Risk factors for postoperative sepsis in laparoscopic gastric bypass

Identification of a Susceptible and High-Risk Population for Postoperative Systemic Inflammatory Response Syndrome in Older Adults: Machine Learning-Based Predictive Model

BACKGROUND

Systemic inflammatory response syndrome (SIRS) is a serious postoperative complication among older adult surgical patients that frequently develops into sepsis or even death. Notably, the incidences of SIRS and sepsis steadily increase with age. It is important to identify the risk of postoperative SIRS for older adult patients at a sufficiently early stage, which would allow preemptive individualized enhanced therapy to be conducted to improve the prognosis of older adult patients. In recent years, machine learning (ML) models have been deployed by researchers for many tasks, including disease prediction and risk stratification, exhibiting good application potential.

OBJECTIVE

We aimed to develop and validate an individualized predictive model to identify susceptible and high-risk populations for SIRS in older adult patients to instruct appropriate early interventions.

METHODS

Data for surgical patients aged ≥65 years from September 2015 to September 2020 in 3 independent medical centers were retrieved and analyzed. The eligible patient cohort in the Third Affiliated Hospital of Sun Yat-sen University was randomly separated into an 80% training set (2882 patients) and a 20% internal validation set (720 patients). We developed 4 ML models to predict postoperative SIRS. The area under the receiver operating curve (AUC), F1 score, Brier score, and calibration curve were used to evaluate the model performance. The model with the best performance was further validated in the other 2 independent data sets involving 844 and 307 cases, respectively.

RESULTS

The incidences of SIRS in the 3 medical centers were 24.3% (876/3602), 29.6% (250/844), and 6.5% (20/307), respectively. We identified 15 variables that were significantly associated with postoperative SIRS and used in 4 ML models to predict postoperative SIRS. A balanced cutoff between sensitivity and specificity was chosen to ensure as high a true positive as possible. The random forest classifier (RF) model showed the best overall performance to predict postoperative SIRS, with an AUC of 0.751 (95% CI 0.709-0.793), sensitivity of 0.682, specificity of 0.681, and F1 score of 0.508 in the internal validation set and higher AUCs in the external validation-1 set (0.759, 95% CI 0.723-0.795) and external validation-2 set (0.804, 95% CI 0.746-0.863).

CONCLUSIONS

We developed and validated a generalizable RF model to predict postoperative SIRS in older adult patients, enabling clinicians to screen susceptible and high-risk patients and implement early individualized interventions. An online risk calculator to make the RF model accessible to anesthesiologists and peers around the world was developed.

Risk Factors for Chronic Abdominal Pain After RYGB: Are Patients Adequately Selected Beforehand?

PURPOSE

Chronic abdominal pain after RYGB is a known issue. Identifying the potential patient-related and modifiable risk factors might contribute to diminish the risk for this undesirable outcome.

METHODS

A single-center retrospective cohort study with prospective data collection was conducted with inclusion of all patients who underwent RYGB surgery between 2015 and 2021. Data from the NBSR and medical records were used. Patients with chronic abdominal pain were defined when pain lasting or recurring for more than 3 to 6 months.

RESULTS

Six hundred sixty-four patients who underwent RYGB surgery were included with a median follow-up of 60.5 months. Forty-nine patients (7.3%) presented with chronic abdominal pain. Postoperative complications (OR 13.376, p = 0.020) and diagnosis of depression (OR 1.971, p = 0.037) were associated with developing abdominal pain. On the other hand, ex-smokers (OR 0.222, p = 0.040) and older age (0.959, p = 0.004) presented as protective factors.

CONCLUSION

Postoperative complications and diagnosis of depression are risk factors for chronic pain after RYGB. The role of the bariatric MDT remains crucial to select these patients adequately beforehand.

Textbook Outcome in Bariatric Surgery: Evolution During 15 Years in a Referral Center

BACKGROUND

Textbook outcome (TO) is a multidimensional measure used to assess the quality of care. It is the "ideal" surgical result, based on a series of established indicators. In the field of bariatric surgery (BS), only one publication on TO is available.

OBJECTIVES

To determine TO in our BS unit and identify the factors linked to TO.

SETTING

University public hospital in Alicante (Spain).

METHODS

Retrospective observational study of all primary BS was performed. TO for BS was defined in relation to the following features: no major postoperative complications (Clavien-Dindo >II), hospital stay <75th percentile, and no mortality or readmissions within 30 days of surgery. Comparative analysis of the characteristics of the TO and non-TO groups was performed, as well as univariate and multivariate logistic regressions, to identify the independent factors associated with obtaining TO.

RESULTS

In 970 patients, TO was achieved in 71.5%. The hospital stay was the one that most affected achievement of TO. Analysis according to the type of procedure (sleeve gastrectomy and gastric bypass) did not reveal any differences between both procedures in terms of obtaining TO (71.5 vs 71.26%). Logistic regression identified smoking, heart disease, operative time, and upper gastrointestinal bleeding as independent factors associated with obtaining TO (p<0.05). Analysis of the annual evolution of TO reveals a progressive increase in its achievement (7.7-86.4%).

CONCLUSION

In our series, TO was obtained in 71.5% of patients. The standardization of the technique and the experience gained over the years has improved our TO results.

Development and validation of a patient-specific model to predict postoperative SIRS in older patients: A two-center study

Introduction

Postoperative systemic inflammatory response syndrome (SIRS) is common in surgical patients especially in older patients, and the geriatric population with SIRS is more susceptible to sepsis, MODS, and even death. We aimed to develop and validate a model for predicting postoperative SIRS in older patients.

Methods

Patients aged ≥65 years who underwent general anesthesia in two centers of Third Affiliated Hospital of Sun Yat-sen University from January 2015 to September 2020 were included. The cohort was divided into training and validation cohorts. A simple nomogram was developed to predict the postoperative SIRS in the training cohort using two logistic regression models and the brute force algorithm. The discriminative performance of this model was determined by area under the receiver operating characteristics curve (AUC). The external validity of the nomogram was assessed in the validation cohort.

Results

A total of 5,904 patients spanning from January 2015 to December 2019 were enrolled in the training cohort and 1,105 patients from January 2020 to September 2020 comprised the temporal validation cohort, in which incidence rates of postoperative SIRS were 24.6 and 20.2%, respectively. Six feature variables were identified as valuable predictors to construct the nomogram, with high AUCs (0.800 [0.787, 0.813] and 0.822 [0.790, 0.854]) and relatively balanced sensitivity (0.718 and 0.739) as well as specificity (0.718 and 0.729) in both training and validation cohorts. An online risk calculator was established for clinical application.

Conclusion

We developed a patient-specific model that may assist in predicting postoperative SIRS among the aged patients.

Nomogram for predicting the prognosis of tumor patients with sepsis after gastrointestinal surgery

BACKGROUND

There were few studies on the prognosis of tumor patients with sepsis after gastrointestinal surgery and there was no relevant nomogram for predicting the prognosis of these patients.

AIM

To establish a nomogram for predicting the prognosis of tumor patients with sepsis after gastrointestinal surgery in the intensive care unit (ICU).

METHODS

A total of 303 septic patients after gastrointestinal tumor surgery admitted to the ICU at Peking University Cancer Hospital from January 1, 2013 to December 31, 2020 were analysed retrospectively. The model for predicting the prognosis of septic patients was established by the R software package.

RESULTS

The most common infection site of sepsis after gastrointestinal surgery in the ICU was abdominal infection. The 90-d all-cause mortality rate was 10.2% in our study group. In multiple analyses, we found that there were statistically significant differences in tumor type, septic shock, the number of lymphocytes after ICU admission, serum creatinine and total operation times among tumor patients with sepsis after gastrointestinal surgery (P < 0.05). These five variables could be used to establish a nomogram for predicting the prognosis of these septic patients. The nomogram was verified, and the initial C-index was 0.861. After 1000 internal validations of the model, the C-index was 0.876, and the discrimination was good. The correction curve indicated that the actual value was in good agreement with the predicted value.

CONCLUSION

The nomogram based on these five factors (tumor type, septic shock, number of lymphocytes, serum creatinine, and total operation times) could accurately predict the prognosis of tumor patients with sepsis after gastrointestinal surgery.

Bacterial translocation in patients undergoing major gastrointestinal surgery and its role in postoperative sepsis

Bacteria of the human intestinal microflora have a dual role. They promote digestion and are part of a defense mechanism against pathogens. These bacteria could become potential pathogens under certain circumstances. The term "bacterial translocation" describes the passage of bacteria of the gastrointestinal tract through the intestinal mucosa barrier to mesenteric lymph nodes and other organs. In some cases, the passage of bacteria and endotoxins could result in blood stream infections and in multiple organ failure. Open elective abdominal surgery more frequently results in malfunction of the intestinal barrier and subsequent bacterial translocation and blood stream infections than laparoscopic surgery. Postoperative sepsis is a common finding in patients who have undergone non-elective abdominal surgeries, including trauma patients treated with laparotomy. Postoperative sepsis is an emerging issue, as it changes the treatment plan in surgical patients and prolongs hospital stay. The association between bacterial translocation and postoperative sepsis could provide novel treatment options.

Prevalence and Risk Factors for Chronic Abdominal Pain After Roux-en-Y Gastric Bypass Surgery: A Cohort Study

OBJECTIVE

To investigate the prevalence and risk factors for chronic abdominal pain after Roux-en-Y gastric bypass (RYGB) surgery.

SUMMARY BACKGROUND DATA

Abdominal pain is a frequent postoperative complication after RYGB surgery. Even if there have been defined several long-term complications, the literature regarding patients with unexplained chronic abdominal pain is sparse.

METHODS

A single-center register-based cohort study with inclusion of all patients who underwent RYGB surgery between 2010 and 2015. Data from multiple registries, medical records, and a questionnaire were used. Patients with chronic abdominal pain were defined as those using strong analgesics, diagnosed with chronic pain, or referred to a specialized pain clinic. Patients with severe self-reported abdominal pain were defined as those reporting abdominal pain more than 2 times weekly within the last month.

RESULTS

A total of 787 patients were followed for a median of 63 months. The prevalence of postoperative chronic abdominal pain was 11% and the prevalence of severe self-reported abdominal pain was 21%. Preoperative use of strong analgesics was a risk factor for chronic abdominal pain (OR, 2.26; 95% CI, 1.59-3.23) and severe self-reported abdominal pain (OR 2.82, 95% CI 1.64-4.84). Further risk factors for severe self-reported pain were unemployment or retirement (OR 1.80, 95% CI 1.09-2.93), postoperative complications (OR 2.75, 95% CI 1.44-5.22), and smoking (OR 1.80, 95% CI 1.09-2.96).

CONCLUSIONS

One in 10 patients undergoing RYGB surgery developed chronic abdominal pain requiring strong analgesics, and one in five suffered from severe abdominal pain. Risk factors were preoperative use of strong analgesics, unemployment, postoperative complications, and smoking.

Intersection of smoking, e-cigarette use, obesity, and metabolic and bariatric surgery: a systematic review of the current state of evidence

BACKGROUND

Millions of Americans qualify for metabolic and bariatric surgery (MBS) based on the proportion of the population with severe obesity. Simultaneously, the use of electronic nicotine/non-nicotine delivery systems (ENDS) has become epidemic.

OBJECTIVE

We conducted a timely systematic review to examine the impact of tobacco and ENDS use on post-operative health outcomes among MBS patients.

METHODS

PRISMA guidelines were used as the search framework. Keyword combinations of either "smoking," "tobacco," "e-cigarette," "vaping," or "ENDS" and "bariatric surgery," "RYGB," or "sleeve gastrectomy" were used as search terms in PUBMED, Science Direct, and EMBASE. Studies published in English between January 1990 and June 2020 were screened.

RESULTS

From the 3251 articles found, a total of 48 articles were included in the review. No articles described a relationship between ENDS and post-operative health outcomes in MBS patients. Seven studies reported smokers had greater post-MBS weight loss, six studies suggested no relationship between smoking and post-MBS weight loss, and one study reported smoking cessation pre-MBS was related to post-MBS weight gain. Perioperative use of tobacco is positively associated with several post-surgery complications and mortality in MBS patients.

CONCLUSIONS

Combustible tobacco use among MBS patients is significantly related to higher mortality risk and complication rates, but not weight loss. No data currently is available on the impact of ENDS use in these patients. With ENDS use at epidemic levels, it is imperative to determine any potential health effects among patients with severe obesity, and who complete MBS.

Postoperative sepsis after primary bariatric surgery: an analysis of MBSAQIP

BACKGROUND

Identifying patients at higher risk of postoperative sepsis (PS) may help to prevent this life-threatening complication.

OBJECTIVES

This study aimed to identify the rate and predictors of PS after primary bariatric surgery.

SETTING

An analysis of the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) 2015-2017.

METHODS

Patients undergoing elective sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB) were included. Exclusion criteria were revisional, endoscopic, and uncommon, or investigational procedures. Patients were stratified by the presence or absence of organ/space surgical site infection (OS-SSI), and patients who developed sepsis were compared with patients who did not develop sepsis in each cohort. Logistic regression was used to identify independent predictors of PS.

RESULTS

In total, 438,752 patients were included (79.4% female, mean age 44.6±12 years). Of those, 661 patients (.2%) developed PS of which 245 (37.1%) developed septic shock. Out of 892 patients with organ/space surgical site infections (OS-SSI), 298 (45.1%) developed sepsis (P <.001). Patients who developed PS had higher mortality (8.8% versus .1%, P < .001), and this was highest in patients without OS-SSI (11.8% versus 5%, P = .002). The main infectious complications associated with PS in patients without OS-SSI were pneumonia and urinary tract infection. Independent predictors of PS in OS-SSI included RYGB versus SG (OR, 1.8), and age ≥50 years (OR, 1.4). Independent predictors of PS in patients without OS-SSI were conversion to other approaches (OR, 6), operation length >2 hours (OR, 5.7), preoperative dialysis (OR, 4.1), preoperative therapeutic anticoagulation (OR, 2.8), limited ambulation most or all of the time (OR, 2.4), preoperative venous stasis (OR, 2.4), previous nonbariatric foregut surgery (OR, 2), RYGB versus SG (OR, 2), hypertension on medication (OR, 1.5), body mass index ≥50 kg/m²(OR, 1.4), age ≥50 years (OR, 1.3), obstructive sleep apnea (OR, 1.3).

CONCLUSION

Development of OS-SSI after primary bariatric surgery is associated with sepsis and increased 30-day mortality. Patients without OS-SSI who develop PS have a significantly higher mortality rate compared with patients with OS-SSI who develop PS. Early identification and intervention in patients with PS, including those without OS-SSI, may improve survival in this high-risk group.

Sepsis and septic shock after craniotomy: Predicting a significant patient safety and quality outcome measure

OBJECTIVES

Sepsis and septic shock are important quality and patient safety metrics. This study examines incidence of Sepsis and/or septic shock (S/SS) after craniotomy for tumor resection, one of the most common neurosurgical operations.

METHODS

Multicenter, prospectively collected data from the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database was used to identify patients undergoing craniotomy for tumor (CPT 61510, 61521, 61520, 61518, 61526, 61545, 61546, 61512, 61519, 61575) from 2012-2015. Univariate and multivariate logistic regression models were used to identify risk factors for S/SS.

RESULTS

There were 18,642 patients that underwent craniotomy for tumor resection. The rate of sepsis was 1.35% with a mortality rate of 11.16% and the rate of septic shock was 0.65% with a 33.06% mortality rate versus an overall mortality rate of 2.46% in the craniotomy for tumor cohort. The 30-day readmission rate was 50.54% with S/SS vs 10.26% in those without S/SS. Multiple factors were identified as statistically significant (p <0.05) for S/SS including ascites (OR = 33.0), ventilator dependence (OR = 4.5), SIRS (OR = 2.8), functional status (OR = 2.3), bleeding disorders (OR = 1.7), severe COPD (OR = 1.6), steroid use (OR = 1.6), operative time >310 minutes (OR = 1.5), hypertension requiring medication (OR = 1.5), ASA class ≥ 3 (OR = 1.4), male sex (OR = 1.4), BMI >35 (OR = 1.4) and infratentorial location.

CONCLUSIONS

The data indicate that sepsis and septic shock, although uncommon after craniotomy for tumor resection, carry a significant risk of 30-day unplanned reoperation (35.60%) and mortality (18.21%). The most significant risk factors are ventilator dependence, ascites, SIRS and poor functional status. By identifying the risk factors for S/SS, neurosurgeons can potentially improve outcomes. Further investigation should focus on the creation of a predictive score for S/SS with integration into the electronic health record for targeted protocol initiation in this unique neurosurgical patient population.

Risk factors associated with the development of sepsis after reconstructive flap surgery. J Plast Surg Hand Surg 2019;53:328-334. [PMID: 31204583 DOI: 10.1080/2000656x.2019.1626738]

Sepsis is a serious and potentially life-threatening condition. Risk factors that are associated with the development of sepsis may differ as it relates to reconstructive flap surgery. The purpose of this study is to identify the incidence and predictors for sepsis in patients undergoing reconstructive flap surgery. The ACS-NSQIP database was queried from 2005 to 2016 for factors related to sepsis in patients undergoing reconstructive flap surgery. CPT codes were used to identify patient cohorts. A sepsis group was compared to a control group that underwent the same procedures without the postoperative manifestations of sepsis. Statistical analyses were performed to ascertain risk factors associated with the development of sepsis. 24,257 patients who underwent flap reconstruction were included in this study. Of these, 511 developed sepsis postoperatively (2.1%). Multivariate analysis showed that male gender (p < .001), African-American race (p < .001), hypertension requiring medication (p < .001), smoking (p < .001), a higher Charlson comorbidity Index score (p < .001), evidence of preoperative wound infection (p < .001), chronic steroid use (p < .001), and prolonged operative time (p < .001) all significantly were associated with the development of sepsis. Sepsis resulted in a higher chance of 30-day mortality (p < .001) and increased the risk of developing septic shock (OR: 2.578, CI: 1.241-5.354) This study shows that postoperative sepsis is a serious complication of reconstructive flap surgery. Risk reduction and prevention of potentially life-threatening complications is always a priority. Awareness of the risk factors contributing to the development of sepsis is crucial for early intervention and treatment.

Outcomes after bariatric surgery according to large databases: a systematic review

PURPOSE

The rapid development of technological tools to record data allows storage of enormous datasets, often termed "big data". In the USA, three large databases have been developed to store data regarding surgical outcomes: the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP), the Healthcare Cost and Utilization Project (HCUP) National Inpatient Sample (NIS) and the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP). We aimed to evaluate the clinical impact of studies found in these databases concerning outcomes of bariatric surgery.

METHODS

We performed a systematic review using the Meta-analysis of Observational Studies in Epidemiology guidelines. Research carried out using the PubMed database identified 362 papers. All outcomes related to bariatric surgery were analysed.

RESULTS

Fifty-four studies, published between 2005 and February 2017, were included. These articles were divided into (1) outcomes related to surgical techniques (12 articles), (2) morbidity and mortality (12), (3) 30-day hospital readmission (10), (4) outcomes related to specific diseases (11), (5) training (2) and (6) socio-economic and ethnic observations in bariatric surgery (7). Forty-two papers were based on data from ACS-NSQIP, nine on data from NIS and three on data from MBSAQIP.

CONCLUSIONS

This review provides an overview of surgical management and outcomes of bariatric surgery in the USA. Large databases offer useful complementary information that could be considered external validation when strong evidence-based medicine data are lacking. They also allow us to evaluate infrequent situations for which randomized control trials are not feasible and add specific information that can complement the quality of surgical knowledge.

Utilization of the NSQIP-Pediatric Database in Development and Validation of a New Predictive Model of Pediatric Postoperative Wound Complications

BACKGROUND

Surgical wound classification, introduced in 1964, stratifies the risk of surgical site infection (SSI) based on a clinical estimate of the inoculum of bacteria encountered during the procedure. Recent literature has questioned the accuracy of predicting SSI risk based on wound classification. We hypothesized that a more specific model founded on specific patient and perioperative factors would more accurately predict the risk of SSI.

STUDY DESIGN

Using all observations from the 2012 to 2014 pediatric National Surgical Quality Improvement Program-Pediatric (NSQIP-P) Participant Use File, patients were randomized into model creation and model validation datasets. Potential perioperative predictive factors were assessed with univariate analysis for each of 4 outcomes: wound dehiscence, superficial wound infection, deep wound infection, and organ space infection. A multiple logistic regression model with a step-wise backwards elimination was performed. A receiver operating characteristic curve with c-statistic was generated to assess the model discrimination for each outcome.

RESULTS

A total of 183,233 patients were included. All perioperative NSQIP factors were evaluated for clinical pertinence. Of the original 43 perioperative predictive factors selected, 6 to 9 predictors for each outcome were significantly associated with postoperative SSI. The predictive accuracy level of our model compared favorably with the traditional wound classification in each outcome of interest.

CONCLUSIONS

The proposed model from NSQIP-P demonstrated a significantly improved predictive ability for postoperative SSIs than the current wound classification system. This model will allow providers to more effectively counsel families and patients of these risks, and more accurately reflect true risks for individual surgical patients to hospitals and payers.