A pilot study to explore patterns and predictors of delayed kidney decline after cardiopulmonary bypass.

There is no current consensus on the follow up of kidney function in patients undergoing cardiopulmonary bypass (CPB). The main objectives of this pilot study is to collect preliminary data on kidney function decline encountered on the first postoperative visit of patients who have had CPB and to identify predictors of kidney function decline post hospital discharge. Design: Retrospective chart review. Adult patients undergoing open heart procedures utilizing CPB. Patient demographics, type of procedure, pre-, intra-, and postoperative clinical, hemodynamic echocardiographic, and laboratory data were abstracted from electronic medical records. Acute kidney disease (AKD), and chronic kidney disease (CKD) were diagnosed based on standardized criteria. Interval change in medications, hospital admissions, and exposure to contrast, from hospital discharge till first postoperative visit were collected. AKD, and CKD as defined by standardized criteria on first postoperative visit. 83 patients were available for analysis. AKD occurred in 27 (54%) of 50 patients and CKD developed in 12 (42%) out of 28 patients. Older age was associated with the development of both AKD and CKD. Reduction in right ventricular cardiac output at baseline was associated with AKD (OR: 0.5, 95% CI: 0.3, 0.79, P = 0.01). Prolongation of transmitral early diastolic filling wave deceleration time was associated with CKD (OR: 1.02, 95% CI: 1.01, 1.05, P = 0.03). In-hospital acute kidney injury (AKI) was a predictor of neither AKD nor CKD. AKD and CKD occur after CPB and may not be predicted by in-hospital AKI. Older age, right ventricular dysfunction and diastolic dysfunction are important disease predictors. An adequately powered longitudinal study is underway to study more sensitive predictors of delayed forms of kidney decline after CPB.

End-of-Procedure Volume Responsiveness Defined by the Passive Leg Raise Test Is Not Associated With Acute Kidney Injury After Cardiopulmonary Bypass.

OBJECTIVES: Renal hypoperfusion is a common mechanism of cardiac surgery-related acute kidney injury (CS-AKI). However, the optimal amount of volume resuscitation to correct systemic hypoperfusion and prevent the postoperative development of CS-AKI has been a subject of debate. The goal of this study was to assess the association of volume responsiveness determined by stroke volume variation using the passive leg raise test (PLRT) at chest closure, with the development of CS-AKI according to the Kidney Disease Improving Global Outcomes criteria. DESIGN: Single-center, prospective observational study. SETTING: Tertiary hospital. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: A total of 131 patients were studied from January 2015 until May 2017. All patients underwent cardiac surgery that required cardiopulmonary bypass. Volume responsiveness was assessed at chest closure using the PRLT. Stroke volume variation from the sitting to the recumbent positions was measured by transesophageal echocardiography. Fluid responsiveness was defined as an increase of >12% of stroke volume from sitting to recumbent positions. A total of 82 (68.3%) patients were fluid-responsive versus 38 (31.6%) who were fluid-unresponsive. CS-AKI occurred in 30% of patients. There was no difference in CS-AKI between fluid-responsive and fluid-nonresponsive groups. However, CS-AKI was associated independently with an increases in body mass index and preoperative diastolic blood pressure. CS-AKI also was associated with prolonged intensive care unit length of stay. CONCLUSION: End-of-procedure volume responsiveness is not associated with a high risk for postoperative CS-AKI.

Timing and mechanism of ischemic stroke due to extracranial blunt traumatic cerebrovascular injury.

OBJECT: Extracranial cerebrovascular injury is believed to be an important cause of neurological injury in patients who have suffered blunt trauma. The authors sought to determine the timing and mechanisms of ischemic stroke in patients who suffered traumatic cerebrovascular injury (TCVI). METHODS: This is a prospective study of all patients with TCVI who were admitted to a Level I trauma center during a 28-month period. All patients who suffered blunt trauma and had risk factors for TCVI underwent screening CT angiography (CTA) of the head and neck on admission. All patients with either an ischemic stroke or CTA suggesting TCVI underwent confirmatory digital subtraction angiography (DSA). Patients with DSA-confirmed TCVI were treated with 325 mg aspirin daily; all patients were observed during their hospitalization for the occurrence of new ischemic stroke. In addition, a subset of patients with TCVI underwent transcranial Doppler ultrasonography monitoring for microembolic signals. RESULTS: A total of 112 patients had CTA findings suggestive of TCVI; 68 cases were confirmed by DSA. Overall, 7 patients had an ischemic stroke in the territory of the affected artery prior to or during admission. Four of the patients had their event prior to diagnosis with CTA and 2 occurred prior to DSA. In 1 patient the ischemic stroke was found to be due to an extracranial atherosclerotic carotid plaque, and this patient was excluded from further analysis. All patients with ischemic stroke had brain CT findings consistent with an embolic mechanism. Two (8.7%) of 23 monitored patients with TCVI had microembolic signals on transcranial Doppler ultrasonography. CONCLUSIONS: Most ischemic strokes due to TCVI are embolic in nature and occur prior to screening CTA and initiation of treatment with aspirin.