The epidemiology and outcomes of acute kidney injury following orthopaedic procedures: A retrospective cohort study.

BACKGROUND: Acute kidney injury (AKI) is a serious complication following major surgery. This study examined the incidence and risk factors of AKI following orthopaedic surgeries in an Icelandic cohort, as well as the association between AKI and patient- and surgery-related factors. METHODS: This retrospective cohort study comprised all patients 18 years and older who underwent orthopaedic surgeries at Landspitali - The National University Hospital in the years 2006-2018 with available serum creatinine (SCr) measurements adjacent to the surgery to stage AKI. AKI was defined according to SCr portion of the KDIGO criteria. Logistic regression was used to identify patient- and surgical factors related to progression of AKI and Poisson-regression was used to explore changes in incidence. RESULTS: A total of 222 cases of AKI following 3208 surgeries (6.9%) were identified in the study period with a rise in the incidence by about 17% per year. Higher age (odds ratio (OR), 1.02, 95% confidence interval (CI), 1.01-1.04 per year) and underlying reduction in kidney function (OR 1.93 (1.30-2.81), 3.24 (2.08-4.96) and 4.08 (2.35-6.96) for estimated glomerular filtration rate (eGFR) of 30-59, 15-29 and <15 mL/min/1.73 m2 compared with eGFR >60 mL/min/1.73 m2 ) were associated with higher risk of AKI, but female sex was associated with decreased odds (OR = 0.73; 95% CI, 0.54-0.98). After correcting for age, sex, preoperative kidney function, emergency surgery and underlying comorbidities and frailty, there was an increased risk of long-term mortality in patients with AKI (HR 1.41, 95% CI 1.08-1.85), and patients who developed AKI also had accelerated progression of chronic kidney disease compared with patients who did not develop AKI. CONCLUSIONS: The incidence of AKI following orthopaedic surgeries is increasing and is associated with adverse outcomes. It is important that elderly individuals and patients who have reduced kidney function receive adequate monitoring and surveillance in the perioperative period.

Postoperative Acute Kidney Injury Is Associated With Progression of Chronic Kidney Disease Independent of Severity.

BACKGROUND: Both postoperative acute kidney injury (AKI) and preoperative chronic kidney disease (CKD) are associated with significantly worse outcomes following surgery. The relationship of both of these conditions with each other and with CKD progression after surgery remains poorly studied. Our objective was to assess if there was an interaction between preoperative kidney function estimated by preoperative estimated glomerular filtration rate (eGFR)/CKD stage, postoperative AKI, and eGFR/CKD progression within 1 year of surgery. Our hypothesis was that AKI severity would be associated with a faster time to eGFR/CKD stage progression within 1 year of surgery in a graded-fashion, which would be exacerbated by preoperative kidney dysfunction. METHODS: This was a retrospective cohort study at Landspitali University Hospital in Iceland, which serves about 75% of the population. Participants included adults receiving their first major anesthetic between 2005 and 2018. Patients with CKD stage 5, undergoing major urologic procedures, or having missing creatinine values for follow-up of eGFR stage were excluded from analysis. The primary exposure was postoperative AKI stage within 7 days after surgery classified by the kidney disease improving global outcome (KDIGO) criteria. The primary outcome was time to progression of CKD by at least 1 eGFR/CKD stage within 1-year following surgery. Multivariable Cox proportional hazards models were used to estimate hazard of eGFR/CKD stage progression, including an interaction between AKI and preoperative CKD on eGFR/CKD stage progression. RESULTS: A total of 5548 patients were studied. In the multivariable model adjusting for baseline eGFR/CKD stage, when compared to patients without AKI, postoperative AKI stage 1 (hazard ratio [HR], 5.91; 95% confidence interval [CI], 4.34-8.05), stage 2 (HR, 3.86; 95% CI, 1.82-8.16), and stage 3 (HR, 3.61; 95% CI, 1.49-8.74) were all independently associated with faster time to eGFR/CKD stage progression within 1 year following surgery, though increasing AKI severity did not confer additional risk. The only significant interaction between the degree of AKI and the preexisting renal function was for stage 1 AKI, where the odds of 1-year eGFR/CKD stage progression actually decreased in patients with preoperative CKD categories 3a, 3b, and 4. CONCLUSIONS: KDIGO-AKI was independently associated with eGFR/CKD stage progression within the year following surgery after adjustment for baseline eGFR/CKD stage and without an interaction between worse preoperative kidney function and higher stage AKI. Our observations suggest that further studies are warranted to test whether CKD progression could be prevented by the adoption of perioperative kidney protective practices.

Long-term survival after intensive care: A retrospective cohort study.

Background Limited data exist on long-term survival of patients requiring admission to intensive care units (ICUs). The aim of this study was to investigate long-term survival of ICU patients in Iceland and assess changes over a 15-year period. Methods Data were collected on age, gender, admission cause, length of stay, comorbidities, mechanical ventilation and survival of patients 18 years and older admitted to the ICUs in Landspitali during 2002-2016. Long-term survival of patients surviving more than 30 days from admission was estimated and its predictors assessed with Cox regression analysis. Long-term survival was compared to the survival of an age- and gender-matched reference group from the general population. Results Of 15 832 ICU admissions, 55% was medical, 38% was surgical and 7% was due to trauma. The 5-year survival of medical, surgical and trauma patients was 66%, 76% and 92% respectively. Significant survival differences were found between admission subgroups. Higher age and comorbidity burden was related to decreased survival in all patient groups. After correcting for age, gender, comorbidities, length of ICU stay and mechanical ventilation, patient survival improved during the study period only for patients admitted for infections. There was a high variability in the estimated time point where the ICU admission had no residual effect on survival. Conclusions Long-term survival of ICU patients is substantially decreased compared to the general population, but varies based on admission causes. Improved long-term survival of patients admitted with infections could be explained by earlier detection and improved treatment of septic shock.

Postoperative Acute Kidney Injury: Focus on Renal Recovery Definitions, Kidney Disease Progression and Survival.

BACKGROUND: The aim of this study was to examine different definitions of renal recovery following postoperative acute kidney injury (AKI) and how these definitions associate with survival and the development and progression of chronic kidney disease (CKD). METHODS: This was a retrospective study of all patients who underwent abdominal, cardiothoracic, vascular, or orthopedic surgery at a single university hospital between 1998 and 2015. Recovery of renal function following postoperative AKI was assessed comparing 4 different definitions: serum creatinine (SCr) (i) < 1.1 × baseline, (ii) 1.1-1.25 × baseline, (iii) 1.25-1.5 × baseline, and (iv) > 1.5 × baseline. One-year survival and the development or progression of CKD within 5 years was compared with a propensity score-matched control groups. RESULTS: In total, 2,520 AKI patients were evaluated for renal recovery. Risk of incident and progressive CKD within 5 years was significantly increased if patients did not achieve a reduction in SCr to < 1.5 × baseline (hazard ratio [HR] 1.50; 95% CI 1.29-1.75) and if renal recovery was limited to a fall in SCr to 1.25-1.5 × baseline (HR 1.32; 95% CI 1.12-1.57) within 30 days. The definition of renal recovery that best predicted survival was a reduction in SCr to < 1.5 × baseline within 30 days. One-year survival of patients whose SCr decreased to < 1.5 × baseline within 30 days was significantly better than that of a propensity score-matched control group that did not achieve renal recovery (85 vs. 71%, p < 0.001). CONCLUSIONS: These findings should be considered when a consensus definition of renal recovery after AKI is established.

Acute Kidney Injury After Abdominal Surgery: Incidence, Risk Factors, and Outcome.

BACKGROUND: Acute kidney injury (AKI) is a serious complication after major surgical procedures. We examined the incidence, risk factors, and mortality of patients who sustained AKI after abdominal surgery in a large population-based cohort. METHODS: All patients who underwent open and laparoscopic abdominal surgery (excluding genitourinary and abdominal vascular procedures), between 2007 and 2014 at the University Hospital in Reykjavik were identified and their perioperative serum creatinine (SCr) measurements used to identify AKI after surgery employing the Kidney Disease: Improving Global Outcome (KDIGO) criteria. Risk factors were evaluated using multivariate logistic regression analysis and 30-day mortality compared with a propensity score-matched control group. RESULTS: During the 8-year period, a total of 11,552 abdominal surgeries were performed on 10,022 patients. Both pre- and postoperative SCr measurements were available for 3902 (33.8%) of the surgical cases. Of these, 264 (6.8%) were complicated by AKI; 172 (4.4%), 49 (1.3%), and 43 (1.1%) were classified as KDIGO stages 1, 2 and 3, respectively. The overall incidence of AKI for patients with available SCr values was 67.7 (99% confidence interval [CI], 57.7-78.6) per 1000 surgeries. In logistic regression analysis, independent risk factors for AKI were female sex (odds ratio [OR] = 0.68; 99% CI, 0.47-0.98), hypertension (OR = 1.75; 99% CI, 1.10-2.74), preoperative chronic kidney disease (OR= 1.68; 99% CI, 1.12-2.50), ASA physical status classification of IV (OR = 9.48; 99% CI, 3.66-29.2) or V (OR = 21.4; 99% CI, 5.28-93.6), and reoperation (OR = 4.30; 99% CI, 2.36-7.70). Patients with AKI had greater 30-day mortality (18.2% vs 5.3%; P < 0.001) compared with propensity score-matched controls. CONCLUSIONS: AKI is an important complication of abdominal surgery. In addition to sex, hypertension, and chronic kidney disease, ASA physical status classification is an independent predictor of AKI. Individuals who develop AKI have substantially worse short-term outcomes, including higher 30-day mortality, even after correcting for multiple patient- and procedure-related risk factors.

Improved long-term survival and renal recovery after acute kidney injury in hospitalized patients: A 20 year experience.

AIM: Acute kidney injury (AKI) is a common complication of medical and surgical interventions in hospitalized patients and associates with high mortality. Our aim was to examine renal recovery and long-term survival and time trends in AKI survival. METHODS: Changes in serum creatinine (SCr) were used to define AKI in patients at Landspitali University Hospital in Iceland from 1993 to 2013. Renal recovery was defined as SCr < 1.5× baseline. RESULTS: Out of 25 274 individuals who had their highest measured SCr during hospitalization and an available baseline SCr, 10,419 (41%) had AKI during hospitalization (H-AKI), 19%, 11% and 12% with Stage 1, 2 and 3, respectively. The incidence of H-AKI increased from 18.6 (95% CI, 14.7-22.5) to 29.9 (95% CI, 26.7-33.1) per 1000 admissions/year over the study period. Survival after H-AKI was 61% at 90-days and 51% at one year. Comparing H-AKI patients to propensity score matched individuals the hazard ratio for death was 1.49 (1.36-1.62), 2.17 (1.95-2.41) and 2.95 (2.65-3.29) for Stage 1, 2 and 3, respectively. One-year survival of H-AKI patients improved from 47% in 1993-1997 to 57% in 2008-2013 and the adjusted hazard ratio for mortality improved, compared to the first 5-year period, 0.85 (0.81-0.89), 0.67 (0.64-0.71), and 0.57 (0.53-0.60) for each subsequent 5-year interval. Recovery of renal function was achieved in 88%, 58% and 44% of patients in Stages 1, 2 and 3, respectively, improving with time. CONCLUSIONS: Acute kidney injury is an independent predictor of long-term mortality in hospitalized patients but there has been a marked improvement in survival and renal recovery over the past two decades.

Association Between Preoperative Opioid and Benzodiazepine Prescription Patterns and Mortality After Noncardiac Surgery.

Importance: The number of patients prescribed long-term opioids and benzodiazepines and complications from their long-term use have increased. Information regarding the perioperative outcomes of patients prescribed these medications before surgery is limited. Objective: To determine whether patients prescribed opioids and/or benzodiazepines within 6 months preoperatively would have greater short- and long-term mortality and increased opioid consumption postoperatively. Design, Setting, and Participants: This retrospective, single-center, population-based cohort study included all patients 18 years or older, undergoing noncardiac surgical procedures at a national hospital in Iceland from December 12, 2005, to December 31, 2015, with follow-up through May 20, 2016. A propensity score-matched control cohort was generated using individuals from the group that received prescriptions for neither medication class within 6 months preoperatively. Data analysis was performed from April 10, 2018, to March 9, 2019. Exposures: Patients who filled prescriptions for opioids only, benzodiazepines only, both opioids and benzodiazepines, or neither medication within 6 months preoperatively. Main Outcomes and Measures: Long-term survival compared with propensity score-matched controls. Secondary outcomes were 30-day survival and persistent postoperative opioid consumption, defined as a prescription filled more than 3 months postoperatively. Results: Among 41 170 noncardiac surgical cases in 27 787 individuals (16 004 women [57.6%]; mean [SD] age, 56.3 [18.8] years), a preoperative prescription for opioids only was filled for 7460 cases (17.7%), benzodiazepines only for 3121 (7.4%), and both for 2633 (6.2%). Patients who filled preoperative prescriptions for either medication class had a greater comorbidity burden compared with patients receiving neither medication class (Elixhauser comorbidity index >0 for 16% of patients filling prescriptions for opioids only, 22% for benzodiazepines only, and 21% for both medications compared with 14% for patients filling neither). There was no difference in 30-day (opioids only: 1.3% vs 1.0%; P = .23; benzodiazepines only: 1.9% vs 1.5%; P = .32) or long-term (opioids only: hazard ratio [HR], 1.12 [95% CI, 1.01-1.24]; P = .03; benzodiazepines only: HR, 1.11 [95% CI, 0.98-1.26]; P = .11) survival among the patients receiving opioids or benzodiazepines only compared with controls. However, patients prescribed both opioids and benzodiazepines had greater 30-day mortality (3.2% vs 1.8%; P = .004) and a greater hazard of long-term mortality (HR, 1.41; 95% CI, 1.22-1.64; P < .001). The rate of persistent postoperative opioid consumption was higher for patients filling prescriptions for opioids only (43%), benzodiazepines only (23%), or both (66%) compared with patients filling neither (12%) (P < .001 for all). Conclusions and Relevance: The findings suggest that opioid and benzodiazepine prescription fills in the 6 months before surgery are associated with increased short-and long-term mortality and an increased rate of persistent postoperative opioid consumption. These patients should be considered for early referral to preoperative clinic and medication optimization to improve surgical outcomes.

Acute kidney injury following coronary angiography: a nationwide study of incidence, risk factors and long-term outcomes.

BACKGROUND: We studied the incidence and risk factors of acute kidney injury (AKI) following coronary angiography (CA) and examined short- and long-term outcomes of patients who developed AKI, including progression of chronic kidney disease (CKD). METHODS: This was a retrospective study of all patients undergoing CA in Iceland from 2008 to 2015, with or without percutaneous coronary intervention. All procedures were performed with iso-osmolar contrast. AKI was defined according to the SCr component of the KDIGO criteria. Patients without post-procedural SCr were assumed to be free of AKI. Incident CKD was defined as 90-day sustained estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2, and progression of CKD as worsening at least one stage sustained over 90 days. RESULTS: AKI was detected in 231 of 13,561 cases (1.7%). There was an interaction between contrast dose and preexisting kidney function, where the risk for AKI was only significant at a dose > 150 mL in patients with baseline eGFR < 45 mL/min/1.73 m2 (OR 5.3, 95% CI 2.1-14.2). The AKI patients had worse short-and long-term survival, as well as elevated hazard of both new-onset CKD (HR 3.7, 95% CI 2.7-5.0) and progression of preexisting CKD (HR 2.0, 95% CI 1.5-2.6) over a median follow-up of 3.3 years (range 0.1-8.4 years), compared to a propensity score-matched control group. CONCLUSIONS: For iso-osmolar contrast, the risk of AKI related to contrast dose was evident for higher amount of contrast in patients with baseline eGFR < 45 mL/min/1.73 m2. In addition to association with adverse short- and long-term survival AKI had a strong association with new-onset or progression of CKD when patients were followed longitudinally.