Risk calculator for predicting postoperative pneumonia after gastroenterological surgery based on a national Japanese database

Development and validation of a prediction model for postoperative pneumonia in patients who received spinal surgery: A retrospective study

Objectives

To develop and validate a risk prediction model by identifying the preoperative factors associated with an increased risk of pneumonia after spinal surgery.

Methods

This study included patients with spinal disease from two hospitals between January 2021 and June 2023. The patients were divided into the training and validation sets, which were categorized as postoperative pneumonia (POP) or non-POP, respectively. This study identified the independent risk variables for POP using a multivariate logistic regression analysis. A nomogram prediction model was developed and validated using risk factors, receiver operating characteristic (ROC) curves, calibration curves, and decision curve analysis (DCA) to assess predictive performance.

Results

Following exclusion, 2223 patients from Changzheng Hospital were enrolled in the training set and 357 patients from the No. 905 Hospital of PLA Navy were enrolled in the validation set. Univariate and multivariate logistic regression analyses revealed that operation time, American Society of Anesthesiologists (ASA) grade, smoking, non-wearing of medical masks, lack of preoperative respiratory training, chronic obstructive pulmonary disease (COPD), underlying diseases, and spinal section were risk factors for POP development in patients with spinal diseases. The area under the ROC curve of the training set was 0.950, whereas that of the validation set was 0.879. The model calibration curves demonstrated good agreement, and the DCA indicated a high expected net benefit value.

Conclusion

The POP risk prediction model has high accuracy and efficiency in predicting POP in patients with spinal diseases. POP development is influenced by factors such as operation length, ASA grade, smoking, non-wearing of medical masks, lack of preoperative respiratory training, COPD, underlying diseases, and lumbar surgery.

Deep Learning-Based Computer-Aided Detection System for Preoperative Chest Radiographs to Predict Postoperative Pneumonia

RATIONALE AND OBJECTIVES

The role of preoperative chest radiography (CR) for prediction of postoperative pneumonia remains uncertain. We aimed to develop and validate a prediction model for postoperative pneumonia incorporating findings of preoperative CRs evaluated by a deep learning-based computer-aided detection (DL-CAD) system MATERIALS AND METHODS: This retrospective study included consecutive patients who underwent surgery between January 2019 and March 2020 and divided into development (surgery in 2019) and validation (surgery between January and March 2020) cohorts. Preoperative CRs obtained within 1-month before surgery were analyzed with a commercialized DL-CAD that provided probability values for the presence of 10 different abnormalities in CRs. Logistic regression models to predict postoperative pneumonia were built using clinical variables (clinical model), and both clinical variables and DL-CAD results for preoperative CRs (DL-CAD model). The discriminative performances of the models were evaluated by area under the receiver operating characteristic curves.

RESULTS

In development cohort (n = 19,349; mean age, 57 years; 11,392 men), DL-CAD results for pulmonary nodules (odds ratio [OR, for 1% increase in probability value], 1.007; p = 0.021), consolidation (OR, 1.019; p < 0.001), and cardiomegaly (OR, 1.013; p < 0.001) were independent predictors of postoperative pneumonia and were included in the DL-CAD model. In validation cohort (n = 4957; mean age, 56 years; 2848 men), the DL-CAD model exhibited a higher AUROC than the clinical model (0.843 vs. 0.815; p = 0.012).

CONCLUSION

Abnormalities in preoperative CRs evaluated by a DL-CAD were independent risk factors for postoperative pneumonia. Using DL-CAD results for preoperative CRs led to an improved prediction of postoperative pneumonia.

Limited effect of sugammadex on postoperative pulmonary complications in patients undergoing spine surgery in prone position intraoperatively: A retrospective analysis of matched cohort data

Postoperative pulmonary complications (PPCs) increase postoperative mortality, hospital stays, and healthcare costs. Whether the use of sugammadex could reduce PPCs remains controversial. This study aimed to determine if sugammadex could more effectively reduce PPCs than acetylcholinesterase inhibitor (AChEi) in patients who had undergone spine surgery, in prone position intraoperatively. From March 2019 to February 2021, adult patients who underwent elective spine surgery were eligible. Primary outcomes were PPCs (including atelectasis on chest radiograph, pneumonia, acute respiratory distress syndrome, and aspiration pneumonitis) and respiratory failure that occurred within 28 days after surgery. Secondary outcomes were length of hospital stay, in-hospital death, and readmission rate within 30 days. Patients were divided into 2 groups (Sugammadex group and AChEi group) and compared by 1:1 propensity score matching. Of a total of 823 patients who underwent spinal surgery, 627 were included. After 1:1 propensity matching, 142 patients were extracted for each group. PPCs occurred in 9 (6.3%) patients in both groups (P = 1.000). Respiratory failure occurred in 7 (4.9%) patients in the Sugammadex group and 5 (3.5%) patients in the AChEi group (P = .77). There was no significant difference in secondary outcomes between the 2 groups. Although there have been some evidences showing that the use of sugammadex can attenuate the development of PPCs, this study did not show positive effects of sugammadex on patients who underwent spine surgery in the prone position.

Association of preoperative COVID-19 and postoperative respiratory morbidity during the Omicron epidemic wave: the DROMIS-22 multicentre prospective observational cohort study

BACKGROUND

Preoperative COVID-19 has been associated with excess postoperative morbi-mortality. Consequently, guidelines were developed that recommended the postponement of surgery for at least 7 weeks after the infection. We hypothesised that vaccination against the SARS-CoV-2 and the large predominance of the Omicron variant attenuated the effect of a preoperative COVID-19 on the occurrence of postoperative respiratory morbidity.

METHODS

We conducted a prospective cohort study in 41 French centres between 15 March and 30 May 2022 (ClinicalTrials NCT05336110), aimed at comparing the postoperative respiratory morbidity between patients with and without preoperative COVID-19 within 8 weeks prior to surgery. The primary outcome was a composite outcome combining the occurrence of pneumonia, acute respiratory failure, unexpected mechanical ventilation, and pulmonary embolism within the first 30 postoperative days. Secondary outcomes were 30-day mortality, hospital length-of-stay, readmissions, and non-respiratory infections. The sample size was determined to have 90% power to identify a doubling of the primary outcome rate. Adjusted analyses were performed using propensity score modelling and inverse probability weighting.

FINDINGS

Of the 4928 patients assessed for the primary outcome, of whom 92.4% were vaccinated against the SARS-CoV-2, 705 had preoperative COVID-19. The primary outcome was reported in 140 (2.8%) patients. An 8-week preoperative COVID-19 was not associated with increased postoperative respiratory morbidity (odds ratio 1.08 [95% CI 0.48-2.13]; p = 0.83). None of the secondary outcomes differed between the two groups. Sensitivity analyses concerning the timing between COVID-19 and surgery, and the clinical presentations of preoperative COVID-19 did not show any association with the primary outcome, except for COVID-19 patients with ongoing symptoms the day of surgery (OR 4.29 [1.02-15.8]; p = 0.04).

INTERPRETATION

In our Omicron-predominant, highly immunised population undergoing general surgery, a preoperative COVID-19 was not associated with increased postoperative respiratory morbidity.

FUNDING

The study was fully funded by the French Society of Anaesthesiology and Intensive Care Medicine (SFAR).

Risk factors for postoperative pneumonia after hepatectomy with extrahepatic bile duct resection

BACKGROUND

The present study investigated the incidence of postoperative pneumonia (POP) after hepatectomy with extrahepatic bile duct resection (BDR) and elucidated risk factors for POP.

METHODS

A total of 257 patients undergoing hepatectomy with BDR between 2011 and 2019 were retrospectively reviewed to evaluate the incidence of POP, defined by the Clavien-Dindo grade ≥ II. The predictive factors for POP were identified using logistic regression analysis of the pre- and intraoperative evaluable factors.

RESULTS

Postoperative pneumonia developed in 15 patients (5.8%), diagnosed as grade IV or V in five patients. In a multivariate analysis, a vital capacity ratio (%VC) <80% (odds ratio [OR] 7.30, P = .005), age ≥ 74 years old (OR 5.39, P = .026), and future liver volume remnant (FLR) ratio ≤ 40% (OR 4.97, P = .045) were independent risk factors for POP. Among patients with performing spirometry, the incidence of developing POP was 1.0%, 8.8%, and 60% in patients with 0, 1-2, and 3 risk factors, respectively.

CONCLUSIONS

The incidence of POP in patients undergoing hepatectomy with BDR was 5.8%. A %VC <80%, age ≥74 years old, and FLR ratio ≤40% were identified as preoperative predictive factors of developing POP.

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.

Association between age and short-term outcomes of gastroenterological surgeries in older patients: an analysis using the National Clinical Database in Japan

PURPOSE

The association between advanced age and postoperative morbidity and mortality after major gastroenterological surgeries remains unclear. This study aimed to assess the association between old age and the short-term postoperative outcomes of gastroenterological surgeries.

METHODS

We evaluated 327,642 patients who underwent any of the seven major gastroenterological surgeries-esophagectomy, total gastrectomy, distal gastrectomy, right hemicolectomy, low anterior resection, hepatectomy, and pancreatoduodenectomy-and were registered with the Japanese national surgical registry between January 2011 and December 2013. Perioperative characteristics, frequency/nature of postoperative morbidities, and postoperative mortality were compared according to age at the time of surgery.

RESULTS

Overall, 18% (59,182/327,642) of the entire cohort were aged ≥ 80 years. The overall mortality rates in the entire cohort and in those aged ≥ 80 years were 1.7% and 3.3%, respectively. The postoperative mortality increased with increasing age for all procedures, with the trend persisting even after adjusting for various confounding factors. The incidence of postoperative pneumonia increased with increasing age, and with all procedures, except esophagectomy, subjects aged ≥ 80 years had a markedly higher risk of developing postoperative pneumonia than those aged < 60 years.

CONCLUSION

Advanced age is associated with significantly worse short-term outcomes in older patients undergoing gastroenterological surgeries. However, we could not identify any distinct cutoff age beyond which major gastroenterological surgery could be considered as being contraindicated. The mortality risk should be carefully considered before recommending major gastroenterological surgeries for older patients.

Development of gastroenterological surgery over the last decade in Japan: analysis of the National Clinical Database

The National Clinical Database (NCD) of Japan was established in 2010 with the board certification system. A joint committee of 16 gastroenterological surgery database-affiliated organizations has been nurturing this nationwide database and utilizing its data for various analyses. Stepwise board certification systems have been validated by the NCD and are used to improve the surgical outcomes of patients. The use of risk calculators based on risk models can be particularly helpful for establishing appropriate and less invasive surgical treatments for individual patients. Data obtained from the NCD reflect current developments in the surgical approaches used in hospitals, which have progressed from open surgery to endoscopic and robot-assisted procedures. An investigation of the data acquired by the NCD could answer some relevant clinical questions and lead to better surgical management of patients. Furthermore, excellent surgical outcomes can be achieved through international comparisons of the national databases worldwide. This review examines what we have learned from the NCD of gastroenterological surgery and discusses what future developments we can expect.

Low platelet count is a risk factor of postoperative pneumonia in patients with type A acute aortic dissection

Background

Previous studies have already established that low platelet count is related to adverse outcomes in patients with type A acute aortic dissection (AAAD). However, there are yet limited studies investigating the association of platelet count and the risk of postoperative pneumonia in AAAD patients.

Methods

This retrospective cohort study was conducted in Xiangya Hospital of Central South University from January 2014 to May 2019. Clinical and laboratory data were collected. The correlation between platelet count and postoperative pneumonia was analyzed using multivariate logistic regression and the area under the receiver operating characteristic curve (AUC) was used to assess the predictive power of platelet count on pneumonia.

Results

A total of 268 patients with AAAD were enrolled. The overall incidence of pneumonia was 36.94% (n=99). Multivariate logistic regression revealed that platelet count was negatively associated with the risk of postoperative pneumonia (OR 0.93; 95% CI: 0.88–0.98) after adjusting for the confounders. Compared to the lowest platelet count tertile (T1), medium platelet count (T2) and highest platelet count (T3) had a lower risk of postoperative pneumonia after adjusting for the confounders (OR 0.80, 95% CI: 0.40–1.60; OR 0.30, 95% CI: 0.13–0.66; respectively). A similar trend was observed when the platelet count was handled as categorical variables (tertiles). The area under the ROC curve was 0.635 (95% CI: 0.565–0.707), with a sensitivity of 76.77%, a specificity of 50.89% and an accuracy of 60.45%.

Conclusions

Our findings indicate that low platelet count is an independent risk factor of postoperative pneumonia in patients with AAAD and has a specific predictive power on the risk of postoperative pneumonia.

The effect of the visceral fat area on the predictive accuracy of C-reactive protein for infectious complications after laparoscopy-assisted gastrectomy

AIM

To investigate the influence of visceral fat area on postoperative C-reactive protein levels and whether it affects its ability to diagnose infectious complications after laparoscopy-assisted gastrectomy.

METHODS

A total of 435 consecutive patients who underwent laparoscopy-assisted resection for gastric cancer from 2008 to 2017 were reviewed and divided into four groups according to visceral fat area quartiles. We evaluated the relationship between C-reactive protein and visceral fat area and whether visceral fat area affects the sensitivity and specificity of C-reactive protein in diagnosing postoperative infectious complications.

RESULTS

Postoperative C-reactive protein levels increased with increasing visceral fat areas at every postoperative assessment. Multiple linear regression revealed that levels on postoperative day 3 significantly positively correlated with visceral fat area. Postoperative day 3 levels also showed moderate accuracy for diagnosing infectious complications (area under the curve, 0.78; sensitivity, 0.86; specificity, 0.65), with an optimal cut-off of 11.8 mg/dL. The sensitivity for predicting infectious complications was low in the 1st visceral fat area quartile group but high in the 2nd, 3rd, and 4th groups (0.43 vs 1.0 vs 1.0 vs 0.94, respectively). By contrast, the specificity was high in the 1st and 2nd group but low in the 3rd and 4th (0.84 vs 0.70 vs 0.54 vs 0.48, respectively).

CONCLUSION

Visceral fat area positively correlated with postoperative C-reactive protein levels and this affected its accuracy in diagnosing infectious complications. A uniform C-reactive protein cut-off may not provide accurate predictions in patients with more extreme visceral fat areas.

Preoperative predictors of postoperative complications after gastric cancer resection

Risk management is becoming an increasingly important healthcare issue. Gastrectomy with lymphadenectomy is still the mainstay of treatment for localized gastric cancer, but it is sometimes associated with postoperative complications that compromise the patient’s quality of life, tolerability of adjuvant treatment, and prognosis. Parameters based exclusively on preoperative factors can identify patients most at risk of postoperative complications, whereby surgeons can provide the patient with precise informed consent information and optimal perioperative management. Ultimately, these predictive tools can also help minimize medical costs. In this context, many studies have identified factors that predict postoperative complications, including indicators based on body constitution, nutrition, inflammation, organ function and hypercoagulation. This review presents our current understanding and discusses some future perspectives of preoperatively identified factors predictive of complications after resection for gastric cancer.