Tumor lysis syndrome Rapid cell death on starting chemotherapy for rapidly proliferating le ukemia, lymphoma, myeloma, and some germ cell tumors can result in a rise in serum urate, K + , and phosphate, precipitating renal failure. Prevention is with good hydration and rasb uricase or allopurinol 24 h before chemotherapy; dose example if renal function is good: 30 0 mg/12 h PO. If creatinine >1.2 mg/dL: 100 mg on alternate days. Inappropriate ADH secretion (p. 669); febrile neutropenic regimen (p. 625) Table 12.6 Treating hypercalcemia with bisphosphonates Ensure adequate hydration (e.g., with 0.9% saline IVI). Zoledronic acid and pamidronate are two options. Disodium pamidronate Calcium (mg/dL; corrected) <12 12 \200\22314 >14 Single-dose pamidronate (mg) 30 60 90 Infuse slowly, e.g., 30 mg in 300 mL 0.9% saline over 3 h via a large vein. Max dose: 90 mg . Response starts at 3 \200\2235 d, peaking at 1 wk. SE: Flu-like symptoms, bone pain, PO 4 3 \200\223 \206\223, bone pain, myalgia, nausea, vomiting, headache, lymphocytopenia, Mg 2+ \206\223 , seizures (rare). Zoledronic acid is significantly more effective in reducin g serum Ca 2+ than previously used bisphosphonates. Usually, a single dose of 4 mg IVI over 2 h will normalize plasma Ca 2+ within a week. A higher dose should be used if corrected C a 2+ is 12 mmol/L. SE: Flu-like symptoms, bone pain, PO 4 3 \200\223 \206\223, confusion, thirst, taste disturbance, nausea, pulse \206\223 , WBC \206\223 , creatinine \206\221 . 430 Symptom control in severe cancer Pain Do not under treat with analgesia: Aim to prevent or eliminate pain. y g o o c n O l Types of pain Don \200\231t assume that the cancer is the cause (abdominal pain, e.g., may be from constipation). Seek the mechanism. Pain caused by nerve infiltration and damage via local pressure may respond to amitriptyline (e.g., 10 \200\22350 mg at night) rather than opioids. Bone pain (e.g., presenting with back pain) may respond to NSAIDs, radiotherapy, o r a nerve block. Identify each symptom and type of pain. Management (1) Pain is affected by mood, morale, and meaning. Explain its origin to both th e patient and relatives, and plan rehabilitation goals. (2) Use oral analgesics if possible \200\224aim to prevent pain with regular prophylactic doses (e.g., q4h); do not wait for p ain to recur. (3) Modify the pathological process where possible (e.g., radiotherapy, hormo nes, chemotherapy, surgery). With analgesia, work up the pain ladder until pain is relieved (see Table 12.7). Monitor response carefully. Laxatives and antiemetics are often needed w ith analgesics. Adjuvant analgesics: NSAIDs, steroids, muscle relax- ants, anxiolytic, anti depressants. Giving oral morphine: Start with aqueous morphine 5 \200\22310 mg/4 h PO. A do uble dose at night can be used to promote 8 h of sleep. Most patients need no more than 30 mg/4 h PO. A few need much more. Aim to change to extended-release morphine (e.g., MS-Conti n tablets q12h) when daily morphine needs are known. In morphine-resistant pain (persisting when 60 mg/4 h is given), consider adjuvant analgesics, methadone, or ketamine (specialist use only). Vomiting: Prevent from before the first dose of chemotherapy, to avoid anticipa tory vomiting before the next dose. Give orally if possible, but if severe vomiting prevent s this, give rectally or subcutaneously. Agents to try: Metoclopramide 10 mg/8 h PO; ondans etron 4 \200\2238 mg/8 \200\22312 h PO/IV; haloperidol 0.5 \200\2232 mg/24 h (max 5 mg). Sh ortness of breath: Consider supplementary O 2 or morphine. Use of relaxation techniques and benzodiazepines can be effective. Assess for pleural or pericardial effusion. If there is significant pleural effusion, consider thoracocentesis pleurodesis. If there is a malign ant pericardial effusion, consider pericardiocentesis (p. 147), pericardiectomy, pleuroperi cardial windows, external beam radiotherapy, percutaneous balloon pericardiotomy, or perica rdial instillation of immunomodulators or sclerosing bleomycin. Venipuncture problems: Repe ated venipuncture with the attendant risk of painful extravasation and phlebitis may be avo ided by insertion of skin tunneled catheter (e.g., a Hickman line) \200\224a single or mult ilumen line \200\224into a major central vein (e.g., subclavian or internal jugular). It is inserted using a strict antiseptic technique. Patients can look after their own lines at h ome and give their own drugs. Problems include infection, blockage (flush with 0.9% saline or dilute heparin, e.g., every week); axillary, subclavian, or superior vena cava thrombosi s/obstruction; and line slippage. Even more convenient portable delivery devices are availa ble, allowing drugs to be given at a preset time without the patient \200\231s intervention . 431 Table 12.7 The analgesic ladder Rung 1 Aspirin; acetaminophen; NSAID Nonopioid Weak opioid Rung 2 Codeine, dihydrocodeine, dextropropoxy- phene, tramadol, oxycodone (some place this on rung 3) Rung 3 Strong opioid Morphine, diamorphine, hydromorphone, fentanyl adjuvant analgesics. If 1 drug fails to relieve pain, move up ladder; do not try other drugs at the same level. In new, severe pain, rung 2 may be omitted. IV delivery of opioids, haloperidol, cyclizine and metoclopramide, and hyoscine, giving 24 h cover. Or suppositories (below) or fentanyl t rans- dermal patches: If not previously exposed to morphine, start with one low-strength pa tch (25 mcg/h). Remove after 72 h, and place a new patch at a different site. 25, 50, 75, a nd 100 mcg/h patches are made. t \211\210 17 h. Suppositories can also be used if unabl e to tolerate oral route. For pain: Try oxycodone 30 mg suppositories (e.g., 30 mg/8 h 3 0 mg morphine). Agitation : Try diazepam 10 mg/8 h suppositories. Other agents and procedur es to know about (alphabetically listed) \212Bisacodyl tablets (5 mg), 1 \200\2232 at night, help opioid-induced constipation. \212Cholestyramine 4 g/6 h PO (1 h after other drugs) helps itch in jaundice. \212Enemas , e.g., arachis oil, may help resistant constipation. \212H 2 -antagonists (e. g., cimetidine 400 mg/12 h PO) help gastric irritation; e.g., associated with gastric carcinoma. \212Haloperidol 0.5 \200\2235 mg/24 h PO helps agitation, nightmares, hallucina- tions, and vomiting. \212Hydrogen peroxide 6% cleans an unpleasant-feeling coated tongue. \212Hyoscine hydrobr omide 0.4 \200\2230.6 mg/8 h SC or 0.3 mg sublingual helps with vomiting from upper GI obst ruction or bronchial congestion. \212Low-residue diets may be needed for postradiotherapy diarrhea. \212Metronidazole 400 mg/8 h PO mitigates anaerobic odors from tumors; so do charcoal dressings (Actisorb ). \212Nerve blocks may lastingly relieve pleural or other resistant pains. \212Polyethylene glycol sachets 2 \200\2234/12 h for 48 h to shift resistant constipa- tion with overflow. 432 \212Naproxen 250 mg/8 h with food: Fevers caused by malignancy or bone pain from metastases (consider splinting joints if this fails). \212Spironolactone 100 mg bd PO + bumetanide 1 mg/24 h PO for ascites. \212Steroids: Dexa methasone : Give 8 mg IV stat to relieve symptoms of superior vena cava or bronchial obstru ction, or lymphangitis carcino- matosa. Tablets are 2 mg ( 15 mg prednisolone). 4 mg/12 \200\22324 h PO may stimulate appetite, reduce ICP headache, or induce (in some patients) a satisfactory sense of euphoria. \212Supplemental humidified O 2 helps hypoxic dyspnea. \212Thoracocentesis ( bleomycin pleurodesis) helps in pleural effusion. Cancer therapy It is beyond the scope of this chapter to provide a comprehensive review of treatment options for each malignancy. However, as noted earlier, there have been some rema rkable achievements in the management of some solid tumors, such as germ cell tumors. The s ensitivity of germ cell tumors to platinum-based chemotherapy, together with radiation and surgical mea- sures, has led to a cure rate of >99% in early stage disease. Cancer manageme nt Management requires a multidisciplinary team, and communication is vital. Most patients wish to have some part in decision making at the various stages of their treatment and to b e informed of their options. Patients are becoming better informed through self-help groups and access to the Internet. Most patients undergo a variety of treatments during the treat ment of their cancer, and your job may be to orchestrate these. Surgery In many cases, a ti ssue diagnosis of cancer is made with either a biopsy or formal operation to remove the pri mary tumor. Although it is sometimes the only treatment required in early tumors of the GI tract, soft tissue sarcomas, and gynecological tumors, it is often the case that best resul ts follow the combination of surgery and chemotherapy. Surgery also has a role in palliatin g advanced disease. Chemotherapy Cytotoxics should be given under expert guidance by people trained in their administration. Drugs are often given in combination with a variety of in tents. Neoadjuvants to shrink tumors to reduce the need for major surgery (e.g., mastectomy ). There is also a rationale that considers early control of micrometastasis. Primary thera py as the sole treatment for hematological malignancies. Adjuvants to reduce the chance of relapse (e.g., breast and bowel cancers). Palliative to provide relief from symptomatic met astatic disease and possibly to prolong survival. Important classes of drugs include: \212 Alkylating agents (e.g., cyclophosphamide, chlorambucil, busulfan) \212Antimetabolites (e. g., methotrexate, 5-fluorouracil) \212Vinca alkaloids (e.g., vincristine, vinblastine) \212Antitumor antibiotics (e.g., actinomycin d, doxorubicin) \212Others (e.g., etoposide, taxanes, platinum compounds) Side effects depend on the types of drugs used. Nausea/vomitin g are most feared by patients and are preventable or controllable in most. Alopecia can als o have a profound impact on quality of life. Neutropenia is most commonly seen 10 \200\2231 4 d after chemotherapy (but can occur within 7 d for taxanes), and sepsis requires immediat e attention (p. 625). Extravasation of a chemotherapeutic agent: Suspect if there is pain, burn- ing, or swelling at infusion site. Management: Stop the infusion, attempt to aspirate blood from the cannula, and then remove. Administer steroids and consider antidotes. Eleva te the arm and mark site affected. Review regularly and apply steroid cream. Apply cold pac k (unless a vinca alkaloid, in which case a heat compress should be applied). As was also n oted earlier, what has impeded systematic progress in achiev- ing similar successes in othe r cancers has been the realization that the molecular signaling pathways that ultimately le ad to cell proliferation and growth were largely unrecognized. The identification of molecu lar target- specific therapy would provide the potential of maximal therapeutic benefit whi le minimizing toxicity to normal cells. Ligand-dependent or -independent growth factor rece ptors Activate downstream signaling pathways via their ability to phosphorylate and thereby activate downstream proteins to effect unregulated cellular y g o o c n O l 433 proliferation. As such, inhibitors of receptor kinases with high specificity are currently being tested as anticancer drugs. The discovery of the molecular defect associated with the constitutively active tyrosine kinase fusion protein BCR-ABL, which results from the recip rocal DNA exchange between the long arms of chromosomes 9 and 22 [t(9;22) Philadelphia chro mosome], has been identified in >90% of patients with CML. The clinical features of CML and the biology of BCR-ABL have recently been elegantly summarized. The variability in the bre akpoint on chromosome 22 is well described and has implications for the disease phenotype. As a result, BCR-ABL inhibition represented an ideal target for drug therapy. This strategy has been validated in clinical trials of CML with imatinib that culminated in its approval in May 2001 by the FDA. In the chronic phase, the hematologic response rate is 95% and cyt ogenetic response rates range from 50 \200\22380%, depending on the stage of disease. Moreo ver, response rates were also high in blast crisis patients, despite the presence of multip le oncogenic abnormalities in addition to BCR-ABL. Epidermal growth factor receptor (EGFR) Includes a family of receptor tyrosine kinases comprised of four related receptors: EGFR (E rbB1/EGFR/Her1), ErbB2 (Her2/neu), ErbB3 (Her3), and ErbB4 (Her4). The formation of recepto r homo- or hetero-dimerization through either ligand-dependent or -independent activation l eads to constitutively activated receptor signaling and has been associated with amplificat ion of downstream signals involving a number of nonlinear cellular pathways. The end produc t of this signaling cascade leads to increased cellular proliferation, migration, tissue st romal invasion, resistance to apoptotic signals, and angiogenesis. In addition, EGFR is ove rexpressed in a significant percentage of solid tumors and is believed to be a marker for p oor prognosis and decreased survival. These properties provide the rationale for the develo pment and testing of EGFR inhibitors. Inhibitors to EGFR have already been tested in clinic al trials with FDA approval in 2003 of the oral EGFR tyrosine kinase inhibitor gefitinib (I ressa , AstraZeneca) for third-line therapy of advanced non-small cell lung cancer. Many i mportant challenges for the use of EGFR small-molecule inhibitors remain, including identif ying appropriate surrogate markers of activity and in best integrating these therapies with other treatment modalities. Cetuximab (Erbitux , Imclone Systems) is an IgG1 monoclonal a ntibody against EGFR that has demonstrated activity in patients with Irinotecan-refractory colorectal cancer. Cetuximab has also shown response to treatment and improvement in progre ssion- free progression in patients with locally advanced head and neck cancer refractory t o platinum-based chemotherapy. The association of an acne-like rash with activity of drug h as been suggested. The formation of new blood vessels to keep pace with growing tumors is a n enormously complicated process that occurs in response to a vast array of molecular signa ls, including oxygen tension (hypoxia inducing fac- tor) and growth factors such as fibrobl ast growth factor (FGF), transform- ing growth factor and \222 (TGF- and TGF- \222 ), tumor necrosis factor- (TNF- ), insulin growth factor, and platelet-derived growth factor (PDGF). Vascular endothelial growth factor (VEGF) signaling is a critical rate-limi ting step in angiogenesis. Inhibitors to VEGF have already been approved in CRC (bevacizuma b) and in breast cancer (trastuzumab) and have been examined in lung, renal, pan- creas, he ad and neck, hepatocellular cancer, and non-Hodgkin \200\231s lymphoma in ongoing trials. M utations to other driver pathways such as BRAF and translocations between alk and EML-4 are thought to occur at lower frequencies in non- small cell lung cancer. Mutations to other d river pathways such as BRAF and translocations between alk and EML-4 are thought to occur a t lower 434 frequencies in non-small cell lung cancer. There are now approved drugs that target inhibit ors of alk tyrosine kinase (crizotinib) in non-small cell lung cancer. Mutations in BRAF ar e thought to occur at higher frequencies in other cancers such as melanoma. As such, inhibi tors of BRAF specifically targeting mutations at V600E in melanoma (vemurafenib) have been tested and approved in the United States in 2011. In addition, there has been a better unde rstanding of the complex rela- tionship that affects the balance between antigen recognitio n and develop- ment of immune tolerance between the immune system and cancer. In the past f ew years, there has been FDA approval of the CTLA-4 inhibitor Ipilimumab (Yervoy; in 2011) for melanoma and for the autologous immu- notherapy treatment consisting of prostatic acid phosphatase (PAP)linked to the immune cell activator GM-CSF known as sipuleucel-T (Provenge ; approved in 2010). y g o o c n O l Radiotherapy Radiotherapy uses ionizing radiation to produce free radicals that damage DNA. Normal cells are better at repairing this damage than are cancer cells, so are able to rec over before the next dose (or fraction) of treatment. Radical treatment is given with curat ive intent. The total doses given range from 40 to 70 Gy (1 Gy = 100 cGy = 100 rads) in 15 \200\22335 daily fractions. Some regimens involving giving several smaller fractions a day with a gap of 6 \200\2238 h. Combined chemoradiation is used in some sites (e.g., anus and esophagus) to increase response rates. Palliation aims to relieve symptoms. Doses: 8 \200 \22330 Gy, given in 1, 2, 5, or 10 fractions. Bone pain, hemoptysis, cough, dyspnea, and bl eeding are helped in >50% of patients. Early reactions occur during or soon after treatment . \212Tiredness: Common after radical treatments; can last weeks to months. \212Skin reac tions: These vary from erythema to dry desquamation to moist desquamation to ulceration; on completing treatment, use moisturizers. \212Mucositis: All patients receiving head and ne ck treatment should have a dental check-up before commencing therapy. Avoid smoking, alcoho l, and spicy foods. Antiseptic mouthwashes may help. Soluble analgesics are helpful. Treat oral thrush. \212Nausea and vomiting: Occur when stomach, liver, or brain is treated. Try a dopamine antagonist first. If unsuccessful, try 5HT3 antagonist. 435 \212Diarrhea: Usually after abdominal or pelvic treatments. Maintain good hydration. Avoid high-fiber bulking agents; try loperamide. \212Dysphagia: Thoracic treatments. \212Cystitis: Pelvic treatments. Drink plenty of flui ds. NSAIDs. \212Bone marrow suppression: More likely after chemotherapy or when large areas are being treated. Usually reversible. Late reactions occur months or years after the treatment. \212CNS: Somnolence : 6 \200\223 12 wks after brain radiotherapy. Treat with steroids. Spinal cord myelopathy : Progressive weakness. MRI is needed to exclude cord compression. Brachial plexopathy : Numb, weak, and painful arm after axillary radiotherapy. Reduced IQ can occur in children receiving brain i rradiation if <6 yrs. \212Lung: Pneumonitis may occur 6 \200\22312 wks after thoracic treatment (e.g., with dry cough dyspnea). Treatment : Prednisolone 40 mg reducing over 6 wks. GI: Xerostomia (redu ced saliva). Treat with pilocarpine 5 mg/8 h or arti- ficial saliva. Care must be taken wit h all future dental care as healing \212 is reduced. Benign strictures of esophagus or bowel : Treat with dilatation. Fistulae need surgical intervention. GU: Urinary frequency from small fibrosed bladder after pelvic treat ments. Fertility: Pelvic radiotherapy (and cytotoxics) may affect fertility, so ova or sper m storage should be considered. This is a complex area: Get expert help. In premature femal e menopause or reduced testosterone, replace hormones. Vaginal stenosis and dyspareunia. Im potence can occur several years after pelvic radiotherapy. \212 \212Others: Panhypopituitarism following radical treatment involving pituitary fossa. Chil dren need hormones checked regularly, as growth hormone may be required. Hypothyroidism may follow neck treatments (e.g., for Hodgkin \200\231s lymphoma). Cataracts. Secondary cancer s (e.g., sarcomas usu- ally 10 yrs later). 436 This page intentionally left blank Surgery Susan L. Gearhart , M.D. y r e g r u S Contents Introduction 439 Surgical terms 439 The preoperative evaluation 440 Preoperative tests 441 Preoperative medical assessment 442 Prophylactic antibiotics and bowel preparation 445 Veno thromboembolic risk assessment and prevention 446 Informed consent 447 Perioperative IV flu id and electrolyte management 448 Electrolyte management in the surgical patient 450 The co ntrol of pain 452 Deep vein thrombosis and swollen legs 453 Glucose management and the diab etic patient 455 Blood transfusion and blood products 456 Nutritional support 458 Parentera l (IV) nutrition 460 Drains, wounds, and stoma care 461 Thyroid disease, hepatic failure, s teroids, anticoagulation, and surgery 463 Postoperative care 464 The acute abdomen 466 Inte stinal ischemia 468 Gastrointestinal bleeding 470 Trauma 472 Aortic aneurysm and dissection 474 Limb ischemia 476 Acute appendicitis 478 Diverticular disease 480 Hernias 482 Inguinal hernias 483 Benign diseases of the biliary tract 485 Pancreatitis 487 Intestinal obstructi on 489 Rectal prolapse (procidentia) 490 Fecal incontinence 490 Hemorrhoids 491 Anal fissur e 492 Gastric and duodenal ulcer disease 493 Surgery for duodenal ulcer 495 Surgery for gas troesophageal reflux disease 496 Obesity surgery 496 Breast lumps and breast cancer 497 Col orectal adenocarcinoma 500 Pancreatic cancer 502 Thyroid nodules and cancer 504 Esophageal cancer 505 Gastric cancer 506 3 1 438 Cutaneous neoplasms 507 Common urological disorders 508 Urinary tract malignancies 511 Urin ary incontinence 513 Bladder tumors 514 Gynecology 515 y r e g r u S Introduction The goal of the following chapter is to give the reader some insight into comm only managed surgical disorders. This chapter is not intended to be comprehensive. A great emphasis has been placed on the perioperative management of the surgical patient. This is p articularly timely given the development of American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP). This program contains several rec- ommendations, b ased on peer-reviewed studies, to improve surgical out- comes for patients. Further informa tion regarding this program can be obtained through the ACS NSQIP website: http://site.acsn sqip.org Surgical terms Commonly used surgical terms are listed in Figure 13.1. Figure 13.1 Surgical terms Incisions have names Abdominal areas 439 1, 2: 3, 4: 5, 6: 7: 8: 9: Right & left upper quadrants Right & left flanks Right & left lower quadrants Epigastrium Central area (periumbilical) Suprapubic area (Continued) Figure 13.1 (Continued) A cavity containing pus To do with tubes or blood vessels The surgical removal of something , e.g., Abscess Angio- -ectomy appendectomy Chole- Cyst Docho- To do with bile A fluid-filled sac To do with ducts Fistula An abnormal communication between two epithelial surfaces; e.g., enterocutaneous be tween the bowel and the skin; endothelial in arte- riovenous fistulae); gastrocolic fistula (stomach/colon). Fistulae may close spontaneously but will not do so in the presence of ch ronic inflamma- tion, distal obstruction, epithelialization of the tract, foreign bodies, o r malignant tissue. Ileus Used in this book to mean adynamic bowel (e.g., no bowel sounds). Lith Stone; e.g., nephrolithotomy (cutting kidney open to get to a stone). Ostomy An openi ng usually made to create a new connection between two conduits or between a conduit and th e outside world (e.g., colos- tomy: The colon is made to open onto the skin (p. 462). Stoma or mouth. Otomy Surgical opening; e.g., laparotomy (opening of abdomen). Plasty A remoldin g or reforming of something to make it work; e.g., pyloroplasty relieves pyloric (gastric o utlet) obstruction. Percutaneous Entering through the skin (invasive). Sinus A blind ending tract typically lined by epithelium from which it opens. Stent Artificial tube inserted in to a biological tube to keep it open. Trans Going across a structure. Ulcer An abnormal bre ak in an epithelial surface. 440 The preoperative evaluation The purpose of the preoperative evaluation is: 1 To determine t he need for surgical intervention 2 To assess the anesthetic risk to the patient 3 To coord inate surgical, anesthetic, and nursing care for the safety of the patient. The care team may require additional testing to determine if surgery is indicated and safe to perform. For example, a 64-yr-old man with a newly diagnosed rectal cancer and a history of smoking will need local staging with an ultrasound (US) exam of the tumor, a computed t omography (CT) scan of the abdomen and pelvis to evaluate for metastatic disease, a chest X -ray, electrocardiogram (ECG), and the following laboratory work: CBC, comprehensive panel, prothrombin time (PT), partial thromboplastin time (PTT). If the patient has cardiac risk factors, an echocardiogram and/or cardiac stress test may need to be performed. For further assessment of any pulmonary condi tions, pulmonary function tests may be necessary as well. More discussion is included with the individual descriptions of the disorders or diseases. y r e g r u S Preoperative tests Commonly oredered preoperative tests are listed in Table 13.1. Table 13.1 Preoperative tests Use the history and examination as well as local protocols as your guide. Blood tests Routi ne blood tests include CBC, comprehensive panel, and coagulation profile (PT, PTT) in most patients. If hemoglobin (Hgb) <10 g/dL, tell anes- thesiologist. Investigate/treat as appro priate. A comprehensive panel is partic- ularly important if the patient is starved, diabet ic, on diuretics, has significant burns, has hepatic or renal diseases, has an ileus, or is parenterally fed. In healthy adults <45 yrs of age, no preoperative testing may be neces- sary. Recommendations are based on the guidelines put forth by most institutions. The only exception is \222 -human chorionic gonadotropin (HCG) which is mandatory in all premenopau sal women. Cross-matching: Type and cross is recommended for most major surgical cases. For major cardiac, vascular and spine cases, up to 6 units should be available for surgery. Sp ecific blood tests: Liver function tests (LFTs) in jaundice, malignancy, or alcohol abuse. Urinalysis: Routine prior to prosthetic device insertion as well as routine abdominal surge ry. \222 -HCG: Mandatory in all premenopausal women. Drug levels: As appropriate (e.g., di goxin, Dilantin, lithium). Coagulations studies: In liver disease, disseminated intravascul ar coagula- tion (DIC), massive blood loss, patients already on valproic acid, war- farin, or heparin. Sickle test: In those from Africa, West Indies, or Mediterranean \200\224and ot h- ers whose origins are in malarial areas (including most of India). Thyroid function test s: In those with thyroid disease who have not had annual testing. Additional tests Chest x- ray (CXR): If known smoker, evidence of cardiopulmonary dis- ease, pathology or symptoms, p ossible lung metastases, or \211 50 yrs old. ECG: Patients with prior coronary revascular ization or admission to a hospital for cardiac reasons. Asymptomatic males >45, females >55 with- out significant comorbidities (diabetes, obesity, hypertension). Echocardiogram (ECG )/stress test: Any patient with cardiac symptoms (chest pain, shortness of breath [SOB]), k nown cardiac disease (particu- larly heart failure) that has not been evaluated recently or has progressed in symptoms to assess adequacy of medical therapy. Pulmonary function test (PFT): Chronic smoker, known pulmonary dis- ease, sleep apnea, especially before thoracic s urgery Lower or upper extremity venous duplex: Patients with a history of VTE (venothrombot ic events), prolonged hospitalizations, malignancy, inflam- matory bowel disease, etc. (see deep vein thrombosis [DVT] prophy- laxis). If positive test, may consider vena cava filter prior to operation. 441 (Continued) Table 13.1 (Continued) American Society of Anesthesiologists (ASA) classification 1 Normally healthy 2 Mild system ic disease 3 Severe systemic disease that limits activity; not incapacitating 4 Incapacitat ing systemic disease that poses a threat to life 5 Moribund; not expected to survive 24 h e ven with operation You will see a space for an ASA number on most anesthetic charts. It is a health index at the time of surgery . The prefix E is used in emergen- cies. This classif ication is commonly used to assess the risk of anesthetic complication. Patients with an AS A of 1 have virtually <1% risk of death, whereas patients with an ASA of 5 run a 50% risk o f intraoperative mortality. Preoperative medical assessment Begin with the medical history of the patient and family an d a general review of systems. Assess cardiopulmonary system, exercise tolerance, existing ill- nesses, drugs, and allergies. Assess past history of myocardial infarction, diabetes, asthma, hypertension, rheumatic fever, epilepsy, jaundice. Assess any specific risks: Is th e patient pregnant? Has there been previous anes- thesia? Were there any complications? Fam ily history may be relevant, as in malignant hyperthermia, myotonic dystrophy, porphyria, c holinesterase problems, sickle-cell disease. Drugs: Any drug/antiseptic/latex allergies? In form the anesthesiologist about all drugs, even if over-the-counter. Antibiotics: Tetracycl ine, neomycin and others may \206\221 neuromuscular block- ade. Anticoagulants: Tell the s urgeon. See Cardiac Risk Assessment regarding anti- coagulation and cardiac stents. Avoid e pidural, spinal, and regional blocks. Anticonvulsants: Give as usual preop. Postop, give dr ugs IV (or by NGT) until able to take orally. Valproate: Give usual dose IV. Phenytoin: Giv e IV slowly (<50 mg/min; monitor ECG). IM phenytoin absorption is unreliable. Avastin (BEV) : Should be stopped 1 month prior to surgery; may cause coagulopathy. Antihypertensives: Ch ronic use should be continued. Consider calcium-channel blockers in patients who have contr aindication to \222 -blockade. \222 -blockers: Continue up to and including the day of su rgery as this precludes a labile cardiovascular response. Estrogen replacement or oral cont raceptives: Stop 4 wks before major sur- gery because of the risk of thromboembolic event a nd ensure alternative contraception is used. Diabetic medicine: Insulin therapy/oral hypogl ycemic. See Glucose Manage- ment in the Diabetic Patient. Digoxin: Continue up to and inclu ding morning of surgery. Check for toxic- ity (ECG; plasma level); do plasma K + and Ca 2+ (succinylcholine \206\221 K + and can lead to ventricular arrhythmias in the fully digital ized). Diuretics: Beware hypokalemia, dehydration. Herbal Supplements: Should be stopped 1 month prior to surgery; may cause coagulopathy 442 Levodopa: Possible arrhythmias when patient under GA. Lithium: Get expert help; it may pote ntiate neuromuscular blockade and cause arrhythmias. MAOI: Get expert help as interaction w ith opiates and anesthetics may cause hypotensive/hypertensive crises. Eye-drops: Many be a bsorbed; anticholinesterases \206\221 (succinylcholine). Tricyclics: These enhance epineph rine and arrhythmias. Difficult Airway Management Predictors of difficult intubation I do n ot know of any area of medicine where proper preparation is more important in preventing co mplications. The overall incidence of difficult intubation is reportedly 5.8%. The incidenc e for obese patients is 15.8%. Currently, the best method of determining the potential for a difficult air- way includes the patient \200\231s history and physical exam. Any patient who has had a difficult intubation in the past is given an alert bracelet indicating this. Furthermore, a history of maxillofacial trauma, reconstructive surgery, or radiation should alert the anesthetist of potential difficulties. Is the neck unstable (e.g., arthritis com plicating intubation)? Is the neck/jaw immobile (intubation risk)? Other assessment tools i nclude the following: Mallampati classi \201 cation: Estimates the size of the tongue rela tive to the oral cavity; alone this test is marginally helpful. Thyromental distance: Dista nce from thyroid notch to mentum (<4 \200\2236 cm) is an indication of mouth opening capabi lity Sternomental distance: Distance from sternum to mentum (<12.5 \200\22313.5 cm) is an i ndication of mouth opening capability Mouth opening: Ability to visualize the glottis on mo uth opening; inconsistent Wilson risk score: Simple summation of risk factor; somewhat reli able score is \211 2 Most operating rooms will have an airway management team that includ es anesthesiologists, surgeons, nurses, and technicians. A dedicated difficult air- way car t should be readily accessible to the team and should contain items that would assist in an airway emergency(ask anesthesia coordinator). y r e g r u S Cardiac risk assessment The American College of Cardiology and the American Heart Associati on have published guidelines regarding cardiac risk assessment in noncardiac surgery in 199 6; these were updated in 2002. The European Society of Cardiology and the European Society of Anesthesiology have also published similar guidelines in 2010. Some of these guidelines have been summarized here. Preoperative risk strati \201 cation: 1. Low risk (<1% risk of myocardial infarction (MI) or death) 443 Type of procedures: Breast, endocrine, eye, genitourinary (GU) \200\224minor, gastrointesti nal(GI) \200\224minor, plastic/reconstructive, orthopedic-minor 2. Intermediate risk (1 \200\2235% risk of MI or death Types of procedures: GI-major, GU-major, vascular (carotid, endo- vascular, peripheral vasc ular angioplasty), head and neck, neurologic/ orthopedic-major, transplant (lung, renal, li ver) 3. High risk (>5% risk or MI or death) Types of procedures: Open abdominal aorta, peripheral vascular surgery Lee Index: Clinical factors predictive of cardiac complication following surgery: 1. Ischem ic heart disease 2. Heart failure 3. Stroke/transient ischemic attack 4. Diabetes requiring insulin therapy 5. Renal dysfunction/hemodialysis 6. High-risk surgery 1 point assigned to each clinical factor. For total points assigned, estimated incidence (% per 100 cases) of major cardiac complication is as follows: 0 point 0.4% 1 point 0.9% 2 points 7% 3 points 11% Noninvasive preoperative testing: Active, uncontrolled bleeding or high Aims at provid ing information on three cardiac risk markers: lv function, myo- cardial ischemia, and valv e abnormalities. Should occur if two of the three following factors are true in any patient : 1 Intermediate clinical predictors are present (Canadian class 1 or 2 angina, prior MI, c ompensated or prior heart failure, diabetes, renal insufficiency) 2 Poor functional capacity (<4 metabolic equivalent levels on Duke Activity Status Index AJC 1989) 3 High surgical risk procedure (emergency major operation, aortic or peripheral vascular di sease (PVD) surgery, prolonged surgery with large fluid shifts) Several studies have demonstrated that a left ventricular ejection fraction (LVEF) <35% is associated with an increased risk of a coronary event in patients undergoing noncardiac sur gery. Invasive perioperative evaluation: Recommended for the following patients prior to un dergoing surgery: 1 Patients with suspected or known coronary artery disease (CAD) who have demonstrated a high risk of adverse outcome based on noninvasive testing 2 Unstable angina or angina not responsive to medical therapy 3 Equivocal noninvasive test results in patients undergoing high-risk surgery 4 Urgent noncardiac surgery while convalescing from an acute mi 5 Perioperative MI 6 Candid ate for liver, lung, or renal transplant \211 40 yrs, as part of evaluation for transplan tation, unless noninvasive testing reveals high risk for adverse outcome 444 7 Patients should undergo preoperative coronary bypass grafting before high-risk surgery if their long-term outcome would be improved Other factors: 1 Prior to surgical intervention, severe hypertension (diastolic >110 mm Hg) should be controlled. 2 Symptomatic stenotic lesions (mitral or aortic) are associated with risk of perioperative severe heart failure and should be treated with intense medical therapy or surgical correc tion when possible. 3 Arrhythmias and conduction abnormalities: Management is identical to nonoperative setting ; however, pacemakers and implantable cardioverter defibrillator (ICDs) will need to be pro grammed off prior to surgery because of the concern of electrocautery use. 4 Medical therapy, particularly \222 -blockade, should be started days prior to planned su rgery and continued postoperatively with a dose titrated to achieve a resting heart rate ar ound 50 \200\22360 bpm. Patients who have a contraindication to \222 -blockade (chronic ob structive pulmonary disease [COPD]) may be started on -adrenergic agonists. y r e g r u S 5 Some studies indicate that maintenance of normothermia and adequate analgesia prevents cardiac events. 6 Because 95% of coronary events may be silent, postoperative ECG moni- toring should be performed in high-risk patients. All patients who smoke should be encouraged to discontinue smoking prior to surgery. Prophylactic antibiotics and bowel preparation The rate of wound infection following surger y ranges from <5% for clean cases without entry into the GI tract to >50% for intra-abdomin al perforation. Successful prevention has been demonstrated with the use of IV antibiotics only. Preoperative mechanical bowel preparation In the era of routine IV antibiotics, mecha nical bowel preparation prior to surgery has not shown to be beneficial in the prevention o f anastomotic complications or wound infections. However, most surgeons find it more esthet ically pleasing, and it facilitates bowel anastomosis and the identification of intralumina l lesions. The mechanical bowel preparations utilized, either polyethylene glycol 4 L or Mi raLax, do not cause significant electrolyte abnormalities and therefore are beneficial in p atients with cardiac disease or renal insufficiency, and in the elderly. Previously, sodium phosphate hypertonic solutions were utilized; however, dehydration and significant electro lyte abnormalities( \206\221 Na, \206\221 Phos, K, Ca) have led to the removal of these p reparations from the market. Preoperative oral antibiotics There has been much debate over the use of preoperative oral antibiotics, especially with the use of IV antibiotics. Curren tly, there are sufficient data to suggest that the use of preoperative oral antibiotics is beneficial in the prevention of surgical site infections, and their use is endorsed by many surgical societies. Preoperative iv antibiotics The surgical literature supports the routi ne use of IV antibiotics in the prevention of wound infections. To be effective, the dose s hould be given 1 h prior to incision. Meta-analysis has demonstrated that a single dose is all that is necessary, although frequently three doses are given. 1 First-generation cephal osporin is given in noncontaminated surgery with- out entry into the GI tract(e.g., Ancef 1 g q6h while in the operating room). 445 2 Second-generation cephalosporin is given in cases in which limited con- tamination is exp ected, including entry into the GI tract. This antibiotic covers aerobic and anaerobic bact eria (e.g., cefotetan 2 g q6h while in the operating room). 3 For penicillin-allergic patients, cephalosporins should be avoided as well (5% cross-reac tivity). Alternatives include clindamycin or vancomycin. 4 For intra-abdominal perforation, coverage with a third-generation cepha- losporin and metronidazole, a broad-spectrum penic illin, or fluoroqui- nolone is acceptable (e.g., cefuroxime 1.5 g and metronidazole 500 mg) . Venothromboembolic risk assessment and prevention Table 13.2 lists the current method of ri sk assessment for venous throm- boembolic disease. Table 13.2 Risk factors for venous thromboembolic disease Serious risk factors \212 \212 \212 \212 \212 \212 \212 \212 Other risk factors \212 \212 \212 \212 \212 \212 \212 \212 \212 \212