Evaluation of fever and infections in cardiac surgery patients

Postoperative Inflammation and Fever After Elective Aortic Valve and Aortic Root Replacement: A Retrospective Cohort Study

Background

Fever after cardiac surgery is common. More knowledge of postoperative fever could lead to better patient selection for diagnostic workup and empirical antibiotic treatment. We aimed to analyze the postoperative course of inflammation and fever after elective aortic valve and aortic root replacement.

Methods

In a retrospective single-center cohort study, we included 3 groups of patients after elective cardiac surgery: aortic root with aortic valve replacement (Bentall procedure, from 2014 to 2021), valve-sparing root replacement (VSRR, from 2014 to 2021), and isolated surgical aortic valve replacement (SAVR, from 2018 to 2021). Exclusion criteria were age <18 years, cardiac surgery other than described, use of deep-hypothermic circulatory arrest, reoperations, and preexisting infections. Primary outcome measure was the number of patients per group with postoperative fever (≥38°C). Secondary outcome measures were the percentage of patients per group with infections and outcome.

Results

Among 307 patients included (76 Bentall, 40 VSRR, 191 SAVR), 71% had postoperative fever. Fever occurred significantly more often in the Bentall (84%) and VSRR group (83%) compared with patients after SAVR (64%, P = .001). Seventeen patients had fever due to infection versus 202 with diagnoses of postoperative inflammation. In case of infection, fever was significantly higher (38.8°C vs 38.4°C, P = .03), and both the number of days with fever and hospital admission duration were significantly longer.

Conclusions

Postoperative fever is more often observed after Bentall procedure and VSRR compared to SAVR. In diagnoses of infection, there is a higher and prolonged fever.

Increase in body temperature in pediatric patients after costal cartilage harvest in microtia reconstruction: A retrospective observational study

BACKGROUND

Previous evidence has clearly shown that maintaining normothermia in children undergoing surgery is difficult and is associated with adverse outcomes. Therefore, this study aimed to retrospectively analyze the changes in body temperature over time in 2 different types of microtia reconstruction surgeries, namely, embedding, and elevation surgeries.

METHODS

We performed a retrospective chart review of patients who underwent microtia reconstruction (embedding and elevation) between July 2012 and February 2015 (n = 38). The changes in body temperature between the 2 types of surgeries were compared.

RESULTS

During microtia reconstruction, the body temperature in the embedding surgery group was significantly higher than that in the elevation surgery group from 1 hour after the start of surgery to 1 day after the surgery (P < .001). Time, group, and time-group interaction were associated with an increase in body temperature (P < .001) but not the warming method.

CONCLUSION

We found an increase in body temperature in patients with microtia who underwent embedding surgery (autologous costal cartilage harvest surgery), and this was related to the type of surgery and not to the warming method. Therefore, further research is warranted to determine the cause of the increase in body temperature during this surgery.

A novel predictive model for new-onset atrial fibrillation in patients after isolated cardiac valve surgery

Background

Postoperative atrial fibrillation (POAF) is a severe complication after cardiac surgery and is associated with an increased risk of ischemic stroke and mortality. The main aim of this study was to identify the independent predictors associated with POAF after isolated valve operation and to develop a risk prediction model.

Methods

This retrospective observational study involved patients without previous AF who underwent isolated valve surgery from November 2018 to October 2021. Patients were stratified into two groups according to the development of new-onset POAF. Baseline characteristics and perioperative data were collected from the two groups of patients. Univariate and multivariate logistic regression analyses were applied to identify independent risk factors for the occurrence of POAF, and the results of the multivariate analysis were used to create a predictive nomogram.

Results

A total of 422 patients were included in the study, of which 163 (38.6%) developed POAF. The Multivariate logistic regression analysis indicated that cardiac function (odds ratio [OR] = 2.881, 95% confidence interval [CI] = 1.595–5.206; P &lt; 0.001), Left atrial diameter index (OR = 1.071, 95%CI = 1.028–1.117; P = 0.001), Operative time (OR = 1.532, 95%CI = 1.095–2.141; P = 0.013), Neutrophil count (OR = 1.042, 95%CI = 1.006–1.08; P = 0.021) and the magnitude of fever (OR = 3.414, 95%CI = 2.454–4.751; P &lt; 0.001) were independent predictors of POAF. The above Variables were incorporated, and a nomogram was successfully constructed with a C-index of 0.810. The area under the receiver operating characteristic curve was 0.817.

Conclusion

Cardiac function, left atrial diameter index, operative time, neutrophil count, and fever were independent predictors of POAF in patients with isolated valve surgery. Establishing a nomogram model based on the above predictors helps predict the risk of POAF and may have potential clinical utility in preventive interventions.

Post-implantation syndrome after frozen elephant trunk is associated with the volume of new-onset aortic thrombus

Background

Post-implantation syndrome (PIS) is defined as non-infectious continuous fever and a concomitant rise in inflammatory markers shortly after endovascular aortic repair. PIS occurrence after hybrid procedures, such as the frozen elephant trunk (FET) technique, has not been adequately investigated. The current study aims to define the incidence of PIS after the FET and to identify possible risk factors associated with its occurrence.

Methods

The clinical charts of 59 patients undergoing the FET between February 2015 and April 2020 were reviewed retrospectively. The occurrence of PIS was defined as the presence of fever (>38 °C lasting longer than one day during the hospitalisation) and leucocytosis (white blood cell count >12,000/µL). Patients with concomitant conditions possibly leading to fever and/or leucocytosis were excluded. Beside demographic and procedure-related data, serum/plasma inflammatory markers were evaluated before surgery and daily up to seven days postoperatively. Computed tomography scans (CT) were examined to calculate the volume of pre-existent and new-onset mural thrombus after the FET.

Results

Thirty-eight patients met the inclusion criteria. The study cohort was divided into two groups based on the occurrence of PIS (17 cases; 44.7%). Patients with PIS were significantly younger than those without PIS (53.5±8.9 vs. 62.5±9.6 years; P=0.005). Female patients were less likely to develop PIS (5.2% vs. 26.3%, P=0.018). Patients with PIS had a higher volume of new-onset thrombus in the postoperative CT (P<0.001). Patients treated for post-dissection aneurysm had, postoperatively, significantly more thrombus material developed in a false lumen (P=0.02). Among the PIS markers, CRP (C-reactive protein) levels on the third postoperative day were independently associated with the volume of new-onset thrombus (P=0.011). After multivariate analysis, the volume of new-onset thrombus (P=0.028) and age (P=0.036) remained the variable associated with a statistically significant increased incidence of PIS.

Conclusions

PIS can occur after the frozen elephant trunk procedure. The volume of new-onset thrombus seems to be associated with an increased incidence of PIS. These findings need to be confirmed in larger patient cohorts.

Management of Postoperative Fever in Adult Cardiac Surgical Patients

Postoperative fever after cardiac surgery is a common occurrence. Most fevers are benign and self-limiting resulting from inflammation caused by surgical trauma and blood contact with cardiopulmonary bypass circuit resulting in the release of cytokines. Only a small percentage of time is postoperative fever due to an infection complicating surgery. The presence of fever frequently triggers a battery of diagnostic tests that are costly, could expose the patient to unnecessary risks, and can produce misleading or inconclusive results. It is therefore important that fever be evaluated in a systematic, prudent, clinically appropriate, and cost-effective manner. This article focuses on the current evidence regarding pathophysiology, incidence, causes, evaluation, and management of fever in postoperative adult cardiac surgical patients.

Absorption fever characteristics due to percutaneous renal biopsy-related hematoma

This study aims to describe the unique characteristics of absorption fever in patients with a hematoma after percutaneous renal biopsy (PRB) and distinguish it from secondary infection of hematoma.We retrospectively studied 2639 percutaneous renal biopsies of native kidneys. We compared the clinical characteristics between 2 groups: complication group (gross hematuria and/or perirenal hematoma) and no complication group. The axillary temperature of patients with a hematoma who presented with fever was measured at 06:00, 10:00, 14:00, and 18:00. The onset and duration of fever and the highest body temperature were recorded. Thereafter, we described the time distribution of absorption fever and obtained the curve of fever pattern.Of 2639 patients, PRB complications were observed in 154 (5.8%) patients. Perirenal hematoma was the most common complication, which occurred in 118 (4.5%) of biopsies, including 74 small hematoma cases (thickness ≤3 cm) and 44 large hematoma cases (thickness >3 cm). Major complications were observed in only 6 (0.2%) cases resulting from a large hematoma. Of 118 patients with a perirenal hematoma, absorption fever was observed in 48 cases. Furthermore, large hematomas had a 5.23-fold higher risk for absorption fever than the small ones.Blood pressure, renal insufficiency, and prothrombin time could be risk factors for complications. Fever is common in patients with hematoma because of renal biopsy and is usually noninfectious. Evaluation of patients with post-biopsy fever is necessary to identify any obvious infection sources. If no focus is identified, empiric antibiotic therapy should not be initiated nor should prophylactic antibiotics be extended for prolonged durations. Absorption fevers will resolve in time without specific therapeutic interventions.