Risk factors for postoperative delirium in orthopaedic hip surgery patients: a database review

BACKGROUND

Postoperative delirium is a common problem affecting admitted patients that decreases patient satisfaction and increases the cost and complexity of care. The purpose of this study was to use the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database to compare rates and risk factors of postoperative delirium for total hip arthroplasty (THA) and hemiarthroplasty patients indicated for osteoarthritis or proximal femur fracture.

METHODS

The 2021 NSQIP database was queried for patients using Current Procedural Terminology (CPT) codes for THA and hemiarthroplasty and ICD-10 codes for osteoarthritis or proximal femur fracture. Demographic, past medical history, preoperative labs, and functional status data were recorded. Procedural data were also collected. Finally, postoperative outcomes and complications were reviewed.

RESULTS

Overall, 16% of patients had postoperative delirium. Delirium patients were older on average (82.4 years vs. 80.7 years, p < 0.001), had a lower BMI (19.5 vs. 24.8, p < 0.001), were more likely to have a history of dementia (54.6% vs. 13.6%, p < 0.001), were less likely to have an independent functional status (p < 0.001) or live alone (p < 0.001), and were more likely to have sustained a recent fall (p < 0.001). Delirium patients were more likely to be hyponatremic or hypernatremic (p = 0.002), anemic (p < 0.001), and severely dehydrated (p < 0.001), among other lab abnormalities. Delirium patients were also more likely to experience additional postoperative complications, including pneumonia, pulmonary embolism, urinary tract infection, stroke, cardiac arrest, sepsis, and unplanned reoperation and readmission after discharge (all p < 0.05).

CONCLUSIONS

In this study, factors associated with postoperative delirium in patients undergoing hemiarthroplasty and THA were identified, including older age, lower BMI, certain medical conditions, decreased functional status, certain lab abnormalities, and postoperative complications. These findings can be used by clinicians to better inform care and to determine when orthopaedic joint replacement patients may be at an increased risk for postoperative delirium.

Preoperative demographics and laboratory markers may be associated with early dislocation after total hip arthroplasty

PURPOSE

The purpose of this study was to identify modifiable medical comorbidities, laboratory markers and flaws in perioperative management that increase the risk of acute dislocation in total hip arthroplasty (THA) patients.

METHODS

All THA with primary indications of osteoarthritis from 2007 to 2020 were queried from the National Surgical Quality Improvement Program (NSQIP) database. Demographic data, preoperative laboratory values, recorded past medical history, operative details as well as outcome and complication information were collected. The study population was divided into two cohorts: non-dislocation and dislocation patients. Statistics were performed to compare the characteristics of both cohorts and to identify risk factors for prosthetic dislocation (α < 0.05).

RESULTS

275,107 patients underwent primary THA in 2007 to 2020, of which 1,258 (0.5%) patients experienced a prosthetic hip dislocation. Demographics between non-dislocation and dislocation cohorts varied significantly in that dislocation patients were more likely to be female, older, with lower body mass index and a more extensive past medical history (all p < 0.05). Moreover, hypoalbuminemia and moderate/severe anemia were associated with increased risk of dislocation in a multivariate model (all p < 0.05). Finally, use of general anesthesia, longer operative time, and longer length of hospital stay correlated with greater risk of prosthetic dislocation (all p < 0.05).

CONCLUSIONS

Elderly female patients and patients with certain abnormal preoperative laboratory values are at risk for sustaining acute dislocations after index THA. Careful interdisciplinary planning and medical optimization should be considered in high-risk patients as dislocations significantly increase the risk of sepsis, cerebral vascular accident, and blood transfusions on readmission.

A Cross-Sectional Study of the Impact of the COVID-19 Pandemic and Lockdown Orders on Injury Prevalence in National Collegiate Athletic Association (NCAA) Division I Athletes

Objective The purpose of this study was to analyze the effect of the coronavirus disease 2019 (COVID-19) on injury prevalence in National Collegiate Athletic Association (NCAA) varsity athletes following mandatory state-issued stay-at-home orders in March 2020. A secondary objective was to evaluate the relationship between COVID-19 infection and injury prevalence. Methods The respondents were recruited during pre-participation evaluations held at a Division I university in California in the summer of 2021, as well as via emails shared by athletic trainers at the institution. Data was collected using the Qualtrics Survey Platform (Qualtrics, Provo, UT). For all questions regarding the effects of the COVID-19 pandemic, the participants were asked to compare March 2020-March 2021 ("post-pandemic") to March 2019-March 2020 ("pre-pandemic"). Injury was defined as a physical complaint or condition sustained by an athlete during participation in training or competition that resulted in at least one missed day of practice or competition. The study participants were also asked to disclose their history of laboratory-confirmed COVID-19 infection. Results One hundred forty-six respondents completed the survey, with a 72.3% response rate. Of the respondents, 33.6% (n=49) reported sustaining at least one injury in the year preceding the pandemic, whereas 45.2% (n=66) of respondents reported sustaining at least one injury within the first year of the pandemic, a 34.5% relative increase in injuries (RR=1.35; 95% CI=1.01, 1.80). There was no significant difference in the number of upper body (RR=1.64; 95% CI=0.8, 3.34; p=0.177) versus lower body (RR=1.31; 95% CI=0.94, 1.82; p=0.11) injuries before and after the pandemic onset. Thirty-two respondents reported a history of COVID-19 infection. The athletes who reported a prior COVID-19 diagnosis were no more likely than the athletes with no prior COVID-19 diagnosis to obtain an injury from March 2020 to February 2021 (p=0.85). Conclusion This study indicates that the COVID-19 pandemic and stay-at-home orders were associated with a greater risk of injury in this cohort of collegiate athletes. Interestingly, a history of laboratory-confirmed COVID-19 infection was not associated with increased risk of injury.

Alkaline Phosphatase is an Independent Risk Factor for Periprosthetic Fractures in Total Joint Arthroplasty

BACKGROUND

Serum alkaline phosphatase (ALP) is a biomarker for chronic low-grade inflammation along with hepatobiliary and bone disorders. High abnormal ALP levels in blood have been associated with metabolic bone disease and high bone turnover.

METHODS

All primary total hip and knee arthroplasties from 2005 to 2019 were queried from the National Surgical Quality Improvement Program database. Patients with available serum ALP levels were included and stratified to low (<44 IU/L), normal (44 to 147 IU/L), and high (>147 IU/L). A risk-adjusted multivariate logistic regression was used to analyze ALP as an independent risk factor of complications.

RESULTS

The analysis included 324,592 patients, consisting of 11,427 low ALP, 305,977 normal ALP, and 7,188 high preoperative ALP level patients undergoing total joint arthroplasty. Adjusted multivariate logistic regression analysis showed high ALP level patients had an overall increased risk of readmission within 30 days of surgery compared with the control group (odds ratio [OR], 1.69; P < 0.01). High ALP patients also had an increased risk of postoperative periprosthetic fracture (OR, 1.6), postoperative wound infection (OR, 1.81), pneumonia (OR, 2.24), renal insufficiency (OR, 2.39), cerebrovascular disease (OR, 2.2), postoperative bleeding requiring transfusion (OR, 1.83), sepsis (OR, 2.35), length of stay > 2 days (OR, 1.47), Clostridium difficile infection (OR, 2.07), and discharge to a rehab facility (OR, 1.41) (all P < 0.05). A low ALP level was also associated with increased postoperative bleeding transfusion risk (OR, 1.12; P < 0.01) and developing a deep vein thrombosis (OR, 1.25; P = 0.03).

CONCLUSION

Abnormal serum ALP levels in patients undergoing primary total joint arthroplasty are associated with increased postoperative periprosthetic fracture risk and medical complications requiring increased length of stay and discharge to a rehabilitation facility.

Preoperative Malnutrition and Metabolic Markers May Predict Periprosthetic Fractures in Total Hip Arthroplasty

Background

Periprosthetic fractures are a devastating complication of total hip arthroplasty (THA) and are associated with significantly higher mortality rates in the postoperative period. Given the strain that periprosthetic fractures place on the patient as well as the healthcare system, identifying and optimizing medical comorbidities is essential in reducing complications and improving outcomes.

Methods

All THA with primary indications of osteoarthritis from 2007 to 2020 were queried from the National Surgical Quality Improvement Program database. Demographic data, preoperative laboratory values, medical comorbidities, hospital course, and acute complications were collected and compared between patients with and without readmission for a periprosthetic fracture. A multivariate logistic regression analysis was performed to determine associated independent risk factors for periprosthetic fractures after index THA.

Results

The analysis included 275,107 patients, of which 2539 patients were readmitted for periprosthetic fractures. Patients with postoperative fractures were more likely to be older (>65 years), females, BMI >40, and increased medical comorbidities. Preoperative hypoalbuminemia, hyponatremia, and abnormal estimated glomerular filtration rates were independent risk factors for sustaining a periprosthetic fracture and readmission within 30 days. Modifiable patient-related factors of concurrent smoking and chronic steroid use at the time of index THA were also independent risk factors for periprosthetic fractures. Inpatient metrics of longer length of stay, operative time, and discharge to rehab predicted postarthroplasty fracture risk. Readmitted fracture patients subsequently had increased risks of developing a surgical site infection, urinary tract infection, and requiring blood transfusions.

Conclusions

Patients with hypoalbuminemia, hyponatremia, and abnormal estimated glomerular filtration rate are at increased risk for sustaining periprosthetic fractures after THA. Preoperative optimization with close monitoring of metabolic markers and modifiable risk factors may help not only prevent acute periprosthetic fractures but also associated infection and bleeding risk with fracture readmission.

The impact of dehydration on short-term postoperative complications in total knee arthroplasty

BACKGROUND

As healthcare economics shifts towards outcomes-based bundled payment models, providers must understand the evolving dynamics of medical optimization and fluid resuscitation prior to elective surgery. Dehydration is an overlooked modifiable risk factor that should be optimized prior to elective total knee arthroplasty (TKA) to reduce postoperative complications and inpatient costs.

METHODS

All primary TKA from 2005 to 2019 were queried from the National Surgical Quality Improvement Program (NSQIP) database, and patients were compared based on dehydration status: Blood Urea Nitrogen Creatinine ratio (BUN/Cr) < 20 (non-dehydrated), 20 ≤ BUN/Cr ≤ 25 (moderately-dehydrated), 25 < BUN/Cr (severely-dehydrated). A sub-group analysis involving only elderly patients > 65 years and normalized gender-adjusted Cr values was also performed.

RESULTS

The analysis included 344,744 patients who underwent TKA. Adjusted multivariate logistic regression analysis showed that the severely dehydrated cohort had a greater risk of non-home discharge, postoperative transfusion, postoperative deep vein thrombosis (DVT), and increased length of stay (LOS) (all p < 0.01). Among the elderly, dehydrated patients had a greater risk of non-home discharge, progressive renal insufficiency, urinary tract infection (UTI), postoperative transfusion, and extended LOS (all p < 0.01).

CONCLUSION

BUN/Cr > 20 is an important preoperative diagnostic tool to identify at-risk dehydrated patients. Providers should optimize dehydration to prevent complications, decrease costs, and improve discharge planning.

LEVEL OF EVIDENCE

Level III; Retrospective Case-Control Design; Prognosis Study.

Repeat High-Dose Dexamethasone May Improve Recovery 48 Hours after Total Hip Arthroplasty

Objectives

Perioperative dexamethasone is an effective anti-emetic and systemic analgesic in total hip arthroplasty (THA) that may reduce opioid consumption and enhance rapid recovery. However, there is no consensus on the optimal perioperative dosing that is safe and effective for faster rehabilitation and improved pain control while maintaining safe blood glucose levels.

Methods

A retrospective review of 101 primary THA patients at a single institution who received perioperative dexamethasone was conducted. Patients were stratified by dexamethasone induction dosage (10 mg as high, <6mg as low) and whether a repeat dose was given 16-24 hours postoperatively. Age, gender, BMI, diabetes status, and ASA were controlled between groups. The pain was evaluated with inpatient morphine milligram equivalents (MME) requirements and visual analog scale (VAS) at 8, 16, and 24 hours postoperatively. Mobility was assessed by inpatient ambulation distance, Boston AM-PAC mobility score, and percentage of gait assistance as determined by a physical therapist. Secondary outcomes included postoperative nausea and vomiting (PONV) limiting therapy sessions, PONV requiring breakthrough anti-emetics, glucose levels, surgical site infection, wound healing complications, and discharge destination.

Results

Compared to patients receiving one dose of high or low dexamethasone, patients receiving two dosages of high-dose dexamethasone had significantly further ambulation distance and lower percentage of gait assistance on postoperative day 2. A generalized linear model also predicted that any repeat dexamethasone, regardless of dosage, significantly improved ambulation distance and gait assistance compared to the one-dose cohort. There was no statistically significant difference between VAS scores, MME requirements, PONV, postoperative glucose levels >200, discharge destination, or risk of infection between groups.

Conclusion

A repeat high-dose dexamethasone, the morning after surgery, may improve percentage of gait assistance and ambulation endurance on postoperative day two. There was no risk of uncontrolled glucose levels or infections compared to receiving one dose of dexamethasone at induction.

Kinematic Alignment May Reduce Opioid Consumption and Length of Stay Compared to Mechanically Aligned Total Knee Arthroplasty

OBJECTIVE

Previous studies have sought to determine the effects of total knee arthroplasty (TKA) using kinematic alignment (KA) versus mechanical alignment (MA) to reproduce the native knee alignment and soft tissue envelope for improved patient satisfaction. There are limited studies that compare acute perioperative outcomes between KA and MA patients as it pertains to pain-related opioid consumption and hospital length of stay (LOS). This study aims to compare early KA and MA in restoring function and rehabilitation after surgery to reduce hospitalization and opioid consumption.

METHODS

A retrospective review of 42 KA and 58 MA primary TKA patients performed by a single surgeon between 2020-2021 was conducted. Demographics were controlled between groups and radiographic measurements and functional outcomes were compared. Pain was evaluated with inpatient/outpatient morphine milligram equivalents (MME) and visual analogue scale (VAS) scores. Mobility was assessed using multiple measures by a physical therapist. Mean preoperative and 3-month postoperative flexion range of motion (ROM) were analyzed, and overall complications, LOS, and non-home discharge between groups compared. Continuous variables were compared using the Wilcoxon rank-sum test, and categorical variables were compared using the chi-square or Fisher exact test. Statistical significance was set at P < 0.05.

RESULTS

KA patients had shorter LOS (1.8 vs 3.1 days) and less cumulative opioid requirements compared to MA patients (578 vs 1253 MME). On postoperative day 0, KA patients ambulated on average twice the distance of MA patients (20 vs 6.5 feet). KA patients had residual tibia component in varus (1.4° vs -0.3°), femoral component in valgus (-1.9° vs 0.2°), and valgus joint line obliquity compared with MA (-1.5° vs 0.2°). There were no significant differences between 3-month postoperative flexion arc motion, discharge destination, KOOS or SF-12 outcomes, and surgical complication rates between groups.

CONCLUSIONS

By restoring the native joint line obliquity and minimizing the frequency of ligament releases, KA for TKA may improve pain relief, early mobility, and decreased length of stay compared with traditional methods of establishing neutral limb axis by MA.

Youth Sports Specialization and Its Effect on Professional, Elite, and Olympic Athlete Performance, Career Longevity, and Injury Rates: A Systematic Review

BACKGROUND

Limited data are available on the long-term consequences of early sports specialization in high-level athletes.

PURPOSE

To evaluate the existing literature on the effects of sports specialization among professional, Olympic, and other elite athletes.

STUDY DESIGN

Systematic review; Level of evidence, 3.

METHODS

We performed a systematic review of studies from 1990 to 2021 on youth sports specialization in professional, elite, and/or Olympic athletes following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. An elite athlete was defined as one who performed at the highest level of his or her sport, beyond college level. Data were summarized according to 6 objectives: (1) definitions of specialization, age at specialization, and participation in other sports; (2) motivation for specialization; (3) athlete perspectives on specialization; (4) performance data; (5) specialization and injury risk; and (6) career longevity.

RESULTS

From 8756 articles, 29 studies were included, of which 17 (58.6%) were survey-based studies. Of the 8 articles that commented on injury risk, all demonstrated reduction in injury risk in athletes who delayed specialization. Performance benefits were apparent with later specialization in 7 of 9 articles; the remaining 2 showed benefit with earlier specialization in marathon runners and soccer players. There were less definitive results on career longevity, with 5 of 9 articles finding no association between career longevity and sports specialization.

CONCLUSION

Although current data on sports specialization in elite, professional, and Olympic athletes are mostly retrospective and survey-based evidence, most sports demonstrate better performance after youth multisport engagement, and youth sports specialization was linked with increased injury risk in athletes at the highest levels of competition.

Prior Diagnosis of COVID Has No Increased Complications in Total Joint Arthroplasty

Introduction

Although a substantial portion of the United States population has been infected with and recovered from Coronavirus Disease-19 (COVID-19), many patients may have persistent symptoms and complications from disease-driven respiratory disease, arrhythmias, and venous thromboembolism (VTE). With institutions resuming elective total joint arthroplasties (TJA), it is unclear whether a prior resolved diagnosis of COVID has any implications on postoperative outcomes.

Methods

All elective TJA performed in 2021 at our institution were retrospectively reviewed and a history of prior COVID+ result recorded. Baseline demographics, days from prior COVID+ result to surgery date, preoperative methicillin-resistant Staphylococcus aureus (MRSA) nares colonization, and laboratory markers were obtained to determine baseline characteristics. Postoperative estimated blood loss (EBL), length of stay (LOS), rate of revision surgery, and discharge destination were compared between groups. Perioperative and postoperative rates of VTE, urinary tract infection (UTI), pneumonia, postoperative oxygen supplementation, cardiac arrhythmia, renal disease, sepsis, and periprosthetic joint infections within six months of surgery were recorded.

Results

Of the 155 elective TJA performed in 2021, 24 patients had a prior COVID+ diagnosis with a mean of 253 days from positive result to surgery date. There were no significant differences in baseline demographics, comorbidities, and preoperative lab markers between groups. Surgeries on patients with a prior COVID+ had a significantly higher EBL (260 vs 175cc), but postoperative outcomes of VTE, UTI, pneumonia, oxygen supplementation requirement, nares MRSA+, cardiac disease, and infection rates between groups were similar. Bivariate logistic regression revealed increased days from COVID+ diagnosis (>6 months) to surgery date were associated with a shorter LOS.

Conclusion

Although a prior COVID+ diagnosis had increased intraoperative blood loss, there were no significant differences in respiratory, infectious, cardiac, and thromboembolic complications up to six months after elective TJA. This study suggests that asymptomatic C+ patients receiving elective TJA do not require more aggressive prophylactic anticoagulation or antibiotic regimens to prevent VTE or perioperative infections. As institutions around the nation resume pre-COVID rates of arthroplasty surgeries, a prior diagnosis of COVID appears to have no effects on postoperative complications.

Chlorhexidine gluconate lavage during total joint arthroplasty may improve wound healing compared to dilute betadine

PURPOSE

Intraoperative wound irrigation prior to closure during total joint arthroplasty (TJA) is an essential component of preventing infections and limiting health care system costs. While studies have shown the efficacy of dilute betadine in reducing infection risk, there remains concerns over its safety profile and theoretical inactivation by blood and serum. This study aims to compare infection and wound complications between chlorhexidine gluconate (CHG) and betadine lavage during TJA.

METHODS

All primary TJA between 2019-2021 were analyzed at a single institution, and periprosthetic joint infection (PJI), wound drainage, 30 and 90-day emergency room (ER) readmission due to wound complications, aseptic loosening, and revision surgery rate were compared between patients undergoing intraoperative CHG versus betadine lavage prior to closure. Baseline demographics were controlled, and multivariate logistic regression was performed to compare complication rates.

RESULTS

A total of 410 TJA, including 160 hip and 250 knee arthroplasties were included. Compared to the dilute betadine cohort, all TJA patients undergoing CHG lavage had a statistically significant lower 30 and 90-day emergency room readmission rate due to wound complications. Both hip and knee arthroplasty patients with CHG had a statistically significant lower rate of postoperative superficial drainage and dressing saturation at clinic follow-up, but only knee arthroplasty patients had significant decreased readmission rate for incisional wound vacuum placement and close inpatient monitoring of wound healing. Among all TJA, there was no significant association in the rate of PJI requiring return to the OR between groups.

CONCLUSIONS

Although betadine is cost-effective and has been shown to reduce PJI rates, there remains concerns in the literature over soft tissue toxicity and wound healing. This study suggests CHG may be as efficacious as dilute betadine in preventing PJI while also decreasing the risk of superficial drainage and wound complications needing unplanned ER visits during the acute postoperative period.

982 Higher General Surgical Trainee preferences for Annual Review of Competency Progression during COVID-19 Pandemic

Aim

The COVID-19 pandemic has caused significant disruption in surgical training. We aim to explore the preferences of higher general surgical trainees for Annual Review of Competency Progression (ARCP) also compare the responses across different training grades.

Method

All higher general surgical trainee in a single deanery were invited to participate in an online voluntary anonymous survey. The respondents were divided in two groups: junior (ST3-ST5) and senior higher surgical trainees (ST6-ST8) and responses compared.

Results

Sixty-four of 88 trainees responded. Thirty-three (51.6%) were ST3–ST5, 24 (37.5%) were ST6–ST8 and 7 (10.9%) were out-of-training. More trainees in ST3–ST5 group preferred to defer the next rotation for 12 months (18.2% vs 0%, p = 0.034), repeat current sub-specialty (33.3% vs 4.2%, p = 0.009), or add 12 months to training and delay predicted CCT date by 12 months (18.2% vs 0%, p = 0.034). Most trainees in both groups preferred the option of prolonging training should be offered to all trainees with an option to decline extension if ARCP competencies met (66.7% vs 50.0%, p = 0.276).

Conclusions

The preference for ARCP and length of training was different between two training groups, hence the need of trainees should be considered by training committees when addressing the impact of COVID-19.

930 Impact of the COVID-19 Pandemic on Higher General Surgical Training – A West of Scotland Experience

Introduction

COVID-19 pandemic has caused significant disruption in all aspects of training. Our aim was to explore the degree of impact caused by the pandemic on higher general surgical trainees.

Method

All higher general surgical trainees in a single UK deanery were invited to participate in an online, voluntary, anonymous survey via SurveyMonkey.

Results

64 (72.7%) of the trainees responded. 39.1% were ST3/4, 29.7% were ST5/6, 20.3% were ST7/8 and 10.9% were out of training (maternity & research). Thirty-five (55.6%) worked in district general hospitals. Forty (68.9%) trainees felt that they had fewer opportunities to be primary surgeon. Forty-two (67.7%) trainees did not have access to laparoscopic simulation trainers. Fifty-two (88.1%) trainees had their courses and 2 (3.4%) had their FRCS part 2 exam postponed. 16 (27.1%) trainees reported they had been off-sick, with a median of 7 days off (range 3-35 days). Thirty-three (55.9%) trainees felt more stressed due to the pandemic and 35 (59.4%) had symptoms of burnout.

Conclusions

The COVID-19 pandemic has had an unprecedented impact on all aspects of higher surgical training. The most noticeable impact has been on the reduction in the confidence in laparoscopic and endoscopic skills.

Oxidative Stress and Cardiovascular Risk in Type 1 Diabetes Mellitus: Insights From the DCCT/EDIC Study

Background

Hyperglycemia leading to increased oxidative stress is implicated in the increased risk for the development of macrovascular and microvascular complications in patients with type 1 diabetes mellitus.

Methods and Results

A random subcohort of 349 participants was selected from the DCCT / EDIC (Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications) cohort. This included 320 controls and 29 cardiovascular disease cases that were augmented with 98 additional known cases to yield a case cohort of 447 participants (320 controls, 127 cases). Biosamples from DCCT baseline, year 1, and closeout of DCCT , and 1 to 2 years post‐ DCCT ( EDIC years 1 and 2) were measured for markers of oxidative stress, including plasma myeloperoxidase, paraoxonase activity, urinary F 2α isoprostanes, and its metabolite, 2,3 dinor‐8 iso prostaglandin F 2α . Following adjustment for glycated hemoblobin and weighting the observations inversely proportional to the sampling selection probabilities, higher paraoxonase activity, reflective of antioxidant activity, and 2,3 dinor‐8 iso prostaglandin F 2α , an oxidative marker, were significantly associated with lower risk of cardiovascular disease (−4.5% risk for 10% higher paraoxonase, P <0.003; −5.3% risk for 10% higher 2,3 dinor‐8 iso prostaglandin F 2α , P =0.0092). In contrast, the oxidative markers myeloperoxidase and F 2α isoprostanes were not significantly associated with cardiovascular disease after adjustment for glycated hemoblobin. There were no significant differences between DCCT intensive and conventional treatment groups in the change in all biomarkers across time segments.

Conclusions

Heightened antioxidant activity (rather than diminished oxidative stress markers) is associated with lower cardiovascular disease risk in type 1 diabetes mellitus, but these biomarkers did not change over time with intensification of glycemic control.

Clinical Trial Registration

URL : https://www.clinicaltrials.gov . Unique identifiers: NCT 00360815 and NCT 00360893.

The management of acute seizures in Naval Service personnel

Seizures are a relatively common Emergency Department (ED) presentation among young adult populations, considered for the purpose of this report as being aged 15-59. Due to the varied aetiologies involved, understanding of the potential causes and their presentation is key to managing these patients. Although seizure incidence within the United Kingdom (UK) Armed Forces population is generally low, it is not negligible. Therefore, awareness of the initial management is required by all those involved in patient care from the Medical Assistant (MA) at the Role 1 facility, through to the senior doctors at Role 3 establishments. All management should be in line with the Clinical Guidelines for Operations (CGOs) and Advanced Life Support (ALS) principles, with resuscitation, seizure control and patient stabilisation taking precedence initially. Ultimately, the use of laboratory testing and imaging at a Role 3 setting will be required to accurately confirm a diagnosis. Information obtained during these assessments may serve to assist the Naval Service Medical Board of Survey (NSMBOS) in determining suitability for continued Service retention and employment.

Estrogen and xenoestrogens upregulate the brain aromatase isoform (P450aromB) and perturb markers of early development in zebrafish (Danio rerio)

Estrogen synthesized in the brain itself by the action of cytochrome P450 aromatase (P450arom) is known to have permanent organizing effects on the developing CNS. In fish, estrogen upregulates the predominant brain isoform (P450aromB), implying that xenoestrogens (XE) could act as neurodevelopmental toxicants by altering P450aromB. To test this hypothesis, zebrafish embryos were exposed to 17beta-estradiol (E(2)), diethylstilbestrol (DES, a potent agonist), and bisphenol A (BPA, a weak agonist). RT-PCR/Southern transfer analysis showed that E(2) (0.01-10 microM) upregulated P450aromB in a dose-response manner. The effect of DES (0.01 microM) was similar to 1 microM E(2) (three- to four-fold higher than control), but BPA was less effective (<threefold increase at 10 microM). mRNA levels of the predominant ovarian isoform (P450aromA) were unchanged by estrogen. Treatment with E(2) (0.1-10 microM) between 2 and 72 hpf had dose-response effects on mortality and hatching and induced a 'curved tail down' phenotype characteristic of mutants with defects of early CNS development. The critical period of estrogen sensitivity for effects on mortality and curved tails was 2-24 hpf, whereas hatching effects were both stage- and duration-dependent. Developmental effects of DES and BPA were similar to E(2) but testosterone, and 5alpha-dihydrotestosterone were ineffective. 17alpha-Estradiol showed a small but significant effect on curved tails. We conclude that P450aromB mRNA is a sensitive marker of XE effect during embryogenesis, but further studies are required to determine whether changes in neural aromatase expression and estrogen biosynthesis have consequences for CNS development.

Effect of scavenging on the psychomotor and cognitive function of subjects sedated with nitrous oxide and oxygen inhalation

Maximizing scavenger effectiveness using a 45 L/min evacuation rate as recommended by the National Institute of Occupational Safety and Health (NIOSH) may alter the sedation level of the dental patient. The purpose of this pilot study was to determine if scavenging at the recommended NIOSH evacuation rate reduced psychomotor and cognitive impairment as a result of inhaling nitrous oxide. Computer-administered neurobehavioral tests of human psychomotor and cognitive function previously established in controlled trials to be sensitive to nitrous oxide inhalation were employed in this blind, randomized, crossover study of 30 healthy adult subjects. The results indicated that scavenging produced statistically significant improvement in finger-tapping speed, symbol/digit coding speed, and recall accuracy. Hand/eye coordination was not improved significantly by scavenging. Enhancement of psychomotor skills and cognitive functioning was interpreted as an undesirable side effect of scavenging that could potentially influence dental patient anxiety management when using nitrous oxide inhalation. The results of this pilot study suggested that scavenger operation under the conditions tested could reduce the level of psychosedation achieved with nitrous oxide inhalation.

Cryopreservation and the maintenance of cell lines

Techniques for cell-line preservation which enable reliable and reproducible recovery of material with unchanged, defined characteristics are essential in many biotechnology industries. Cryopreservation is one such technique, and in this review we explore some of its problems, successes and potential future applications.

Observations on the use of music in rehabilitation of stroke patients

A preliminary investigation was initiated to explore the use of music as a means of improving general mobility, social interaction, and emotional stability in patients who have suffered a stroke. A literature search had revealed very little information on the use of music in the rehabilitation of such patients. The investigators videotaped a series of sessions involving group movement-to-music, group music-making, and individual movement-to-music. An individual case study in music-making was carried out as well. All videotapes were reviewed and we observed that an increase in the range and ease of movement of the patients occurred during weight-shifting activities, when appropriate music with a tempo of 58 to 63 beats per minute was used. Our observations supported the findings of recent research concerning preferred tempi for certain activities and reinforcement of movement by appropriate tempi. Other factors in our study, such as size of group, placement, cueing, and the opportunity to touch, appeared to affect the responses obtained in group situations. As the result of our observations, we have concluded that music enhances the general mobility and social interaction of patients who have sustained a cerebrovascular accident and that it may also improve a patient's emotional stability.