Oxygen Delivery During Cardiopulmonary Bypass and Acute Renal Failure After Coronary Operations

doi:10.1016/j.athoracsur.2005.05.069

The Annals of Thoracic Surgery

Volume 80, Issue 6, December 2005, Pages 2213-2220

https://doi.org/10.1016/j.athoracsur.2005.05.069 Get rights and content

Background

The degree of hemodilution during cardiopulmonary bypass has recently been identified as an independent risk factor for acute renal failure after cardiac operations. In this prospective observational study we have investigated the role of the lowest oxygen delivery, lowest hematocrit, and pump flow during cardiopulmonary bypass as possible risk factors for acute renal failure and renal dysfunction.

Methods

One thousand forty-eight consecutive patients undergoing coronary operations have been studied. For each patient we have recorded the lowest hematocrit on cardiopulmonary bypass, the correspondent lowest oxygen delivery, and the pump flow around the time of these determinations. The three variables have been explored in a multivariable model as possible risk factors for acute renal failure and postoperative serum creatinine levels increase. The role of transfusions in determining acute renal failure was subsequently included in the model.

Results

The best predictor for acute renal failure and peak postoperative serum creatinine levels was the lowest oxygen delivery, with a critical value at 272 mL · min⁻¹ · m⁻². The lowest hematocrit was an independent risk factor with a lowest predictive value at a cutoff of 26%. When corrected for the need for transfusions, only the lowest oxygen delivery remained an independent risk factor.

Conclusions

A high degree of hemodilution during cardiopulmonary bypass is a risk factor for postoperative renal dysfunction; however, its detrimental effects may be reduced by increasing the oxygen delivery with an adequately increased pump flow.

Section snippets

Study Design

The study design consisted of a prospective observational study conducted during 6 months of activity in the cardiac surgery department of our institution. All the patients gave their written consent to the scientific treatment of the data. The local ethical committee waived the need for approval.

Patient Population

One thousand forty-eight consecutive patients scheduled for surgical coronary revascularization were admitted to the study. Exclusion criteria were chronic dialytic treatment and patients receiving

Results

Twenty-eight patients (2.6%) met the criteria for postoperative RR-ARF. This group had a significantly higher mortality rate (11% vs 1.7%; p = 0.014), longer ICU stay (5.2 ± 1.2 days vs 2.5 ± 0.9 days; p < 0.001), and postoperative hospital stay (15.3 ± 3 vs 7.4 ± 0.2 days; p < 0.001) than patients without RR-ARF. The PPSC value was 1.12 ± 0.8 mg/dL (not significantly different from the baseline value of 1.06 ± 0.64 mg/dL).

Oxygen Flow Variables and Renal Dysfunction

In agreement with previously published articles [9, 10, 11, 12, 13, 14], this study confirms the association between lowest HCT on CPB and adverse renal outcomes in coronary operations. However, our findings introduce the lowest DO₂ indexed on CPB as a new and probably more reliable predictor of RR-ARF. In a multivariable predictive model for RR-ARF, the lowest DO₂ indexed on CPB is a more significant risk factor than the lowest HCT on CPB or the pump flow indexed; moreover, in a predictive

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Perioperative Care in Cardiac Surgery: A Joint Consensus Statement by the Enhanced Recovery After Surgery (ERAS) Cardiac Society, ERAS International Society, and The Society of Thoracic Surgeons (STS)
2024, Annals of Thoracic Surgery
Enhanced Recovery After Surgery (ERAS) programs have been shown to lessen surgical insult, promote recovery, and improve postoperative clinical outcomes across a number of specialty operations. A core tenet of ERAS involves the provision of protocolized evidence-based perioperative interventions. Given both the growing enthusiasm for applying ERAS principles to cardiac surgery and the broad scope of relevant interventions, an international, multidisciplinary expert panel was assembled to derive a list of potential program elements, review the literature, and provide a statement regarding clinical practice for each topic area. This article summarizes those consensus statements and their accompanying evidence. These results provide the foundation for best practice for the management of the adult patient undergoing cardiac surgery.
Oxygen Delivery Thresholds During Cardiopulmonary Bypass and Risk for Acute Kidney Injury
2023, Annals of Thoracic Surgery
Postoperative acute kidney injury (AKI) in cardiac surgery patients is multifactorial and associated with low oxygen delivery (DO₂) during cardiopulmonary bypass.
Cardiac surgical patients undergoing full cardiopulmonary bypass between May 1, 2016 and December 31, 2021 were included, whereas those on preoperative dialysis, undergoing circulatory arrest procedures, or lacking minute-to-minute physiologic data were excluded. A 5-minute running average of indexed DO₂ (DO₂i, mL/min/m²) was calculated ([pump flow] × [hemoglobin] × 1.36 [hemoglobin saturation] + 0.003 [arterial oxygen tension]/body surface area). AKI was defined using established Kidney Disease: Improving Global Outcomes criteria. The threshold of nadir DO₂i on the effect of AKI was estimated using risk-adjusted Constrained Broken-Stick models.
Postoperative AKI occurred among 1155 patients (29.4%), with 276 (7.0%) having stage 2 to 3 AKI. The median nadir DO₂i was lower for those with (vs without) AKI (197.9 mL/min/m² [interquartile range {IQR}, 166.3-233.2] vs 217.2 mL/min/m² [IQR, 184.5-252.2], P < .001) and stage 2 to 3 AKI relative to stage 1 or none (186.9 mL/min/m² [IQR, 160.1-220.5] vs 213.8 mL/min/m² [IQR, 180.4-249.4]). In risk-adjusted analyses the estimated threshold for nadir DO₂i was 231.2 mL/min/m² (95% CI, 173.6-288.8) for any AKI and 103.3 (95% CI, 68.4-138.3) for stage 2 to 3 AKI.
Decreasing nadir DO₂i was associated with an increased risk of AKI. The identified nadir DO₂i thresholds suggest management and treatment of nadir DO₂i during cardiopulmonary bypass may decrease a patient’s postoperative AKI risk.
Oxygen delivery in pediatric cardiac surgery and its association with acute kidney injury using machine learning
2023, Journal of Thoracic and Cardiovascular Surgery
Acute kidney injury (AKI) after pediatric cardiac surgery with cardiopulmonary bypass (CPB) is a frequently reported complication. In this study we aimed to determine the oxygen delivery indexed to body surface area (Do₂i) threshold associated with postoperative AKI in pediatric patients during CPB, and whether it remains clinically important in the context of other known independent risk factors.
A single-institution, retrospective study, encompassing 396 pediatric patients, who underwent heart surgery between April 2019 and April 2021 was undertaken. Time spent below Do₂i thresholds were compared to determine the critical value for all stages of AKI occurring within 48 hours of surgery. Do₂i threshold was then included in a classification analysis with known risk factors including nephrotoxic drug usage, surgical complexity, intraoperative data, comorbidities and ventricular function data, and vasoactive inotrope requirement to determine Do₂i predictive importance.
Logistic regression models showed cumulative time spent below a Do₂i value of 350 mL/min/m² was associated with AKI. Random forest models, incorporating established risk factors, showed Do₂i threshold still maintained predictive importance. Patients who developed post-CPB AKI were younger, had longer CPB and ischemic times, and required higher inotrope support postsurgery.
The present data support previous findings that Do₂i during CPB is an independent risk factor for AKI development in pediatric patients. Furthermore, the data support previous suggestions of a higher threshold value in children compared with that in adults and indicate that adjustments in Do₂i management might reduce incidence of postoperative AKI in the pediatric cardiac surgery population.
Oxygen delivery-guided perfusion for the prevention of acute kidney injury: A randomized controlled trial
2023, Journal of Thoracic and Cardiovascular Surgery
The reduction of postoperative acute kidney injury in patients undergoing cardiopulmonary bypass surgery using an oxygen delivery-guided perfusion strategy (oxygen delivery strategy) for cardiopulmonary bypass management compared with a fixed flow perfusion (conventional strategy) remains controversial. The purpose of this study was to determine whether a oxygen delivery strategy would reduce the incidence of postoperative acute kidney injury in patients undergoing cardiopulmonary bypass surgery.
We randomly enrolled 300 patients undergoing cardiopulmonary bypass surgery. Patients were randomly assigned to a oxygen delivery strategy (maintaining a oxygen delivery index value >300 mL/min/m² through pump flow adjustments during cardiopulmonary bypass) or a conventional strategy (a target pump flow was determined on the basis of the body surface area). The primary end point was the development of acute kidney injury. Secondary end points were the red blood cell transfusion rate and number of red blood cell units, intubation time, postoperative length of stay in the intensive care unit and the hospital, predischarge estimated glomerular filtration rate, and hospital mortality.
Acute kidney injury occurred in 20 patients (14.6%) receiving the oxygen delivery strategy and in 42 patients (30.4%) receiving the conventional strategy (relative risk, 0.48; 95% confidence interval, 0.30-0.77; P = .002). The secondary end points were not significantly different between strategies. In a prespecified subgroup analysis of patients who had nadir hematocrit less than 23% or body surface area less than 1.40 m², the oxygen delivery strategy seemed to be superior to the conventional strategy and the existence of quantitative interactions was suggested.
An oxygen delivery strategy for cardiopulmonary bypass management was superior to a conventional strategy with respect to preventing the development of acute kidney injury.
ERAS Cardiac society turnkey order set for patient blood management: Proceedings from the AATS ERAS Conclave 2023
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There are multiple published guidelines on comprehensive patient blood management (PBM), centered on the 3 pillars of PBM: managing preoperative anemia, minimizing blood loss, and tolerating intraoperative/postoperative anemia. We sought to create an order set to facilitate widespread implementation of evidence-based PBM for cardiac surgery patients.
Subject matter experts were consulted to translate existing guidelines and literature into a sample turnkey order set (TKO) for PBM. Orders derived from consistent class I, class IIA, or equivalent recommendations across referenced guidelines and consensus manuscripts appear in the TKO in bold type. Selected orders that were inconsistently class I or IIA, class IIB, or supported by published evidence are presented in italic type.
Preoperatively, there are strong recommendations to screen and treat preoperative anemia with iron replacement and erythropoietin and to discontinue dual antiplatelet therapy if the patient can safely wait for surgery. Intraoperative orders outline the routine use of an antifibrinolytic agent, cell saver, point of care viscoelastic testing, and use of a standard transfusion algorithm. The order set also reflects strong recommendations intraoperatively and postoperatively for agreed-upon hemoglobin thresholds to consider transfusion of packed red blood cells. A hemoglobin threshold should be adopted according to local team consensus and should trigger a discussion regarding transfusion.
The benefit of a multidisciplinary PBM care pathway in cardiac surgery has been well established, yet implementation remains variable. Using recommendations from existing guidelines, we have created a TKO to facilitate the implementation of PBM.
Preoperative Anemia and Postoperative Outcomes in Cardiac Surgery: A Mediation Analysis Evaluating Intraoperative Transfusion Exposures
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Original articleCardiovascularOxygen Delivery During Cardiopulmonary Bypass and Acute Renal Failure After Coronary Operations

Background

Methods

Results

Conclusions

Section snippets

Study Design

Patient Population

Results

Oxygen Flow Variables and Renal Dysfunction

Ann Thorac Surg

Ann Thorac Surg

J Thorac Cardiovasc Surg

J Thorac Cardiovasc Surg

Ann Thorac Surg

Renal dysfunction after myocardial revascularizationrisk factors, adverse outcomes, and hospital resources utilization

Ann Intern Med

Renal dysfunction after cardiac surgery with normothermic cardiopulmonary bypassincidence, risk factors, and effect on clinical outcome

Anesth Analg

Preoperative renal risk stratification

Circulation

Acute renal failure following cardiopulmonary bypassa changing picture

Intens Care Med

Acute renal failure following cardiac surgery

Nephrol Dial Transplant

Acute renal failure following cardiac surgeryincidence, outcomes, and risk factors

Aust NZ J Med

Original article
Cardiovascular
Oxygen Delivery During Cardiopulmonary Bypass and Acute Renal Failure After Coronary Operations