Preoperative risk factors for unexpected postoperative intensive care unit admission: A retrospective case analysis

Surgical Aortic Valve Replacement and Renal Dysfunction: From Acute Kidney Injury to Chronic Disease

Background: Surgical aortic valve replacement (SAVR) is often complicated by acute kidney injury (AKI). Identifying patients at risk of AKI is important to start nephroprotective strategies or renal replacement therapy (RRT). This study investigated the incidence and risk factors of post-operative AKI in SAVR patients. Chronic kidney disease (CKD) developed in the post-cardiac-surgery follow-up period was also assessed. Methods: A total of 462 SAVR patients were retrospectively enrolled. The primary endpoint was the occurrence rate of AKI after surgery. Kidney recovery, during two planned outpatient clinic nephrological visits within 12 months after the surgery, was assessed. Results: A total of 76 patients experienced an AKI event. A Kaplan-Meier analysis revealed that subjects with CKD stage IV had a time to progression of 2.7 days, compared to patients with stages I-II, who were characterized by the slowest progression time, >11.2 days. A Cox regression indicated that CKD stages predicted a higher risk of AKI independently of other variables. During their ICU stay, 23 patients died, representing 5% of the population, most of them requiring RRT during their ICU stay. A severe CKD before the surgery was closely related to perioperative mortality. During the follow-up period, 21 patients with AKI worsened their CKD stage. Conclusions: AKI represents a common complication for SAVR patients in the early post-operative period, prolonging their ICU stay, with negative effects on survival, especially if RRT was required. Pre-operative CKD >3 stage is an independent risk factor for AKI in patients undergoing SAVR.

Usefulness of the N-Terminal of the Prohormone Brain Natriuretic Peptide in Predicting Acute Kidney Injury Requiring Renal Replacement Therapy in Patients Undergoing Heart Valve Surgery

Background and Objectives: By definition, acute kidney injury (AKI) is a clinical syndrome diagnosed when the increase in serum creatinine concentration is >0.3 mg/dL in 48 h or >1.5-fold in the last seven days or when diuresis < 0.5 mL/kg/h for a consecutive 6 h. AKI is one of the severe complications that may occur in the early postoperative period in patients undergoing heart valve surgery, significantly increasing the risk of death. Early implementation of renal replacement therapy increases the chances of improving treatment results in patients with postoperative AKI. The study assessed the predictive ability of selected preoperative and perioperative parameters for the occurrence of postoperative AKI requiring renal replacement therapy in the early postoperative period in a group of patients with severe valvular heart disease. Materials and Methods: A prospective study was conducted on a group of patients undergoing consecutive heart valve surgeries. The primary endpoint was postoperative AKI requiring renal replacement therapy. AKI was diagnosed with an increase in serum creatinine > 0.3 mg/dL in 48 h or >1.5-fold in the previous 7 days and/or a decrease in diuresis < 0.5 mL/kg/h for 6 h. The observation period was until the patient was discharged home or death occurred. Logistic regression analysis was used to assess which variables were predictive of primary endpoint, and odds ratios (OR) were calculated with a 95% confidence interval (CI). Multivariate analysis was based on the result of single factor logistic regression, i.e., to further steps, all statistically significant variables were taken into consideration. Results: A total of 607 patients were included in the study. The primary endpoint occurred in 50 patients. At multivariate analysis: NT-proBNP (OR 1.406; 95% CI 1.015-1.949; p = 0.04), CRP (OR 1.523; 95% CI 1.171-1.980; p = 0.001), EuroSCORE II (OR 1.090; 95% CI 1.014-1.172; p = 0.01), age (OR 1.037; 95% CI 1.001-1.075; p = 0.04) and if they stayed in the intensive care unit longer than 2 days (OR 9.077; 95% CI 2.026-40.663; p = 0.004) remained the independent predictors of the primary endpoint. The mean preoperative NT-proBNP level was 2063 pg/mL (±1751). Thirty-eight patients with AKI requiring renal replacement therapy died in intrahospital follow-up. Conclusions: The results of the presented study indicate that a high preoperative level of NT-proBNP and postoperative hemodynamic instability may be associated with a significant risk of a postoperative AKI requiring renal replacement therapy. The results of the study may also suggest that qualifying for heart valve surgery earlier may be associated with improved prognosis in this group of patients.

Standardized Nursing Diagnoses in a Surgical Hospital Setting: A Retrospective Study Based on Electronic Health Data

Introduction

In electronic health records (EHRs), standardized nursing terminologies (SNTs), such as nursing diagnoses (NDs), are needed to demonstrate the impact of nursing care on patient outcomes. Unfortunately, the use of NDs is not common in clinical practice, especially in surgical settings, and is rarely included in EHRs.

Objectives

The aim of the study was to describe the prevalence and trend of NDs in a hospital surgical setting by also analyzing the relationship between NDs and hospital outcomes.

Methods

A retrospective study was conducted. All adult inpatients consecutively admitted to one of the 15 surgical inpatient units of an Italian university hospital across 1 year were included. Data, including the Professional Assessment Instrument and the Hospital Discharge Register, were collected retrospectively from the hospital's EHRs.

Results

The sample included 5,027 surgical inpatients. There was a mean of 6.3 ± 4.3 NDs per patient. The average distribution of NDs showed a stable trend throughout the year. The most representative NANDA-I ND domain was safety/protection. The total number of NDs on admission was significantly higher for patient whose length of stay was longer. A statistically significant correlation was observed between the number of NDs on admission and the number of intra-hospital patient transfers. Additionally, the mean number of NDs on admission was higher for patients who were later transferred to an intensive care unit compared to those who were not transferred.

Conclusion

NDs represent the key to understanding the contribution of nurses in the surgical setting. NDs collected upon admission can represent a prognostic factor related to the hospital's key outcomes.

The level of postoperative care influences mortality prediction by the POSPOM score: A retrospective cohort analysis

BACKGROUND

The Preoperative Score to Predict Postoperative Mortality (POSPOM) assesses the patients' individual risk for postsurgical intrahospital death based on preoperative parameters. We hypothesized that mortality predicted by the POSPOM varies depending on the level of postoperative care.

METHODS

All patients age over 18 years undergoing inpatient surgery or interventions involving anesthesia at a German university hospital between January 2006, and December 2017, were assessed for eligibility for this retrospective study. Endpoint was death in hospital following surgery. Adaptation of the POSPOM to the German coding system was performed as previously described. The whole cohort was divided according to the level of postoperative care (normal ward vs. intensive care unit (ICU) admission within 24 h vs. later than 24 h, respectively).

RESULTS

199,258 patients were finally included. Observed intrahospital mortality was 2.0% (4,053 deaths). 9.6% of patients were transferred to ICU following surgery, and mortality of those patients was increased already at low POSPOM values of 15. 17,165 patients were admitted to ICU within 24 h, and these patients were older, had more comorbidities, or underwent more invasive surgery, reflected by a higher median POSPOM score compared to the normal-ward group (29 vs. 17, p <0.001). Mortality in that cohort was significantly increased to 8.7% (p <0.001). 2,043 patients were admitted to ICU later than 24 h following surgery (therefore denoted unscheduled admission), and the median POSPOM value of that group was 23. Observed mortality in this cohort was highest (13.5%, p <0.001 vs. ICU admission <24 h cohort).

CONCLUSION

Increased mortality in patients transferred to high-care wards reflects the significance of, e.g., intra- or early postoperative events for the patients' outcome. Therefore, scoring systems considering only preoperative variables such as the POSPOM reveal limitations to predict the individual benefit of postoperative ICU admission.

A clinical nomogram predicting unplanned intensive care unit admission after hip fracture surgery

BACKGROUND

Despite the improvement of surgical procedures and perioperative management, a portion of patients were still at high risk for intensive care unit admission owing to severe morbidity after hip fracture surgeries. The purpose of this study was to analyze influencing factors and to construct a clinical nomogram to predict unscheduled intensive care unit admission among inpatients after hip fracture surgeries.

METHODS

We enrolled a total of 1,234 hip fracture patients, with 40 unplanned intensive care unit admissions, from January 2011 to December 2018. Demographics, chronic coexisting conditions at admission, laboratory tests, and surgical variables were collected and compared between intensive care unit admission and nonadmission groups using univariate analysis. The optimal lasso model was refined to the whole data set, and multivariate logistic regression was used to assign relative weights. A nomogram incorporating these predictors was constructed to visualize these predictors and their corresponding points of the risk for unplanned intensive care unit admission. The model was validated temporally using an independent data set from January 2019 to December 2019 by receiver operating characteristic area under the curve analysis.

RESULTS

In the development group, we identified age, chronic heart failure, coronary heart disease, chronic obstructive pulmonary disease, Parkinson disease, and serum albumin and creatinine concentration were associated with unscheduled intensive care unit admission using multivariate analysis. The final model had an area under the curve of 0.854 (95% confidence interval, 0.742-0.966). The median calculated odds ratio of intensive care unit admission based on the nomogram was significantly higher for patients in the intensive care unit admission group than in the non-intensive care unit admission group (65.93% vs 0.02%, P < .01). The validation group proved its high predictive power with an area under the curve of 0.96 (95% confidence interval, 0.91-0.99).

CONCLUSION

In this study, we identified several independent factors that may increase the risk for unexpected intensive care unit admission after hip fracture surgery and developed a clinical nomogram based on these variables. Preoperative evaluation using this nomogram might facilitate advanced intensive care unit resource management for high-risk patients whose conditions might easily deteriorate if not closely monitored in general wards after surgeries.

Surgical Apgar score is strongly associated with postoperative ICU admission

Immediate postoperative intensive care unit (ICU) admission can increase the survival rate in patients undergoing high-risk surgeries. Nevertheless, less than 15% of such patients are immediately admitted to the ICU due to no reliable criteria for admission. The surgical Apgar score (SAS) (0–10) can be used to predict postoperative complications, mortality rates, and ICU admission after high-risk intra-abdominal surgery. Our study was performed to determine the relationship between the SAS and postoperative ICU transfer after all surgeries. All patients undergoing operative anesthesia were retrospectively enrolled. Among 13,139 patients, 68.4% and < 9% of whom had a SASs of 7–10 and 0–4. Patients transferred to the ICU immediately after surgery was 7.8%. Age, sex, American Society of Anesthesiologists (ASA) class, emergency surgery, and the SAS were associated with ICU admission. The odds ratios for ICU admission in patients with SASs of 0–2, 3–4, and 5–6 were 5.2, 2.26, and 1.73, respectively (P < 0.001). In general, a higher ASA classification and a lower SAS were associated with higher rates of postoperative ICU admission after all surgeries. Although the SAS is calculated intraoperatively, it is a powerful tool for clinical decision-making regarding the immediate postoperative ICU transfer.

Elective infrainguinal lower extremity bypass for claudication is associated with high postoperative intensive care utilization

BACKGROUND

The overall use of intensive care units (ICUs) in the United States has been steadily increasing and is associated with tremendous health care costs. We suspect that the burden of ICU utilization after elective infrainguinal lower extremity bypass (LEB) procedures is high, despite relatively low risks of complications in the immediate postoperative period. We sought to identify the burden of ICU utilization after elective LEB in patients with claudication.

METHODS

We queried the Premier Healthcare Database for all adult patients undergoing first recorded elective infrainguinal LEB for claudication from 2009 to 2015. Baseline characteristics and ICU utilization on postoperative day 0 (POD 0) were identified for each patient using Premier room and board chargemaster codes. A bivariate logistic regression was performed and postestimation concordance statistics were calculated to identify predictors of postoperative ICU vs regular surgical floor admission immediately after surgery.

RESULTS

There were 6010 patients who met the selection criteria, of whom 2772 (46.1%) were admitted to the ICU and 3238 (53.9%) to the regular surgical floor on POD 0. Whereas patient-level factors were responsible for minor differences found in postoperative admission to the ICU after elective LEB, hospital characteristics made up the majority of variation in admission practices. Specifically, patients undergoing elective infrainguinal LEB in rural, nonteaching, small hospitals and those in certain geographic regions were more likely to be admitted to the ICU than to the floor (all, P < .001). Patient-level factors were poorly predictive of admission to the ICU immediately postoperatively, with C statistics ranging from 0.50 to 0.53. In contrast, hospital-level factors had higher C statistics ranging from 0.51 to 0.66, with geographic location being the strongest predictor of post-LEB ICU admission. There were no significant differences in the incidence of postoperative wound complications, major adverse limb events, major adverse cardiac events, or in-hospital mortality between groups (all, P ≥ .32). The median total hospital cost was $2340 higher for ICU compared with floor admission ($13,273 [interquartile range, $10,136-$17,883] vs $10,927 [interquartile range, $8342-$14,523]; P < .001).

CONCLUSIONS

Nearly half of patients are admitted to an ICU directly after elective infrainguinal LEB for claudication. This practice is associated with significantly higher hospital cost and is predominantly influenced by hospital-level rather than by patient-level factors. Perioperative morbidity and mortality were similar regardless of postoperative disposition. To minimize ICU utilization, postoperative care intensity should be determined by clinical severity of the patient rather than by hospital routine.

Anisocytosis predicts postoperative renal replacement therapy in patients undergoing heart valve surgery

BACKGROUND

Acute kidney injury (AKI) is one of the serious postoperative complications in patients undergoing heart valve surgery. The aim of the present study was to identify selected biomarkers to predict AKI requiring renal replacement.

METHODS

A prospective study was conducted on a group of 751 patients undergoing heart valve surgery. The data on risk factors, preoperative complete blood count, course of operations and postoperative period was assessed. The primary endpoint at the 30-day follow-up was postoperative AKI requiring renal replacement therapy. The secondary end-point was death from all causes in patients with postoperative AKI requiring renal replacement.

RESULTS

The primary endpoint occurred in 46 patients. At multivariate analysis: age, red cell distribution width (RDW) and C-reactive protein remained independent predictors of the primary endpoint. Hemoglobin and RDW were associated with an increased risk of death.

CONCLUSIONS

Elevated RDW is associated with a higher risk of postoperative AKI and death in patients with AKI.