Efficacy and tolerability of lumiracoxib versus placebo in patients with osteoarthritis of the hand

OBJECTIVE

This multicentre, randomized, double-blind, placebo-controlled parallel-group study was undertaken to investigate the efficacy, safety and tolerability of lumiracoxib (Prexige), a cyclooxygenase-2 selective inhibitor, in patients with primary osteoarthritis (OA) of the hand.

METHODS

The study randomized 594 patients aged > or = 18 years with symptomatic OA of the hand. Patients underwent a 3 to 7-day washout for previous nonsteroidal anti-inflammatory drugs and those with pain intensity > or = 40 mm on a 100 mm Visual Analogue Scale (VAS) in the target hand during the 24 hours prior to baseline and an increase in pain intensity of either > or = 20% or > or = 10 mm VAS since screening (whichever was greater) were randomized to lumiracoxib 200 mg once daily (od) (n=205), lumiracoxib 400 mg od (n=193) or placebo (n=196). The primary efficacy variable was overall OA pain intensity (VAS mm) in the target hand after 4 weeks of treatment. Safety and tolerability assessments were performed.

RESULTS

After 4 weeks of treatment, overall OA pain intensity in the target hand was significantly lower for patients treated with lumiracoxib compared with patients treated with placebo (both doses p<0.001). There was no significant difference between lumiracoxib doses in terms of the reduction in overall OA pain intensity. Lumiracoxib was well tolerated. The incidence of adverse events was similar for active treatment groups and placebo.

CONCLUSIONS

Lumiracoxib 200 and 400 mg od were effective and well tolerated treatments for OA of the hand. Lumiracoxib significantly improved overall OA pain intensity in the target hand versus placebo, with a tolerability profile similar to placebo.

Randomised trial comparing an interactive multimedia decision aid with a leaflet and a video to give information about prenatal screening for Down syndrome

OBJECTIVES

(1)To compare an interactive multimedia decision aid (IMDA) with a leaflet and a video to give information about prenatal screening for Down syndrome and (2) to determine the women's acceptance of IMDA.

METHODS

Two hundred and one women were recruited from the prenatal clinic of a university teaching hospital and randomised into the intervention group (IMDA, video, and information leaflet) or the control group (video and information leaflet).

RESULTS

There were no significant differences in the initial decision for and the final uptake of the prenatal screening test between the control and intervention groups. The proportion of women who were undecided was less than 10% in both groups. Of the women in the intervention group, 86.6% and 78.9% agreed that IMDA was user-friendly and acceptable, respectively. Significantly more women aged < 35 (88.1%) accepted IMDA than women aged > or = 35 (68.3%) (P = 0.030), but the logistic regression analysis did not confirm this finding after adjusting for other factors (computer knowledge and usage of computer).

CONCLUSION

The use of IMDA did not affect the women's overall uptake rate of the prenatal screening test for Down syndrome. More women less than 35 years accepted IMDA probably because they used computer more frequently and had more computer knowledge.

Prenatal diagnosis of the Meckel-Gruber syndrome from 11th to 20th gestational week

INTRODUCTION

The Meckel-Gruber syndrome (MKS) is a rare autosomal recessive disorder that is characterized by typical sonographical findings: occipital encephalocele, postaxial polydactyly and cystic enlargement of the kidneys. Its recurrence risk of 25 % demands an exact diagnosis.

METHOD

Retrospective analysis of the sonographic characteristics in relation to the gestational age in eight cases with the pathologic diagnosis of MKS.

RESULTS

The sonographic characteristics depend on the gestational age. The classic trias was solely seen in the case diagnosed before 14 (th) week of gestation. In the other seven cases, diagnosed between the 17 (th) and 20 (th) week of gestational age, only two of three characteristic signs of MKS could be visualised by US. Polydactyly was missed by ultrasound in all seven cases due to the marked oligohydramnion.

CONCLUSION

The Meckel-Gruber syndrome can be confidently detected and diagnosed by sonography at the 11th to 14th gestational week. Later in the pregnancy, severe oligohydramnion makes it more difficult to establish the diagnosis by US alone. In these cases a meticulous autopsy is necessary to establish the diagnosis of MKS.

The frequency of intratubular embryonal carcinoma: implications for the pathogenesis of germ cell tumours

AIMS

To define the frequency and distribution of intratubular embryonal carcinoma (IEC) in an attempt to shed light on the pathogenesis of non-seminomatous germ cell tumours (NSGCTs). Intratubular germ cell neoplasia of unclassified type (IGCNU) is common in NSGCT; however, IEC is rarely described.

METHODS AND RESULTS

Sixty-two germ cell tumours were reviewed. Immunochemistry for CD30, placental alkaline phosphatase (PLAP) and c-kit was performed. The distribution, immunohistochemistry and morphology of the intratubular neoplasia were noted. All cases showed widespread IGCNU with PLAP and c-kit staining. CD30 showed strong focal intratubular positivity in 20/31 NSGCTs, 1/29 seminomas and 1/4 mixed seminomas/NSGCTs. In 17 of these cases, the CD30+ tubules were not easily identified as IEC on routine stains. These tubules were scanty in number and c-kit was negative, though some showed patchy PLAP staining. The cells within these tubules differed morphologically from IGCNU.

CONCLUSIONS

IEC defined by CD30 positivity is not always easily identified on haematoxylin and eosin staining. We suggest that IEC is a common intermediate step between IGCNU and NSGCTs. The patchy and focal distribution of IEC suggests it may evolve quickly to invasive disease.

The effect of optic disc diameter on vertical cup to disc ratio percentiles in a population based cohort: the Blue Mountains Eye Study

OBJECTIVE

The 97.5th percentile for vertical cup to disc ratio (VCDR) has been proposed as a useful tool to assist in the diagnosis of glaucoma in population studies. Previous reports of VCDR percentiles have either not been adjusted for disc size or have been calculated by regression analysis from small hospital based cohorts. The authors' aim was to generate VCDR percentiles in a large, population based sample.

METHODS

Data were collected from 3654 individuals, aged 49 years or older, living in the Blue Mountains, west of Sydney. Vertical disc diameter and VCDR were determined by planimetry from stereo optic disc photographs. The distribution of VCDR and percentiles (95th, 97.5th, 99th) were calculated.

RESULTS

6678 eyes were included in the analysis. Median cup to disc ratio, 95th, 97.5th, and 99th percentile increased with vertical optic disc diameter in a linear fashion. An increase of 0.2 in median VCDR (0.35 to 0.55) was observed between small (1.1-1.3 mm) and large (1.8-2.0 mm) optic discs. An equivalent increase of 0.2 (0.59 to 0.74) was observed for the 97.5th percentile from small to large discs.

CONCLUSION

VCDR percentiles for a "normal" population, adjusted for vertical optic disc diameter are presented. One quarter of all discs fell within the small or large disc categories highlighting the importance for estimating optic disc size. These data may assist in the diagnosis of glaucoma in clinical practice as well as providing a normative database. Sole use of VCDR percentile cut offs in defining glaucoma cases in population surveys requires further validation.

How did general practitioners protect themselves, their family, and staff during the SARS epidemic in Hong Kong?

CONTEXT

Severe acute respiratory syndrome (SARS) is a newly emerging infectious disease and how the frontline community doctors respond to it is not known.

OBJECTIVES

To explore the impact of SARS on general practitioners (GPs) in Hong Kong.

DESIGN

A cross sectional survey.

SETTING

Community based primary care clinics.

PARTICIPANTS

183 family medicine tutors affiliated with a local university. Postal survey sent to all tutors with a 74.8% response rate.

MAIN OUTCOME MEASURES

Change of clinical behaviour and practices during the epidemic; anxiety level of primary care doctors.

RESULTS

All agreed SARS had changed their clinical practices. Significant anxiety was found in family doctors. Three quarters of respondents recalled requesting more investigations while a quarter believed they had over-prescribed antibiotics. GPs who were exposed to SARS or who had worked in high infection districts were less likely to quarantine themselves (10.8% versus 33.3%; p<0.01; 6.5% versus 27.5%; p<0.01 respectively). Exposure to SARS, the infection rates in their working district, and anxiety levels had significant impact on the level of protection or prescribing behaviour.

CONCLUSION

The clinical practice of GPs changed significantly as a result of SARS. Yet, those did not quarantine themselves suggesting other factors may have some part to play. As failure to apply isolation precautions to suspected cases of SARS was one major reason for its spread, a contingency plan from the government to support family doctors is of utmost importance. Interface between private and public sectors are needed in Hong Kong to prepare for any future epidemics.

Improved delivery of ipratropium bromide/fenoterol from Respimat® Soft MistTM Inhaler in patients with COPD

We performed a multicentre, randomised, double-blind (within-device), placebo- and active-controlled, parallel-group study to compare the efficacy and safety of ipratropium bromide plus fenoterol hydrobromide (IB/FEN; Berodual) delivered via the novel, propellant-free Respimat Soft Mist Inhaler (SMI) and from a chlorofluorocarbon (CFC)-metered-dose inhaler (MDI) in moderate-to-severe chronic obstructive pulmonary disease (COPD) patients. After 2-weeks' run-in (CFC-MDI [IB 20 microg/FEN 50 microg per actuation] two actuations q.i.d. [MDI 40/100]), 892 patients were randomised to Respimat SMI containing IB 10 microg/FEN 25 microg (Respimat SMI 10/25), IB 20 microg/FEN 50 microg (Respimat SMI 20/50) or placebo (one actuation q.i.d.), or a CFC-MDI containing IB 20 microg/FEN 50 microg (MDI 40/100) or placebo (two actuations q.i.d.) for 12 weeks. Analysis of the primary endpoint (change in forced expiratory volume in 1 s [FEV1] in the first 60 min after dosing [area under the curve; AUC0-1h]) on day 85 showed that the efficacy of Respimat SMI 20/50 (but not Respimat SMI 10/25) was not inferior to that of MDI 40/100. The safety profile of Respimat SMI was comparable to CFC-MDI. Switching from MDI 40/100 to Respimat SMI was well tolerated. Respimat SMI enables a 50% reduction of the nominal inhaled dose of IB/FEN in COPD patients while offering similar therapeutic efficacy and safety to the CFC-MDI.

The association between global self-esteem, physical self-concept and actual vs ideal body size rating in Chinese primary school children

OBJECTIVE

To investigate whether the discrepancy between actual and ideal body size rating is related to Chinese children's global self-esteem and global physical self-concept.

DESIGN

A cross-sectional study of school children who completed questionnaires related to global self-esteem, global physical self-concept, and actual vs ideal body size.

SUBJECTS

A total of 386 Chinese children (44% girls and 56% boys) aged 7-13 y from a primary school in Hong Kong, China.

MEASUREMENTS

Global self-esteem and physical self-concept were measured using the physical self-descriptive questionnaire. Actual vs ideal body size discrepancy was established using the silhouette matching task.

RESULTS

No significant relationship was found between global self-esteem and actual-ideal body size discrepancy of children. Global physical self-concept had a moderate negative correlation (r=-0.12) with the body size discrepancy score and the discrepancy score explained very limited variance (R(2)=0.015; F(1, 296)=4.51; P<0.05) in global physical self-concept. Three body size discrepancy groups (none, positive, and negative) were examined to see if there were any significant differences in global self-esteem, global physical self-concept, and specific dimensions of physical self-concept. A significant overall difference was found between groups for global physical self-concept (F=3.73, P<0.05) and the physical self-concept subscales of physical activity (F=3.25, P<0.05), body fat (F=61.26, P<0.001), and strength (F=5.26, P<0.01). Boys scored significantly higher than girls on global physical self-concept-especially in the sport competence, strength, and endurance subscales.

CONCLUSION

This study revealed that the actual-ideal body size discrepancy rating of Chinese children was not predictive of global physical self-concept and global self-esteem. These findings are contrary to those reported in Western children, which may mean that culture plays a role in the formation of body attitude.

Foetal facial clefts: prenatal evaluation of lip and primary palate by 2D and 3D ultrasound

INTRODUCTION

To examine whether three-dimensional ultrasound (3D US) is an accurate diagnostic method of clinical use in the ability to define the location and extent of facial clefting prenatally, compared to two-dimensional ultrasound (2D US).

METHODS

18 foetuses suspected or diagnosed to suffer from a facial cleft by 2D US were examined with a targeted 3D US. 2D US and 3D US results were compared with postnatal outcome.

RESULTS

Comparison of the number of foetuses with a cleft lip + primary palate diagnosed correctly with 2D US with the results of adjunctive 3D US (true positive + true negative) showed that adjunctive 3D US correctly diagnosed more cleft lips (100 %; 15/15 foetuses vs. 66 %; 12/18 foetuses) and more cleft primary palates (100 %; 12/12 foetuses vs. 58 %; 7/12 foetuses).

CONCLUSION

Interactive review of standardised 3D multiplanar images allows to systematically evaluate lip defects and abnormalities of the maxillary tooth-bearing alveolar ridge. The accuracy of adjunctive 3D ultrasound is superior to 2D ultrasound alone for extensive prenatal diagnosis of cleft lip with or without cleft primary palate.

Supplementary oxygen for elective Caesarean section under spinal anaesthesia: useful in prolonged uterine incision-to-delivery interval? †

BACKGROUND

The benefit of administering supplementary oxygen during elective Caesarean section under regional anaesthesia is controversial. It has been hypothesized that its use would improve fetal oxygenation in the event of a prolonged uterine incision-to-delivery (U-D) interval. Our aim was to test this hypothesis in a prospective, randomized, double-blinded, controlled study.

METHODS

We allocated randomly 204 women having elective Caesarean section under spinal anaesthesia to breathe 21, 40 or 60% oxygen. We recorded the U-D interval, umbilical arterial (UA) and venous (UV) blood gases and oxygen content and Apgar scores. Subgroup analysis was performed according to whether the U-D interval was prolonged (>180 s) or not.

RESULTS

The U-D interval was <180 s in 159 patients and >180 s in 45 patients. There were no differences in UV or UA blood gases, oxygen content or Apgar scores between cases with and without a prolonged U-D interval. In cases without a prolonged U-D interval, administering 60% oxygen increased UV PO(2) (mean 4.3 (SD 1.1) vs 3.7 (1.0) kPa, P=0.003) and oxygen content (14.4 (3.3) vs 12.9 (2.7) ml dl(-1), P=0.007) compared with air. In cases with a prolonged U-D interval, administering 60% oxygen increased UV PO(2) (4.6 (0.6) vs 3.9 (0.8) kPa, P=0.019) compared with air but there was no difference in UV oxygen content. There was no increase in the UV PO(2) or oxygen content when 40% oxygen was administered compared with air.

CONCLUSIONS

Supplementary oxygen did not increase fetal oxygenation in cases where the U-D interval was prolonged. Our data do not support the routine administration of supplementary oxygen during elective Caesarean section for this purpose.

How would schools step up public health measures to control spread of SARS?

The severe acute respiratory syndrome (SARS) is a rapidly progressive, and sometime fatal disease with more than 1800 patients in over a dozen countries in Asia, Europe, and North America (including the United States and Canada) within two months. On 12 March 2003, the World Health Organisation (WHO) issued a global alert about SARS so it became a global challenge. Strengthening the public health measures at schools would protect children as well as providing the students an opportunity to learn about infectious disease control through life event approach. The public health measures at schools include two important components: basic understanding of the disease so schools would put on high alert on caution cases, and the measures to improve environmental hygiene at schools and preventive measures to stop infectious disease transmission. This will help to empower the whole community the readiness to deal with other outbreaks in the future.

Youth risk behaviour in a Chinese population: a territory-wide youth risk behavioural surveillance in Hong Kong

This cross-sectional study investigated the prevalence rates of different categories of youth risk behaviour by age, sex and parental education. The study population consisted of 26,111 Hong Kong students, aged 10-19 years, recruited from 48 primary (primary grades 4-6) and secondary schools (secondary grades 1-7). Less than one-third of subjects participated in vigorous exercise regularly, about one-third consumed an unhealthy diet frequently, 18% had tried smoking, and 14.5% had seriously considered attempting suicide. Although only 3.4% of students reported experience of sexual intercourse, less than half used a contraceptive device. Older students had higher prevalence rates of health-compromising behaviours than younger students. Female students were more likely to report suicide-related behaviour, attempting weight loss, and non-participation in vigorous physical activities. Students with parents of a lower educational background were more likely to report rarely or never wearing seat belts and bicycle helmets, suicide-related behaviour, smoking, sexual intercourse before 13 years of age, and attempting weight loss. The availability of data on youth health risk behaviours would enable health educators, public health practitioners and clinicians to plan appropriate screening and counselling for risk behaviours in early adolescents.

Lumiracoxib is effective in the treatment of osteoarthritis of the knee: a 13 week, randomised, double blind study versus placebo and celecoxib

OBJECTIVES

To compare the efficacy and safety of lumiracoxib with placebo and celecoxib for osteoarthritis OA in a 13 week, multicentre, randomised, double blind study.

METHODS

After a 37 day washout period for nonsteroidal antiinflammatory drugs, 1702 patients with knee OA were randomised to lumiracoxib 200 or 400 mg once daily od, celecoxib 200 mg od, or placebo 2221. A visual analogue scale VAS pain intensity > or =40 mm was required. Primary efficacy variables were OA pain intensity VAS mm in the target knee, patients global assessment of disease activity VAS mm, and WOMAC pain subscale and total scores at 13 weeks. OA pain intensity, patients and physicians global assessment of disease activity, and WOMAC total and all subscale scores were analysed by visit as secondary variables.

RESULTS

Lumiracoxib showed significant improvements in all primary and secondary variables compared with placebo. Lumiracoxib 200 mg od and celecoxib 200 mg od achieved similar improvements in OA pain intensity and functional status. Lumiracoxib 400 mg od demonstrated better efficacy for OA pain intensity and patients global assessment of disease activity at weeks 2, 4, and 8 and similar efficacy at week 13 compared with celecoxib 200 mg od. The incidence of adverse events AEs, serious AEs, and discontinuations due to AEs was similar in each group.

CONCLUSION

Lumiracoxib demonstrated significant improvement in OA pain intensity, patients global assessment of disease activity, and the WOMAC pain subscale and total scores compared with placebo. Lumiracoxib was well tolerated in this study, with overall tolerability similar to that of placebo and celecoxib.

The effect of bovine lactoferrin and lactoferricin B on the ability of feline calicivirus (a norovirus surrogate) and poliovirus to infect cell cultures

AIMS

To characterize the effect of bovine lactoferrin and lactoferricin B against feline calicivirus (FCV), a norovirus surrogate and poliovirus (PV), as models for enteric viruses.

METHODS AND RESULTS

Crandell-Reese feline kidney (CRFK) cells were used for the propagation of FCV and monkey embryo kidney (MEK) cells for PV. The assays included visual assessment of cell lines for cytopathic effects and determination of the percentage cell death using MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium] dye reduction assay. Incubation of bovine lactoferrin with CRFK cells either prior to or together with FCV inoculation substantially reduced FCV infection. In contrast, the interference of lactoferrin with the infection of cells with PV was demonstrated only when lactoferrin was present with cell lines and virus for the entire assay period. Using indirect immunofluorescence, lactoferrin was detected on the surface of both CRFK and MEK cells, suggesting that the interference of viral infection may be attributed to lactoferrin binding to the surfaces of susceptible cells, thereby preventing the attachment of the virus particles. Lactoferricin B, a cationic antimicrobial peptide derived from the N-terminal domain of bovine lactoferrin, reduced FCV but not PV infection.

CONCLUSION

Lactoferrin was shown to interfere with the infection of cells for both FCV and PV. However, lactoferricin B showed no interference of infection with PV and interference with infection for FCV required the presence of lactoferricin B together with the cell line and virus.

SIGNIFICANCE AND IMPACT OF THE STUDY

An in vitro basis is provided for the effects of bovine lactoferrin and lactoferricin B in moderating food-borne infections of enteric viruses.

Stimulation of the wrist acupuncture point P6 for preventing postoperative nausea and vomiting

BACKGROUND

Postoperative nausea and vomiting (PONV) are common complications following surgery and anaesthesia. Drug therapy to prevent PONV is only partially effective. An alternative approach is to stimulate a P6 acupoint on the wrist. Although there are many trials examining this technique, the results are conflicting.

OBJECTIVES

To determine the efficacy and safety of P6 acupoint stimulation in preventing PONV.

SEARCH STRATEGY

We searched CENTRAL (The Cochrane Library, Issue 1, 2003), MEDLINE (January 1966 to January 2003), EMBASE (January 1988 to January 2003) and the National Library of Medicine publication list of acupuncture studies up to and including January 2003. Reference lists of retrieved papers and reviews were consulted for additional references.

SELECTION CRITERIA

All randomized trials of techniques that stimulated the P6 acupoint compared with: sham treatment or drug therapy for the prevention of PONV. Interventions used in these trials included acupuncture, electro-acupuncture, transcutaneous nerve stimulation, laser stimulation, acustimulation device and acupressure.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed methodological quality and extracted the data. Primary outcomes were incidences of nausea and vomiting. Secondary outcomes were the need for rescue antiemetic therapy and adverse effects. A random effects model was used and relative risk (RR) with associated 95% confidence intervals (95% CI) are reported. Egger's test was used to measure the asymmetry of the funnel plot.

MAIN RESULTS

Twenty-six trials (n = 3347) were included, none of which reported adequate allocation concealment. There were significant reductions in the risks of nausea (RR 0.72, 95% CI 0.59 to 0.89), vomiting (RR 0.71, 95% CI 0.56 to 0.91) and the need for rescue antiemetics (RR 0.76, 95% CI 0.58 to 1.00) in the P6 acupoint stimulation group compared with the sham treatment, although many of the trials were heterogeneous. There was no evidence of difference in the risk of nausea and vomiting in the P6 acupoint stimulation group versus individual antiemetic groups. However, when different antiemetics were pooled, there was significant reduction in the risk of nausea but not vomiting in the P6 acupoint stimulation group compared with the antiemetic group (RR 0.70, 95% CI 0.50 to 0.98; RR 0.92, 95% CI 0.65 to 1.29 respectively). The side effects associated with P6 acupoint stimulation were minor. There was some evidence of asymmetry of the funnel plot.

REVIEWERS' CONCLUSIONS

This systematic review supports the use of P6 acupoint stimulation in patients without antiemetic prophylaxis. Compared with antiemetic prophylaxis, P6 acupoint stimulation seems to reduce the risk of nausea but not vomiting.

Effects of nonsteroidal anti-inflammatory drugs on postoperative renal function in adults with normal renal function

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) can play a major role in the management of acute pain in the peri-operative period. However, there are conflicting views on whether NSAIDs are associated with adverse renal effects.

OBJECTIVES

The primary objective of this review was to determine the effects of NSAIDs on postoperative renal function in adults with normal preoperative renal function.

SEARCH STRATEGY

Electronic searches for relevant randomised and quasi-randomised controlled trials in Cochrane Central Register of Controlled Trials, MEDLINE and EMBASE were performed. Attempts were also made to identify trials from citation lists of relevant trials, review articles and clinical practice guidelines. Handsearching of conference abstracts published in major anaesthetic journals was also performed. (Search date: 7 February 2003)

SELECTION CRITERIA

The inclusion criteria were randomised or quasi-randomised comparisons of individual NSAIDs with either each other or placebo for treatment of postoperative pain, with relevant postoperative renal outcome measures, in adult surgical patients with normal renal function.

DATA COLLECTION AND ANALYSIS

The data was extracted independently by two reviewers. The primary outcome measure was creatinine clearance within the first two days after surgery. Secondary outcome measures included serum creatinine, urine volume, urinary sodium level, urinary potassium level, fractional excretion of sodium, fractional excretion of potassium, need for dialysis and need for diuretic or dopamine treatment for renal insufficiency. Weighted mean differences for continuous outcomes and relative risk for dichotomous outcomes were estimated.

MAIN RESULTS

Nineteen trials ( n = 1204) fulfilled the selection criteria for this review. NSAIDs reduced creatinine clearance by 16 ml/min (95%CI 5 to 28) and potassium output by 38 mmol/day (95%CI 19 to 56) on the first day after surgery compared to placebo. There was no significant difference in serum creatinine on the first day (0 umol/L, 95%CI -5 to 4) compared to placebo. No significant reduction in urine volume during the early postoperative period was found. There was no significant difference in serum creatinine in the early postoperative period between patients receiving diclofenace and ketorolac (or indomethacin). No cases of postoperative renal failure requiring dialysis were described. The trials were homogeneous for the primary outcome.

REVIEWERS' CONCLUSIONS

NSAIDs caused a clinically unimportant transient reduction in renal function in the early postoperative period in patients with normal preoperative renal function. NSAIDs should not be withheld from adults with normal preoperative renal function because of concerns about postoperative renal impairment.