Clinical pearls in perioperative medicine.

Hospital Practice

ISSN: 2154-8331 (Print) 2377-1003 (Online) Journal homepage: http://www.tandfonline.com/loi/ihop20

Clinical Pearls in Perioperative Medicine Karen F. Mauck MD, MSc, Scott C. Litin MD & John B. Bundrick MD To cite this article: Karen F. Mauck MD, MSc, Scott C. Litin MD & John B. Bundrick MD (2014) Clinical Pearls in Perioperative Medicine, Hospital Practice, 42:1, 23-30 To link to this article: http://dx.doi.org/10.3810/hp.2014.02.1088

Published online: 13 Mar 2015.

Submit your article to this journal

Article views: 3

View related articles

View Crossmark data

Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=ihop20 Download by: [Central Michigan University]

Date: 05 October 2015, At: 09:15

C l i n i c a l F o c u s : H o s p i ta l A d m i s s i o n s , l at e s t P r o t o c o l s , p e r i o p e r at i v e M e d i c i n c e , a n d t r a n s i t i o n s o f c a r e

Clinical Pearls in Perioperative Medicine DOI: 10.3810/hp.2014.02.1088

Downloaded by [Central Michigan University] at 09:15 05 October 2015

Karen F. Mauck, MD, MSc 1 Scott C. Litin, MD 1 John B. Bundrick, MD 1 1 Division of General Internal Medicine, Department of Medicine, Mayo Clinic, Rochester, MN

Abstract: At the 2001 annual meeting of the American College of Physicians (ACP), a new and innovative teaching format, the “Clinical Pearls” session, was introduced. Clinical Pearls sessions were designed to teach physicians using clinical cases. The session format involves specialty speakers presenting a number of short cases to a physician audience. Each case is followed by a multiple-choice question, answered by each attendee using an electronic audienceresponse system. After a summary of the answer distribution is shown, the correct answer is displayed and the speaker discusses important teaching points and clarifies why one answer is most clinically appropriate. Each case presentation ends with 1 or 2 “Clinical Pearls,” defined as a practical teaching point, supported by the literature, and generally not well known to most internists. The Clinical Pearls sessions are consistently one the most popular and well attended sessions at the American College of Physicians’ national meeting each year. Herein, we present the Clinical Pearls in Perioperative Medicine, presented at the ACP National Meeting in San Francisco, California, April 11‒13, 2013. Keywords: perioperative management; preoperative evaluation; postoperative complications; perioperative medicine; preoperative testing

Introduction

Clinical Pearls is one of the most well-attended sessions offered each year at the American College of Physicians national meeting. The teaching format is popular because it provides an opportunity for interactive learning where clinicians can problem-solve by reviewing a short patient vignette, followed by a clinical question, with the opportunity to respond using audience-response technology. A summary of audience responses is displayed, followed by discussion. Finally a clinical pearl is presented, defined as a concise and practical teaching point, supported by the literature but not well known to many clinicians. “Clinical Pearls in Perioperative Medicine” was presented at the 2013 American College of Physicians annual meeting, April 11‒13, 2013, San Francisco, CA, and is reproduced herein.

Case 1 Correspondence: Karen F. Mauck, MD, MSc, Division of General Internal Medicine, Department of Medicine, Mayo Clinic, 200 1st Street SW, Rochester MN 55905. Tel: 507-284-2511 Fax: 507-284-5370 E-mail: [email protected]

You are asked to see a 72-year-old woman currently hospitalized after repair of a left hip fracture 2 days ago. Her past medical history is significant for coronary artery disease (CAD) for which she had coronary artery bypass grafting 5 years ago. Her last cardiac evaluation, performed last year, revealed a preserved ejection fraction. The patient also has a history of hypertension, hyperlipidemia, and chronic kidney disease (CKD), stage 3. Her medications include lisinopril 40 mg daily, metoprolol 25 mg twice daily, low-dose aspirin daily, atorvastatin 20 mg daily, dalteparin 5000 units subcutaneously daily, calcium, and vitamin D.

© Hospital Practice, Volume 42, Issue 1, February 2014, ISSN – 2154-8331 ResearchSHARE®: www.research-share.com • Permissions: [email protected] • Reprints: [email protected] Warning: No duplication rights exist for this journal. Only JTE Multimedia, LLC holds rights to this publication. Please contact the publisher directly with any queries.

03_Mauck.indd 23

23

1/31/14 5:13 PM


Mauck et al

Her past surgical history is significant for a right total knee arthroplasty 3 weeks ago and a left total knee arthroplasty 4 months ago. In reviewing her hospital record, you note that she underwent operative repair of the hip fracture with , 250 mL of blood loss. On postoperative day 2, she is feeling well and is tolerating a regular diet and physical therapy. She denies shortness of breath, angina, or lightheadedness. On physical examination, her blood pressure is 135/75 mm Hg, pulse is 72 beats per minute, and regular; her temperature is 38.2°C. The surgical wound is intact with no hematoma. Her laboratory tests reveal a serum creatinine level of 1.5 mg/dL (her baseline); hemoglobin level is 8.2 g/dL; the platelet and white blood cell counts are within normal limits. Given her history of CAD and significant anemia, you consider blood transfusion. What should you recommend at this time? A. Transfuse to a hemoglobin goal of 10 g/dL B. Transfuse to a hemoglobin goal of 9 g/dL C. Transfuse to a hemoglobin goal of 8.5 g/dL D. Transfuse patient only if she develops symptoms of anemia Answer: D. Transfuse patient only if she develops symptoms of anemia. Discussion: The optimal hemoglobin level associated with the least morbidity and mortality for the surgical patient with cardiac disease has not been well established in the medical literature. In the past, observational evidence suggested that a hemoglobin level of . 10 g/dL was optimal, however, emerging data from more recent clinic trials suggest a more restrictive strategy is preferable. A multicenter, randomized, controlled trial of liberal versus restrictive transfusion strategies in . 2000 elderly patients (aged $ 65 years) with hip fracture and cardiac disease (or risk factors for cardiac disease), helped to shed light on this issue.1 In the study, patients in the restrictive transfusion group were given red blood cell transfusion if they developed signs or symptoms of anemia or at physician discretion if hemoglobin level dropped to , 8 g/dL. Patients in the liberal transfusion group were given red cell transfusion to keep the hemoglobin level . 10 g/dL. There was no difference in mortality, myocardial infarction [MI], unstable angina or ability to walk independently between the 2 groups at 60 days. Because red cell transfusion is not without associated risk,2 a restrictive transfusion strategy in this patient population seems to be the best option. Clinical Pearl: In elderly patients (aged $ 65 years) with cardiac disease, transfusion in the postoperative setting 24

03_Mauck.indd 24

should be based on symptoms or signs rather than a particular hemoglobin level.

Case 2

You are asked to provide preoperative risk assessment for a 70-year-old woman who is scheduled to undergo elective resection of a lipoma on her upper back. She has a history of type 2 diabetes mellitus (T2DM), hypertension, and degenerative joint disease. She underwent total knee arthroplasty 1 year ago without complications. She is able to ride a stationary bike for 30 minutes daily and performs all activities of daily living without limitation. Her medications include metformin 500 mg twice daily, amlodipine 10 mg daily, low-dose aspirin daily, and a multivitamin. She denies alcohol or tobacco use. Review of symptoms is negative. A preoperative electrocardiogram (ECG), performed 1 year ago, was normal. She had laboratory testing 4 months ago and at that time her blood creatinine level was 1.2 mg/ dL, her complete blood count and electrolytes were within normal ranges, and her glycosylated hemoglobin (HbA1c) level was 7.1%. What preoperative testing should you recommend prior to her lipoma resection surgery? A. ECG B. Creatinine C. ECG and creatinine D. Creatinine and electrolytes E. No additional testing Answer: E. No additional testing. Discussion: Routine preoperative testing can result in unnecessary costs and potential surgical delay. All testing should be directed by the clinical history and physical examination and should not be performed unless there is a clear clinical indication. Clinical practice guidelines can be helpful to direct the clinician regarding best practice. The American College of Cardiology/American Heart Association (ACC/AHA) guidelines on perioperative cardiovascular evaluation3 suggest that an ECG is not useful in asymptomatic patients undergoing low-risk procedures; rather, a preoperative ECG is recommended in patients with $ 1 clinical risk factor (known CAD, history of heart failure, diabetes mellitus requiring insulin, history of cerebrovascular disease, or a serum creatinine level . 2 mg/dL) who require vascular surgical procedures or in patients with atherosclerotic cardiovascular disease who require intermediate-risk procedures. The patient in the presented case had no clinical risk factors, was undergoing a low-risk surgical procedure,


1/31/14 5:13 PM


Clinical Pearls in Perioperative Medicine

and had a normal ECG 1 year ago. Repeating the ECG at this time would not be indicated. Laboratory tests have limited utility when attempting to predict adverse perioperative outcomes for the patient. There are guidelines available that make recommendations regarding preoperative laboratory testing, all of which are based on low-level evidence.4 Most guidelines suggest that preoperative testing of electrolytes and creatinine level should be directed by elements of the patient history that would increase the likelihood of finding an abnormality of clinical significance. Historical features, such as hypertension, heart failure, CKD, complicated diabetes mellitus, liver disease, and certain medications, such as diuretics, angiotensinconverting enzyme inhibitors, angiotensin receptor blockers, nonsteroidal anti-inflammatory drugs, and digoxin, should drive the decision to review electrolytes and creatinine level. In our patient, although she does have a history of hypertension, she had creatinine and electrolyte measurements in the recent past and is not taking any medications that affect renal function. Repeat electrolyte and creatinine measurement would not likely reveal a significant change. In this patient, no additional testing is necessary preoperatively. Clinical Pearl: Preoperative testing needs to be individualized based on the patient’s clinical condition and findings from the history and physical examination.

Case 3

A 76-year-old man is seen for preoperative risk assessment prior to hip fracture repair. His health has been good and he has not seen a physician in 15 years. He is asymptomatic from a cardiac standpoint and has no significant comorbidities. He has poor functional capacity due to severe hip degenerative joint disease; he uses a cane to ambulate. Physical examination of the heart reveals a normal apical impulse, a 3/6 systolic murmur heard best over the right upper sternal border, which radiates to the carotids and to the right clavicle. The murmur is mid-peaking, and a single, second heart sound is appreciated, but it does not seem to be diminished. There is no delay in the carotid upstrokes, but the patient’s body habitus limits your ability to assess for a decrease in carotid amplitude or jugular venous distention. The lung exam is clear and no lower extremity edema is noted. His ECG reveals normal sinus rhythm with minimal voltage criteria for left ventricular hypertrophy, but is otherwise normal. What is the most appropriate next step? A. Proceed with surgery

B. Postpone the surgical procedure until transthoracic echocardiography can be done C. Postpone the surgical procedure until dobutamine stress echocardiography can be done D. Postpone the surgical procedure until a cardiology consultation can be done Answer: B. Postpone the surgical procedure until transthoracic echocardiography can be done. Discussion: The patient has asymptomatic aortic stenosis, but his poor functional capacity may be masking symptoms. Some features of his physical exam are suggestive that the patient may indeed have significant aortic stenosis. Typical physical examination findings indicative of severe aortic stenosis are a sustained apical impulse, a mid-to-late-peaking and prolonged systolic murmur, a delayed and/or diminished carotid upstroke, and an absent or diminished second heart sound.5 In general, physical examination findings correlate with severity of aortic stenosis; however, sometimes the physical examination findings are limited by the experience of the clinician and coexisting patient conditions that may affect how these findings are interpreted.6 The audible characteristics of the murmur of aortic stenosis are determined by the velocity and direction of the jet, but are also affected by the presence of post-stenotic aortic dilation and variable transmission through the chest wall. The timing of the peak-murmur intensity can be affected by the presence of coexisting aortic insufficiency. Aortic regurgitation frequently coexists with aortic stenosis and is associated with backward flow of blood during diastole from the aorta into the left ventricle. The resulting increase in left ventricular volume ejected through the aortic valve occurs earlier in systole and can potentially obscure the impact of significant aortic stenosis on the timing of the murmur. Coexisting hypertension and atherosclerosis can result in a brisk carotid upstroke with an early peak and normal amplitude due to increased vessel wall stiffness, even when severe aortic stenosis is present. The intensity and splitting of the second heart sound can be affected by poor sound transmission, concomitant mitral regurgitation, pulmonary hypertension, or a ventricular conduction delay. The goal is to reliably exclude severe valvular obstruction because this could adversely impact patient perioperative outcome.7 Unfortunately, none of the physical examination findings are sensitive enough to reliably rule out severe aortic stenosis, and therefore his surgery should be postponed until transthoracic echocardiography can be done. The patient does not meet the criteria for noninvasive testing outlined in the ACC/AHA guidelines on perioperative cardiovascular evalu-


03_Mauck.indd 25

25

1/31/14 5:13 PM

Mauck et al

ation based on his history (his revised cardiac risk index is 0),3 therefore, a dobutamine stress echocardiogram would not be indicated. Similarly, a cardiology consultation is likely not needed unless results from the transthoracic echocardiogram indicate the presence of severe aortic stenosis. Clinical Pearl: Severe aortic stenosis cannot reliably be ruled out by physical examination findings alone in most cases.


Case 4

A 54-year-old woman is seen on postoperative day 1 after a hemicolectomy for colon cancer, and you are consulted for recommendations for deep vein thrombosis (DVT) prophylaxis. The patient has a history of DVT 20 years ago. She has stage 4 CKD; her baseline creatinine level is 2.3 mg/dL. Her surgical procedure went well, with no complications or significant bleeding. The physical examination is normal. Her surgical wound is intact with no evidence of hematoma. An epidural catheter is in place for pain control. Intermittent pneumatic compression (IPC) devices are in place on both lower extremities. Her laboratory tests reveal a hemoglobin level of 10 g/dL, a platelet count of 200 000, and a creatinine level of 2.7 mg/dL. What should you recommend regarding DVT prophylaxis for this patient? A. IPC devices alone B. IPC devices plus unfractionated heparin (UH) 5000 units subcutaneously (SC) 3 times daily beginning now C. IPC devices plus UH 5000 units SC 3 times daily beginning after the epidural catheter is removed D. IPC devices plus dalteparin 5000 units SC daily after the epidural catheter is removed. Answer: C. IPC devices plus UH 5000 units SC 3 times daily beginning after the epidural catheter is removed. Discussion: The patient is at high risk for perioperative DVT. Her Caprini score8 is 8 (1 point for age, 2 points for malignancy, 2 points for major surgery, 3 points for history of DVT), which is associated with a very high risk of venous thromboembolism (VTE) postoperatively. Her bleeding risk is modestly increased due to renal failure, malignancy, and the presence of an epidural catheter. The 9th edition of the American College of Chest Physicians guidelines on antithrombotic therapy and prevention of thrombosis9 recommend that patients undergoing general and abdominal‒pelvic surgery, who are high risk for VTE (Caprini score, $ 5), and who are not at high risk for major bleeding complications, 26

03_Mauck.indd 26

should receive pharmacologic prophylaxis with low molecular weight heparin (LMWH) or low-dose UH in addition to mechanical prophylaxis. In patients with cancer, extended duration pharmacologic prophylaxis with LMWH is recommended for 4 weeks. The presence of the epidural catheter should give one pause when considering pharmacologic prophylaxis and indeed, there is a black box warning regarding the risk of epidural and spinal hematoma when LMWH and heparinoids are used in patients who have neuraxial interventions.10,11 It is best to wait a minimum of $ 2 hours after the catheter is removed before initiating heparin products. This patient also has significant renal insufficiency, which can increase her risk for significant bleeding with the use of LMWH. The package insert for dalteparin recommends that if the drug is used in cancer patients with a creatinine clearance , 30 mL/min, anti‒factor-Xa (anti-Xa) blood levels should be monitored.12 Given the patient’s high risk of DVT, modest risk of bleeding, significant renal insufficiency, and use of an epidural catheter, the best option would be for her to continue with IPC devices for now and initiate UH after the epidural catheter is removed. Clinical Pearl: Postoperative prophylaxis for DVT needs to be individualized based on patient comorbidities, DVT risk, and bleeding risk.

Case 5

A 66-year-old woman is scheduled for a total abdominal hysterectomy, oophorectomy, and resection of omental metastasis for treatment of ovarian cancer. You are asked to see her for a preoperative evaluation. Her past medical history is significant for hypothyroidism treated with levothyroxine and a history of obstructive sleep apnea (OSA), diagnosed 4 years ago with an overnight sleep study. She was not able to tolerate the continuous positive airway pressure (CPAP) device and no alternative treatment options were explored at that time. She has since lost about 20 kg. Her only medication at this time is levothyroxine. Recent laboratory testing revealed normal thyroid testing; results from complete blood count, lipid panel, and creatinine level were all within normal limits. Her ECG and chest radiograph were also normal. Exam: Her body mass index is 31 kg/m2. Her blood pressure is 140/88 mm Hg and her pulse is 60 beats per minute and regular. Examination of her posterior oropharynx shows a Mallampati classification of 3, which is associated with a more difficult intubation and higher risk of OSA. The rest of her examination is otherwise normal.


1/31/14 5:13 PM



What should you advise regarding her OSA perioperatively? A. Postpone surgery to obtain a formal sleep study for CPAP initiation B. Recommend the use of a spinal anesthetic C. Initiate auto-titrating CPAP in the recovery room D. Postoperative monitoring with centrally monitored pulse oximetry Answer: D. Postoperative monitoring with centrally monitored pulse oximetry. Discussion: The patient carries a diagnosis of untreated OSA. She has lost significant weight since the diagnosis was made, however, we do not know the initial severity of her OSA and if it is still an issue. Patients with OSA not only have a higher rate of postoperative pulmonary complications such as reintubation, hypercapnia, and oxygen desaturation, but also have a higher rate of cardiac arrhythmias and myocardial injury in the perioperative period.13 These complications can lead to unplanned transfers to the intensive care unit and prolonged hospital stays postoperatively. Anesthetics significantly blunt the sleep arousal mechanism that normally occurs with OSA and many anesthetic and sedating agents reduce pharyngeal muscle tone, depress respirations, and the ventilatory response to carbon dioxide. These effects can linger for several days after surgery, which puts the patient at significant risk postoperatively, especially within the first 24 to 48 hours.14 Postoperative management for this patient would include keeping the patient in a semi-upright position, optimizing postoperative pain control to limit opioid analgesics (using regional anesthetics, non-opioid analgesics, and analgesic adjuncts as appropriate), and continuous pulse oximetry monitoring should be considered for patients who are high risk.14 High-risk patients can be identified by using a sleep apnea clinical scoring system in combination with postanesthesia clinical findings.15 Supplemental oxygen use is recommended postoperatively in patients with known or suspected OSA, however, its use may increase the duration of apneic episodes and may hinder detection of transient apnea and hypoventilation. Certainly for patients who are considering elective surgery, postponement of the surgical procedure to evaluate and treat OSA would be reasonable; however, this may not be the best approach for this patient, who is scheduled for a more urgent procedure. While regional anesthetic techniques may reduce the risk of obstructive symptoms postoperatively, a spinal anesthetic would not be appropriate in this patient, who will likely require a prolonged and complicated surgical procedure. It is best to leave the

anesthesia recommendations to the anesthesiologist. If the patient does develop evidence of desaturation, auto-titrating CPAP can be used; however, it would not be appropriate to automatically initiate it in the recovery room if she has no evidence of obstruction.16 Clinical Pearl: Continuous pulse oximetry monitoring postoperatively is recommended for high-risk patients with suspected OSA.

Case 6

A 73-year-old woman is scheduled for a left femoral-topopliteal arterial bypass graft to treat claudication. You are asked to see her for preoperative risk assessment. She has T2DM, which is well controlled on oral agents; mild CKD, with a baseline creatinine level of 1.4 mg/dL; and a history of CAD. She had an inferior MI 5 years ago. She did not have revascularization at that time and has done well with medical management. Her functional capacity is limited due to the claudication; she is able to walk less than a block, but does not experience angina or dyspnea, only claudication. On examination, her blood pressure is 140/80 mm Hg. Her pulse is 74 beats per minute and regular. The rest of the physical examination is noncontributory, other than noting diminished pulses in her left lower extremity. Her medications include lisinopril, hydrochlorothiazide, aspirin, atorvastatin, metoprolol, metformin, and glipizide. An ECG reveals normal sinus rhythm with Q waves in lead 3 and a#VF with non-specific ST-T wave abnormalities. A dipyridamole-sestamibi cardiac stress test shows a fixed inferior wall defect with a small amount of peri-infarct reversibility. The ischemia involves , 5% of the myocardium. The left ventricular ejection fraction is estimated to be 50%. What should you recommend? A. Proceed with surgery, recommending adequate β-blockade and blood pressure control in the perioperative period B. Postpone surgery, refer the patient for dobutamine stress echocardiography C. Postpone the surgery, refer the patient for coronary angiography, and if indicated, revascularization D. Cancellation of the surgery because of high surgical risk Answer: A. Proceed with surgery, recommending adequate β-blockade and blood pressure control in the perioperative period. Discussion: This patient has a history of an inferior MI and her ECG and myocardial perfusion imaging study confirm this. Most of the defect in the inferior wall is fixed,


03_Mauck.indd 27

27

1/31/14 5:13 PM


Mauck et al

indicating non-functioning myocardium. However, there is evidence of a small amount of reversibility around the infarcted area. Because the extent of reversibility involves such a small area, it is likely not to increase the patient’s risk of postoperative adverse cardiac outcomes. A meta-analysis of semiquantitative dipyridamole perfusion imaging for cardiac-risk assessment prior to noncardiac vascular surgery found that patients with reversibility of . 20% of the myocardial segments had increasing risk of postoperative complications. However, patients with reversible defects in , 20% of the myocardial segments did not have an increased risk of perioperative cardiac complications.17 Obtaining another noninvasive stress test is unlikely to change management in this patient, so dobutamine stress echocardiography would not be indicated. Similarly, coronary angiography is also not indicated. The indications for preoperative coronary angiography are similar to those in the nonoperative setting. Recently published appropriate-use criteria for diagnostic cardiac catheterization have suggested that cardiac catheterization would be inappropriate in a patient with known previous obstructive coronary disease who is medically managed, asymptomatic, and has low-risk noninvasive study findings.18 Cancellation of the surgery based on high surgical risk in the patient would also be inappropriate. The estimated risk of postoperative MI or cardiac death would be acceptable to proceed without any additional testing. It is therefore most appropriate to proceed with the planned surgical procedure with the appropriate risk-reduction strategies of heart rate and blood pressure control.19 Clinical Pearl: Patients with low-risk findings on noninvasive stress testing do not have an increased risk of postoperative adverse cardiac outcomes and do not need additional testing.

Case 7

You are asked to see a 54-year-old man for preoperative risk assessment. He is being considered for repair of an umbilical hernia. He has been told in the past that he has liver problems secondary to alcohol abuse and chronic hepatitis C, but he has not sought medical care in several years. He denies the use of alcohol for the last 5 years. He takes no medications. On examination, his blood pressure is 105/77 mm Hg, his pulse is 92 beats per minute, and regular. He is alert and oriented. He is noted to have mild scleral icterus, gynecomastia, and spider angiomata. His abdomen is protuberant with a large umbilical hernia and possible ascites; no hepatomegaly or splenomegaly is noted. His neurologic examination is normal. 28

03_Mauck.indd 28

His laboratory testing reveals a sodium level of 133 mmol/L, creatinine level of 1.9 mg/dL, total bilirubin level of 2.3 mg/dL, INR of 2.2, albumin level of 2.7 g/dL, and a platelet count of 110 000. An ultrasound of the abdomen confirms a cirrhotic liver with moderate ascites. His Child-Turcotte-Pugh (CTP) score is 11 (class C); his Model for End-Stage Liver Disease (MELD) score is 25. What should you recommend? A. Recommend fresh frozen plasma (FFP) and proceed with surgery B. Recommend oral vitamin K for 3 days and proceed with surgery C. Refer patient for consideration of a Transjugular Intrahepatic Portosystemic Shunt (TIPS) prior to surgery D. Refer patient for liver transplant evaluation prior to surgery Answer: D. Refer patient for liver transplant evaluation prior to surgery. Discussion: Surgical procedures in patients with cirrhotic liver disease are associated with significant risk of morbidity and mortality. This risk is related to multiple factors, including an increased propensity to infection, coagulopathy, hypoxia, hypotension, encephalopathy, difficulty with fluid management, organ failure, and altered wound healing. Perioperative mortality can be estimated with the use of patient CTP classification and MELD score.20 Both scoring systems have been good predictors of patient 30-day mortality postoperatively. The CTP classification system incorporates the presence of encephalopathy and ascites, in addition to laboratory values, such as bilirubin, albumin and INR. The general surgical 30-day mortality estimates are 10% for CTP class A, 31% for CTP class B, and 76% for CTP class C.20 The MELD score, which is considered more precise, is calculated using the INR, serum total bilirubin, and serum creatinine concentration.20 The 30-day mortality rises linearly by 1% for each point in the MELD score , 20 and 2% for higher scores.21 For this patient with a MELD score of 25, his 30-day postoperative mortality is estimated to be 37%, which would be excessive risk for an elective surgical procedure for umbilical hernia repair, a surgery that would otherwise be low risk in a patient without liver disease. The patient should not have elective surgery at this time; he should be referred for evaluation for liver transplantation.22,23 As a rule of thumb, it has been suggested that patients with a MELD score of # 10 can undergo elective surgery; patients with a score of 10 to 15 can proceed with surgery with caution


1/31/14 5:13 PM



(will still need medical optimization and close monitoring postoperatively); patients with a score . 15 should avoid elective surgery.23 Although some data have suggested potential benefit of TIPS procedure prior to specific surgeries in patients with portal hypertension,24 existing guidelines do not recommend the use of TIPS preoperatively given limited data.25 The patient does have a coagulopathy, which might respond somewhat to the use of vitamin K (or transiently to FFP), however, improving his INR somewhat would not reduce overall surgical risk significantly. Clinical Pearl: Patients with significant liver disease should be referred for liver transplant evaluation prior to elective surgery.

Case 8

You are consulted by the orthopedic surgical service to see a 72-year-old-male who is 12 hours post-op from a bipolar hemiarthroplasty to treat a right hip fracture. His urine output has diminished and appears concentrated. You are asked to help manage his fluid balance. His past medical history is significant for hypertension treated with amlodipine; he is otherwise healthy. The intraoperative record reports 420 cc of blood loss and 3.8 liters of lactated ringers given during the surgical procedure. His weight is currently 72.9 kg, which is increased 2.9 kg from admission. He is eating and drinking and sitting up in bed. His urine output has averaged 15 mL/hr since he came to the surgical unit from the recovery room. Physical examination reveals a blood pressure of 125/72 mm Hg, pulse of 76 beats per minute and regular, unlabored respirations at 14 per minute, oxygen saturation on 1 L of oxygen is 98%. He is alert, his tongue is moist; his heart exam is normal with jugular venous pressure noted 2 cm above the clavicle when the patient is sitting at a 30° angle. His lungs are clear. He has 3 mm of pitting edema on the right mid-tibial region and 1 mm on the left mid-tibial region. Review of his laboratory testing reveals the values in Table 1. Table 1. Laboratory Testing Results for Case 8 Patient Component

Preop value

Current value

Hemoglobin

13.5 g/dL

11.2 g/dL

Sodium

137 mmol/L

133 mmol/L

Potassium

4.6 mmol/L

4.1 mmol/L

Creatinine

1.0 mg/dL

1.0 mg/dL

How would you manage this patient? A. Give a 500 cc intravenous (IV) bolus of normal saline B. Give 25 grams of IV albumin C. Give 20 mg of IV furosemide D. Continued observation of volume status Answer: D. Continued observation of volume status. Discussion: Managing fluid balance is challenging in the perioperative period. Understanding the physiologic changes that occur in the surgical setting is critical to knowing how best to manage fluid balance postoperatively. Several stress hormones act to conserve fluid in the perioperative setting and this hormonal response is proportional to the invasiveness of the surgical procedure and the amount of tissue disruption that occurs.26 Increases in adrenocorticotropic hormone (ACTH), cortisol, and plasma renin-aldosterone are all fairly short lived postoperatively, with peak effect within the first 24 hours. However, increases in anti-diuretic hormone (ADH) and interleukin (IL)-6 secretion may linger for $ 3 days. Due to the fluid-conserving effect of these hormones, oliguria with concentrated urine is very common intraoperatively and in the first 12 to 24 hours after surgery, however, there is no correlation with postoperative renal failure in this context.27 Generally, by 48 to 72 hours postoperatively, the patient will begin to auto-diurese the excess fluid. In most cases, patients without significant underlying cardiac, pulmonary, or renal disease, who are given no significant restriction to fluids, will handle this fluid excess without the need for additional intervention. In patients with underlying medical comorbidities or in patients where more invasive surgery with increasing blood losses and greater alterations in fluid balance are expected, fluid therapy should be goal directed under careful and frequent assessment of fluid balance.28 Generally, this means giving maintenance IV fluids and replacement of insensible losses as appropriate until auto-diuresis commences at 48 to 72 hours. Some of the typical physical examination signs of hypovolemia are not reliable indicators of a reduced intravascular fluid status in the postoperative period. Pulse and blood pressure can be altered by anesthetic agents, drugs, and the body’s stress response to surgery. However, for most patients, thirst, dry mucous membranes, and reduced urinary output (beyond the first 24 hours) are still important predictors of hypovolemia in the postoperative clinical setting when central monitoring is either not available or not indicated.29 In this patient, physical examination findings are not concerning for volume depletion or volume overload; his tongue is moist, his jugular venous pressure is not elevated, and his


03_Mauck.indd 29

29

1/31/14 5:13 PM

Mauck et al

lungs are clear. There is no need to provide fluids or diuresis in this setting. Continued observation of volume status is the most appropriate management at this time. Clinical Pearl: Physiologic changes due to the stress response to surgery cause fluid retention in the perioperative period that is proportional to the invasiveness of the surgical procedure. Most patients without significant comorbidities will auto-diurese this fluid excess within 72 hours without the need for additional intervention.

Conflict of Interest Statement


Karen F. Mauck, MD, MSc, Scott C. Litin, MD, and John B. Bundrick, MD, disclose no conflicts of interest.

References 1. Carson JL, Terrin ML, Noveck H, et al; FOCUS Investigators. Liberal or restrictive transfusion in high-risk patients after hip surgery. N Engl J Med. 2011;365(26):2453–2462. 2. Chatterjee S, Wetterslev J, Sharma A, Lichstein E, Mukherjee D. Association of blood transfusion with increased mortality in myocardial infarction: a meta-analysis and diversity-adjusted study sequential analysis. JAMA Intern Med. 2013;173(2):132–139. 3. American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the 2002 Guidelines on Perioperative Cardiovascular Evaluation for Noncardiac Surgery); American Society of Echocardiography; American Society of Nuclear Cardiology; Heart Rhythm Society; Society of Cardiovascular Anesthesiologists; Society for CardiovascularAngiography and Interventions; Society for Vascular Medicine and Biology; Society for Vascular Surgery, Fleisher LA, Beckman JA, Brown KA, et al. ACC/AHA 2007 guidelines on perioperative cardiovascular evaluation and care for noncardiac surgery: executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the 2002 Guidelines on Perioperative Cardiovascular Evaluation for Noncardiac Surgery). Anesth Analg. 2008;106(3):685–712. 4. Feely MA, Collins CS, Daniels PR, Kebede EB, Jatoi A, Mauck KF. Preoperative testing before noncardiac surgery: guidelines and recommendations. Am Fam Physician. 2013;87(6):414–418. 5. McGee S. Evidence-Based Physical Diagnosis. 3rd ed. Philadelphia, PA: Elsevier Saunders; 2012. 6. Munt B, Legget ME, Kraft CD, Miyake-Hull CY, Fujioka M, Otto CM. Physical examination in valvular aortic stenosis: correlation with stenosis severity and prediction of clinical outcome. Am Heart J. 1999;137(2):298–306. 7. Christ M, Sharkova Y, Geldner G, Maisch B. Preoperative and perioperative care for patients with suspected or established aortic stenosis facing noncardiac surgery. Chest. 2005;128(4):2944–2953. 8. Caprini JA. Thrombosis risk assessment as a guide to quality patient care. Dis Mon. 2005;51(2–3):70–78. 9. Gould MK, Garcia DA, Wren SM, et al; American College of Chest Physicians. Prevention of VTE in nonorthopedic surgical patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest. 2012;141(2 Suppl):e227S–e277S. 10. Wysowski DK, Talarico L, Bacsanyi J, Botstein P. Spinal and epidural hematoma and low-molecular-weight heparin. N Engl J Med. 1998;338(24):1774–1775. 11. Horlocker TT, Wedel DJ, Rowlingson JC, et al. Regional anesthesia in the patient receiving antithrombotic or thrombolytic therapy: American Society of Regional Anesthesia and Pain Medicine Evidence-Based Guidelines (Third Edition). Reg Anesth Pain Med. 2010;35(1):64–101. 12. Fragmin [package insert]. New York, NY: Pfizer Inc; 2007.

30

03_Mauck.indd 30

13. Liao P, Yegneswaran B, Vairavanathan S, Zilberman P, Chung F. Postoperative complications in patients with obstructive sleep apnea: a retrospective matched cohort study. Can J Anaesth. 2009;56(11):819–828. 14. Adesanya AO, Lee W, Greilich NB, Joshi GP. Perioperative management of obstructive sleep apnea. Chest. 2010;138(6):1489–1498. 15. Gali B, Whalen FX, Schroeder DR, Gay PC, Plevak DJ. Identification of patients at risk for postoperative respiratory complications using a preoperative obstructive sleep apnea screening tool and postanesthesia care assessment. Anesthesiology. 2009;110(4):869–877. 16. Gross JB, Bachenberg KL, Benumof JL, et al; American Society of Anesthesiologists Task Force on Perioperative Medicine. Practice guidelines for the perioperative management of patients with obstructive sleep apnea: a report by the American Society of Anesthesiologists Task Force on Perioperative Management of patients with obstructive sleep apnea. Anesthesiology. 2006;104(5):1081–1093; quiz 1117–1118. 17. Etchells E, Meade M, Tomlinson G, Cook D. Semiquantitative dipyridamole myocardial stress perfusion imaging for cardiac risk assessment before noncardiac vascular surgery: a meta-analysis. J Vasc Surg. 2002;36(3):534–540. 18. Diagnostic Catherterization Writing Group; Technical Panel; Appropriate Use Criteria Task Force. ACCF/SCAI/AATS/AHA/ASE/ASNC/ HFSA/HRS/SCCM/SCCT/SCMR/STS 2012 appropriate use criteria for diagnostic catheterization: a report of the American College of Cardiology Foundation Appropriate Use Criteria Task Force, Society for Cardiovascular Angiography and Interventions, American Association for Thoracic Surgery, American Heart Association, American Society of Echocardiography, American Society of Nuclear Cardiology, Heart Failure Society of America, Heart Rhythm Society, Society of Critical Care Medicine, Society of Cardiovascular Computed Tomography, Society for Cardiovascular Magnetic Resonance, Society of Thoracic Surgeons. J Thorac Cardiovasc Surg. 2012;144(1):39–71. 19. American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines; American Society of Echocardiography; American Society of Nuclear Cardiology; Heart Rhythm Society; Society of Cardiovascular Anesthesiologists; Society for Cardiovascular Angiography and Interventions; Society for Vascular Medicine; Society for Vascular Surgery, Fleisher LA, Beckman JA, Brown KA, et al. 2009 ACCF/AHA focused update on perioperative beta blockade incorporated into the ACC/AHA 2007 guidelines on perioperative cardiovascular evaluation and care for noncardiac surgery. J Am Coll Cardiol. 2009;54(22):e13–e118. 20. Nicoll A. Surgical risk in patients with cirrhosis. J Gastroenterol Hepatol. 2012;27(10):1569–1575. 21. Teh SH, Nagorney DM, Stevens SR, et al. Risk factors for mortality after surgery in patients with cirrhosis. Gastroenterology. 2007;132(4):1261–1269. 22. Cho SW, Bhayani N, Newell P, et al. Umbilical hernia repair in patients with signs of portal hypertension: surgical outcome and predictors of mortality. Arch Surg. 2012;147(9):864–869. 23. Hanje AJ, Patel T. Preoperative evaluation of patients with liver disease. Nat Clin Pract Gastroenterol Hepatol. 2007;4(5):266–276. 24. Kim JJ, Dasika NL, Yu E, Fontana RJ. Cirrhotic patients with a transjugular intrahepatic portosystemic shunt undergoing major extrahepatic surgery. J Clin Gastroenterol. 2009;43(6):574–579. 25. Krajina A, Hulek P, Fejfar T, Valek V. Quality improvement guidelines for Transjugular Intrahepatic Portosystemic Shunt (TIPS). Cardiovasc Intervent Radiol. 2012;35(6):1295–1300. 26. Desborough JP. The stress response to trauma and surgery. Br J Anaesth. 2000;85(1):109–117. 27. Alpert RA, Roizen MF, Hamilton WK, et al. Intraoperative urinary output does not predict postoperative renal function in patients undergoing abdominal aortic revascularization. Surgery. 1984;95(6):707–711. 28. Corcoran T, Rhodes JE, Clarke S, Myles PS, Ho KM. Perioperative fluid management strategies in major surgery: a stratified meta-analysis. Anesth Analg. 2012;114(3):640–651. 29. McGee S, Abernethy WB 3rd, Simel DL. The rational clinical examination. Is this patient hypovolemic? JAMA. 1999;281(11):1022–1029.


1/31/14 5:13 PM

Clinical pearls in perioperative medicine.

Clinical pearls in general internal medicine.

Clinical pearls in vascular medicine and anticoagulation.

Clinical pearls in complementary and integrative medicine (CIM).

Clinical Pearls.

Clinical pearls.

Clinical pearls in dermatology.

Clinical pearls in neurology.

Clinical pearls in rheumatology.

Clinical pearls in dermatology 2013.

Clinical pearls in gastroenterology (2013).

Clinical pearls in dermatology 2014.

Clinical pearls in gastroenterology 2012.

Clinical pearls in pediatric neurology.

Immunomodulation in perioperative medicine.

Update in perioperative medicine 2013.

Welcome to perioperative medicine.

[Obstetrical aspects of perioperative medicine].

The year in review: perioperative medicine 2013.

[New oral anticoagulants in perioperative medicine].

Managing depression in Parkinson's patients: risk factors and clinical pearls.

Perioperative medicine: why do we care?

Update in perioperative medicine: evidence published in 2014.

Erdheim - Chester disease: Clinical pearls for the anesthesiologist.