SARS-CoV-2 Specific Nanobodies Neutralize Different Variants of Concern and Reduce Virus Load in the Brain of h-ACE2 Transgenic Mice.

Since the beginning of the COVID-19 pandemic, there has been a significant need to develop antivirals and vaccines to combat the disease. In this work, we developed llama-derived nanobodies (Nbs) directed against the receptor binding domain (RBD) and other domains of the Spike (S) protein of SARS-CoV-2. Most of the Nbs with neutralizing properties were directed to RBD and were able to block S-2P/ACE2 interaction. Three neutralizing Nbs recognized the N-terminal domain (NTD) of the S-2P protein. Intranasal administration of Nbs induced protection ranging from 40% to 80% after challenge with the WA1/2020 strain in k18-hACE2 transgenic mice. Interestingly, protection was associated with a significant reduction in virus replication in nasal turbinates and a reduction in virus load in the brain. Employing pseudovirus neutralization assays, we identified Nbs with neutralizing capacity against the Alpha, Beta, Delta, and Omicron variants, including a Nb capable of neutralizing all variants tested. Furthermore, cocktails of different Nbs performed better than individual Nbs at neutralizing two Omicron variants (B.1.529 and BA.2). Altogether, the data suggest the potential of SARS-CoV-2 specific Nbs for intranasal treatment of COVID-19 encephalitis.

Abbe Flap Division Before Two Weeks' Time: Harmful or Advantageous?

INTRODUCTION: The Abbe flap is a standard intervention to treat upper lip deformities in patients with bilateral cleft lip. This two-stage procedure requires a 2 to 3-week period in which the superior and inferior lips remain connected. This study evaluates the safety of Abbe flap division and inset prior to 14 days' time. MATERIALS AND METHODS: A single institution, 8-year review of all patients with a bilateral cleft lip who underwent Abbe flap reconstruction was performed. Patients were classified into two groups: those whom division was performed 14 days or later and those with division earlier than 14 days. RESULTS: A total of 26 patients were identified. Patients who underwent Abbe flap division in less than 14 days (n = 10) demonstrated an average time to division of 9.7 days (range 7-13 days) with no evidence of flap loss, wound breakdown or infection. Patients who underwent Abbe flap division within 14 days or more (n = 16) demonstrated an average time to division of 15 days with four minor complications and no flap loss. CONCLUSION: Dividing the Abbe flap after the first postoperative week appears to be safe and without additional risk to flap loss or wound breakdown. A shorter time to Abbe flap division may decrease the burden of care on patients and their caregivers.

Exploring the immunogenicity of an insect-specific virus vectored Zika vaccine candidate.

Zika virus (ZIKV) is an important re-emerging flavivirus that presents a significant threat to human health worldwide. Despite its importance, no vaccines are approved for use in humans. Insect-specific flaviviruses (ISFVs) have recently garnered attention as an antigen presentation platform for vaccine development and diagnostic applications. Here, we further explore the safety, immunogenicity, and efficacy of a chimeric ISFV-Zika vaccine candidate, designated Aripo-Zika (ARPV/ZIKV). Our results show a near-linear relationship between increased dose and immunogenicity, with 1011 genome copies (i.e., 108 focus forming units) being the minimum dose required for protection from ZIKV-induced morbidity and mortality in mice. Including boosters did not significantly increase the short-term efficacy of ARPV/ZIKV-vaccinated mice. We also show that weanling mice derived from ARPV/ZIKV-vaccinated dams were completely protected from ZIKV-induced morbidity and mortality upon challenge, suggesting efficient transfer of maternally-derived protective antibodies. Finally, in vitro coinfection studies of ZIKV with Aripo virus (ARPV) and ARPV/ZIKV in African green monkey kidney cells (i.e., Vero-76) showed that ARPV and ARPV/ZIKV remain incapable of replication in vertebrate cells, despite the presence of active ZIKV replication. Altogether, our data continue to support ISFV-based vaccines, and specifically the ARPV backbone is a safe, immunogenic and effective vaccine strategy for flaviviruses.

Global Prevalence and Burden of Orofacial Clefts: A Systematic Analysis for the Global Burden of Disease Study 2019.

Orofacial clefts, in particular cleft lip and cleft palate, are among the most common congenital anomalies. Despite guidelines recommending early surgical correction, a global backlog of untreated patients persists. This has made orofacial clefts an attractive target for global cleft care initiatives. The most recent global burden of orofacial clefts was estimated to be 529,758.92 disability-adjusted life years (95% uncertainty interval: 362,492.88-798,419.69 disability-adjusted life years), whereas the global prevalence of orofacial clefts was estimated to be 4.6 million (95% uncertainty interval: 3.8-5.7 million). An inverse relationship exists between the Sociodemographic Index and the burden of orofacial clefts. Sub-Saharan Africa, Middle East/North Africa, and South Asia are the regions carrying the most significant burden of orofacial clefts. This manuscript provides updated estimates of the global burden and prevalence of orofacial clefts, acting as a guide to direct future investments, resources, and initiatives from individuals and organizations engaged in global cleft care delivery with the goal of building sustainable cleft care capacity where it is needed the most.

Nanobodies against SARS-CoV-2 reduced virus load in the brain of challenged mice and neutralized Wuhan, Delta and Omicron Variants.

In this work, we developed llama-derived nanobodies (Nbs) directed to the receptor binding domain (RBD) and other domains of the Spike (S) protein of SARS-CoV-2. Nanobodies were selected after the biopanning of two VHH-libraries, one of which was generated after the immunization of a llama (lama glama) with the bovine coronavirus (BCoV) Mebus, and another with the full-length pre-fused locked S protein (S-2P) and the RBD from the SARS-CoV-2 Wuhan strain (WT). Most of the neutralizing Nbs selected with either RBD or S-2P from SARS-CoV-2 were directed to RBD and were able to block S-2P/ACE2 interaction. Three Nbs recognized the N-terminal domain (NTD) of the S-2P protein as measured by competition with biliverdin, while some non-neutralizing Nbs recognize epitopes in the S2 domain. One Nb from the BCoV immune library was directed to RBD but was non-neutralizing. Intranasal administration of Nbs induced protection ranging from 40% to 80% against COVID-19 death in k18-hACE2 mice challenged with the WT strain. Interestingly, protection was not only associated with a significant reduction of virus replication in nasal turbinates and lungs, but also with a reduction of virus load in the brain. Employing pseudovirus neutralization assays, we were able to identify Nbs with neutralizing capacity against the Alpha, Beta, Delta and Omicron variants. Furthermore, cocktails of different Nbs performed better than individual Nbs to neutralize two Omicron variants (B.1.529 and BA.2). Altogether, the data suggest these Nbs can potentially be used as a cocktail for intranasal treatment to prevent or treat COVID-19 encephalitis, or modified for prophylactic administration to fight this disease.

Hyperbaric Oxygen Therapy for Threatened Nipple-Sparing Mastectomy Flaps: An Adjunct for Flap Salvage.

BACKGROUND: Nipple-sparing mastectomy (NSM) is emerging as the standard of care for treatment of breast cancer because of its oncologic safety and superior aesthetic outcomes. However, ischemia or necrosis of the skin flap and/or nipple-areola complex remain frequent complications. Hyperbaric oxygen therapy (HBOT) has emerged as a potential adjunct for flap salvage, although it is not currently a widely accepted practice. Here we review our institution's experience using a protocol of HBOT in patients with signs of flap ischemia or necrosis after NSM. METHODS: Retrospective review identified all patients treated with HBOT at our institution's hyperbaric and wound care center because of signs of ischemia after NSM. Treatment parameters consisted of 90-minute dives at 2.0 atmosphere once or twice daily. Patients unable to tolerate dives were considered a treatment failure, whereas those lost to follow-up were excluded from analysis. Patient demographics, surgical characteristics, and treatment indications were recorded. Primary outcomes assessed were flap salvage (no operative revision), need for revision procedures, and treatment complications. RESULTS: A total of 17 patients and 25 breasts met the inclusion criteria. The mean ± SD time to initiation of HBOT was 9.47 ± 12.7 days. The mean ± SD age was 46.7 ± 10.4 years, and mean ± SD follow-up time was 36.5 ± 25.6 days. Indications for NSM included invasive cancer (41.2%), carcinoma in situ (29.4%), and breast cancer prophylaxis (29.4%). Initial reconstruction included tissue-expander placement (47.1%), autologous reconstruction with deep inferior epigastric flaps (29.4%), and direct-to-implant reconstruction (23.5%). Hyperbaric oxygen therapy indications included ischemia or venous congestion for 15 breasts (60.0%) and partial thickness necrosis for 10 breasts (40.0%). Flap salvage was achieved in 22 of 25 breasts (88.0%). Reoperation was required for 3 breasts (12.0%). Hyperbaric oxygen therapy-related complications were observed in 4 patients (23.5%), which included 3 patients with mild ear pain and 1 patient with severe sinus pressure leading to treatment abortion. CONCLUSIONS: Nipple-sparing mastectomy is an invaluable tool for breast and plastic surgeons to achieve oncologic and cosmetic goals. However, ischemia or necrosis of the nipple-areola complex or mastectomy skin flap remains frequent complications. Hyperbaric oxygen therapy has emerged as a possible intervention for threatened flaps. Our results demonstrate the utility of HBOT in this population to achieve excellent NSM flap salvage rates.

LeFort III/I for Beckwith-Wiedemann Syndrome: A Case Report.

This case presents a facially mature patient with Beckwith-Wiedemann Syndrome (BWS) who presented with severe class III malocclusion. Computed tomography imaging revealed an anterior crossbite of 19 mm and a narrow pharyngeal airway at the level of the tongue base precluding mandibular setback surgery. The patient was indicated for a LeFort III combined with a LeFort I advancement, each of 10 mm, for a 20 mm combined advancement. Stable, functional occlusion was achieved without airway compromise. This novel use of the combined LeFort III/I can restore stable class I occlusion in patients with BWS at risk for tongue base airway compromise.

Reawakening Neuritis of the Median Nerve after Carpal Tunnel Release: Defining and Predicting Patients at Risk.

BACKGROUND: Patients with long-standing carpal tunnel symptoms may develop transient and, paradoxically, worsened neuropathic pain immediately following release. The authors have termed this "reawakening phenomenon." The purpose of this study was to compare the characteristics of patients with this phenomenon to those with a standard postoperative course. METHODS: A retrospective chart review was performed on all patients who underwent carpal tunnel release at a single institution between January of 2012 to December of 2017. Patients demonstrating increased neuropathic pain in the median nerve distribution postoperatively without evidence of complex regional pain syndrome were included. A comparison cohort was composed of the remaining patients identified. Demographic data, medical history, carpal tunnel history, and electromyogram and nerve conduction study findings were recorded. RESULTS: A total of 640 patients were identified; 440 met criteria. Seventeen patients were found to have symptoms consistent with median nerve reawakening phenomenon. The reawakening cohort was older (71.1 versus 56.8 years), more likely to have evidence of thenar muscle atrophy (58.8 percent versus 13.48 percent), and more likely to have fibrillations and sharp waves on electrodiagnostic studies. Although not statistically significant, they also had a longer duration of symptoms (4.9 versus 2.9 years). Of those patients with reawakening phenomenon, 14 had resolution of their symptoms at an average period of 4.4 months. Three remaining patients who were subjectively symptomatic had normal or improved postoperative electromyogram and nerve conduction studies. CONCLUSIONS: Reawakening of the median nerve has not been previously described but occurs in 3.9 percent of hands following routine carpal tunnel release. Preoperative counseling of patients at high risk for reawakening phenomenon is recommended. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.

Novel murine models for studying Cache Valley virus pathogenesis and in utero transmission.

Cache Valley virus (CVV) is a prevalent emerging pathogen of significant importance to agricultural and human health in North America. Emergence in livestock can result in substantial agroeconomic losses resulting from the severe embryonic lethality associated with infection during pregnancy. Although CVV pathogenesis has been well described in ruminants, small animal models are still unavailable, which limits our ability to study its pathogenesis and perform preclinical testing of therapeutics. Herein, we explored CVV pathogenesis, tissue tropism, and disease outcomes in a variety of murine models, including immune -competent and -compromised animals. Our results show that development of CVV disease in mice is dependent on innate immune responses, and type I interferon signalling is essential for preventing infection in mice. IFN-αßR-/- mice infected with CVV present with significant disease and lethal infections, with minimal differences in age-dependent pathogenesis, suggesting this model is appropriate for pathogenesis-related, and short- and long-term therapeutic studies. We also developed a novel CVV in utero transmission model that showed high rates of transmission, spontaneous abortions, and congenital malformations during infection. CVV infection presents a wide tissue tropism, with significant amplification in liver, spleen, and placenta tissues. Immune-competent mice are generally resistant to infection, and only show disease in an age dependent manner. Given the high seropositivity rates in regions of North America, and the continuing geographic expansion of competent mosquito vectors, the risk of epidemic and epizootic emergence of CVV is high, and interventions are needed for this important pathogen.

Proliferation in the developing intestine is regulated by the endosomal protein Endotubin.

During postnatal intestinal development, the intestinal epithelium is highly proliferative, and this proliferation is regulated by signaling in the intervillous and crypt regions. This signaling is primarily mediated by Wnt, and requires membrane trafficking. However, the mechanisms by which membrane trafficking regulates signaling during this developmental phase are largely unknown. Endotubin (EDTB, MAMDC4) is an endosomal protein that is highly expressed in the apical endocytic complex (AEC) of villus enterocytes during fetal and postnatal development, and knockout of EDTB results in defective formation of the AEC and giant lysosome. Further, knockout of EDTB in cell lines results in decreased proliferation. However, the role of EDTB in proliferation during the development of the intestine is unknown. Using Villin-CreERT2 in EDTBfl/fl mice, we deleted EDTB in the intestine in the early postnatal period, or in enteroids in vitro after isolation of intervillous cells. Loss of EDTB results in decreased proliferation in the developing intestinal epithelium and decreased ability to form enteroids. EDTB is present in cells that contain the stem cell markers LGR5 and OLFM4, indicating that it is expressed in the proliferative compartment. Further, using immunoblot analysis and TCF/LEF-GFP mice as a reporter of Wnt activity, we find that knockout of EDTB results in decreased Wnt signaling. Our results show that EDTB is essential for normal proliferation during the early stages of intestinal development and suggest that this effect is through modulation of Wnt signaling.

Violence Depicted in Superhero-Based Films Stratified by Protagonist/Antagonist and Gender.

The objective of this study was to describe and quantify acts of violence depicted in a select number of superhero-based films, further stratified by protagonist/antagonist characters and gender. A total of 10 superhero-based films released in 2015-2016 were analyzed by five independent reviewers. The average number of acts of violence associated with protagonist and antagonist characters for all included films was 22.7 and 17.5 mean events per hour, respectively (p=0.019). The average number of acts of violence associated with male and female characters for all included films was 33.4 and 6.5 mean events per hour, respectively (p<0.001). The most common acts of violence for all major characters were "fighting", "use of a lethal weapon", "bullying/intimidation/torture", "destruction of property", and "murder" (14.9, 11.4, 3.5, 3.4, and 2.4 mean events per hour, respectively). Based on our sample of superhero-based films, acts of violence were associated more with protagonist characters and male characters.

Leveraging the Medical Context to Increase Upper Extremity Reconstruction Among Patients With Tetraplegia: A Qualitative Analysis.

OBJECTIVES: To (1) characterize patients' medical experiences from initial injury until they become candidates for upper extremity reconstruction (UER); and (2) identify points in this medical context that may be most amenable to interventions designed to increase UER utilization. DESIGN: A qualitative cross-sectional study using grounded theory methodology and constant comparative analysis of data collected through semistructured individual interviews. SETTING: Community. PARTICIPANTS: A sample of individuals with C4 to C8 cervical spinal injuries (N=19) who sustained injuries at least 1 year before interview. Nine patients had undergone reconstruction, and 10 had not. The study sample was predominantly male (79%) and white (89%), and American Spinal Injury Association grades A through D were represented (A, 42%; B, 32%; C, 16%; D, 10%). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Participants' self-report of their medical experiences from the time of injury through the early recovery period. RESULTS: We identified 3 domains that formed patients' medical context before UER candidacy: (1) their ability to achieve and maintain health; (2) their relationship with health care providers; and (3) their expectations regarding clinicians' tetraplegia-specific expertise. Trust emerged as a major theme driving potential intervention targets. Patients transferred to referral centers had higher trust in tertiary providers relative to local physicians. In the outpatient setting, patients' trust correlated with the tetraplegia-specific expertise level they perceived the specialty to have (high for physical medicine and rehabilitation, intermediate for urology, low for primary care). CONCLUSIONS: In appropriate candidates, UER produces substantial functional gains, but reconstruction remains underused in the tetraplegic population. By analyzing how patients achieve health and build trust in early recovery/injury, our study provides strategies to improve UER access. We propose that interventions targeting highly trusted points of care (transfer hospitals) and avoiding low-trust points (primary care physicians, home health) will be most effective. Urology may represent a novel entry point for UER interventions.

Checkpoints to Progression: Qualitative Analysis of the Personal and Contextual Factors That Influence Selection of Upper Extremity Reconstruction Among Patients With Tetraplegia.

PURPOSE: Patients with tetraplegia consistently rank better use of the upper extremity as their top functional priority. Multiple case series have demonstrated that upper extremity reconstruction (UER) is well-tolerated and can produce substantial functional improvements for appropriate candidates; however, UER remains critically underutilized. The mechanisms that drive differences in provider practice and referral patterns have been studied, but comprehensive examination of the patient factors that influence UER decisions has not been performed for American patients. METHODS: Nineteen patients with C4-8 cervical spinal injuries were selected using purposive sampling: 9 patients had undergone UER, 10 had not undergone UER. Semistructured interviews were conducted and transcripts evaluated using grounded theory methodology. RESULTS: Our study yielded a conceptual model that describes the characteristics common to all patients who undergo UER. Patients who selected reconstruction proceeded stepwise through a shared sequence of steps: (1) functional dissatisfaction, (2) awareness of UER, and (3) acceptance of surgery. Patients' ability to meet these criteria was determined by 3 checkpoints: how well they coped, their access to information, and the acceptability of surgery. Extremely positive or negative coping prevented patients from moving from the Coping to the Information Checkpoint; thus, they remained unaware of UER and did not undergo surgery. A lack of knowledge regarding reconstruction was the strongest barrier to surgery among our participants. CONCLUSIONS: We built a conceptual model that outlines how patients' personal and contextual factors drive their progression to UER. Moving from functional dissatisfaction to understanding that they were candidates for UER was a substantial barrier for participants, particularly those with very high and very low coping skills. CLINICAL RELEVANCE: To improve utilization for all patients, interventions are needed to increase UER awareness. Standardizing introduction to UER during the rehabilitation process or improving e-content may represent key awareness access points.

Comparison of non-invasive assessments of strength of the proximal femur.

It is not clear which non-invasive method is most effective for predicting strength of the proximal femur in those at highest risk of fracture. The primary aim of this study was to compare the abilities of dual energy X-ray absorptiometry (DXA)-derived aBMD, quantitative computed tomography (QCT)-derived density and volume measures, and finite element analysis (FEA)-estimated strength to predict femoral failure load. We also evaluated the contribution of cortical and trabecular bone measurements to proximal femur strength. We obtained 76 human cadaveric proximal femurs (50 women and 26 men; age 74±8.8years), performed imaging with DXA and QCT, and mechanically tested the femurs to failure in a sideways fall configuration at a high loading rate. Linear regression analysis was used to construct the predictive model between imaging outcomes and experimentally-measured femoral strength for each method. To compare the performance of each method we used 3-fold cross validation repeated 10 times. The bone strength estimated by QCT-based FEA predicted femoral failure load (R2adj=0.78, 95%CI 0.76-0.80; RMSE=896N, 95%CI 830-961) significantly better than femoral neck aBMD by DXA (R2adj=0.69, 95%CI 0.66-0.72; RMSE=1011N, 95%CI 952-1069) and the QCT-based model (R2adj=0.73, 95%CI 0.71-0.75; RMSE=932N, 95%CI 879-985). Both cortical and trabecular bone contribute to femoral strength, the contribution of cortical bone being higher in femurs with lower trabecular bone density. These findings have implications for optimizing clinical approaches to assess hip fracture risk. In addition, our findings provide new insights that will assist in interpretation of the effects of osteoporosis treatments that preferentially impact cortical versus trabecular bone.

Cost Analysis of 48 Burn Patients in a Mass Casualty Explosion Treated at Chang Gung Memorial Hospital.

INTRODUCTION: Little is known about the costs of treating burn patients after a mass casualty event. A devastating Color Dust explosion that injured 499 patients occurred on June 27, 2015 in Taiwan. This study was performed to investigate the economic effects of treating burn patients at a single medical center after an explosion disaster. METHODS: A detailed retrospective analysis on 48 patient expense records at Chang Gung Memorial Hospital after the Color Dust explosion was performed. Data were collected during the acute treatment period between June 27, 2015 and September 30, 2015. The distribution of cost drivers for the entire patient cohort (n=48), patients with a percent total body surface area burn (%TBSA)≥50 (n=20), and those with %TBSA <50 (n=28) were analyzed. RESULTS: The total cost of 48 burn patients over the acute 3-month time period was $2,440,688, with a mean cost per patient of $50,848 ±36,438. Inpatient ward fees (30%), therapeutic treatment fees (22%), and medication fees (11%) were found to be the three highest cost drivers. The 20 patients with a %TBSA ≥50 consumed $1,559,300 (63.8%) of the total expenses, at an average cost of $77,965±34,226 per patient. The 28 patients with a %TBSA <50 consumed $881,387 (36.1%) of care expenses, at an average cost of $31,478±23,518 per patient. CONCLUSIONS: In response to this mass casualty event, inpatient ward fees represented the largest expense. Hospitals can reduce this fee by ensuring wound dressing and skin substitute materials are regionally stocked and accessible. Medication fees may be higher than expected when treating a mass burn cohort. In preparation for a future event, hospitals should anticipate patients with a %TBSA≥50 will contribute the majority of inpatient expenses.

Ketamine enantiomers in the rapid and sustained antidepressant effects.

Recent evidence has suggested that the N-methyl-D-aspartate receptor antagonist ketamine shows significant therapeutic effects in major depression and bipolar disorder. This effect is especially important in treatment-resistant depression and depression with suicidal ideation. In this review we explain the mechanism of action, drug efficacy, and the side effects of ketamine; the antidepressive effects of ketamine; the individual effects of ketamine isomers, R(-) ketamine and S(+) ketamine; the effects of the combination of ketamine with electroconvulsive therapy; and the possible use of ketamine in treating depression.

Prostate cancer markers: An update.

As the most common noncutaneous malignancy in American men, prostate cancer currently accounts for 29% of all diagnosed cancers, and ranks second as the cause of cancer fatality in American men. Prostatic cancer is rarely symptomatic early in its course and therefore disease presentation often implies local extension or even metastatic disease. Thus, it is extremely critical to detect and diagnose prostate cancer in its earliest stages, often prior to the presentation of symptoms. Three of the most common techniques used to detect prostate cancer are the digital rectal exam, the transrectal ultrasound, and the use of biomarkers. This review presents an update regarding the field of prostate cancer biomarkers and comments on future biomarkers. Although there is not a lack of research in the field of prostate cancer biomarkers, the discovery of a novel biomarker that may have the advantage of being more specific and effective warrants future scientific inquiry.

A Novel Point-of-Care Biomarker Recognition Method: Validation by Detecting Marker for Diabetic Nephropathy.

Biological fluid collection to identify and analyze different disease markers is a routine and normal procedure in health care settings. Body fluids are as varied as urine, blood, mucus, cerebrospinal fluid (CSF), tears, semen, etc. The volumes of the collected fluids range from micro liters (e.g., tears, CSF) to tens and hundreds of milliliters (blood, urine, etc.). In some manifestations, a disease marker (particularly protein markers) can occur in trace amounts, yet the fluids collected are in large volumes. To identify these trace markers, cumbersome methods, expensive instruments, and trained personnel are required. We developed an easy method to rapidly capture, concentrate, and identify protein markers in large volumes of test fluids. This method involves the utilization of two antibodies recognizing two different epitopes of the protein biomarker. Antibody-1 helps to capture and concentrate the biomarker and Antibody-2 adsorbed or conjugated to nanogold beads will detect the biomarker. This method was validated in capturing and detecting lipocalin type prostaglandin-D2 synthase, a marker in urine that implicates diabetic nephropathy. A one-step collection, concentration, and detection device was designed based on this method. This device can replace many of the normal body fluid collection devices such as tubes and containers. A one-step fluid collection and biomarker capture and concentration device for rapid diagnosis of diseases has tremendous advantage in terms of cost and providing timely results.

Lower-Dose Mepivacaine Plus Fentanyl May Improve Spinal Anesthesia for Knee Arthroscopy.

BACKGROUND: Previous work indicates that 30 mg isobaric mepivacaine 1.5% plus 10 µg fentanyl produces reliable anesthesia for knee arthroscopy with a more rapid recovery profile than 45 mg mepivacaine. QUESTIONS/PURPOSES: This randomized controlled trial compared plain mepivacaine to three reduced doses of mepivacaine with 10 µg fentanyl for spinal anesthesia. METHODS: Following written informed consent, subjects undergoing outpatient knee arthroscopy were prospectively randomized into one of four groups: mepivacaine 37.5 mg (M37.5); mepivacaine 30 mg plus fentanyl 10 µg (M30/F10); mepivacaine 27 mg plus fentanyl 10 µg (M27/F10); and mepivacaine 24 mg plus fentanyl 10 µg (M24/F10). The spinal was evaluated by the blinded anesthetist and surgeon. In the post-anesthesia care unit, sensory and motor block resolution was assessed. Subjects rated their satisfaction with the overall experience. RESULTS: Group M30/F10 (n = 6) had two "fair" anesthetics, and group M27/F10 (n = 10) had one "fair" and one "inadequate" anesthetic. Both groups were eliminated from further enrollment per study protocol. The recovery profiles showed little difference between groups M37.5 and M30/F10, except for motor block resolution (median (25th percentile, 75th percentile): 171 (135, 195) and 128 (120, 135), respectively). Groups M27/F10 and M24/F10 demonstrated recovery profiles that were faster than group M37.5. Patient satisfaction was 10/10 for all groups. CONCLUSIONS: Adding fentanyl 10 µg to a lower dose of mepivacaine 1.5% can lead to quicker recovery profiles. However, this advantage of a quicker recovery must be weighed against the likelihood of an incomplete anesthetic.