Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Problems of Adolescents Sexuality

Recent discussions highlighted adolescents’ sexual behaviour, but published studies concentrate on specific problems or subgroups of patients without addressing factors related to sexuality. To obtain a broad picture we studied two groups of adolescents attending genito-urinary medicine/sexually transmitted disease (STD) clinics in contrasting areas of Britain, inner London and Swansea. These were evaluated for referral pattern, sexual partner, contraception, obstetric history, sexually transmitted disease, and cervical cytology findings.

Over half the adolescents referred themselves but few doctors other than general practitioners referred patients. Sexual partners were regarded by males as casual but by females as regular. Only 66% (81) of females practised contraception. Adolescents had more STD's than the total clinic population except for genital herpes simplex infection, and a high prevalence of genital warts in females has important future implications.

The main conclusions were that there is a need for sexually related education targetted at adolescents and their health care providers, especially doctors.

Diagnostic disagreement between tests of evacuatory function: a prospective study of 100 constipated patients

BACKGROUND

Evacuatory dysfunction (ED) is a common cause of constipation and may be sub-classified on the basis of specialist tests. Such tests may guide treatment e.g., biofeedback therapy for 'functional' defecatory disorders (FDD). However, there is no gold standard, and prior studies have not prospectively and systematically compared all tests that are used to diagnose forms of ED.

METHODS

One hundred consecutive patients fulfilling Rome III criteria for functional constipation underwent four tests: expulsion of a rectal balloon distended to 50 mL (BE50 ) or until patients experienced the desire to defecate (BEDDV ), evacuation proctography (EP) and anorectal manometry. Yields and agreements between tests for the diagnosis of ED and FDD were assessed.

KEY RESULTS

Positive diagnostic yields for ED were: BEDDV 18%, BE50 31%, EP 38% and anorectal manometry (ARM) 68%. Agreement was substantial between the two balloon tests (k = 0.66), only fair between proctography and BE50 (k = 0.27), poor between manometry and proctography (k = 0.01), and there was no agreement between the balloon tests and manometry (k = -0.07 for both BE50 and BEDDV ). For the diagnosis of FDD, there was only fair agreement between ARM and EP (k = 0.23), ARM ± BE50 and EP (k = 0.18), ARM and EP ± BE50 (k = 0.30) and ARM ± BE50 and EP ± BE50 (k = 0.23).

CONCLUSIONS & INFERENCES

There is considerable disagreement between the results of various tests used to diagnose ED and FDD. This highlights the need for a reappraisal of both diagnostic criteria, and what represents the 'gold standard' investigation.

A double-blinded randomized multicentre study to investigate the effect of changes in stimulation parameters on sacral nerve stimulation for constipation

AIM

Sacral nerve stimulation (SNS) may be offered to patients with constipation who have failed to improve with conservative treatment. The response to SNS is variable, with a significant loss of efficacy in some patients. An increased frequency of stimulation may improve the efficacy of SNS for faecal incontinence. This study aimed to see if alteration of the pulse width or frequency improved the outcome for those with constipation.

METHOD

Eleven patients with constipation currently being treated by SNS were recruited from three centres. They were randomized to five different protocols of stimulation each applied for 5 weeks. Group 1 used standard settings (pulse width 210 μs, frequency 14 Hz); in the other four groups (Groups 2-5) the pulse width and/or frequency were halved or doubled. Patients and investigators were blinded to the group allocation.

RESULTS

The Cleveland Clinic constipation score varied significantly between the five groups. Group 1 achieved the lowest score mean (± SD) 13.4 (± 4.4) (P = 0.03). The number of digitations per defaecation was the lowest in Group 4, 90 μs and 14 Hz (P < 0.01). No other variable changed significantly. Standard settings were the most preferred by the recruited patients.

CONCLUSION

Alteration of pulse width or frequency of stimulation had no significant effect on the outcome of SNS for constipation.

Systematic review of tibial nerve stimulation to treat faecal incontinence

Background

Two forms of tibial nerve stimulation are used to treat faecal incontinence (FI): percutaneous (PTNS) and transcutaneous (TTNS) tibial nerve stimulation. This article critically appraises the literature on both procedures.

Methods

A systematic review was performed adhering to the PRISMA framework. A comprehensive literature search was conducted, with systematic methodological quality assessment and data extraction. Summary measures for individual outcome variables are reported.

Results

Twelve articles met eligibility criteria; six related to PTNS, five to TTNS, and one to both procedures. These included ten case series and two randomized clinical trials (RCTs). Case series were evaluated using the National Institute for Health and Care Excellence quality assessment for case series, scoring 3–6 of 8. RCTs were evaluated using the Jadad score, scoring 4 of a possible 5 marks, and the Cochrane Collaboration bias assessment tool. From one RCT and case series reports, the success rate of PTNS, based on the proportion of patients who achieved a reduction in weekly FI episodes of at least 50 per cent, was 63–82 per cent, and that of TTNS was 0–45 per cent. In an RCT of TTNSversus sham, no patient had a reduction in weekly FI episodes of 50 per cent or more, whereas in an RCT of PTNSversus TTNSversus sham, 82 per cent of patients undergoing PTNS, 45 per cent of those having TTNS, and 13 per cent of patients in the sham group had treatment success.

Conclusion

PTNS and TTNS result in significant improvements in some outcome measures; however, TTNS was not superior to sham stimulation in a large, adequately powered, RCT. As no adequate RCT of PTNSversus sham has been conducted, conclusions cannot be drawn regarding this treatment.

A tale of 2 cities: a comparison of demographic details, source of referral, spectrum of infection and contraceptive practice in patients under 16 years attending genitourinary medicine clinics in London and Swansea

Sexually transmitted infections (STIs) in young people are increasing, with children aged less than 16 years being particularly vulnerable. We compared the demographic details, spectrum of infection, contraceptive practice and source of referral in patients aged less than 16 years attending 2 genitourinary clinics, one in Swansea and the other in London. In the London population, children aged less than 16 years represented 0.7% of the total new attendances compared with 1.4% in Swansea. The female to male ratio was almost 4:1 in both clinics with most infections confined to female attenders. In females the incidence of chlamydial infection, genital warts and anaerobic (bacterial) vaginosis was 5.5%, 19% and 8%, respectively in London compared with 27%, 32% and 36% in Swansea. Seventy-two per cent of patients attending the clinic in London were self referred compared with 40% in Swansea. Contraceptive practice was also markedly different in the 2 populations, and over one-third of children in both clinics used no contraception. The high incidence of STIs in both populations and low use of contraception has serious implications for the sexual health of young people and emphasizes the need for effective sexual health education at an early age.

Comparison of risk factors for four sexually transmitted infections: results from a study of attenders at three genitourinary medicine clinics in England

OBJECTIVE

To compare the risk factors for four common sexually transmitted infections (STIs) in attenders at three large urban genitourinary medicine (GUM) clinics in England.

METHODS

Clinical, demographic, and behavioural data on attenders at two clinics in London and one in Sheffield were collected. Risk factors associated with first episodes of genital warts and genital herpes simplex virus (HSV), and uncomplicated gonorrhoea and chlamydia were investigated using the presence of each of these STIs as the outcome variable in separate multiple logistic regression analyses.

RESULTS

Using data on the first attendance of the 18,238 patients attending the clinics in 1996, the risk of a gonorrhoea or chlamydia diagnosis was strongly associated with teenagers compared with those aged over 34, with black Caribbeans and black Africans compared with whites, and increased with the number of sexual partners. The risk of genital warts or HSV diagnosis was lowest in black Caribbeans and black Africans compared with whites and was not associated with the number of sexual partners. While genital warts were associated with younger age, odds ratios were much lower compared with those for the bacterial infections. Genital HSV diagnoses were not associated with age.

CONCLUSIONS

This study of GUM clinic attenders suggests a reduction in the incidence of bacterial STIs may be achievable through targeted sexual health promotion focusing particularly on black ethnic minorities, teenagers, and those with multiple sexual partnerships. Viral STIs were less clearly associated with population subgroups and a broader population based approach to sexual health promotion may be more effective in controlling these infections.

Behavioural and demographic characteristics of attenders at two genitourinary medicine clinics in England

OBJECTIVES

To investigate how attenders with sexually transmitted disease (STD) differ from the general population with respect to sexual behaviour, and to identify which attenders at genitourinary medicine (GUM) clinics are at particular behavioural risk for acquiring STD.

DESIGN

Multicentre cross sectional survey.

SETTING

Two genitourinary medicine clinics, one in London and one in Sheffield

SUBJECTS

20,516 patients attending the two clinics over an 18 month period.

MAIN OUTCOME MEASURES

Behavioural and demographic characteristics and clinical diagnoses were recorded for each patient.

RESULTS

8862 patients, in whom 12,506 diagnoses were made, were seen in the Sheffield clinic, and 11,654 patients, in whom 20,243 diagnoses were made, were seen in the London clinic. When compared with the reported results from a general population survey, there were higher proportions of clinic attenders reporting two or more sexual partners in the preceding 12 months (p < 0.001), and a higher proportion of males reporting homosexual contact (13% compared with 1%, p < 0.001). Only age and number of sexual partners in the past 12 months were significantly associated with acute STDs for each sex in each clinic. Acute STDs tended to occur with greater frequency in the younger age groups, peaking among 16-19 year olds, particularly among females.

CONCLUSIONS

The results have confirmed that patients with STDs exhibit higher risk sexual behaviour than the general population, and have highlighted the problem of continuing high risk behaviour among younger attenders, particularly younger homosexual men. This study has demonstrated that among GUM clinic attenders age and number of sexual partners are key risk factors for the acquisition of an acute STD. The results of this survey also indicate, however, that half of the females and more than one quarter of males with acute STDs reported only one sexual partner in the past 12 months, suggesting that health education messages should point out that it is not only those who have multiple recent sexual partners, or who have recently changed sexual partner, that are at risk of STD, including HIV.