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.

EP.FRI.978 Colonoscopy perforation: A single centre experience

Aims

Colonic perforation is an adverse event of colonoscopy. This is around 1/1500 in diagnostic colonoscopy, 1/500 in polypectomy procedures & 1/50 in EMR procedure. This study is to evaluate the management of colonic perforation at a single centre.

Methods

Colonoscopy carried out on patients with colorectal cancer symptoms, family history, colorectal cancer & polyp surveillance. Retrospective study carried out since 2012 on all colonoscopies with evaluation of colonoscopy perforation. 

Conclusion

7 colonoscopy perforations encountered over 8 years, with incidence of 0.03 - 0.06 % per year. Surgery undertaken in 5 cases  with concomitant disease bowel (2 IBD’s & 3 diverticulitis). 2 cases of conservative management. Surgical resection of diseased bowel occurred in 4 cases with 4 cases of diversion stoma. One case of diversion stoma was subsequently reversed, whilst other 2 case were deemed medically unfit. Colonoscopy is carried out by JAG accredited endoscopists. Colonic perforation during colonoscopy is increased in: polypectomy (right colonic), therapeutic EMR, diseased bowel (IBD, diverticular disease), challenging colons. Management of colonoscopy perforation should individualized with early clinical & radiological diagnosis.

EP.FRI.974 NELA 30 day mortality: A single centre experience

Aims

National emergency laparotomy audit (NELA) developed in 2014 in the UK, aims to improve of quality of care of patients undergoing emergency laparotomy. NELA highlights the importance of identifying high risk patients for potential significant morbidity and mortality. The aim of this study is to review the NELA 30 day mortality at a single centre.

Methods

This is a retrospective review of all 30 day NELA mortality patients since 2014 carried out at East Cheshire NHS Trust until January 2020. The NELA survivors beyond 30 days were used as controls.

Results

Conclusion

The overall NELA 30 day mortality rate was 9.8 %. NELA deaths occurred in the older, frail, multi-comorbid & high ASA status patients. Most NELA deaths occur within 90 days, whereas patient survival curve appears to plateau out beyond 90 days. P possum can be used to identify high risk patients, where early collaborative senior assessment by consultant surgeons, anaesthetists and intensivists may identify and allocate appropriate surgical intervention. 

EP.FRI.976 ERAS after malignant colorectal resections: A single centre experience

Aims

ERAS employs a multi-modal rehabilitation aids post-op recovery following colorectal resections. ERAS applied in both laparoscopic + open surgery. This study aims to assess effectiveness of ERAS at a single centre.

Methods

A retrospective study at East Cheshire NHS Trust, since 2008. Descriptive demography & post-operative features were collected for all elective colorectal resections.

Results

Conclusion

ERAS associated with longer operative time (p < 0.05) (laparoscopic surgery), a shorter hospital stay was achieved (p < 0.05). Delayed ERAS occurred in 26.2 % of cases & can result in delayed discharge. Early ERAS deviations occurred in the presence of major surgical complications (ileus, anastomotic leaks, collections). Despite post-operative cardiac & pulmonary events, ERAS was maintained. A targeted rehabilitation programme especially in the elderly patients can lead to earlier recovery. 

EP.TH.1029Surgery for retained gallstones: A single centre experience

Aims

Lost spilled gallstones during laparoscopic cholecystectomy is a rare inadvertent complication results in recurrent delayed sepsis. Diagnosis is made via retrospective review of operative notes. 2 cases of retained gallstones were removed surgically, following several years after the initial laparoscopic cholecystectomy.

Conclusion

2 cases presented with delayed symptoms of abdominal pain, sepsis with intra-abdominal collections. Intra-abdominal abscesses treated with percutaneous USS guided drainage & antibiotics. Abscesses arise in right subphrenic space, right anterior abdominal wall & iliacus as a result of gallstone migration. Diagnosis of “spilled lost gallstones” was delayed until confirmation of retained gallstones on radiological imaging. Combination of USS, CT and MRI scan enabled to detect retained gallstones (radiolucent or radio-opaque) within an abscess cavity.

Multi-disciplinary approach allowed a more concerted management i.e. diagnosis of retained gallstones & planning surgical exploration for retained gallstones.

Ultimately, abscesses should be drained (percutaneously or surgically), and retained stones should be removed. Ideally this is done via minimally invasive techniques, but open surgery is often required. Use of laparoscopy enables exploration of the peritoneal cavity and any abscess cavity. This exploration will extract any fragment of gallstone that could be a nidus for continuous infection.

Behavioral changes and growth deficits in a CRISPR engineered mouse model of the schizophrenia-associated 3q29 deletion

The 3q29 deletion confers increased risk for neuropsychiatric phenotypes including intellectual disability, autism spectrum disorder, generalized anxiety disorder, and a >40-fold increased risk for schizophrenia. To investigate consequences of the 3q29 deletion in an experimental system, we used CRISPR/Cas9 technology to introduce a heterozygous deletion into the syntenic interval on C57BL/6 mouse chromosome 16. mRNA abundance for 20 of the 21 genes in the interval was reduced by ~50%, while protein levels were reduced for only a subset of these, suggesting a compensatory mechanism. Mice harboring the deletion manifested behavioral impairments in multiple domains including social interaction, cognitive function, acoustic startle, and amphetamine sensitivity, with some sex-dependent manifestations. In addition, 3q29 deletion mice showed reduced body weight throughout development consistent with the phenotype of 3q29 deletion syndrome patients. Of the genes within the interval, DLG1 has been hypothesized as a contributor to the neuropsychiatric phenotypes. However, we show that Dlg1^+/- mice did not exhibit the behavioral deficits seen in mice harboring the full 3q29 deletion. These data demonstrate the following: the 3q29 deletion mice are a valuable experimental system that can be used to interrogate the biology of 3q29 deletion syndrome; behavioral manifestations of the 3q29 deletion may have sex-dependent effects; and mouse-specific behavior phenotypes associated with the 3q29 deletion are not solely due to haploinsufficiency of Dlg1.

Delayed presentation of iatrogenic ventriculoperitoneal shunt transection following laparoscopic weight loss surgery in a patient with idiopathic intracranial hypertension

Idiopathic intracranial hypertension is strongly associated with central obesity and consequential raised intra-abdominal pressure. If left untreated it poses significant risk to vision and can eventually cause blindness. Owing to its pathophysiology, this condition is managed by both medical and surgical specialities. When medical management fails neurosurgeons commonly treat idiopathic intracranial hypertension by permanent cerebrospinal fluid peritoneal shunting. Weight reduction surgery provides patients who are obese with a multitude of benefits and it is not uncommon for the general surgeon to be presented with a patient with idiopathic intracranial hypertension and a cerebrospinal fluid peritoneal shunt in place. This provides a potential challenging situation in weight-loss surgical procedures. We describe an interesting case where laparoscopic bariatric surgery resulted in transection of the abdominal catheter with a delayed presentation of recurrent symptoms and an abdominal cerebrospinal fluid collection in a patient with idiopathic intracranial hypertension. We discuss how this could be avoided and its management.

Impact of the Increased Use of Preoperative Imaging and Laparoscopy on Appendicectomy Outcomes

The diagnosis of appendicitis is based on clinical picture. The aim of this retrospective study was to analyse variation of outcomes and impact of increasing use of radiological investigations and laparoscopy over a 5-year period. A retrospective audit of appendicectomies over the last 5 years (01 January 2007-31 December 2011) was conducted. The negative appendicectomy rate (NAR), perforation rate and complication rate were used as outcome endpoints. A statistical analysis was performed to evaluate the difference in outcomes with surgical approach and use of radiology. One thousand fifty-five appendicectomies were performed in this period. The NAR was 22.65 % (21 % for open and 28 % for laparoscopic) and perforation rate was 14 %. There was no statistically significant difference in NAR with the use of ultrasound (P 0.3814) but there was a significant reduction in NAR with the use of computed tomography (CT) (P <0.0001). Intra-abdominal abscess (2.3 %) and wound infection (1.4 %) were the common complications with the former being higher with laparoscopy and the latter with open appendicectomy. Over 5 years, there were no significant changes in appendicectomy outcomes. The impact of diagnostic imaging on NAR varies with age, gender and the use of CT. CT can significantly reduce the negative appendicectomy rate in equivocal presentations. Complication rates vary with surgical approach.

The pathophysiology of chronic graft failure in the cardiac transplant patient

Following cardiac transplantation, many patients develop chronic deterioration of graft function, which may lead to a clinical syndrome similar to native chronic heart failure (CHF). This condition of chronic cardiac graft failure (CGF) may also share pathophysiological processes comparable with that of CHF. However, the unique environment following cardiac transplantation may also contribute with a variety of unique mechanisms, deserved of special attention. This review article discusses the complex pathophysiology of CGF after cardiac transplantation, an important yet neglected condition of transplant medicine.

Co-morbid medical and psychiatric illness and substance abuse in HCV-infected and uninfected veterans

Comorbidities may affect the decision to treat chronic hepatitis C virus (HCV) infection. We undertook this study to determine the prevalence of these conditions in the HCV-infected persons compared with HCV-uninfected controls. Demographic and comorbidity data were retrieved for HCV-infected and -uninfected subjects from the VA National Patient Care Database using ICD-9 codes. Logistic regression was used to determine the odds of comorbid conditions in the HCV-infected subjects. HCV-uninfected controls were identified matched on age, race/ethnicity and sex. We identified 126 926 HCV-infected subjects and 126 926 controls. The HCV-infected subjects had a higher prevalence of diabetes, anaemia, hypertension, chronic obstructive pulmonary disease (COPD)/asthma, cirrhosis, hepatitis B and cancer, but had a lower prevalence of coronary artery disease and stroke. The prevalence of all psychiatric comorbidities and substance abuse was higher in the HCV-infected subjects. In the HCV-infected persons, the odds of being diagnosed with congestive heart failure, diabetes, anaemia, hypertension, COPD/asthma, cirrhosis, hepatitis B and cancer were higher, but lower for coronary artery disease and stroke. After adjusting for alcohol and drug abuse and dependence, the odds of psychiatric illness were not higher in the HCV-infected persons. The prevalence and patterns of comorbidities in HCV-infected veterans are different from those in HCV-uninfected controls. The association between HCV and psychiatric diagnoses is at least partly attributable to alcohol and drug abuse and dependence. These factors should be taken into account when evaluating patients for treatment and designing new intervention strategies.

Offspring sex ratio in smokers

OBJECTIVE

To assess the ratio of male to female gender in the offspring of smokers and non-smokers.

METHOD

The tool used for the survey was a questionnaire. Four hundred subjects were analyzed and were divided into three age groups.

RESULTS

Out of 400 subjects 56.5% were smokers and 43.5% were nonsmokers. Overall offspring sex ratio in nonsmokers was 1.53 and 0.61 in smokers.

CONCLUSION

The smoking might be a contributing factor to a lower male to female sex ratio of offspring along with Estrogenic pollutants which are everywhere in the environment contaminating food, drinking water and air.

Reduced red-cell folate in mania

Forty-five hospitalised patients with DSM-III-R diagnosis of mania, were found to have a mean red-cell folate level of 193 nmol/l, as compared to 896 nmol/l in the control group (P < 0.00001). Assessment of serum folate in both groups showed no significant differences in the levels. Furthermore the manic patients and the controls were matched by the socio-economic status. This indicated that the reduced red-cell folate in mania is associated with the illness and not due to reduced absorption or dietary deficiency of folate. Considering previous studies that showed reduced red-cell folate in depression, our findings suggest that reduced red-cell folate occurred in both phases of bipolar disorders.

Belief in supernatural causes of mental illness among Malay patients: impact on treatment

The concept of aetiology of mental illness in 134 Malay patients was investigated by means of a 20-item checklist. About 53% of the patients attributed their illnesses to supernatural agents. Witchcraft and possession by evil spirits were regarded as common causes of illness. The number of patients who believed in supernatural causes of their mental illness was significantly higher among those who had consulted bomohs (Malay traditional healers) than among those who had not consulted them. The belief that mental illness is caused by supernatural agents is firmly held by bomohs, who reinforce this notion in those who seek their advice. Belief in supernatural causes of mental illness was not significantly associated with age, gender, level of education or occupation of the patients. Patients who believed in supernatural causes of mental illness were also found to show poor drug compliance, and the number of such patients at 6 months follow-up was significantly lower than the corresponding figure for those who did not believe in supernatural causes. The importance of understanding the patients' cultural background when treating psychiatric patients is highlighted.