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

ALGORITHMS Pre-operative Assessment FeverOliguria DVT Prophylaxis Pain

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? Question: > 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 yr No labs Females Preg Test yr EKG Females Preg Test >60yo 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….. Systems Assessment CNS Pulmonary GI Heme/Onc Medications Seizure/stroke PFT’s, ABG, Bronchodilators, Steroids Liver dz Renal CBC, Lytes CBC,INR,PT,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

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

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

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

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

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

68yo male s/p LAR with loop ileostomy T 37 P 110 BP 110/75 R12 UO 14cc in the last hour

Fe NA = Urine [Na] / Plasma [Na] Urine [Cr] / Plasma [Na] x100 FeNa < 1% prerenal FeNa > 2% renal (ATN) Urinary sodium (meqL) <20 prerenal >40 renal

Venous Thromboembolism DVT 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.The Leapfrog Group Hospital Quality and Safety Survey. Available at: 2.Shojania KG, et al. Making Healthcare Safer: A Critical Analysis of Patient Safety Practices. AHRQ, Available at: 3.White Paper. Deep-vein thrombosis: Advancing awareness to protect patient lives Available at:

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

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

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

Risk Factors for DVT Surgery Surgery Trauma Trauma Immobility, paresis Immobility, paresis Malignancy Malignancy Cancer therapy Cancer therapy Previous VTE Previous VTE Increasing age Increasing age Pregnancy and postpartum Pregnancy and postpartum Estrogen-containing oral contraception or HRT Estrogen-containing oral contraception or HRT Selective estrogen receptor modulators Selective estrogen receptor modulators Acute medical illness Acute medical illness 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 Mechanical Methods Mechanical Methods Graduated Compression Stockings Graduated Compression Stockings Intermittent Pneumatic Compression device Intermittent Pneumatic Compression device Venous foot pump Venous foot pump Studies Studies Not blinded Not blinded High rate of false negative scans High rate of false negative scans Compliance in true practice – poor Compliance in true practice – poor Acceptable option Acceptable option High risk for bleeding High risk for bleeding Adjunct to anticoagulant prophylaxis Adjunct to anticoagulant prophylaxis Improves efficacy when used in combination with anticoagulant prophylaxis Improves efficacy when used in combination with anticoagulant prophylaxis

Anticoagulants Most widely used and studied prophylaxis Most widely used and studied prophylaxis Before 1987, only heparin and warfarin were available Before 1987, only heparin and warfarin were available Now, 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 46 RCT Low Dose Unfractionated Heparin v. placebo or no proph. 46 RCT Low Dose Unfractionated Heparin v. placebo or no proph. Reduced Reduced DVT 22 to 9% DVT 22 to 9% Symptomatic PE 2 to 1.3% Symptomatic PE 2 to 1.3% Fatal PE 3 to.8% Fatal PE 3 to.8% Meta-analysis Meta-analysis No increase in wound hematoma or bleeding No increase in wound hematoma or bleeding

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

General Surgery Low Risk Low Risk Minor Surgery (hernia repair, outpatient surgery) Minor Surgery (hernia repair, outpatient surgery) < 40 years of age < 40 years of age No additional risk factors No additional risk factors Risk Risk DVT Calf – 2%Proximal – 0.4% DVT Calf – 2%Proximal – 0.4% PEClinical – 0.2%Fatal - <0.01% PEClinical – 0.2%Fatal - <0.01% Prevention Strategies Prevention Strategies No specific prophylaxis; early mobilization No specific prophylaxis; early mobilization

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

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

General Surgery Highest Risk Highest Risk Surgery in patients with multiple risk factors Surgery in patients with multiple risk factors Risk Risk DVT Calf – 40-80%Proximal – 10-20% DVT Calf – 40-80%Proximal – 10-20% PE Clinical – 4-10%Fatal % PE Clinical – 4-10%Fatal % Prevention Strategies Prevention Strategies LDUH ( 5,000 q 8 hours) or LDUH ( 5,000 q 8 hours) or LMWH ( 30mg q12h) with LMWH ( 30mg q12h) with GCS and/or IPC GCS and/or IPC

General Surgery Special Considerations Special Considerations High Risk of Bleeding High Risk of Bleeding Properly fitted GCS and/or IPC Properly fitted GCS and/or IPC Major Cancer Surgery Post hospital discharge prophylaxis with LMWH for 2-3 weeks 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 Risk Risk Aortic Surgery - DVT – %No prophylaxis – 41% Aortic Surgery - DVT – %No prophylaxis – 41% Femorodistal – DVT – 0.7 – 9%No prophylaxis – 18% Femorodistal – DVT – 0.7 – 9%No prophylaxis – 18% No routine prophylaxis in patients without risk factors No routine prophylaxis in patients without risk factors LDUH or LMWH in patients with risk factors LDUH or LMWH in patients with risk factors

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

Major Trauma Highest Risk of all Hospitalized Patients Highest Risk of all Hospitalized Patients Risk – without Rx exceeds 50% Risk – without Rx exceeds 50% DVT Calf – 40-80%Proximal – 10-20% DVT Calf – 40-80%Proximal – 10-20% PE Clinical – 4-10%Fatal % PE Clinical – 4-10%Fatal % Risk with routine thromboprophylaxis Risk with routine thromboprophylaxis DVT Calf – 27%Proximal – 7% DVT Calf – 27%Proximal – 7% Increased Risk Factors Increased Risk Factors 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 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 All patients with at least one risk factor receive thromboprophylaxis LMWH as soon as considered ‘safe’ LMWH as soon as considered ‘safe’ If LMWH delayed – Boots If LMWH delayed – Boots Continued thromboprophylaxis until mobility adequate Continued thromboprophylaxis until mobility adequate Duplex ultrasound screening – high risk and suboptimal prophylaxis or no prophylaxis Duplex ultrasound screening – high risk and suboptimal prophylaxis or no prophylaxis

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

Opioid Analgesics

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

Schedules of Controlled Narcotics Schedule IV: Less abuse potential than schedule III, minimal dependence: lorazepam alprazolam, diazepam Schedule IV: Less abuse potential than schedule III, minimal dependence: lorazepam alprazolam, diazepam Schedule V: minimal abuse potential: codiene cough syrup, lomotil 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 Respiratory depression Hypotension, orthostatic hypotension Hypotension, orthostatic hypotension Constipation, nausea,vomiting Constipation, nausea,vomiting Urinary retention Urinary retention Confusion Confusion Rash Rash

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

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

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

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

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

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

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