76 General Issues in Perioperative Care	615

•Early enteral nutrition should be instituted as soon as permissible. If early enteral nutrition cannot be initiated, parenteral nutrition should be started especially in patients with established malnutrition. Consideration should be given for immunonutrition in patients with cancer surgery (see Chap. 43).

•Proper stress ulcer prophylaxis with H2 blockers should be instituted.

•Maintain normothermia perioperatively to reduce incidence of surgical site infection.

•Frequent point of care blood sugar monitoring, keeping it below 150 mg/dL, and avoiding hypoglycemia are useful in preventing postoperative complications (see Chap. 60).

•Thyroid status should be optimized if necessary with thyroid supplementation in hypothyroid patients. Supplemental corticosteroid should be given to patients with history of chronic use of systemic steroids.

Suggested Reading

1.Silverman DG, Rosenbaum SH. Integrated assessment and consultation for the preoperative patient. Med Clin North Am. 2009;93:963–77.

The article describes a framework for documentation, optimization, risk assessment, and planning, as well as a uniform grading of existing morbidities and anticipated perioperative disturbances, for patients requiring integrated assessment and consultation.

2.Geerts WH, Bergqvist D. Prevention of venous thromboembolism: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest. 2008;133(6 Suppl):381S.

Updated guidelines for perioperative thromboembolic prophylaxis.

3.Halaszynski TM, Juda R. Optimizing postoperative outcomes with efficient preoperative assessment and management. Crit Care Med. 2004;32(4 Suppl):S76–86.

The preoperative visit is also an opportunity to perform directed laboratory testing (as opposed to across the board batteries of tests) and to carefully plan out the continuance, discontinuance, or initiation of medications in the perioperative period. It may also be beneficial to stabilize disorders such as hypertension and, when indicated, initiate preoperative optimization of patients with advanced disease.

Web Site

1.http://www.nice.org.uk

National Institute for Health and Clinical Excellence. Reducing the risk of venous thromboembolism

Specific Issues in Perioperative Care	77

Subhash Todi, Shrikanth Srinivasan,

and Jigeeshu V. Divatia

A 60-year-old male patient with triple-vessel disease with reduced left ventricular function and diabetes mellitus underwent coronary artery bypass graft (CABG) with extracorporeal support. He was transferred to the ICU, and his blood pressure was 90/60 mmHg on epinephrine infusion.

A 50-year-old male patient with road trafÞc accident had undergone an emergency decompressive craniectomy due to an expanding intracerebral hematoma. He had arrived in the ICU postoperatively on the ventilator and was paralyzed. His blood pressure was 110/70 mmHg without any vasopressor support.

A 50-year-old male patient had undergone an emergent thoracotomy and left upper lobe resection due to massive hemoptysis not getting controlled with conventional measures. He had arrived in the ICU ventilated with a saturation of 90% on FiO2 of 0.8.

Due to increasing specialization of intensive care, patients with organ-speciÞc surgery (thoracic, cardiac, neurosurgery) are being managed in dedicated ICUs. As these patients have speciÞc perioperative problems, the intensive care physician taking care of these patients should have a working knowledge of their speciÞc perioperative critical issues and should work in close consultation with the surgical and anesthetic team.

S. Todi, M.D., M.R.C.P. (*)

Critical Care & Emergency, A.M.R.I. Hospital, Kolkata, India e-mail: [e-mail]

S. Srinivasan, M.D., F.N.B.

Critical Care, Medanta, Medicity, New Delhi, India

J.V. Divatia, M.D., F.I.S.C.C.M.

Department of Anaesthesiology, Critical Care and Pain, Tata Memorial Hospital, Mumbai, India

R. Chawla and S. Todi (eds.), ICU Protocols: A stepwise approach,	617
DOI 10.1007/978-81-322-0535-7_77, © Springer India 2012

618	S. Todi et al.

77.1Cardiac Surgery

Traditionally, cardiac surgery has been performed via a median sternotomy incision with the use of a cardiopulmonary bypass (CPB) machine that maintains total body oxygenation and perfusion despite cardioplegia. After CPB is initiated, injection of hyperkalemic cardioplegic solution directly into the coronary circulation produces cardiac standstill. Cardioplegic solution also provides necessary nutrients for myocardial preservation despite the absence of cardiac blood ßow. Traditional surgical approaches are associated with varying degrees of hypothermia, coagulopathy, and hemodilution. Usually the patients need varying period of mechanical ventilation postoperatively.

Minimally invasive surgery (MIS) modiÞes one or more of these techniques to accomplish similar surgical goals through small surgical incisions without CPB (i.e., off-pump), or both. MIS has been shown to reduce blood requirements, length of stay, and resource use.

Step 1: Take handover information from operating room staff

¥Patient identiÞcation details

¥Preoperative details

ÐType of coronary artery disease, valve dysfunction, left ventricular function, and pulmonary hypertension

ÐMedications usedÑantiplatelets, diuretics, angiotensin-converting enzyme inhibitors, statins, and calcium channel blockers

ÐComorbiditiesÑdiabetes, hypertension, peripheral vascular disease, stroke, renal dysfunction, and thyroid status

ÐPreoperative functional capacity

ÐPrevious medical records

¥Operation performed (onor off-pump, arterial, venous graft) and problems encountered

¥Current drug infusions

¥Pacemakers and antiarrhythmic drug information

¥Estimated blood loss, blood and blood product administered, and urine output

¥Intraoperative ßuid balance

¥Antibiotics administered and timing

¥Drains (number, placement)

¥Latest arterial blood gas analysis, hematocrit, blood sugar, and electrolytes

Step 2: Checklist on arrival of the patient (A to I)

¥Airway

ÐThe patient is connected to the ventilator.

ÐNote the size of the tube, position of Þxation at the angle of mouth, and cuff pressure.

¥Breathing

ÐLook for chest movement. Auscultate and conÞrm air entry to both the lungs.

77 Specific Issues in Perioperative Care	619

ÐThe usual initial ventilator setting are as follows:

¥Breath rate of 12Ð15/min

¥FiO2 of 0.6Ð0.8

¥Tidal volume of 6Ð8 mL/kg

¥Depending on arterial blood gas (ABG) report, settings are modiÞed subsequently

¥Circulation

ÐSet up the monitor.

ÐCheck

¥ECG for rate, rhythm, and ST segment changes.

¥Arterial pressure, oxygen saturation.

¥Pulmonary artery pressure/central venous pressureÑmeasure the pulmonary artery wedge pressure (PAWP), cardiac output (CO), and systemic vascular resistance.

¥Temperature probeÑif temperature is less than 37¡C, warming blanket should be placed.

¥Low urine output, acidosis, and peripheral examination are not a good indicator of the low perfusion state in these patients, and direct measurement of cardiac output is preferable in unstable patients.

¥Drugs

ÐVasoactive drugsÑcheck infusion pumps labeled with proper drug dosing and dilutions, and calculate infusion rate (mcg/kg/min).

¥Electrolytes

ÐMaintain K+ at 4Ð4.5 mmol/L.

ÐMaintain Mg+ at 0.8Ð1.5 mmol/L.

¥Fluids

ÐIntravenous maintenance ßuids (crystalloid) are started at the rate of 1Ð1.5 mL/ kg/h.

ÐIntermittent colloid to maintain pulmonary capillary wedge pressure at 8Ð15 mmHg.

ÐBlood transfusion to keep hematocrit at more than 25Ð30%.

ÐMaintain urine output at 0.5Ð1.0 mL/kg/h.

¥Glucose control

ÐTight glycemic control (TGC) (80Ð110 mg/dL) is helpful in this group of patients but runs the risk of hypoglycemia, and therefore close monitoring of blood sugar should be done if TGC policy is adopted, otherwise blood sugar should be kept below 150 mg/dL.

ÐIn diabetic and hyperglycemic patients, dextrose infusions should be neutralized with insulin.

¥Hemorrhage

ÐCauses of bleeding after cardiac surgery include:

¥Inadequate surgical hemostasis

¥Inadequate platelet number or function

¥Inadequate reversal of heparin

¥Dilutional coagulopathy

620	S. Todi et al.

¥Heparin rebound

¥Hypothermia

ÐChest tubes are connected to underwater seal. If bleeding is signiÞcant, and coagulation proÞle is normal, the patient needs to go back to the operation theater for re-exploration.

ÐIn adult patients, bleeding is signiÞcant when:

¥>400 ml for 1 h

¥>300 ml/hr for 2 h

¥>200 ml/hr for 3 consecutive hours

¥>100 ml/hr for 4 consecutive hours

ÐCPB may induce coagulation abnormalities in these patients and this may be the cause of excessive bleeding.

ÐAnticoagulation protocols:

¥Valve surgery: Anticoagulation is maintained with intravenous heparin. With mechanical valve prosthesis, oral anticoagulants (warfarin) should be started as soon as oral intake is permitted (48Ð72 h). Initial overlapping therapy of warfarin with heparin is recommended for 48Ð72 h to prevent warfarin-induced hypercoagulability.

ÐCoronary artery bypass graftÑaspirin/clopidogrel in low doses is started as soon as oral feeds are started.

ÐReverse heparin effect by protamine if needed.

¥Investigations

ÐInvestigations should be done within 30 min of arrival.

¥ECG

¥ABG

¥Hct and electrolytes

¥Chest X-raysÑlook for pneumothorax, hemothorax, position of endotracheal tubes, chest tubes, intravascular catheters, pacing wires, lung inÞltrates, and cardiac size.

¥Coagulation proÞle (Prothrombin Time (PT), APTT, ACT)

¥Thromboelastogram (if available)

Step 3: Take general care of the patients

¥PositionÑhead end elevated at 30Ð45¡

¥Neurological assessment

ÐAwake and obeying commands

ÐAble to move all four limbs

Step 4: Look for and manage specific complications

¥Arrhythmias are common, occurring in 25Ð60% of patients. Advanced age, prior atrial Þbrillation, and combined bypass graft/valve surgery are risk factors. Exclude precipitating causes such as hypoxia, hypercarbia, lack of analgesia, and electrolyte imbalance (hypokalemia and hypomagnesemia) before instituting antiarrhythmics. Treat arrhythmias only if hemodynamically signiÞcant. Arrhythmias with signs of ischemia may signal perioperative

77 Specific Issues in Perioperative Care	621

infarction, inadequate revascularization, and blocked graft requiring urgent reoperation.

¥Low-output state: Urgent echocardiogram should be performed to exclude pericardial tamponade. Assess left ventricular function and volume status.

ÐIn cases of pericardial tamponade, the patient should be re-explored with evacuation of hematoma. The chest may have to be reopened in the ICU if tamponade is sudden and severe, leading to hemodynamic collapse.

ÐIn low-output states, rewarming should be gradual. Decrease metabolic demand by proper analgesia, sedation, and muscle relaxant to decrease shivering. Optimize preload by judicious use of ßuid and blood (keep hematocrit 0.25Ð0.35) under monitoring. Add inotropes and if blood pressure permits decrease afterload by adding vasodilators. Due to ischemia reperfusion injury, a phase of stunned myocardium persists, which usually resolves over a variable period and is helped by inotropic support. This phenomenon should be distinguished from ongoing ischemia where inotropic support is detrimental.

ÐAn intra-aortic balloon pump is sometimes used to maintain coronary perfusion in low-output states (see Chap. 101).

¥Postoperative hypertension: It is usually transient but may lead to left ventricular dysfunction, myocardial ischemia, graft and suture line disruption, and increased bleeding. Ensure proper analgesia and sedation. Parenteral vasodilators like nitrates may be used.

¥Atelectasis: Ensure early mobilization and incentive spirometry.

¥Fluid overload: Maintain strict inputÐoutput chart. Low-dose diuretics may be needed.

¥Myocardial ischemia or infarction may be difÞcult to diagnose in postoperative settings as ECG, echocardiogram, and cardiac enzyme may not be able to detect early ischemia and may be false positive.

¥Right ventricular dysfunction: This may occur due to pulmonary hypertension or ischemic reperfusion injury. It presents with low cardiac output syndrome, which may initially be volume responsive. The patient has high right-sided Þlling pressure disproportionate to left-sided pressure, low cardiac index, and low systemic blood pressure. It is managed by maintaining sinus rhythm, appropriate heart rate (by pacing if necessary), optimizing preload, reducing afterload (with pulmonary vasodilators such as inhaled nitric oxide or epoprostenol infusion), inotropic support, and mechanical assist devices if needed.

¥Significant neurological deficit: It occurs in 2Ð3% of patients undergoing coronary artery bypass surgery. This can present as stroke, transient ischemic attack, or global cerebral dysfunction.

Step 5: Take a fast-track approach to extubation

¥The increasing use of off-pump surgery, short anesthesia, and lower doses of sedatives has led to early liberation of patients from ventilators. Many patients can be extubated within 4 h of surgery or even in the operating room.

¥The key to a successful fast-track program is proper patient selection, high-level supervision by a disciplined team, and absence of surgical complications.