Trends and impact of comorbidities on Guyon's Canal release for the treatment of Guyon's Canal syndrome: A decade long nationwide analysis.

Background: Guyon's Canal Syndrome (GCS) is a rare nerve entrapment condition with limited studies exploring the trends of GCS patients undergoing Guyon's Canal release. The aim of this study is to examine the trends associated with GCS: (1) Guyon's Canal release procedures performed; (2) surgically relevant comorbidities; (3) 90-day readmissions; and (4) same-day and 90-day reimbursement. Methods: A retrospective query was performed on the PearlDiver Mariner Database from 2010 to 2020 by CPT code 64719 to identify patients who underwent Guyon's Canal release. A total of 33,3764 patients were identified. Linear regression models were used to analyze trends in procedures performed, comorbidities, readmission, and reimbursement over this period. A P-value less than 0.05 was considered statistically significant. Results: Between 2010 and 2020, there was an overall significant decreasing trend in the number of Guyon's Canal release procedures performed (RC, -127.50; p < 0.001). There was an increase in number of GCS patients that had undergone Guyon's Canal release who drink alcohol (RC, 0.33; p < 0.001), are obese (RC, 0.81; p < 0.001), and use tobacco (RC, 0.56; p < 0.004), and decrease number of GCS patients with a history of diabetes (RC, -0.82; p < 0.001), hypothyroidism (RC, -0.56; p < 0.001), PVD (RC, -0.71; p < 0.001), and RA (RC, -0.33; p < 0.001). We also found an overall increasing trend in 90-day readmissions (RC, 0.09; p = 0.019) and increased same-day (RC, 68.09; p < 0.001) and 90-day average reimbursement (RC, 257.15; p < 0.001) from 2010 to 2020. Conclusion: The study demonstrated a decreasing trend in Guyon's Canal release performed in GCS patients but increasing cost of care implicated by the increased 90-day readmissions and same day and 90-day reimbursement. This may be attributed to the comorbidities present in GCS patients undergoing Guyon's Canal release. Therefore, it is imperative when consulting GCS patients with surgically relevant comorbidities to weigh the risk and benefits of the procedure.

Cannabis Abuse Is Associated With Greater Medical Complications, Emergency Department Visits, and Readmissions Following Open Reduction and Internal Fixation for Distal Radius Fractures.

BACKGROUND: Despite increased legalization, little is known about the influence of cannabis use disorder (CUD) following open reduction and internal fixation (ORIF) for distal radius fractures (DRFs). The aims were to determine whether CUD patients undergoing ORIF for DRF have increased: (1) medical complications; and (2) health care utilization (emergency department [ED] visits and readmission rates). METHODS: Patients were identified from an insurance database from 2010 to 2020 using Current Procedural Terminology codes: 25607, 25608, and 25609. Patients with a history of CUD were 1:5 ratio matched to controls by age, sex, tobacco use, alcohol abuse, opioid dependence, and comorbidities. This yielded 13,405 patients with (n = 2,297) and without (n = 11,108) CUD. Outcomes were to compare 90-day medical complications, ED visits, and readmissions. Multivariable logistic regression models computed the odds ratios of CUD on dependent variables. P values less than .005 were significant. RESULTS: The incidence of CUD among patients aged 20 to 69 years undergoing ORIF increased from 4.0% to 8.0% from 2010 to 2020 (P < .001). Cannabis use disorder patients incurred significantly higher rates and odds of developing 90-day medical complications (15.24% vs 5.76%), including pneumoniae (3.66% vs 1.67%), cerebrovascular accidents (1.04% vs 0.32%), pulmonary emboli (0.57% vs 0.16%), respiratory failures (1.00% vs 0.48%), and surgical site infections (1.70% vs 1.04%; all P < .004). Emergency department visits (2.53% vs 1.14%) and readmission rates (5.79% vs 4.29%) within 90 days were higher among cannabis abusers. CONCLUSIONS: With a greater number of states legalizing cannabis, hand surgeons should be cognizant of the association with increased 90-day complications and health care utilization parameters.

How does depressive disorder impact outcomes in patients with glenohumeral osteoarthritis undergoing primary reverse shoulder arthroplasty?

BACKGROUND: Current literature shows that the prevalence of depressive disorders (DD) is increasing in the United States. Patients with DD have worse outcomes after shoulder arthroplasty; however, properly defined inclusion and exclusion criteria evaluating the effects of DD on primary reverse shoulder arthroplasty (RSA) are limited. The purpose of this study was to compare the outcomes of patients with and without DD undergoing primary RSA, evaluating: (1) in-hospital length of stay (LOS), (2) medical complications, (3) emergency department (ED) utilizations, and (4) cost of care. METHODS: A retrospective query was performed using a nationwide administrative claims database from 2010 to 2020 for all patients who underwent primary RSA for the treatment of glenohumeral osteoarthritis. The query yielded a total of 24,326 patients within the study (DD, n = 4084) and comparison (without DD, n = 20,242) cohorts. The primary end points were in-hospital LOS, 90-day medical complications, and total 90-day episode of care costs. Subanalyses compared whether DD diagnosis and preoperative ED utilization within 6 months of RSA were associated with increased incidence and odds of postoperative ED utilization within 90 days. P values less than .004 were considered statistically significant. RESULTS: Patients with DD undergoing primary RSA had significantly longer LOS (3 vs. 2 days, P < .0001) compared with patients without DD. The study group also had higher frequency and odds ratio (OR) of complications (47.40% vs. 17.63%; OR: 2.27, P < .0001) such as pneumonia (10.04% vs. 2.15%; OR: 2.88, 95% confidence interval [CI]: 2.47-3.35, P < .0001), cerebrovascular accidents (3.13% vs. 0.86%; OR: 2.69, 95% CI: 2.09-3.46, P < .0001), myocardial infarctions (1.98% vs. 0.51%; OR: 2.54, 95% CI: 1.84-3.50, P < .0001), and other adverse events. Among patients who had a diagnosis of DD, preoperative ED utilization within 6 months of RSA was associated with increased odds of postoperative ED utilization within 90 days compared with those without ED utilization preoperatively (15.08% vs. 13.64%; OR: 1.16, 95% CI: 1.04-1.28, P = .003). Controlling for preoperative ED utilization and comorbidities, patients with DD experienced a 2- to 3-fold increase in postoperative ED use within 90 days after surgery (P < .0001). Patients with DD also incurred significantly higher episode of care costs ($19,363.10 vs. $17,927.55, P < .0001). CONCLUSION: This retrospective study shows that patients with DD undergoing primary RSA for the treatment of glenohumeral osteoarthritis have longer in-hospital LOS, higher rates of complications, and increased costs of care. Preoperative health care utilization among patients with DD may be associated with increased utilization postoperatively.

Traumatic Popliteal Artery Occlusion Following Lower Extremity Crush Injury Presenting With Isolated Patellar Dislocation.

While traumatic popliteal artery injury historically has a low incidence, failure to acutely recognize the vascular insult poses a significant risk of limb loss and functional impairment. A 71-year-old male presented with left lower extremity pain in setting of a crush injury working underneath a vehicle resulting in an isolated lateral dislocation of his patella and complete occlusion of the distal popliteal artery. He was taken to the operating room for an in-situ bypass and four-compartment fasciotomy. His hospital stay included three staged washouts/debridements with eventual closure. He was discharged after 38 days to a rehabilitation facility with ability to self-ambulate with assistance within one month. This patient's presentation is unique for his isolated patellar dislocation without associated injuries characteristically associated with a traumatic vascular injury of the popliteal artery and serves to remind the importance of complete examination in the setting of blunt trauma.

Benign prostatic hyperplasia is associated with increased 90-day medical complications but not peri-prosthetic joint infections following reverse shoulder arthroplasty.

INTRODUCTION: Studies have shown male sex to be a predisposing factor for peri-prosthetic joint infections (PJIs). Symptomatic benign prostatic hyperplasia (BPH) has been suggested as an additional risk for PJI. This study aimed to assess the impact of BPH on (1) lengths of stay (LOS), (2) complications (medical and implant-related), (3) readmission rates, and (4) healthcare expenditures after reverse shoulder arthroplasty (RSA). METHODS: Utilizing a nationwide sample from the 2010-2020 PearlDiver insurance database, an analysis was performed retrospectively for all males who underwent primary RSA. Males with BPH (n = 2,184) represented the study group and were ratio-matched with men without a history of BPH (n = 10,832) in a 1:5 manner by medical comorbidities. T-tests compared LOS and healthcare expenditures. Multivariate logistic regression models were used to determine the effect of BPH on 90-day medical complications, 2-year implant complications, and readmissions. A p value less than 0.001 was statistically significant. RESULTS: In-hospital LOS (1.96 days vs. 1.99 days, p = 0.683) did not significantly differ between cohorts. Males with BPH had significantly greater occurrence and odds (34.3% vs. 21.2%, odds ratio (OR):1.84, p < 0.0001) of all 90-day medical complications, including urinary tract infections (9.3% vs. 3.1%, OR:3.23, p < 0.0001), pneumonias (6.0% vs. 3.9%, OR:1.61, p < 0.0001), and acute kidney injuries (7.7% vs. 5.0%, OR:1.60, p < 0.0001). Two-year implant-related complications were comparable between study and control groups (12.2% vs 10.9%, OR:1.14, p = 0.073), including PJIs (2.3% vs. 2.2%, OR:1.02, p = 0.874). Readmission rates (1.88% vs. 2.11%, p = 0.482) and average global 90-day reimbursements ($26,301 vs. $24,399), p = 0.535) were similar between men with and without BPH. DISCUSSION: Males with a history of BPH have greater rates of medical complications, including UTIs and acute kidney injuries, within 90 days following RSA. BPH does not appear to be a risk factor for 2-year implant-related complications including PJIs. LEVEL OF EVIDENCE: III.

Risk factors for nonunion following open reduction and internal fixation for proximal humerus fractures.

PURPOSE: The incidence of proximal humerus fractures (PHF) is rising and surgical intervention carries risk for fracture nonunion. The purpose was (1) to compare patient demographics of those that developed nonunion and (2) identify patient risk factors that predispose to nonunion following open reduction and internal fixation (ORIF) for PHF. METHODS: A retrospective review of the Medicare Claims Database from 2005 to 2014 for patients who underwent primary ORIF for PHFs. Patients who developed nonunion were identified as the study group (n = 1020) and compared to a control group (n = 51,209). Primary endpoints were to compare demographics of the study group and the comparison cohorts and to identify patient-related risk factors associated with nonunion within 6-months following the index procedure. A logistic regression model was constructed to determine the association of comorbid conditions on developing a nonunion. A p value of 0.001 was the significance threshold. RESULTS: Patients who developed nonunion were younger, more likely to be male, and had higher Elixhauser-Comorbidity Index scores (7 vs. 5; p < 0.0001) when compared with controls. Iron deficiency anemia (OR: 1.32; p = 0.0001), tobacco use (OR: 1.32; p = 0.0004), rheumatoid arthritis (OR: 1.29; p = 0.0001), depression (OR: 1.28; p = 0.0002), and BMI range from 30-39 kg/m2 (OR: 1.21; p = 0.001) were significant risk factors for nonunion. CONCLUSIONS: Certain patient risk factors including tobacco use, iron deficiency anemia, rheumatoid arthritis, depression, and a BMI in the range of 30-39 were associated with nonunion within 6 months of ORIF for PHF. This study may help in the risk stratification of these patients.

What are the Causes, Costs and Risk-Factors for Emergency Department Visits Following Primary Total Hip Arthroplasty? An Analysis of 1,018,772 Patients.

BACKGROUND: Well-powered studies analyzing the relationship and nature of emergency department (ED) visits following primary total hip arthroplasties (THAs) are limited. The aim of this study was to: 1) compare baseline demographics of patients with/without an ED visit; 2) determine leading causes of ED visits; 3) identify patient-related risk factors; and 4) quantify 90-day episode-of-care healthcare costs divided by final diagnosis. METHODS: Patients undergoing primary THA between January 1, 2010 and October 1, 2020 who presented to the ED within 90-days postoperatively were identified using the Mariner dataset of PearlDiver, yielding 1,018,772 patients. This included 3.9% (n = 39,439) patients who did and 96.1% (n = 979,333) who did not have an ED visit. Baseline demographics between the control/study cohorts, ED visit causes, risk-factors, and subsequent costs-of-care were analyzed. Using Bonferroni-correction, a P-value less than 0.002 was considered statistically significant. RESULTS: Patients who presented to the ED post-operatively were most often aged 65-74 years old (41.09%) or female sex (55.60%). Nonmusculoskeletal etiologies comprised 66.8% of all ED visits. Risk factors associated with increased ED visits included alcohol abuse, depressive disorders, congestive heart failure, coagulopathy, and electrolyte/fluid derangements (P < .001 for all). Pulmonary ($28,928.01) and cardiac ($28,574.69) visits attributed to the highest costs of care. CONCLUSION: Nonmusculoskeletal causes constituted the majority of ED visits. The top five risk factors associated with increased odds of ED visits were alcohol abuse, electrolyte/fluid derangements, congestive heart failure, coagulopathy, and depression. This study highlights potential areas of pre-operative medical optimization that may reduce ED visits following primary THA.

The influence of prior dental pathology on medical complications and peri-prosthetic joint infections following primary shoulder arthroplasty.

PURPOSE: Antibiotic prophylaxis before invasive dental procedures is a common practice in the USA. Consensus regarding the influence of prior dental pathology (DP) on postoperative complications is lacking. The objectives are to determine the association of DP prior to shoulder arthroplasty (SA) on: (1) lengths of stay (LOS), (2) medical complications, (3) readmissions, (4) implant-related complications including peri-prosthetic joint infections (PJIs) and (5) healthcare expenditures. METHODS: The PearlDiver database was queried for primary shoulder arthroplasty from 2010 to 2020. Patients with history of dental caries or dental implant placement before SA represented the study group (n = 1419). Patients without prior DP represented controls (n = 7062). Study group patients were 1:5 ratio matched to controls by age, sex, and comorbidities. Outcomes included LOS, 90-day complications, readmissions, 2-year implant-related complications, and healthcare reimbursements. Logistic regression was used to calculate odds ratios (OR) of complications and readmissions. T tests compared LOS and costs. P values < 0.003 were significant. RESULTS: LOS (2.17 vs. 2.07 days; p = 0.071) were similar between groups. Patients with DP had higher 90-day medical complications compared to controls (OR: 1.74, p < 0.0001), including myocardial infarctions (2.2% vs. 0.8%; OR: 2.79, p < 0.0001), acute kidney injuries (8.3% vs. 4.6%; OR: 1.92, p < 0.0001), and pneumonias (8.7% vs. 5.3%; OR: 1.72, p < 0.0001). Readmission rates (1.97% vs. 1.54%; p = 0.248) were similar. Two-year implant complications were higher in patients with DP compared to controls (16.1% vs. 11.5%; OR: 1.38, p = 0.0003), including dislocations (6.4% vs. 4.5%; OR: 1.45, p = 0.002) and mechanical loosenings (4.0% vs. 2.4%; OR: 1.67, p = 0.001); however, PJIs were similar (2.2% vs. 1.9%; OR: 1.12, p = 0.583). Healthcare expenditures between groups were similar ($12,611 vs. $12,059; p = 0.075). CONCLUSION: Patients with prior DP have higher 90-day medical complications and 2-year implant-related complications. Two-year incidence of PJIs were similar between groups. These findings can help shoulder surgeons counsel patients with a pertinent dental history. LEVEL OF EVIDENCE III: Retrospective comparative study.

Which surgeon demographic factors influence postoperative complication rates after total knee arthroplasty at U.S. News and World Report top-ranked orthopedic hospitals?

INTRODUCTION: Complication rates are used to evaluate surgical quality-of-care and determine health care reimbursements. The U.S. News & World Report (USNWR) hospital rankings are a highly-referenced source for top hospitals. The objective of this study was to determine the surgeon demographics of those practicing at USNWR Top Ranked Orthopedic Hospitals and if any influence complication rates after total knee arthroplasty (TKA). METHODS: The 2009-2013 USNWR 'Orthopedic' hospital rankings were identified. A database of TKA surgeons with postoperative complication rates was compiled utilizing publicly available data from the Centers for Medicare and Medicaid Services (2009-2013). Using an internet search algorithm, demographic data were collected for each surgeon and consisted of: fellowship training, years in practice, age, gender, practice setting, medical degree type, residency reputation, case volume, and geographic region of hospital. Logistic regression was used to assess the relationship between surgeon demographics and postoperative complication rates. A P value of < 0.008 was considered significant. RESULTS: From 2009 to 2013, 660 orthopedic surgeons performed TKA at 80 different USNWR Top-Ranked Hospitals. Mean TKA case volume was 172 (Range, 20-1323) and age of surgeon was 50.8 (Range, 32-77). A total of 372 (56.8%) completed an orthopedic surgery fellowship. Mean adjusted 30-day complication rate was 2.24% (Range, 1.2-4.5%). After adjustment, factors associated with increased complication rates were surgeon age ≤ 42 (OR 3.15; P = 0.007) and lower case volume (≤ 100 cases) (OR 2.52; P < 0.0001). Gender, hospital geographic region, completion of a fellowship, medical degree type, and residency reputation were not significant factors. DISCUSSION: Complication rates of total knee arthroplasty surgeons may be utilized by patients and hospitals to gauge quality of care. Certain surgeon factors may influence complication rates of surgeons performing TKA at USNWR Top Ranked Orthopedic Hospitals. STUDY TYPE: Level III, retrospective observational study.

The Association of Alcohol Use Disorder with Perioperative Complications following Primary Total Hip Arthroplasty.

PURPOSE: Alcohol use disorder is a leading mental health disorder in the United States. Few studies evaluating the association of alcohol use disorder following primary total hip arthroplasty (THA) have been reported. Therefore, the purpose of this study was to determine whether patients with alcohol use disorder undergoing primary THA have higher rates of: 1) in-hospital lengths of stay (LOS); 2) complications (medical/implant-related); and 3) costs. MATERIALS AND METHODS: Using a nationwide claims database from January 1st, 2005 to March 31st, 2014, patients with alcohol use disorder undergoing primary THA were identified and matched to a comparison group according to age, sex, and various comorbidities, resulting in 230,467 patients who were included in the study (n=38,416) and a matched-cohort (n=192,051). Outcomes of interest included comparison of LOS, 90-day medical and 2-year implant-related complications, and costs. A P-value less than 0.002 was considered statistically significant. RESULTS: Patients with alcohol use disorder had longer in-hospital LOS (4 days vs 3 days; P<0.0001) as well as higher frequency and odds ratio (OR) of 90-day medical (45.94% vs 12.25%; OR, 2.89; P<0.0001) and 2-year implant-related complications (17.71% vs 8.46%; OR, 1.97; P<0.0001). Patients in the study group incurred higher 90-day costs of care ($17,492.63 vs $14,921.88; P<0.0001). CONCLUSION: With the growing prevalence of alcohol use disorder in the United States, the current investigation can be utilized to evaluate the need for interventions prior to THA which can potentially minimize the rates of morbidity and mortality within this population.

COVID-19 Peripheral Neuropathy: A Report of Three Cases.

This study includes three patients with various peripheral neuropathies after contracting coronavirus disease 2019 (COVID-19) infection, treated both conservatively and surgically. While cases of neurological complications have been described, neuropathy associated with COVID-19 is under-reported in orthopaedic literature. These patients presented with ulnar neuropathy, critical care polyneuropathy (CCP) with anterior interosseous nerve (AIN) neuropathy, and lateral femoral cutaneous nerve (LFCN) neuropathy. COVID-19 infection may be associated with peripheral neuropathy in addition to various neurological sequelae. Orthopaedic surgeons should screen patients for recent infections and evaluate the severity of the illness to assess for risk of neurological sequelae of COVID-19 infection.

Causes, risk factors, and costs associated with ninety-day readmissions following primary total hip arthroplasty for femoral neck fractures.

INTRODUCTION: Risk factors associated with primary THA readmissions have not yet been thoroughly analyzed when stratified by underlying indication. Given that a majority of THAs are done electively in the context of osteoarthritis (OA), it remains to be explored whether or not THAs performed non-electively in the trauma setting have different readmission patterns. Therefore, the aims of this study were to identify: 1) causes of readmissions; 2) patient-related risk-factors for readmissions; and 3) costs associated with the reasons for readmissions. MATERIALS AND METHODS: Patients who sustained a femoral neck fracture and underwent primary THA from 2005 to 2014 were identified. Those subsequently readmitted within 90-days following the procedure comprised the study cohort whereas those not readmitted served as the comparison cohort. Primary outcomes included identifying causes of readmissions, identifying patient-related risk-factors associated with readmissions and determining healthcare expenditures associated with the different readmission etiologies. A regression analysis was used to calculate the odds (OR) for readmissions. A p-value less than 0.01 was considered to be statistically significant. RESULTS: The regression model demonstrated the greatest patient-related risk factors included: electrolyte and fluid disorders (OR: 1.80, p < 0.0001), morbid obesity (OR: 1.60, p < 0.0001), pathologic weight loss (OR: 1.58, p < 0.0001), congestive heart failure (OR: 1.41, p < 0.0001), were the leading risk factors for readmissions. Pulmonary-related causes ($42,357.71) of readmission were the leading driver of costs of care. CONCLUSION: Orthopaedic surgeons should identify and optimize pre-operative management of patient-related risk factors that increase readmissions following primary THA for femoral neck fractures. Additionally, pulmonary-related causes of readmission lead to the highest costs of care. LEVEL OF EVIDENCE: III.

Bicruciate Retaining Total Knee Arthroplasty: Short-Term Clinical Outcomes Using a Novel Prosthesis.

There is renewed interest in bicruciate retaining (BCR) total knee arthroplasty (TKA), which preserves anatomy and more closely replicates native kinematics, theoretically allowing for improved functional results when compared to posterior stabilized (PS) TKA or cruciate retaining (CR) TKA. The purpose of this study is to report early clinical and radiographic results for a novel BCR TKA design.

Amyand's hernia complicated with appendicitis: an interval approach with transabdominal laparoscopic appendectomy and laparoscopic hernioplasty-a case report.

Amyand's hernia is a rare classification of inguinal hernia where the vermiform appendix is located within the hernial sac. This case report discusses a patient presenting with abdominal and groin pain shown to be an Amyand's hernia complicated by acute appendicitis on computed tomography. The patient was treated with a two-stage approach, involving transabdominal laparoscopic appendectomy and elective laparoscopic hernioplasty after recovery. As some controversy exists regarding the timing of appendectomy and hernioplasty, we examine the benefits of the interval approach in the reduction of postoperative infection risk compared with a concurrent approach in patients presenting with Amyand's hernia complicated by appendiceal inflammation.

A matched-control analysis on the effects of alcohol use disorder following primary reverse shoulder arthroplasty.

INTRODUCTION: The purpose of this study was to determine whether alcohol use disorder (AUD) patients undergoing reverse shoulder arthroplasty (RSA) have increased: 1) lengths of stay (LOS); 2) complications; and 3) costs. METHODS: The study identified 19,168 patients in the study (n = 3198) and control (n = 15,970) cohort. In-hospital LOS, 90-day complications, and costs were assessed. RESULTS: AUD patients had significantly longer LOS (3- vs. 2-days, p < 0.0001), higher9 0-day medical complications (49.59 vs. 14.81%; p < 0.0001), and 90-day costs of care ($18,763.25 vs. $16,035.49, p < 0.0001). CONCLUSIONS: The study is useful as it can allow healthcare professionals to adequately counsel these patients.

The Effects of Supplementation with p-Synephrine Alone and in Combination with Caffeine on Metabolic, Lipolytic, and Cardiovascular Responses during Resistance Exercise.

OBJECTIVE: The purpose of this study was to examine the metabolic, lipolytic, and cardiovascular responses to supplementation with p-synephrine alone and in combination with caffeine during resistance exercise (RE). METHODS: Twelve healthy men performed a control RE protocol (6 × 10 repetitions of squats) and were randomly assigned (using a double-blind crossover design with random protocol sequencing) to a supplement sequence: p-synephrine (S; 100 mg), p-synephrine + caffeine (SCF; 100 mg of p-synephrine plus 100 mg of caffeine), or a placebo (P). Subjects reported to the lab at a standard time, consumed a supplement, sat quietly for 45 minutes, performed the RE protocol, and sat quietly for 30 minutes. Blood samples were collected at rest (T1), after sitting quietly for 45 minutes (T2), immediately following RE (T3), and 15 minutes (T4) and 30 minutes (T5) postexercise. Oxygen consumption (VO2) and heart rate (HR) data were collected throughout. RESULTS: Serum glycerol was significantly elevated at T2 only in S and SCF and T3 to T5 in all treatments. Nonesterified fatty acid (NEFA) concentrations did not differ between treatments. Plasma glucose was significantly elevated compared to T1 with highest area under the curve values seen in SCF. Mean VO2 and energy expenditure (EE) were significantly higher in S and SCF through 30 minutes postexercise. Fat oxidation rates favored S and SCF between 25 and 30 minutes postexercise. Mean HR during RE was significantly highest in SCF. CONCLUSIONS: Supplementation with S and SCF increases lipolysis primarily at rest and increases VO2, EE, and fat oxidation rates 30 minutes following RE. No HR changes were observed unless caffeine was added.

The effects of supplementation with P-Synephrine alone and in combination with caffeine on resistance exercise performance.

BACKGROUND: Little is known concerning the potential ergogenic effects of p-synephrine supplementation. Therefore, the purpose of the present study was to examine the effects of supplementation with p-synephrine alone and in combination with caffeine on free-weight resistance exercise performance. METHODS: Twelve healthy, college-aged men performed a control (CT) resistance exercise protocol consisting of 6 sets of squats for up to 10 repetitions per set using 80% of their one repetition-maximum (1RM) with 2 min of rest in between sets. Each subject was randomly assigned (in double-blind, balanced manner) to a treatment sequence consisting of use of 3 supplements: p-synephrine (S; 100 mg), p-synephrine + caffeine (SCF; 100 mg of p-synephrine plus 100 mg of caffeine), or a placebo (P). For each supplement treatment (separated by 1 week), subjects consumed the supplement for 3 days prior to each protocol and the morning of each protocol, and subsequently did not consume any supplements for 3 days following (i.e. wash-out period). On each protocol day, subjects reported to the lab at a standard time, consumed a supplement, sat quietly for 45 min, performed the resistance exercise protocol, and sat quietly for 30 min post exercise. Performance (repetition number, force, velocity and power), blood lactate, and ratings of perceived exertion (RPE) data were collected during each protocol. RESULTS: Supplements SCF and S produced a significantly (P < 0.05) greater number of repetitions performed than CT (by 11.0 ± 8.0%) and P (by 6.0 ± 7.0%) and a 10.6 ± 12.0% greater increase in volume load per protocol than CT and P. Most of the differences were seen during the last 3 sets. Mean power and velocity for all 6 sets were significantly higher in SCF compared to CT and P by ~6.2 ± 8.0%. No supplement effects were observed in RPE or blood lactate, and no adverse side effects were observed or reported. CONCLUSIONS: S and SCF augmented resistance exercise performance (total repetitions, volume load) without increasing blood lactate or RPE. The addition of caffeine in SCF increased mean power and velocity of squat performance. These results indicate supplementation with S and SCF can enhance local muscle endurance during resistance exercise.