Is cardiorespiratory fitness associated with cognitive outcomes in mid-adulthood? Findings from the 1958 British birth cohort

Identifying causal factors to intervene on to delay age-related declines in cognitive function is urgently needed. We examined associations between non-exercise testing cardiorespiratory fitness (NETCRF; estimated using sex, age, body mass index, resting heart rate, and physical activity) at 45 years and cognitive function outcomes (immediate and delayed verbal memory; verbal fluency; visual processing speed) at 50 years in 8130 participants from the 1958 British birth cohort. In unadjusted models, higher NETCRF was associated with better cognitive function across all outcomes. When adjusted for confounding factors, associations disappeared. In this cohort, associations between 45 years NETCRF and 50 years cognitive function likely result from confounding factors.

Associations between diabetes status and grip strength trajectory sub-groups in adulthood: findings from over 16 years of follow-up in the MRC National Survey of Health and Development

BACKGROUND

Cross-sectional studies suggest a relationship between diabetes status and weaker grip strength (GS) in adulthood and limited evidence from longitudinal studies has focussed on the association with average change in GS. We aimed to investigate whether diabetes status was related to membership of distinct GS trajectories in mid-to-late adulthood in 2,263 participants in the Medical Research Council National Survey of Health and Development.

METHODS

Grip strength (kg) was measured at 53, 60-64 and 69 years. Pre-/diabetes was defined at 53 years based on HbA1c > 5.6% and/or doctor-diagnosis of diabetes. Sex-specific latent class trajectory models were developed and multinomial logistic regression was used to investigate the association between pre-/diabetes status and membership into GS trajectory classes.

RESULTS

For both males and females, a 3-class solution ('High', 'Intermediate', 'Low') provided the best representation of the GS data and the most plausible solution. There was no evidence that pre-/diabetes status was associated with class membership in either sex: e.g., adjusted odds ratios of being in the 'Low' class (vs. 'High') for males with pre-/diabetes (vs. no-diabetes) was 1.07 (95% CI:0.45,2.55).

CONCLUSION

Using a flexible data-driven approach to identify GS trajectories between 53 and 69 years, we observed three distinct GS trajectories, all declining, in both sexes. There was no association between pre-/diabetes status at 53 years and membership into these GS trajectories. Understanding the diabetes status-GS trajectories association is vital to ascertain the consequences that projected increases in pre-/diabetes prevalence's are likely to have.

Defining the Optimal Treatment Strategy in Patients With Uterine Serous Carcinoma

AIMS

Uterine serous carcinoma (USC) is an aggressive subtype of endometrial cancer with high rates of relapse and death. As adjuvant therapy might be beneficial in early-stage disease, the impact of standard complete surgical staging is questioned. Therefore, we wanted to explore the optimal treatment strategy for women diagnosed with USC.

MATERIALS AND METHODS

A retrospective multicentre study of women diagnosed with primary USC in the UK and the Netherlands. Treatment strategy in relation to overall survival and progression-free survival was recorded and evaluated with Kaplan-Meier and Cox regression analysis. Furthermore, primary surgical staging and/or adjuvant treatment in relation to patterns of recurrence were evaluated.

RESULTS

In total, 272 women with a median age of 70 years were included. Most patients presented with International Federation of Gynecology and Obstetrics (FIGO) stage I disease (44%). Overall, 48% of patients developed recurrent disease, most (58%) with a distant component. Women treated with chemotherapy showed significantly better overall survival (hazard ratio 0.50, 95% confidence interval 0.31-0.81; P = 0.005) and progression-free survival (hazard ratio 0.48, 95% confidence interval 0.28-0.80; P = 0.04) in multivariable analysis. Furthermore, even in surgically staged women with FIGO stage IA disease, a high recurrence rate of 42% was seen.

CONCLUSION

Women with USC who received adjuvant chemotherapy showed better survival rates compared with those who received other or no adjuvant treatment. The benefit of adjuvant chemotherapy was observed across all tumour stages, including surgically staged FIGO stage IA. These data question the role of surgical staging in the absence of macroscopic disease in USC.

Obesity in early adulthood and physical functioning in mid-life: Investigating the mediating role of c-reactive protein

INTRODUCTION

Obesity in adulthood is associated with reduced physical functioning (PF) at older ages. However, mechanisms underpinning this association are not well understood. We investigated whether and the extent to which C-reactive protein (CRP) mediates the association between early-adult obesity and mid-life PF.

METHODS

We used data from 8495 participants in the 1958 British birth cohort study. Body mass index (BMI), CRP and PF were measured at 33, 45 and 50y, respectively. Poor PF was defined as the lowest (sex-specific) 10% on the Short-form 36 Physical Functioning subscale. We accounted for prospectively measured confounders in early-life (e.g., social class at birth) and in mid-adulthood (e.g., 42y comorbidities). We decomposed the total effect of early-adult obesity on mid-life PF into direct and indirect (via CRP) effects, by employing a mediation analysis based on parametric g-computation.

RESULTS

The estimated total effect of obesity at 33y on poor PF at 50y, expressed as an odds ratio (OR), was 2.41 (95% CI: 1.89, 3.08). The direct effect of obesity on poor PF (i.e., not operating via CRP), was 1.97 (95% CI: 1.51, 2.56), with an indirect effect of 1.23 (95% CI: 1.10, 1.37). As such, the proportion of the total effect which was mediated by the effect of obesity on CRP at 45y, was 23.27% (95% CI: 8.64%, 37.90%).

CONCLUSION

Obesity in early-adulthood was associated with over twice the odds of poor PF in mid-life, with approximately 23% of the obesity effect operating via a downstream effect on CRP. As current younger generations are likely to spend greater proportions of their life course in older age and with obesity, both of which are associated with poor PF, there is an urgent need to identify mechanisms, and thus potential modifiable intermediaries, linking obesity to poor PF.

Ensuring a successful transition from Pap to HPV-based primary cervical cancer screening in Canada by investigating the psychosocial correlates of women’s intentions: Protocol for an observational study (Preprint)

Background

Objective

Methods

Results

Conclusions

International Registered Report Identifier (IRRID)

Changes over time in latent patterns of childhood-to-adulthood BMI development in Great Britain: evidence from three cohorts born in 1946, 1958, and 1970

BACKGROUND

Most studies on secular trends in body mass index (BMI) are cross-sectional and the few longitudinal studies have typically only investigated changes over time in mean BMI trajectories. We aimed to describe how the evolution of the obesity epidemic in Great Britain reflects shifts in the proportion of the population demonstrating different latent patterns of childhood-to-adulthood BMI development.

METHODS

We used pooled serial BMI data from 25,655 participants in three British cohorts: the 1946 National Survey of Health and Development (NSHD), 1958 National Child Development Study (NCDS), and 1970 British Cohort Study (BCS). Sex-specific growth mixture models captured latent patterns of BMI development between 11 and 42 years. The classes were characterised in terms of their birth cohort composition.

RESULTS

The best models had four classes, broadly similar for both sexes. The 'lowest' class (57% of males; 47% of females) represents the normal weight sub-population, the 'middle' class (16%; 15%) represents the sub-population who likely develop overweight in early/mid-adulthood, and the 'highest' class (6%; 9%) represents those who likely develop obesity in early/mid-adulthood. The remaining class (21%; 29%) reflects a sub-population with rapidly 'increasing' BMI between 11 and 42 years. Both sexes in the 1958 NCDS had greater odds of being in the 'highest' class compared to their peers in the 1946 NSHD but did not have greater odds of being in the 'increasing' class. Conversely, males and females in the 1970 BCS had 2.78 (2.15, 3.60) and 1.87 (1.53, 2.28), respectively, times higher odds of being in the 'increasing' class.

CONCLUSIONS

Our results suggest that the obesity epidemic in Great Britain reflects not only an upward shift in BMI trajectories but also a more recent increase in the number of individuals demonstrating more rapid weight gain, from normal weight to overweight, across the second, third, and fourth decades of life.

Quality control of ultrasound for fetal biometry: results from the INTERGROWTH-21st Project

OBJECTIVE

To assess a comprehensive package of ultrasound quality control in the Fetal Growth Longitudinal Study of the INTERGROWTH-21^st Project, a large multicenter study of fetal growth.

METHODS

Quality control (QC) measures were performed for 20 313 ultrasound scan images obtained prospectively from 4321 fetuses at 14-41 weeks' gestation in eight geographical locations. At the time of each ultrasound examination, three fetal biometric variables (head circumference (HC), abdominal circumference (AC) and femur length (FL)) were measured in triplicate on separately generated images. All measurements were taken in a blinded fashion. QC had two elements: (1) qualitative QC: visual assessment by sonographers at each study site of their images based on specific criteria, with 10% of images being re-assessed at the Oxford-based Ultrasound Quality Unit (compared using an adjusted kappa statistic); and (2) quantitative QC: assessment of measurement data by comparing the first, second and third measurements (intraobserver variability), remeasurement of caliper replacement in 10% (interobserver variability), both by Bland-Altman plots and plotting frequency histograms of the SD of triplicate measurements and assessing how many were above or below 2 SD of the expected distribution. The system allowed the sonographers' performances to be monitored regularly.

RESULTS

A high level of agreement between self- and external scoring was demonstrated for all measurements (κ = 0.99 (95% CI, 0.98-0.99) for HC, 0.98 (95% CI, 0.97-0.99) for AC and 0.96 (95% CI, 0.95-0.98) for FL). Intraobserver 95% limits of agreement (LoA) of ultrasound measures for HC, AC and FL were ± 3.3%, ± 5.6% and ± 6.2%, respectively; the corresponding values for interobserver LoA were ± 4.4%, ± 6.0% and ± 5.6%. The SD distribution of triplicate measurements for all biometric variables showed excessive variability for three of 31 sonographers, allowing prompt identification and retraining.

CONCLUSIONS

Qualitative and quantitative QC monitoring was feasible and highly reproducible in a large multicenter research study, which facilitated the production of high-quality ultrasound images. We recommend that the QC system we developed is implemented in future research studies and clinical practice. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Obesity in adolescents with chronic fatigue syndrome: an observational study

OBJECTIVE

Identify the prevalence of obesity in patients with chronic fatigue syndrome (CFS) compared with healthy adolescents, and those identified with CFS in a population cohort.

DESIGN

Cross-sectional analysis of multiple imputed data.

SETTING

Data from UK paediatric CFS/myalgic encephalomyelitis (CFS/ME) services compared with data collected at two time points in the Avon Longitudinal Study of Parents and Children (ALSPAC).

PATIENTS

1685 adolescents who attended a CFS/ME specialist service between 2004 and 2014 and 13 978 adolescents aged approximately 13 years and 16 years participating in the ALSPAC study.

MAIN OUTCOME MEASURES

Body mass index (BMI) (kg/m²), sex-specific and age-specific BMI Z-scores (relative to the International Obesity Task Force cut-offs) and prevalence of obesity (%).

RESULTS

Adolescents who had attended specialist CFS/ME services had a higher prevalence of obesity (age 13 years: 9.28%; age 16 years: 16.43%) compared with both adolescents classified as CFS/ME in ALSPAC (age 13 years: 3.72%; age 16 years: 5.46%) and those non-CFS in ALSPAC (age 13 years: 4.18%; age 16 years: 4.46%). The increased odds of obesity in those who attended specialist services (relative to non-CFS in ALSPAC) was apparent at both 13 years (OR: 2.31 (1.54 to 3.48)) and 16 years, with a greater likelihood observed at 16 years (OR: 4.07 (2.04 to 8.11)).

CONCLUSIONS

We observed an increased prevalence of obesity in adolescents who were affected severely enough to be referred to a specialist CFS/ME service. Further longitudinal research is required in order to identify the temporal relationship between the two conditions.

Scientific basis for standardization of fetal head measurements by ultrasound: a reproducibility study

OBJECTIVE

To compare the standard methods for ultrasound measurement of fetal head circumference (HC) and biparietal diameter (BPD) (outer-to-outer (BPDoo) vs outer-to-inner (BPDoi) caliper placement), and compare acquisition of these measurements in transthalamic (TT) vs transventricular (TV) planes.

METHODS

This study utilized ultrasound images acquired from women participating in the Oxford arm of the INTERGROWTH-21(st) Project. In the first phase of the study, BPDoo and BPDoi were measured on stored images. In the second phase, real-time measurements of BPD, occipitofrontal diameter (OFD) and HC in TT and TV planes were obtained by pairs of sonographers. Reproducibility of measurements made by the same (intraobserver) and by different (interobserver) sonographers, as well as the reproducibility of caliper placement and measurements obtained in different planes, was assessed using Bland-Altman plots.

RESULTS

In Phase I, we analyzed ultrasound images of 108 singleton fetuses. The mean intraobserver and interobserver differences were < 2% (1.34 mm) and the 95% limits of agreement were < 5% (3 mm) for both BPDoo and BPDoi. Neither method for measuring BPD showed consistently better reproducibility. In Phase II, we analyzed ultrasound images of 100 different singleton fetuses. The mean intraobserver and interobserver differences were < 1% (2.26 mm) and the 95% limits of agreement were < 8% (14.45 mm) for all fetal head measurements obtained in TV and TT planes. Neither plane for measuring fetal head showed consistently better reproducibility. Measurement of HC using the ellipse facility was as reproducible as HC calculated from BPD and OFD. OFD by itself was the least reproducible of all fetal head measurements.

CONCLUSIONS

Measurements of BPDoi and BPDoo are equally reproducible; however, we believe BPDoo should be used in clinical practice as it allows fetal HC to be measured and compared with neonatal HC. For all head measurements, TV and TT planes provide equally reproducible values at any gestational age, and HC values are similar in both planes. Fetal head measurement in the TT plane is preferable as international standards in this plane are available; however, measurements in the TV plane can be plotted on the same standards. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Small-for-gestational age and large-for-gestational age thresholds to predict infants at risk of adverse delivery and neonatal outcomes: are current charts adequate? An observational study from the Born in Bradford cohort

OBJECTIVES

Construct an ethnic-specific chart and compare the prediction of adverse outcomes using this chart with the clinically recommended UK-WHO and customised birth weight charts using cut-offs for small-for-gestational age (SGA: birth weight <10th centile) and large-for-gestational age (LGA: birth weight >90th centile).

DESIGN

Prospective cohort study.

SETTING

Born in Bradford (BiB) study, UK.

PARTICIPANTS

3980 White British and 4448 Pakistani infants with complete data for gestational age, birth weight, ethnicity, maternal height, weight and parity.

MAIN OUTCOME MEASURES

Prevalence of SGA and LGA, using the three charts and indicators of diagnostic utility (sensitivity, specificity and area under the receiver operating characteristic (AUROC)) of these chart-specific cut-offs to predict delivery and neonatal outcomes and a composite outcome.

RESULTS

In White British and Pakistani infants, the prevalence of SGA and LGA differed depending on the chart used. Increased risk of SGA was observed when using the UK-WHO and customised charts as opposed to the ethnic-specific chart, while the opposite was apparent when classifying LGA infants. However, the predictive utility of all three charts to identify adverse clinical outcomes was poor, with only the prediction of shoulder dystocia achieving an AUROC>0.62 on all three charts.

CONCLUSIONS

Despite being recommended in national clinical guidelines, the UK-WHO and customised birth weight charts perform poorly at identifying infants at risk of adverse neonatal outcomes. Being small or large may increase the risk of an adverse outcome; however, size alone is not sensitive or specific enough with current detection to be useful. However, a significant amount of missing data for some of the outcomes may have limited the power needed to determine true associations.

Toward parametric amplification in plasmonic systems: second harmonic generation enhanced by surface plasmon polaritons

Having in mind parametric amplification of surface plasmon polaritons (SPPs) as the final goal, we took the first step and studied in the Kretschmann geometry a simpler nonlinear optical process - second harmonic generation (SHG) enhanced by SPPs propagating at the interface between gold film and 2-methyl-4-nitroaniline (MNA). The experimentally demonstrated SHG efficiency was nearly 10(6) times larger than the one reported previously in the SPP system with different nonlinear optical material. The experimentally measured nonlinear conversion efficiency is estimated to be sufficient for parametric amplification of surface plasmon polaritons at ultra-short laser pumping.

Repeatability of subjective evaluation of lameness in horses

REASONS FOR PERFORMING STUDY

Previous studies have suggested that agreement between equine veterinarians subjectively evaluating lameness in horses is low. These studies were limited to small numbers of horses, evaluating movement on the treadmill or to evaluating previously-recorded videotape.

OBJECTIVES

To estimate agreement between equine practitioners performing lameness evaluations in horses in the live, over ground setting.

METHODS

131 mature horses were evaluated for lameness by 2-5 clinicians (mean 3.2) with a weighted-average of 18.7 years of experience. Clinicians graded each limb using the AAEP lameness scale by first watching the horse trot in a straight line only and then after full lameness evaluation. Agreement was estimated by calculation of Fleiss' (kappa). Evaluators agreed if they picked the same limb as lame or not lame regardless of the severity of perceived lameness.

RESULTS

After only evaluating the horse trot in a straight line clinicians agreed whether a limb was lame or not 76.6% of the time (kappa= 0.44). After full lameness evaluation clinicians agreed whether a limb was lame or not 72.9% of the time (kappa= 0.45). Agreement on forelimb lameness was slightly higher than on hindlimb lameness. When the mean AAEP lameness score was >1.5 clinicians agreed whether or not a limb was lame 93.1% of the time (kappa= 0.86), but when the mean score was < or = 1.5 they agreed 61.9% (kappa= 0.23) of the time. When given the task of picking whether or not the horse was lame and picking the worst limb after full lameness evaluation, clinicians agreed 51.6% (kappa= 0.37) of the time.

CONCLUSIONS

For horses with mild lameness subjective evaluation of lameness is not very reliable.

POTENTIAL RELEVANCE

A search for and the development of more objective and reliable methods of lameness evaluation is justified and should be encouraged and supported.

Large outbreak of E. coli O157 in 2005, Ireland

In October/November 2005, the largest outbreak of verotoxin-producing Escherichia coli (VTEC) ever recorded in Ireland occurred. Eighteen E. coli O157 culture-positive cases, phage type 32, verotoxin 2 positive, were identified in a small rural area of mid-west Ireland. Half of these patients were asymptomatic. Two children were admitted to hospital with haemolytic uraemic syndrome, one of whom required peritoneal dialysis, and both recovered. All 18 culture-positive patients had indistinguishable or closely related pulsed field gel electrophoresis (PFGE) patterns. Nine of the VTEC O157 culture-positive individuals were in preschool children attending two local crèches. Several culture-positive individuals apparently had exposure to a vulnerable private group water scheme (GWS) in an agricultural area. No microbiological evidence of VTEC was found in food or water. One veterinary sample (an animal rectal swab) was positive for E. coli O157 and the PFGE strain was indistinguishable from the outbreak strain. A case control study showed analytical epidemiological evidence of risk related to potential exposure to the GWS but not related to reported consumption of that water. Selection of cases and controls proved challenging. Transmission occurred primarily in childcare and family settings, with significant person-to-person spread. Control measures included voluntary closure of the crèches, exclusion of culture-positive individuals in risk groups until microbiological clearance was achieved and the issuing of a ‘boil water’ advisory for drinking water pending upgrading of disinfection facilities.

Pulmonary barotrauma-induced cerebral arterial gas embolism with spontaneous recovery: commentary on the rationale for therapeutic compression

Pulmonary barotrauma-induced cerebral arterial gas embolism (CAGE) continues to complicate compressed gas diving activities. Inadequate lung ventilation secondary to inadvertent breath holding or rapid buoyant ascent can quickly generate a critical state of lung over-pressure. Pulmonary over-pressurization may also occur as a consequence of acute and chronic pulmonary pathologies. Resulting barotrauma frequently causes structural failure within the terminal distal airway. Respiratory gases are then free to embolize the systemic circulation via the pulmonary vasculature and the left heart. The brain is a common target organ. Bubbles that enter the cerebral arteries coalesce to form columns of gas as the vascular network narrows. Small amounts of gas frequently pass directly through the cerebral circulation without occlusion. Larger columns of gas occlude regional brain blood flow, either transiently or permanently, producing a stroke-like clinical picture. In cases of spontaneous redistribution, a period of apparent recovery is frequently followed by relapse. The etiology of relapse appears to be multifactoral, and chiefly the consequence of a failure of reperfusion. Prediction of who will relapse is not possible, and any such relapse is of ominous prognostic significance. It is advisable, therefore, that CAGE patients who undergo spontaneous recovery be promptly recompressed while breathing oxygen. Therapeutic compression will serve to antagonize leukocyte-mediated ischemia-reperfusion injury; limit potential re-embolization of brain blood flow, secondary to further leakage from the original pulmonary lesion or recirculation of gas from the initial occlusive event; protect against embolic injury to other organs; aid in the resolution of component cerebral edema; reduce the likelihood of late brain infarction reported in patients who have undergone spontaneous clinical recovery; and prophylax against decompression sickness in high gas loading dives that precede accelerated ascents and omitted stage decompression.

Nonlinear propagation of negatively chirped pulses: Maximizing the peak intensity at the output of a fiber probe

A simple phenomenological scaling behavior is found for the power dependence of the pulse width for negatively pre-chirped pulses propagating in a normally dispersive fiber; the consequences for maximizing nonlinear signals such as two-photon fluorescence excited at the fiber output are considered.

The healthy communities movement and the coalition for healthier cities and communities

Part One of this article describes the principles and origins of the Healthy Communities movement. Part Two describes the Coalition for Healthier Cities and Communities, a national network of partnerships and organizations. The authors argue (a) that to sustain community initiatives, practitioners must move from projects that address symptoms of social problems to changing the underlying community cultures, incentives, and settings that give rise to these symptoms, and (b) that the Coalition's continued relevance depends on its ability to help leaders make that transition.

Introduction

This focus issue of Optics Express is concerned with coherent optical interactions in condensed matter. This field has shown tremendous growth over the past few years - a phenomenon at least partly due to the remarkable progress in ultrafast lasers and measurement techniques which has been a prerequisite to observing coherent transient phenomena on the short time scales required in condensed matter systems. There are many kinds of coherence which can be generated by short optical pulses in solids, including electronic interband and intraband coherence, and coherent phonon fields. The four papers in this issue investigate various aspects of these phenomena.

Compensation of self-phase modulation in chirped-pulse amplification laser systems

Small amounts of self-phase modulation can lead to significant pulse distortions in chirped-pulse amplifiers. However, we show the surprising result that the strong chirp of the pulse can be exploited to remove these distortions completely by linear pulse shaping before amplification.

Do program directors and their chief residents view the role of chief resident similarly?

BACKGROUND

The chief resident plays an important role in family practice residencies and is positioned at the nexus of the relationship between the faculty and the residents. It is unknown if program directors and their respective chief residents view this position and the role of training and faculty development similarly.

METHODS

Parallel surveys were sent to all family practice residency program directors and their respective chief residents to explore their perceptions of the importance of the tasks and roles of the chief resident and the effects that perceived training, feedback, and support have on the chief resident's satisfaction.

RESULTS

Fifty-one percent of chief residents and their program directors returned surveys that could be analyzed in parallel. Program directors placed relatively greater importance on the administrative role of chiefs. Mentioned most frequently as problems were balancing administrative duties with other tasks, dealing with personnel issues, and working with the lack of a clear job description. Chiefs who participated in formal training programs and who perceived better burnout prevention were more satisfied with their position.

CONCLUSIONS

A large number of chief residents perceived gaps in the preparation for their position, particularly with regard to administrative skills. These deficiencies are particularly ironic in light of program directors' perceptions that administrative duties are of the highest importance among the tasks assigned to chief residents. Faculty development strategies and a program of burnout prevention for chief residents should be incorporated into each residency.

Real-time two-photon confocal microscopy using a femtosecond, amplified Ti:sapphire system

The bilateral imaging approach known from confocal applications operating in the line mode was used to realize real-time two-photon imaging. It is shown that the sectioning inherent to two-photon imaging could be improved by the introduction of a confocal line aperture in the imaging path. Using a high-power, low-repetition-rate amplified Ti:sapphire system, various biological objects were visualized including live boar sperm.

Esophagogastroduodenoscopy for the family physician

Esophagogastroduodenoscopy is most commonly performed for evaluation of epigastric pain, severe heartburn, chronic nausea and other dyspepsia syndromes that are not relieved by medical therapy. It should not be performed as an in-office procedure in patients with unstable angina, respiratory failure, active upper gastrointestinal bleeding or hemodynamic instability. Although office esophagogastroduodenoscopy is safe for low-risk patients, the risks associated with anesthesia and the need for postprocedure observation may require other patients to undergo the procedure in a hospital setting. Use of a local anesthetic throat spray reduces the gag response that occurs when the endoscope is swallowed. Sedation is commonly achieved with intravenous administration of a benzodiazepine plus a narcotic, and the effects of these drugs can be rapidly reversed. Complications are rare and most frequently result from medications rather than from the procedure itself.