Preoperative oral magnesium loading to prevent postoperative atrial fibrillation following coronary surgery: a prospective randomized controlled trial.

OBJECTIVES: Postoperative atrial fibrillation (POAF) is common following coronary artery bypass grafting (CABG) surgery. Hypomagnesemia is frequent after CABG surgery. No previous trials have assessed the effect of preoperative magnesium (Mg) loading on POAF incidence. METHODS: This was a single-centre, double-blind, placebo-controlled, parallel-group trial, with balanced randomization [1:1]. The participants were recruited from November 2018 until May 2019. Patients received either 3.2 g of Mg daily (4 tablets of 0.4 g each twice daily) for 72 h preoperatively and 1.6 g of Mg (4 tablets) on the day of surgery or placebo tablets. RESULTS: The primary outcome was the incidence of POAF. Secondary outcomes included time to extubation, transfusion rate, critical care unit and hospital length of stay. Of the 210 randomized participants, 200 (100 in each group) completed the study. A total of 10 (10%) and 22 (22%) subjects developed POAF in the Mg and placebo groups, respectively (RR = 0.45, 95% confidence interval: 0.23-0.91). Hospital and critical care unit length of stay were comparable between the 2 groups. No side effects related to Mg administration were documented. CONCLUSIONS: In this randomized controlled trial, preoperative loading with oral administration of Mg for 3 days in patients admitted for CABG surgery decreases the incidence of POAF compared to placebo. CLINICAL TRIAL REGISTRATION NUMBER: NCT03703349.

Pulse pressure variation predicts fluid responsiveness in elderly patients after coronary artery bypass graft surgery.

OBJECTIVE: To assess the ability of pulse pressure variation to predict fluid responsiveness in mechanically ventilated elderly patients after coronary artery bypass graft surgery. DESIGN: A prospective, interventional study. SETTING: An academic, tertiary referral hospital. PARTICIPANTS: Sixty patients >70 years old and mechanically ventilated after coronary artery bypass graft surgery. INTERVENTIONS: Intravascular volume expansion using 6% hydroxyethyl starch solution, 7 mL/kg over 20 minutes. MEASUREMENTS AND MAIN RESULTS: Heart rate, arterial blood pressure, pulse pressure variation, central venous pressure, pulmonary artery occlusion pressure, and stroke volume index were measured immediately before and after volume expansion. Fluid responsiveness was defined as an increase in stroke volume index ≥ 15% after volume expansion. Forty-one patients were fluid responders and 19 patients were nonresponders. In contrast to central venous pressure or pulmonary artery occlusion pressure, pulse pressure variation was higher in the responders than in the nonresponders (22 ± 6% v 9.3 ± 3%, p = 0.001) and correlated with the percent changes in the stroke volume index after volume expansion (r = 0.47, p = 0.001). The area under the receiver operating characteristic curve for pulse pressure variation was 0.85 (95% confidence interval 0.75-0.94). The threshold value of 11.5% allowed the discrimination between responders and nonresponders with a sensitivity of 80% and a specificity of 74%. CONCLUSIONS: Pulse pressure variation is a reliable predictor of fluid responsiveness in mechanically ventilated elderly patients after coronary artery bypass graft surgery.

[Does nasal decontamination reduce the incidence of infections after cardiac surgery?]. / La décontamination nasale diminue-t-elle la fréquence des infections après chirurgie cardiaque?

INTRODUCTION: Mupirocin applied to the anterior nares four times daily usually eliminates Staphylococcus aureus, including methicillin resistant, within 48 hours. Prophylactic intranasal mupirocin is safe, inexpensive and effective in reducing the overall sternal wound infection after open-heart surgery. This study was designed to determine whether decreasing nasal bacterial colonization by applying mupirocin intra nasally decreases mediastinal, sternal, pulmonary and cutaneous infections after open-heart surgery. MATERIAL & METHODS: After institutional approval and informed consent, 392 patients were included in a randomized, prospective study. Nasal cultures were taken for all patients before surgery. Patients were divided in two groups: Group I (n = 190) receiving mupirocin in the anterior nares 4 times daily for 48 hours before surgery; Group II (n = 202) was the control group. Patients were followed for a month after surgery. All mediastinal, sternal, pulmonary and cutaneous infections were documented and treated with appropriate antibiotics. A Student test for quantitative data and a chi2 test for qualitative data were used for statistical analysis. p < or = 0.05 was considered significant. RESULTS: The two groups had the same demographic characteristics and risk factors. Nasal carriage of Staphylococcus was 36.2% in the two groups. Neither mediastinitis nor sternitis were noticed in any of the two groups. There was no statistical difference between the groups according to the frequency of the cutaneous infections (Group I: 19/190 - Group II: 13/202) and pneumonia (Group I: 7/190 - Group II: 13/202). In patients who had nasal carriage of Staphylococcus, nasal decontamination has not shown a statistical difference of cutaneous infections of the lower limbs nor pneumonia. Although nasal decontamination reduced the incidence of sternal wound infection (Gr I 0/190 - Gr II 4/202 ; p = 0.017). Staphylococcus aureus, in the control group, induced more cutaneous infections (30.8% vs 11.7% ; p = 0.048). CONCLUSION: The usage of mupirocin for nasal decontamination before open-heart surgery reduces the incidence of the sternal wound infection, and does not seem to affect the frequency of cutaneous infections of the lower limbs nor pneumonia after this surgery.

Staged anesthesia for combined carotid and coronary artery revascularization: a different approach.

OBJECTIVE: Combined coronary artery bypass graft (CABG) surgery and carotid endarterectomy (CEA) are performed in an attempt to reduce the risk of postoperative stroke after CABG surgery in patients with significant or symptomatic carotid artery stenosis. The choice between regional and general anesthesia for CEA is still under debate. Regional anesthesia offers an excellent monitoring technique of the neurologic status of the awake patient during carotid clamping. In an attempt to improve monitoring of the neurologic status and avoid the use of temporary shunting in patients undergoing the combined procedure, a different approach is described combining regional anesthesia for CEA followed immediately by general anesthesia for CABG surgery. DESIGN: Prospective nonrandomized case series. SETTING: University hospital. PARTICIPANTS: Twenty patients scheduled for combined CEA and CABG surgery underwent a "staged" anesthetic approach from January to December 2004. INTERVENTIONS: Pulmonary, femoral artery, and urinary catheters were inserted under local anesthesia. A deep cervical plexus block was then performed and supplemented by a superficial cervical plexus block. The patient was draped for standard combined CEA and CABG surgery. CEA was then performed using standard techniques. Without altering the surgical field, general anesthesia was given and endotracheal intubation performed following the successful CEA. Coronary revascularization was then completed. MEASUREMENTS AND MAIN RESULTS: CEA and CABG surgery were completed successfully in all patients. There was no need for conversion from local to general anesthesia. Endotracheal intubation was easily performed in all patients. There was no hospital mortality in this series. No neurologic events were observed during the CEA. A reversible ischemic stroke, ipsilateral to the CEA, occurred postoperatively on awakening from CABG surgery in 1 patient. CONCLUSIONS: This staged anesthetic approach for combined CABG and CEA surgery is an alternative in this complex subset of patients.

[Thoracic epidural and intrathecal analgesia have similar effects on pain relief and respiratory function after thoracic surgery]. / L'analgesie peridurale thoracique et rachidienne ont des effets comparables sur la douleur et la fonction respiratoire apres chirurgie thoracique.

PURPOSE: To compare in a prospective randomized trial the effects of thoracic epidural infusions of fentanyl (F) and bupivacaine (B) to intrathecal morphine (M) and sufentanil (S) on analgesia and respiratory function following thoracotomy. PATIENTS AND METHODS: 55 patients undergoing an elective postero-lateral thoracotomy were randomly assigned to one of two groups: Group I (n = 27): received intrathecal S (5 microg) and M (0.5 mg) one hour before surgery. Group II (n = 28) received, after induction of anesthesia, an initial dose of 10 to 20 mL of a solution of B 0.25% and F 2 microg.mL(-1) via an epidural thoracic catheter previously inserted between T5 and T8. The same solution was infused during surgery. After surgery, patients received a continuous infusion of B 0.1% and F 2 microg.mL(-1) with a bolus every 15 min if needed. Heart rate (HR), mean arterial pressure (MAP), SpO(2), PaCO(2), respiratory rate (RR), forced expiratory volume in one second, peak expiratory flow rate and forced vital capacity were recorded at different times from the day before surgery till T48 = 48 hr after surgery. Subjective pain was assessed using a 10 cm visual analogue scale (VAS) scoring at rest and during cough. RESULTS: No significant difference was noted between both groups concerning VAS, HR, MAP, SpO(2), PaCO(2) and RR. Variations of the respiratory function tests were identical in both groups. CONCLUSION: This study shows that intrathecal M and S offer analgesia comparable to thoracic epidural infusion of B and F.

Postoperative intravenous iron used alone or in combination with low-dose erythropoietin is not effective for correction of anemia after cardiac surgery.

OBJECTIVES: The aim of this study was to examine whether intravenous iron III-hydroxide sucrose complex (IHSC) used alone was sufficient to provide rapid correction of anemia after cardiac surgery and whether additional stimulation of erythropoiesis is possible by means of a single low dose of recombinant-human erythropoietin (r-HuEPO) administration. DESIGN: Prospective, randomized, double-blind study. SETTING: The study was conducted in a university hospital. PARTICIPANTS: One hundred twenty American Society of Anesthesiologists II or III patients, who underwent elective cardiac surgery using cardiopulmonary bypass and in whom postpump hemoglobin ranged between 7 and 10 g/dL. INTERVENTIONS: Patients were divided into 3 groups: group I = control; group II received postoperative intravenous iron supplementation with an iron III-hydroxide sucrose complex (IHSC); and group III received IV iron and a single dose of r-HuEPO (300 U/kg). MEASUREMENTS AND RESULTS: No significant difference in transfusion needs was observed among the 3 groups (22%, 25%, and 17% of patients transfused in groups I, II, and III, respectively). Hemoglobin levels, reticulocyte counts, and serum ferritin levels were evaluated at different time intervals (until day 30 postoperatively). No side effects because of iron administration were noted in the study. Reticulocyte counts increased rapidly at day 5 (2.24% +/- 1.11%, 1.99% +/- 1.44%, and 3.84% +/- 2.02% in groups I, II, and III, respectively) and decreased after day 15 in the 3 groups. Ferritin levels increased significantly at day 5 in the 2 treated groups (899.33 +/- 321.55 ng/mL in group II, 845.75 +/- 289.96 ng/mL in group III v 463.15 +/- 227.74 ng/mL in group I). In group I, ferritin levels, after a slight elevation on day 5, decreased at day 15 to lower than baseline levels. No significant difference in hemoglobin increase was noted among the 3 groups. CONCLUSION: Postoperative intravenous iron supplementation alone or in combination with a single dose of r-HuEPO (300 U/kg) is not effective in correcting anemia after cardiac surgery.

Postoperative oral amiodarone as prophylaxis against atrial fibrillation after coronary artery surgery.

OBJECTIVE: To assess the prophylactic effect of postoperative oral amiodarone on the incidence and severity of atrial fibrillation (AF) after coronary artery surgery. DESIGN: Prospective, randomized, blinded, controlled study. SETTING: University hospital. PARTICIPANTS: Patients who had coronary artery surgery (n = 200). INTERVENTIONS: Patients in group 1 (n = 100) received oral amiodarone, 15 mg/kg, 4 hours after arrival in the intensive care unit, followed by 7 mg/kg/d until hospital discharge. Patients in group 2 (n = 100) received placebo. MEASUREMENTS AND MAIN RESULTS: Incidence, duration, and recurrence of new episodes of AF and maximal ventricular rate response were recorded from day 0 until hospital discharge. Side effects related to amiodarone and complications induced by new-onset AF were noted. The incidence of new-onset AF (12% v 25%) and maximal ventricular rate response (120 +/- 21 beats/min v 135 +/- 24 beats/min) were significantly lower in the amiodarone group. There were no side effects related to the administration of amiodarone. The incidence of complications induced by AF was comparable between the 2 groups. CONCLUSION: Postoperative prophylactic oral amiodarone after coronary artery surgery is safe and effective in reducing the incidence of new-onset AF and maximal ventricular rate response.