Perioperative Assessments Pain Fever Oliguria and DVT Prophylaxis

Peri-operative Assessments, Pain, Fever, Oliguria and DVT Prophylaxis Peter E. Rice, MD Surgical Fundamentals Session #4

ALGORITHMS Pre-operative Assessment Fever Oliguria DVT Prophylaxis Pain

Question: What are the specific pre-operative laboratory tests and/or evaluations that should be performed to confirm or to rule out medical conditions that are likely to impact a patient’s perioperative course? > 3 billion dollars are spent each year on pre-op lab evaluations- and > 60% of these are unnecessary

From the Anesthesiologists Point of View…………. Class Physical Status 48 hr mortality I No systemic disease 0. 07% II Mild systemic disease; no functional limitation (obese, smoker, HTN) 0. 24% III Severe, not incapacitating systemic disease (CAD, CHF, COPD) 1. 4% IV Incapacitating disease that is a constant threat to life 7. 5% V Moribund pt. not expected to survive 24 hrs regardless of surgery 8. 1% E Suffix added to class (emergency) Doubles risk

ASA I 18 -39 yr No labs Females Preg Test 40 -59 yr EKG Females Preg Test >60 yo SMA-7 CXR EKG Lab Tests <35 days acceptable w/o change in condition CXR <6 months EKG <2 months Urine pregnancy on day of surgery

ASA II Laboratory tests as required by ASA I patients and tests as indicated by the patient’s specific disease states CXR in all patients >20 pk-yr smokers

ASA III CBC SMA-12 U/A CXR EKG Upreg Consult from an appropriate physician Tests as indicated by the patient’s specific disease state

Tests as Indicated by the Disease State…. . CNS Seizure/stroke Pulmonary Systems Assessment GI Renal Heme/Onc Medications PFT’s, ABG, Bronchodilators, Steroids Liver dz CBC, Lytes CBC, INR, PTT

Tests as indicated by the patient’s specific disease state And the risk of the planned procedure

The History and Physical will uncover the clinical risk of the patient

A Special Case……. Low risk procedure Hx/PE ? Cardiac Disease. CAD, CHF, Arrhythmia, CVA, PVD Estimate Clinical Risk High risk procedure Exercise Stress Dobutamine w/ Echo Persantine Thallium OR

One Additional Note Perioperative Beta-Blocker Therapy Patients who are receiving beta-blockers to treat angina, arrhythmias, or hypertension n Patients undergoing vascular surgery who are at high cardiac risk n Patients who are at increased cardiovascular risk advanced age diabetes mellitus renal insufficiency n

Fever is a common event but cannot be ignored Two temperature elevations >38. 5 in a 24 -hour period

Postoperative Fever T>38. 5 Early <48 hours Late >48 hours Both evaluations begin with History and Physical Exam • The cause of most postoperative fevers will be elucidated by the history and physical • Check the comorbidities- transfusion, meds, malignancy, FB, diabetes • Always check the operative site

Early <48 hours Physical exam Wind Wound Water Walk Wonder Drugs

cellulitis Wound drainage Respiratory Late >48 hours Physical Examination CXR IV sites GU ? AIE ? infected UA /CX Intra-abdominal Extremity swelling CT Scan Duplex

Oliguria Acute oliguria is the excretion of <400 cc of urine per day, and is often the earliest sign of impaired renal function Oliguria

68 yo male s/p LAR with loop ileostomy T 37 P 110 BP 110/75 R 12 UO 14 cc in the last hour

Fe NA = Urine [Na] / Plasma [Na] x 100 Urine [Cr] / Plasma [Na] Fe. Na < 1% prerenal Fe. Na > 2% renal (ATN) Urinary sodium (meq. L) <20 prerenal >40 renal

DVT Venous Thromboembolism Pulmonary Embolus

National Body Position Statements o Leapfrog 1: • PE is “the most common preventable cause of hospital death in the United States” • Agency for Healthcare Research and Quality (AHRQ)2: Thromboprophylaxis is the number 1 patient safety practice • American Public Health Association (APHA)3: “The disconnect between evidence and execution as it relates to DVT prevention amounts to a public health crisis. ” 1. 2. 3. The Leapfrog Group Hospital Quality and Safety Survey. Available at: www. leapfrog. medstat. com/pdf/Final/doc Shojania KG, et al. Making Healthcare Safer: A Critical Analysis of Patient Safety Practices. AHRQ, 2001. Available at: www. ahrq. gov/clinic/ptsafety/ White Paper. Deep-vein thrombosis: Advancing awareness to protect patient lives. 2003. Available at: www. alpha. org/ppp/DVT_White_Paper. pdf

Rationale for DVT Prophylaxis High Prevalence of DVT n Adverse Consequences of DVT n Efficacy and effectiveness of thromboprophylaxis n n n Highly efficacious in prevention of DVT Highly efficacious in prevention of symptomatic DVT and fatal PE DVT prevention prevents PE Cost effectiveness has been demonstrated

Absolute Risk of DVT in Hospitalized Patients Patient Group DVT Prevalence, % Medical patients General surgery 10 -20 15 -40 Major GYN surgery Major GU surgery 15 -40 Neurosurgery Stroke 15 -40 20 -50 Hip or Knee surgery Major Trauma 40 -60 40 -80 Spinal Cord Injury Critical Care patients 60 -80 10 -80

Thromboprophylaxis Reduces DVT Events n Pulmonary Embolus is the most common preventable cause of hospital death

Risk Factors for DVT n n n Surgery Trauma Immobility, paresis Malignancy Cancer therapy Previous VTE Increasing age Pregnancy and postpartum Estrogen-containing oral contraception or HRT Selective estrogen receptor modulators Acute medical illness n n n n n Heart or respiratory failure Inflammatory bowel disease Nephrotic syndrome Myeloproliferative disorders Paroxysmal nocturnal hemoglobinuria Obesity Smoking Varicose veins Central venous catheterization Inherited or acquired thrombophilia

Methods of Prophylaxis n Mechanical Methods n n Studies n n Graduated Compression Stockings Intermittent Pneumatic Compression device Venous foot pump Not blinded High rate of false negative scans Compliance in true practice – poor Acceptable option n n High risk for bleeding Adjunct to anticoagulant prophylaxis n Improves efficacy when used in combination with anticoagulant prophylaxis

Anticoagulants n n n Most widely used and studied prophylaxis Before 1987, only heparin and warfarin were available Now, 4 low molecular weight heparins 1 Factor Xa inhibitor 3 direct thrombin inhibitors 1 coumarin derivative

Unfractionated Heparin Potentiates inactivation of activated enzymes of clotting cascade, via binding to antithrombin III Effective in preventing DVT in low and moderate risk patients Does not increase risk of hemorrhage

Low Molecular Weight Heparin Higher bioavailability; stable and predictable antithrombotic activity Can be administered once-daily Lower risk of thrombocytopenia More effective for high risk prophylaxis than heparin

General Surgery n 46 RCT Low Dose Unfractionated Heparin v. placebo or no proph. n Reduced n DVT 22 to 9% n Symptomatic PE 2 to 1. 3% n Fatal PE 3 to. 8% n Meta-analysis n No increase in wound hematoma or bleeding

General Surgery n LMWH (Lovenox) n Meta-analysis 2002) n 70 n (Douketis Arch Intern Med % reduction DVT v. no prophylaxis Nine meta-analysis and systematic reviews n No difference in DVT LMWH and UFH n Some trials fewer hematomas and bleeding complications with LMWH n No difference in total mortality, fatal PE between LDUH 5000 units TID and LMWH

General Surgery n Low Risk Minor Surgery (hernia repair, outpatient surgery) n < 40 years of age n No additional risk factors n n Risk DVT n PE n n Calf – 2% Clinical – 0. 2% Proximal – 0. 4% Fatal - <0. 01% Prevention Strategies n No specific prophylaxis; early mobilization

General Surgery n Moderate Risk n n n Minor Surgery with additional risk factors Age 40 -60 with no risk factors Major surgery, < 40 with no risk factors DVT PE Calf - 10 -20% Clinical - 1 -2% Proximal - 2 -4% Fatal - 0. 1 -0. 4 % Prevention Strategies n n LDUH (5, 000 units q 12 hours, start 1 -2 hrs pre-op) LMWH ( 30 mg daily) Graduated Compression Stockings Intermittent Pneumatic Compression Devices

General Surgery n High Risk n n n Risks n n n Non-major surgery in age > 60 yr. or have additional risk factors Major Surgery > 40 or have additional risk factors DVT PE Calf – 20 -40% Clinical – 2 -4 % Prevention Strategies n n LDUH (5, 000 U q 8 hours) LMWH ( 30 mg q 12 h) Proximal – 4 -8% Fatal – 0. 4 -1. 0%

General Surgery n Highest Risk n n n Surgery in patients with multiple risk factors DVT Calf – 40 -80% Proximal – 10 -20% PE Clinical – 4 -10% Fatal - 0. 2 - 5% Prevention Strategies n n n LDUH ( 5, 000 q 8 hours) or LMWH ( 30 mg q 12 h) with GCS and/or IPC

General Surgery n Special Considerations High Risk of Bleeding Properly fitted GCS and/or IPC Major Cancer Surgery Post hospital discharge prophylaxis with LMWH for 2 -3 weeks Prolonged prophylaxis in abdominal and pelvic cancer reduced DVT 12 to 5% Bergqvist NEJM 2002

Vascular Surgery n Risk n Aortic Surgery - DVT – 0. 9 - 12 % No prophylaxis – 41% n Femorodistal – DVT – 0. 7 – 9% prophylaxis – 18% n No routine prophylaxis in patients without risk factors n LDUH or LMWH in patients with risk factors No

Recommendations in Laparoscopy n European Association for Endoscopic Surgery n n SAGES n n Intraoperative IPC for all prolonged laparoscopic procedures Same thromboprophylaxis options with laparoscopic procedures as for the equivalent open surgical procedures ACCP n No risk factors – aggressive early mobilization With risk factors – LDUH, LMWH, IPC or GCS

Major Trauma n n Highest Risk of all Hospitalized Patients Risk – without Rx exceeds 50% n n n Calf – 40 -80% Clinical – 4 -10% Proximal – 10 -20% Fatal - 0. 2 - 5% Risk with routine thromboprophylaxis n n DVT PE DVT Calf – 27% Proximal – 7% Increased Risk Factors n Spinal Cord injury, lower extremity or pelvic Fx, need for surgery, increasing age, femoral venous line insertion or major venous repair, prolonged immobility, prolonged ventilatory support and longer duration of hospital stay, +/ISS

Trauma Recommendations All patients with at least one risk factor receive thromboprophylaxis n LMWH as soon as considered ‘safe’ n If LMWH delayed – Boots n Continued thromboprophylaxis until mobility adequate n Duplex ultrasound screening – high risk and suboptimal prophylaxis or no prophylaxis n

Pain An unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage.

“Pain is whatever the experiencing person says it is and exists whenever he/she says it does. ”

Classes of drugs n Opioid analgesics n Nonsteroidal anti-inflammatory drugs (NSAIDS) (Aspirin, Motrin, Toradol)

Opioid Analgesics

Schedules of Controlled Narcotics n Schedule I: Unacceptable potential for abuse: Heroin, Cocaine, LSD n Schedule II: High potential for abuse and dependence: opioids, amphetamines n Schedule III: Intermediate potential for abuse: codeine+ acetaminophen, hydrocodone + acetaminophen

Schedules of Controlled Narcotics n Schedule IV: Less abuse potential than schedule III, minimal dependence: lorazepam alprazolam, diazepam n Schedule V: minimal abuse potential: codiene cough syrup, lomotil

Action Binds to opiate receptors in the central nervous system. Alters the perception of and response to painful stimuli Produces generalized CNS depression

CNS side effects of opioids Respiratory depression n Hypotension, orthostatic hypotension n Constipation, nausea, vomiting n Urinary retention n Confusion n Rash n

Contraindications & Precautions n Contraindications: n n Hypersensitivity Precautions: Elderly n Respiratory diseases n Head trauma n Liver or kidney disease n Opioid addiction n

Morphine Prototype opioid analgesic n Equianalgesic doses of opioids n Indications: n Severe pain n Pulmonary edema n Pain associated with myocardial infarction. n

Morphine administration routes n Many preparations & routes: Oral: tablets, extended release (MS Contin) n elixir (Roxanol) n Sublingual tablets: 10 mg, rapidly absorbed n IM n IV, PCA n Epidural n

Postoperative pain n Regular & frequent dosing intervals in early postop period, then PRN PCA, Epidural, IV n Opioid + NSAID n Switch to oral dosing when taking po n n Medicate prior to anticipated pain Ambulation & physical therapy n Dressing changes n

PCA: patient controlled analgesia n Self-administration n Very of IV analgesic effective n Prevents delays n Reduces patient anxiety

PCA dosing n Example n n n Morphine PCA 30 mg/30 ml Basal rate 1 mg/hr Demand dose 1 -2 mg Lockout 6 -8 minutes 4 Hour Max

QUESTIONS ?