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

BACKGROUND: With 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. METHODS: We 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. RESULTS: Of 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. CONCLUSIONS: Isobaric 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.

Squeeze Me if You Can: Variability in Force Requirements to Extract a Drop From Common Glaucoma Bottles.

PURPOSE: To determine the force requirements to dispense a single drop from commonly prescribed brand and generic topical glaucoma medications and correlate these findings with pinch strength in a representative patient population. PATIENTS AND METHODS: Four bottles of each medication were tested: 2 in the vertical and 2 in the horizontal orientation. Bottles were housed in a customized force gauge apparatus designed to mimic ballpoint fingertip contact with a bottle tip. For all bottles, each of the first 10 dispensed drops was tested and then tests were performed in increments of 10 until the bottle was empty. For each tested drop, the maximum force and displacement were electronically measured. Concurrently, maximum pinch strength was measured on consecutive glaucoma patients. RESULTS: A total of 84 bottles from 21 bottle designs were tested. There was significant variability across the designs, with roughly a 7-fold (0.67 to 4.49 kgf) and 4-fold (0.81 to 3.00 kgf) difference in force requirements in the vertical and horizontal positions, respectively. Of 53 enrolled patients in the glaucoma clinic, the mean pinch strength was 5.05 (range, 1.23 to 10.4 kgf) and 4.82 (range, 1.47 to 10.67 kgf) kgf for the right and left hands, respectively. CONCLUSIONS: There is statistically significant variability in the force required to squeeze a drop from common glaucoma medications, and a representative sampling of clinic patients suggests that many likely struggle with the force requirements of several bottle designs. These data further support standardization of topical glaucoma drug delivery and design.

Outpatient Hip and Knee Replacement: The Experience From the First 15 Years.

Rapid recovery and early discharge after total joint arthroplasty are becoming more common. To develop a successful, safe, outpatient arthroplasty practice, surgeons must have the support of a multidisciplinary team, which includes an orthopaedic surgeon, an anesthesiologist, nurses, physical therapists, and a discharge planner. The authors of this chapter recommend surgeons start with healthier, motivated patients and focus on total hip replacements and unicompartmental knee replacements in the learning curve phase of the transition to outpatient total joint arthroplasty. It is important for orthopaedic surgeons to establish an outpatient joint arthroplasty protocol as well as ways to avoid complications and delays in discharge.

The long elusive IgM Fc receptor, FcµR.

IgM exists as both a monomer on the surface of B cells and a pentamer secreted by plasma cells. Both pre-immune "natural" and antigen-induced "immune" IgM antibodies are important for protective immunity and for immune regulation of autoimmune processes by recognizing pathogens and self-antigens. Effector proteins interacting with the Fc portion of IgM, such as complement and complement receptors, have thus far been proposed but fail to fully account for the IgM-mediated protection and regulation. A major reason for this deficit in our understanding of IgM function seems to be lack of data on a long elusive Fc receptor for IgM (FcµR). We have recently identified a bona fide FcµR in both humans and mice. In this article we briefly review what we have learned so far about FcµR.

Risk of symptomatic venous thromboembolism associated with flying in the early postoperative period following elective total hip and knee arthroplasty.

Air travel and total joint arthroplasty (TJA) are both risk factors for venous thromboembolism (VTE). Patients are counseled against flying after surgery, however the basis for this recommendation has not been investigated and may be unfounded. A retrospective cohort of 1465 consecutive TJA patients was divided into a study population of 220 patients (15.0%) who flew home at a mean of 2.9 days after surgery (range, 1-10 days) and a control population of 1245 patients (85.0%) who did not fly. We found no differences in the rate of deep vein thrombosis, pulmonary embolism, or overall VTE between the groups, and incidence of all events was low in both groups and comparable with published data. Allowing air travel after TJA appears to be a safe practice.

The ability of healthy volunteers to simulate a neurologic field defect on automated perimetry.

OBJECTIVE: To determine if volunteers can simulate and reproduce 3 types of neurologic field defects: hemianopia, quadrantanopia, and central scotoma. DESIGN: Cross-sectional study. PARTICIPANTS: Thirty healthy volunteers new to perimetry (including automated perimetry). METHODS: After informed consent, volunteers were randomized to 1 of the 3 visual field defects listed above. All visual field testing was performed on the right eye using the Humphrey Field Analyzer (HFA; Carl Zeiss Meditec, Dublin, CA) SITA Fast 24-2 protocol. Each volunteer was provided with standard new patient instructions and was shown a diagram of the defect to be simulated. Two sets of visual fields were performed on the right eye with 10 minutes between tests. Three experts used the Ocular Hypertension Treatment Study reading center criteria and determined if the simulation was successful. MAIN OUTCOME MEASURES: Proportion of volunteers able to simulate the assigned visual field. RESULTS: All 10 volunteers (100%) successfully simulated a hemianopia on the first and second fields. All 10 volunteers (100%) simulated a quadrantanopia on the first field and 9 (90%) did so on the second field. Eight volunteers (80%) successfully simulated a central scotoma in the first field and all 10 (100%) did so on in the second field. Reliability criteria were excellent. Forty-seven fields (78%) had 0 fixation losses, 48 (80%) had 0 false-positive results, and 44 (73%) had 0 false-negative results. CONCLUSIONS: It is easy to simulate reproducible and reliable neurologic field defects on automated perimetry using HFA.

Advances in functional use of sweet potato, [Ipomoea batatas (L.) Lam].

This article reviews the patents that have been presented over the past two decades related to alternative functional use of the Sweet potato, Ipomoea batatas (L.) Lam. The major categories of available patents include alternative food products such as Sweet potato chips and fries, Sweet potato ornamental products, and fuel ethanol production from Sweet potato. The majority of recent patents fall under the category of ornamental products and alternative food products, with only a few fuel ethanol products. Figure 1 shows the major categories of patented alternative products from Sweet potato.

Newer anesthesia and rehabilitation protocols enable outpatient hip replacement in selected patients.

UNLABELLED: Advancements in the surgical approach, anesthetic technique, and the initiation of rapid rehabilitation protocols have decreased the duration of hospitalization and subsequent length of recovery following elective total hip arthroplasty. We assessed the feasibility and safety of outpatient total hip arthroplasty in 150 consecutive patients. A comprehensive perioperative anesthesia and rehabilitation protocol including preoperative teaching, regional anesthesia, and preemptive oral analgesia and antiemetic therapy was implemented around a minimally invasive surgical technique. A rapid rehabilitation pathway was started immediately after surgery and patients had the option of being discharged to home the day of surgery if standard discharge criteria were met. All 150 patients were discharged to home the day of surgery, at which time 131 patients were able to walk without assistive devices. Thirty-eight patients required some additional intervention outside the pathway to resolve nausea, hypotension, or sedation prior to discharge. There were no readmissions for pain, nausea, or hypotension yet there was one readmission for fracture and nine emergency room evaluations in the three month perioperative period. This anesthetic and rehabilitation protocol allowed outpatient total hip arthroplasty to be routinely performed in these consecutive patients undergoing primary total hip arthroplasty. With current reimbursement approaches the modest savings to the hospital in length of stay may be outweighed by the additional costs of personnel, thereby making this outpatient system more expensive to implement. LEVEL OF EVIDENCE: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

The feasibility and perioperative complications of outpatient knee arthroplasty.

UNLABELLED: The duration of hospitalization and subsequent length of recovery after elective knee arthroplasty have decreased. We hypothesized same-day discharge following either a unicompartmental (UKA) or total knee arthroplasty (TKA) in an unselected group of patients would not result in a higher perioperative complication rate than standard-length hospitalization when following a comprehensive perioperative clinical pathway, including preoperative teaching, regional anesthesia, preemptive oral analgesia, preemptive antiemetics, and a rapid rehabilitation protocol. We prospectively followed 111 of all 121 patients who had primary knee arthroplasty completed by noon and who agreed to be followed prospectively; 25 had UKA and 86 TKA. Of the 111 patients, 104 (94%, 24 with UKA and 80 with TKA) met discharge criteria and were discharged directly to home the day of surgery. Nausea requiring additional treatment before discharge was the most common reason for a delay in discharge. There were four (3.6%) readmissions (all with TKA) and one emergency room visit without readmission (in a patient with a TKA) within the first week after surgery, while there were four subsequent readmissions (3.6%) and one additional emergency room visit without readmission within three months of surgery, all among patients undergoing TKA. There were no deaths, cardiac events, or pulmonary complications during this study. Outpatient knee arthroplasty surgery is feasible in a large percentage of patients yet early readmissions may be decreased with a prolonged hospitalization. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Outpatient total knee arthroplasty with a minimally invasive technique.

Fifty consecutive patients were enrolled in this prospective study. This was 37% of the 135 patients undergoing primary total knee arthroplasty (TKA) by one surgeon. The average patient age was 68 years (50-79 years). A comprehensive perioperative management pathway was developed and was implemented, which combined regional anesthesia with a minimally invasive, TKA technique in which the only incision in the capsule and extensor mechanism is a capsular incision from the joint line to the superior pole of the patella. Postoperatively, patients received oral analgesia. After specific discharge criteria were met, 48 patients (96%) chose to go home the day of surgery. No intraoperative complications occurred. There were 3 readmissions, none related to early discharge: gastrointestinal bleed at 8 days, superficial irrigation and debridement at 21 days, and a closed manipulation at 9 weeks. This study demonstrates that, in these selected patients, outpatient TKA was safe with no short-term readmission or complications related to early discharge. This comprehensive pathway may make it possible for this minimally invasive TKA to be done as an outpatient in specialized surgicenters in the future.