A comparison of spinal, epidural, and general anesthesia for outpatient knee arthroscopy

We compared general, epidural, and spinal anesthesia for outpatient knee arthroscopy (excluding anterior cruciate ligament repairs). Forty-eight patients (ASA physical status I-III) were randomized to receive either propofol-nitrous oxide general anesthesia with a laryngeal mask airway with anesthetic depth titrated to a bispectral index level of 40-60, 15-20 mL of 3% 2-chloroprocaine epidural, or 75 mg of subarachnoid procaine with 20 microg fentanyl. All patients were premedicated with <0.035 mg/kg midazolam and <1 microg/kg fentanyl and received intraarticular bupivacaine and 15-30 mg of IV ketorolac during the procedure. Recovery times, operating room turnover times, and patient satisfaction were recorded by an observer using an objective scale for recovery assessment and a verbal rating scale for satisfaction. Statistical analysis was performed with analysis of variance and chi(2). Postanesthesia care unit discharge times for the general and epidural groups were similar (general = 104+/-31 min, epidural = 92+/-18 min), whereas the spinal group had a longer recovery time (146+/-52 min) (P = 0.0003). Patient satisfaction was equally good in all three groups (P = 0.34). Room turnover times did not differ among groups (P = 0.16). There were no anesthetic failures or serious adverse events in any group. Pruritus was more frequent in the spinal group (7 of 16 required treatment) than in the general or epidural groups (no pruritus) (P<0.001). We conclude that epidural anesthesia with 2-chloroprocaine provides comparable recovery and discharge times to general anesthesia provided with propofol and nitrous oxide. Spinal anesthesia with procaine and fentanyl is an effective alternative and is associated with a longer discharge time and increased side effects. Implications: For outpatient knee arthroscopy, anesthesia can be provided adequately with regional or general anesthesia. Epidural and general anesthesia provide equal recovery times and patient satisfaction, whereas spinal anesthesia may prolong recovery and have increased side effects. The choice of anesthesia may depend primarily on the patient's interest in being alert or asleep during the procedure.     

Stereotactic radiosurgery for cavernous malformations

OBJECT: The use of stereotactic radiosurgery to treat cerebral cavernous malformations (CMs) is controversial. To evaluate the efficacy and safety of CM radiosurgery, the authors reviewed the experience at the Mayo Clinic during the past 10 years. METHODS: Seventeen patients underwent radiosurgery for high-surgical-risk CMs in the following sites: thalamus/basal ganglia (four patients), brainstem (12 patients), and corpus callosum (one patient). All patients had experienced at least two documented hemorrhages before undergoing radiosurgery. Stereotactic magnetic resonance (MR) imaging was used for target localization in all cases. The median margin radiation dose was 18 Gy and the median maximum dose was 32 Gy. The median length of follow-up review following radiosurgery was 51 months. The annual hemorrhage rate during the 51 months preceding radiosurgery was 40.1%, compared with 8.8% in the first 2 years following radiosurgery and 2.9% thereafter. In 10 patients (59%) new neurological deficits developed that were associated with regions of increased signal on long-repetition time MR imaging performed a median of 8 months (range 5-16 months) after radiosurgery. Three patients recovered, giving the group a permanent radiation-related morbidity rate of 41%. Compared with 31 patients harboring arteriovenous malformations (AVMs) of sizes and in locations similar to those of the aforementioned CMs, who underwent radiosurgery during the same time period, the patients with CMs were more likely to experience radiation-related complications (any complication, 59% compared with 10%; p < 0.001; permanent complication, 41% compared with 10%; p = 0.02). CONCLUSIONS: It is impossible to conclude that radiosurgery protects patients with CMs against future hemorrhage risk based on the available data, although it appears that some reduction in the bleeding rate occurs after a latency interval of several years. The risk of radiation-related complications after radiosurgery to treat CMs is greater than that found after radiosurgery in AVMs, even when adjusting for lesion size and location and for radiation dose.     

食品中明矾含量的快速测定方法

目的建立一种能简单快速检测食品中明矾含量的方法。方法采用特征离子鉴别方法定性,用Na2EDTA络合滴定方法定量。结果该方法回收率在99.0%~102.8%之间,RSD在0.91%~1.38%之间。结论方法操作简单,准确性好,适合于大批量样本检测。     

Anticoagulation of children undergoing cardiopulmonary bypass is overestimated by current monitoring techniques

HYPOTHESIS: Children who undergo cardiopulmonary bypass (CPB) are proportionally more hemodiluted than adults who undergo CPB. Current methods of monitoring high-dose heparin sulfate anticoagulation are dependent on fibrinogen level. Because of the decreased fibrinogen levels in children, current methods of monitoring heparin anticoagulation overestimate their level of anticoagulation. DESIGN: Prospective controlled trial. MAIN OUTCOME MEASURE: Production of thrombin (adequacy of anticoagulation). METHODS: Children and adults undergoing cardiac surgery who received CPB were anticoagulated in the standard fashion as directed by activated clotting time (ACT) results. Each subject had blood sampled at baseline; heparinization; start of the CPB; CPB at 30, 60, and 90 minutes; and at termination of CPB. Samples were used to assess anticoagulation with the Heparin Management Test (less dependent on fibrinogen level than ACT). We also assessed 2 subclinical markers of thrombosis, thrombin-antithrombin complexes and prothrombin fragment F1.2; a marker of procoagulant reserve, fibrinogen; the natural antithrombotic, antithrombin; and heparin concentration. RESULTS: Ten children and 10 adults completed the study. Children had lower fibrinogen levels than adults throughout CPB (P<.05). All adults had both therapeutic ACT and Heparin Management Test levels measured throughout CPB. Although children had therapeutic ACT levels, their Heparin Management Test levels were subtherapeutic while undergoing CPB. The children had significantly higher thrombin-antithrombin complexes and prothrombin fragment F1.2 than adults, indicating ongoing thrombin production (P<.01). The increases in thrombin-antithrombin complexes and prothrombin fragment F1.2 in children were inversely proportional to their weight. CONCLUSIONS: Children undergoing CPB with heparin dosing adjusted to optimize the ACT manifest inadequate anticoagulation (ongoing thrombin formation). High-dose heparin anticoagulation therapy in children undergoing CPB should be directed by tests (like the Heparin Management Test) that are less dependent on fibrinogen level than ACT.     

Effects of Drinking-Water Filtration on Cryptosporidium Seroepidemiology,Scotland

Continuous exposure to low levels of Cryptosporidium oocysts is associated with production of protective antibodies. We investigated prevalence of antibodies against the 27-kDa Cryptosporidium oocyst antigen among blood donors in 2 areas of Scotland supplied by drinking water from different sources with different filtration standards: Glasgow (not filtered) and Dundee (filtered). During 2006–2009, seroprevalence and risk factor data were collected; this period includes 2007, when enhanced filtration was introduced to the Glasgow supply. A serologic response to the 27-kDa antigen was found for ≈75% of donors in the 2 cohorts combined. Mixed regression modeling indicated a 32% step-change reduction in seroprevalence of antibodies against Cryptosporidium among persons in the Glasgow area, which was associated with introduction of enhanced filtration treatment. Removal of Cryptosporidium oocysts from water reduces the risk for waterborne exposure, sporadic infections, and outbreaks. Paradoxically, however, oocyst removal might lower immunity and increase the risk for infection from other sources.     

Prosthetic mitral valve thrombosis,malfunction, and paroxysmal mitral regurgitation

Intermittent dysfunction of mechanical mitral valve prosthesis is an uncommon condition. It carries serious clinical implications if unrecognized. Here, we present a case of a 28‐year‐old female with a history of rheumatic multivalvular disease, for which she had undergone double valve replacement and tricuspid annuloplasty. Six months later, she presented with heart failure. Clinical examination revealed intermittent loss of closing clicks followed by a pansystolic murmur at the apex, suggestive of mitral prosthetic valve dysfunction. We highlight the echocardiographic findings of paroxysmal mitral valvular regurgitation secondary to prosthetic valve malfunction secondary to prosthetic valve thrombosis.