Common Management Strategies

Shivering

Tends to increase arterial PCO2, decrease arterial PO2 and may interfere with ventilation. Treat with meperidine 25-50 mg i.v., increase the propofol infusion or pancuronium 2 mg i.v. if needed. The patient should be warm and not shivering before reversal of neuromuscular blockade.

Fluids

Most patients require additional volume to maintain optimal filling pressures and adequate urine output. During the first 24 h, avoid large volumes of crystalloids in favor of colloids either as pentaspan 500 cc (max. 2000 cc/24 hr) or 5% albumin 500 cc i.v. After 24 h, patients who are extravascularly volume overloaded may benefit from 25% albumin 100 cc i.v., to help mobilize fluid intravascularly. If patients are intravascularly volume depleted with low filling pressures, low urine output and adequate arterial PO2, give a 500 cc volume challenge of normal saline, pentaspan or 5% albumin.

Autotransfusion

Patients are autotransfused their shed mediastinal blood for up to 6 h postoperatively. Exceptions include patients with actively infected bacterial endocarditis, contaminated circuits or unexplained air leaks in the circuit. The reinfused products represent unwashed red cells, activated tissue factors and any residual circulating heparin. This may exacerbate ongoing bleeding but does allow for maintenance of Hb.

Blood Products

Hemoglobin is initially maintained through autotransfusion and packed red blood cells (PRBC) are given for Hb < 7 g/dL. Sick, elderly or patients with impaired ventricular function (grade 4) may benefit from an Hb closer to 10 g/dL, particularly in the setting of borderline hemodynamics. Healthy patients with a low initial Hb, in the absence of ongoing bleeding or instability, will likely hemoconcentrate over the following 24 h and are unlikely to need transfusions. The decision to transfuse requires individual patient assessment. Patients who pre-donated should receive their own whole blood back postoperatively if they are anemic. Administer additional blood products in the face of ongoing bleeding and documented abnormalities (Appendix 8).

Bleeding

Expect some amount of postoperative bleeding, though the rate and total volume lost elicit different responses from individual surgeons. Each surgeon has a different threshold of wanting to be kept informed and the final decision to reexplore. Consider the following abnormal rates of bleeding and inform the staff surgeon:

• bleeding > 100 cc/hr (after first 4 h, max. 1000 cc)

Extubation

Manage early extubation patients according to the CVICU weaning protocol (Appendix 6). Consider T-piecing or an endotracheal ventilation catheter (ETVC) in patients who are known difficult intubation.

Postoperative Pain

In order to facilitate early extubation, patients receive less intraoperative narcotics than in the past. Patients without renal dysfunction, ulcer disease, diabetes or age > 70 receive indomethacin or diclofenac 50-100 mg rectally before extuba-tion. Pre- and postextubation, patients receive intermittent i.v. boluses of either morphine 2-4 mg or demerol 10-25 mg for additional pain relief. Consider patients who are young or demonstrate high narcotic requirements for patient controlled analgesia (PCA). Within 24 h of extubation most patients are managed by oral analgesics Tylenol #3 or equivalent.

Sedation

Patients who are not early extubation candidates are sedated postoperatively with an infusion of narcotics and or benzodiazepines:

• narcotics: morphine at 1-4 mg/h or Fentanyl at 100-200 ug/h

• benzodiazepine: midazolam at 1-3 mg/h

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