Baroreflex sensitivity and outcomes following coronary surgery

Abstract

Postoperative atrial fibrillation, acute kidney dysfunction and low cardiac output following coronary surgery are associated with morbidity and mortality. The purpose of this study is to determine if the preoperative autonomic control is a determinant of these postoperative complications. This is a prospective cohort study on 150 adult patients undergoing surgical coronary revascularization with cardiopulmonary bypass. The patients received an autonomic control assessment after the induction of anesthesia. Baroreflex sensitivity was computed by spectral analysis and expressed as BRSαHF and BRSαLF for measure respectively in the high and low frequency domains. Atrial fibrillation was adjudicated at any postoperative time during the hospital stay. Acute kidney dysfunction was defined as any increase of serum creatinine levels from preoperative values within the first 48 hours after surgery, and acute kidney injury was adjudicated at a 50% increase. Low cardiac ouput syndrome was defined as the need for inotropic support > 48 hours. Thirty-eight (26.4%) patients experienced postoperative atrial fibrillation; 32 (22.2%) had acute kidney dysfunction and 5 (3.5%) acute kidney injury; 14(10%) had a low cardiac output state. No indices of baroreflex sensitivity were associated with atrial fibrillation or acute kidney injury. A low value of BRSαLF was associated with acute kidney dysfunction and low cardiac output state. A BRSαLF < 3 msec/mmHg was an independent risk factor for acute kidney dysfunction (odds ratio 3.0, 95% confidence interval 1.02–8.8, P = 0.045) and of low cardiac output state (odds ratio 17.0, 95% confidence interval 2.9–99, P = 0.002). Preoperative baroreflex sensitivity is linked to postoperative complications through a number of possible mechanisms, including an autonomic nervous system-mediated vasoconstriction, a poor response to hypotension, and an increased inflammatory reaction.

Perioperative Quality Initiative consensus statement on the physiology of arterial blood pressure control in perioperative medicine

“…62 Impaired responses through loss of baroreflex sensitivity, a key autonomic regulatory mechanism, are associated with poorer perioperative outcomes 63 and linked mechanistically with organ injury. 64,65 The loss of haemodynamic coherence may occur in a highly heterogeneous, organ-specific pattern (Fig 4).…”

Stratifying the Risk of Developing Atrial Fibrillation after Coronary Artery Bypass Graft Surgery Using Heart Rate Asymmetry Indexes

“…We hypothesize that HPA analysis could be helpful to better discriminate subjects who develop AF after CABG from the ones who do not (noAF). This hypothesis is supported by the observation that this peculiar type of nonlinearity depends on the ANS state [3] and ANS plays an important role in the AF development [6].…”

“…Therefore, the aim of this study is to test the association between HPA indexes and the likelihood of developing AF in CABG patients. This association was checked before (PRE) and after (POST) the induction of general anesthesia [6][7][8]. Two indexes, widely utilized for the assessment of HPA, were utilized [1,2].…”

Propofol General Anesthesia Decreases the Coupling Strength Between Mean Arterial Blood Pressure and Mean Cerebral Blood Flow Velocity in Patients Undergoing Coronary Artery Bypass Grafting

“…Subjects signed an informed consent before participating. As described in [9,10], subjects received atropine and fentanyl as premedication, then, intravenous anesthesia was induced and maintained through propofol (induction: bolus 1.5 mg·kg -1 ; maintenance: 3 mg·kg -1 ·h -1 ) and remifentanil (maintenance: from 0.05 to 0.5 μg·kg -1 ·min -1 ) infusion. During anesthesia subjects were mechanically ventilated at 12 to 16 breaths·min -1 with 1:1 oxygen and air.…”