem dysfunction Six of these eight children also had abnormal neurologic examination. Recovery, or at least improvement in the ABR, occurred in six infants who were assessed upon discharge from the hospital, and then again several months post-hospitalization. In each case improvement was attributed to a resolving conductive component.The ABR was found to be effective for identifying hearing impairment and brainstem dysfunction in pediatric patients following central nervous system infection. Objective information, not available from other methods of assessment was obtained.     

Age related changes in muscle protein degradation.

In vitro autolytic degradation of sarcoplasmic proteins in red, white and cardiac muscles increases with advance in age and with increase in temperature, the rate varying with age. Higher activity is seen in the alkaline range in all age groups. Ca2+ activated proteolytic activity also increases with advance in age.     

Effect of acute hypoxia on blood serotonin in human beings and rats.

The object of this study was to see if the blood level of 5-hydroxytryptamine (5-HT) increased under acute hypoxic stress in human beings and rats. Soldiers who had been stationed at high altititudes 2-7 months prior to study were selected. 17 had suffered from pulmonary oedema and the remaining eight, who had not developed the condition, acted as controls. The technique of YUWILER [18] with suitable modifications was used for estimation of 5-HT. No significant change in 5-HT levels was observed either in subjects or controls. Rats exposed to simulated high altitude for 6 h also did not show any significant change in blood 5-HT levels.