Peri-op  TOC  

PERIOPERATIVE POCKET MANUAL 2005  (Contents)  - 3rd Edition

Maracus Magallanes, MD 2005

14. SELECTED PERIOPERATIVE TOPICS

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PATIENTS ON CHRONIC ANTICOAGULATION

ESTIMATED SHORT-TERM RISK OF THROMBO-EMBOLISM OFF CHRONIC ANTICOAGULATION

(OFF ANTICOAGULATION means the interval during which the patient is no longer therapeutically anti-coagulated, not just the interval of withholding coumadin.)

LOW: probably safe 1 week (or more) off anticoagulation

INTERMEDIATE: probably safe 3-5 days off anticoagulation (less than 1 week off advised)

HIGH: no more than 3 days off anticoagulation advised  

(*48 hours or less for prosthetic MITRAL valve if possible)

NOTES:

  1. If PE or DVT history is recurrent or if patient has a known or suspected hypercoagulable state, then thromboembolic risk may be higher and warrant higher risk management.

  2. There is no data demonstrating that recurrent stroke/TIA  of unidentifiable source is a high-risk thromboembolic condition; therefore, the short-term risk of simply withholding coumadin is considered low.   

  3. There is no good data regarding thromboembolic risk for this group of patients.  These guidelines are a best guess.

  4. Unless absolutely necessary, patients with a recent PE or  DVT should not undergo surgery until at least two weeks after diagnosis and anticoagulation for the PE/DVT  (preferably one month or later for non-urgent cases).  
    Strong consideration for IVC filter placement should be given for patients who require major surgery (and reversal of anticoagulation) within two weeks of a PE/DVT.

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REVERSAL OF ANTICOAGULATION FOR SURGERY (INPATIENTS)

If coumadin is simply withheld, it usually takes 3 to 5 days for a therapeutic protime to normalize.  If normalization is needed sooner, reverse coumadin with a single dose of Vitamin K 10mg SQ or PO .  Protime should improve sub-stantially by 24 hours.  Repeat dose only if needed.

(Goal INR for major surgery is less than 1.5.)

For those patients who require continued anticoagulation up until near surgery (while the protime is normalized), heparin drip can be run until 4-6 hours before the procedure and then stopped, without having to recheck PTT.

For more urgent reversal of anticoagulation, Vitamin K 10mg IVPB over 30 minutes can be given with substantial effect by 6 to 8 hours.  This can be done with or without FFP, depending on the timeframe for surgery.  (IV Vitamin K should be reserved for urgent use only.  There have been rare but severe reported reactions with the IV dose.)

If patient needs to go to surgery immediately and protime is significantly elevated due to coumadin, give FFP (2 units if INR <2.5 or 4 units if INR >2.5) before going to the OR in addition to STAT Vitamin K 10mg IVPB over 30 minutes.  This should readily correct the coagulopathy.  REMEMBER that the effect of FFP lasts only about 6 hours; by then the IV Vitamin K will have kicked in.

POSTOP, coumadin can be resumed when patient is able to take pills again.  After restarting, it usually takes 2 to 3 days to notice a bump in the protime and 4-5 days to achieve therapeutic level.  (These numbers may be prolonged if patient received Vitamin K preoperatively.)  For those patients who need to be anticoagulated in the interim, give therapeutic dose enoxaparin (1mg/kg SQ q12h) or heparin drip until protime reaches desired level.  

NOTES:

The therapeutic dose of enoxaparin in patients with renal failure is still unclear. *Generally it is safer to avoid enoxaparin in this group due to major bleeding risk, unless the rapid anti-Xa lab test is available for monitoring and then adjustment of enoxaparin dose can be performed.

There is a general warning regarding enoxaparin use prior to spinal/epidural anesthesia due to reports of spinal/ epidural hematomas.  For surgical inpatients who require anticoagulation up until near surgery, it is simplest and safest to use heparin drip preoperatively rather than therapeutic dose enoxaparin (stopping the heparin drip 4-6 hours before surgery).  However, if for some reason enoxaparin is used instead, the current recommendation is that the last preoperative dose be given 24 hours or more before spinal/epidural anesthesia and surgery in general.  This takes into account the 4.5 hour half-life of enoxaparin and is accepted as a safe interval of cessation.

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PATIENTS ON STEROIDS

*There is a significant risk for acute intraoperative or postoperative adrenal insufficiency in patients who are taking or who have taken corticosteroids within the past one year.  The typical manifestation of acute adrenal insufficiency in the surgical patient is unexplained hypotension.  Other possible manifestations include abdominal pain, emesis, weakness/fatigue, hyponatremia, hyperkalemia, acidosis, and hypoglycemia.

SUGGESTED CANDIDATES FOR STRESS DOSE STEROIDS:

  1.  Any patient who has taken 20mg or more of Prednisone (or equivalent) daily for more than one week within the past one year

  2. Any patient who has taken lower doses of Prednisone (or equivalent) daily for at least one month within the past one year

  3. Any patient with suspected adrenal insufficiency

*The reality is that nobody knows the minimum duration or the lowest dose of steroids that produces adrenal axis suppression.  What is known is that once adrenal axis suppression has occurred, it may take up to 12 months for complete recovery, hence the one year time frame for prior steroid use.  The above recommendations are generally accepted as reasonable guidelines for the patient undergoing major surgery.  Furthermore, very rarely is a cortrosyn stimulation test performed preoperatively to prove or disprove adrenal axis suppression; patients are simply treated empirically based on clinical judgement.  

SUGGESTED STRESS DOSE STEROID REGIMEN:

Hydrocortisone 100mg IV either at the start of surgery or just prior to procedure, followed by 100mg IV q8 hours postop for major surgeries.  Continue 100mg IV q8 hours for at least 24 hours or until the apparent surgical stress begins to subside, at which point the dose should be lowered to 50mg IV q8 hours for 24 to 48 hours and then simply discontinued (or further tapered to 25mg before discontinuation).

If patient was taking oral steroids preoperatively, then the prior oral steroid dose is resumed at the end of the taper.  If patient is still NPO by then, simply continue the IV hydrocortisone—minimum 25mg q8 hours—until patient can resume the oral steroid.

For minor surgeries, a single dose of hydrocortisone 50 to 100mg IV at the start of surgery or just prior to procedure will suffice without any additional dosing.

*There are a number of variations to the stress dose steroid regimen.  The basic principle for the different regimens is the same: administer the maximum amount of steroid at the peak of surgical stress and then taper rapidly as the surgical stress subsides.  The above regimen is simple and reasonable, and it should cover the majority of surgical cases encountered.  The normal adrenal response to stress is approximately 300mg of cortisol (hydrocortisone) per day, hence the equivalent stress steroid dose of 100mg q8 hours.

DURATION AND POTENCY OF DIFFERENT STEROID AGENTS:

                                               Glucocorticoid      |     Mineralocorticoid    |  Biologic 

                                                       Potency                    Potency              Half-life (hr)

HYDROCORTISONE                            1                           1                    8-12  

PREDNISONE                                       4                           0.5                 18-36

METHYL- PREDNISOLONE               5                             0                   18-36

DEXAMETHASONE                           30                            0                     >48

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HIP FRACTURE

*Hip fracture patients represent a high-risk group of surgical patients.  Statistically, mortality is 5-10% within 30 days of hip fracture surgery and up to 20% within 3 months.  The major causes of mortality are pneumonia, CHF, pulmonary emboli, MI, and sepsis (in that order); these account for over 90% of post-hip fracture deaths.

TYPES OF HIP FRACTURES

1)      Anatomic location: femoral neck, intertrochanteric, subtrochanteric

2)      Garden classification: incomplete (Garden 1), complete + nondisplaced (Garden 2), complete + partially displaced (Garden 3), completely displaced (Garden 4)

TYPES OF REPAIR PROCEDURES

1)      Pinning—lowest risk procedure, but the least likely to lead to functional recovery.

2)      Internal fixation—generally used in patients with nondisplaced or minimally displaced fractures; also an option in younger patients with displaced fractures.

3)      Prosthetic replacement—either arthroplasty or hemiarthroplasty; generally preferred in older patients with displaced fractures.

TIMING OF SURGERY

As a general rule, the sooner the better.  The preferable time frame is within 24 to 48 hours of admission, thus minimizing the period of immobility and the associated problems with prolonged bedrest before surgery.  Further surgical delay to stabilize acute medical issues (such as CHF, pneumonia, cardiac ischemia, etc.) may be necessary, but the surgical complication rate does increase significantly the longer the immobility—probably after 72 hours—although the definitive timeframe is unclear.

Conservative management—meaning no surgery—is an option only for terminally ill or very high operative risk patients.  The mortality rate for nonoperated hip fractures is high, and the associated immobility due to the hip fracture is prolonged indefinitely.

MANAGEMENT ISSUES

1)      DVT prophylaxis—enoxaparin at prophylactic dose (30 mg SQ BID or 40mg SQ qD) is the preferred agent.  It can be administered postoperatively either the same day surgery is performed or 8 to 12 hours after the procedure if an epidural or spinal anesthetic was employed (due to concern about spinal hematoma).  Additionally, enoxaparin should not be given if an indwelling epidural catheter for analgesia is left in-place postoperatively until 8 to 12 hours after removal of the catheter.  

Administration of enoxaparin in the interval before surgery is certainly warranted if surgical repair is not anticipated within 24 hours. The final dose of preoperative enoxaparin should be given 24 hours or more before the procedure, so that there is ample time for the anticoagulant effect to wear off by the time of surgery (particularly if spinal/epidural anesthesia is anticipated).  

2)      Infectious complications—pneumonia, UTI, wound infection are common.  Early mobilization is key to prevention.  Remove foley catheter as soon as patient can use a bedpan or urinal.  Antibiotic wound prophylaxis is routine.  (Postop fever is very common and frequently does not represent a true infection.  Postop inflammation and/or atalectasis can cause fever soon after surgery.)  

3)      Postoperative delirium—also common.  In general, I recommend avoiding demerol and all benzodiazepine agents in very elderly patients or patients with underlying cognitive dysfunction.  PO pain meds and IV morphine are less likely to cause delirium, although certainly they can be causative themselves.  Other contributing factors to watch for are electrolyte disturbances, anemia, hypoxia, hypo/hyperglycemia, and occult infection.  

4)      Why did the patient fall?  Do not overlook the etiology of the patient’s injury.  A fall may represent syncope (cardiac or non-cardiac), seizure, stroke, vertigo, intoxication, weakness, or—in its most benign form—a simple slip.  Clearly the etiology of a fall can have serious implications for surgery.

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POSTOPERATIVE DELIRIUM

*Postop delirium is characterized by waxing and waning lucidity, confusion, possible psychosis, and a variable degree of behavior ranging from somnolence to agitation.  Onset may be subtle or abrupt, and recovery back to baseline may take anywhere from a few days to a few weeks or even months, depending on severity.  The single most important risk factor for postoperative delirium is preoperative cognitive status.  Additional significant risk factors include advanced age, psychiatric illness, underlying organic brain disorder (such as stroke, hydrocephalus, Parkinson’s disease, dementia, etc.) and substance abuse, particularly alcohol.  

MANAGEMENT:

1)      Avoid demerol and all benzodiazepine drugs.  Narcotic agents may need to be switched, dose-adjusted, perhaps even held in patients who are confused post-op.  (Benzodiazepine drugs would only be appropriate in patients with suspected alcohol withdrawal.)

2)      Drugs with anticholinergic effects (such as benadryl and vistaril) should also be avoided.  Additional common medications which may contribute to delirium include steroids, cimetidine, propranolol, anticonvulsants, and digoxin. *Pharmacy can be asked to check the side effect profile of all the medications being used, specifically for confusion.

3)      Cut out unnecessary medications and keep the number of inpatient drugs to an absolute minimum, especially in the very elderly.

4)      Check and correct electrolyte abnormalities, particularly sodium, calcium, and magnesium.

5)      Check glucose for hypo/hyperglycemia.

6)      Check oxygen saturation; if indicated, an ABG to rule-out CO2 narcosis.

7)      Need also rule-out underlying infection, cardiac ischemia, hepatic dysfunction, and CVA.  ( Head CT scan is NOT routinely required unless neurologic exam reveals focal abnormality, obtundation, headache, or if patient is considered high risk for stroke or bleed.)

8)      Thiamine 100 mg daily ( PO , IM, or in IVF) is recommended for suspected or known alcoholics.

9)      Agitation should be managed with low dose haldol.  The typical dose initially is 1 to 5 mg IM q 4 hours prn agitation.  If necessary for prolonged confusion/agitation, a standing dose of PO haldol can be written TID or QID, and then eventually discontinued as delirium subsides.

*The etiology of postoperative delirium is typically multifactorial.  It is common not to be able to determine a single precipitating factor as cause.

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PERIPHERAL VASCULAR DISEASE

*The pathophysiology and risk factors for peripheral vascular disease and for coronary artery disease are essentially identical, so much so that patients with PVD can simply be assumed to have underlying CAD.  What is more clinically relevant in these patients is the degree of the underlying CAD, which is particularly difficult to assess because a majority of these patients are asymptomatic from a cardiac standpoint.

CORONARY ANGIOGRAPHY STUDY (Hertzer, 1984)

A total of 1000 angiograms performed routinely prior to elective vascular surgery:

Normal coronaries—8% only

            Mild/moderate CAD—32%

            Advanced to severe CAD—60%

*These patients had neither a history of nor symptoms of ischemic heart disease.

BOTTOM LINE:  Just assume that your patient with peripheral vascular disease—be it carotid arteries, aorta, or lower extremities—has underlying CAD and manage the patient based on that assumption.  Clearly all patients with PVD should be considered for perioperative beta-blocker therapy (if not already on a beta-blocker).  Other interventions for CAD in the surgical patient should also be considered on a case-by-case basis.  Heightened awareness for perioperative myocardial ischemia is warranted as well.

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PERIOPERATIVE BETA-BLOCKERS 

*The use of beta-blockers perioperatively has been shown to reduce the incidence of postoperative myocardial ischemia and the incidence of cardiovascular complications and mortality for as long as two years after surgery.  The study group consisted of patients either who had clinical evidence or history of coronary artery disease or who were at high risk of underlying CAD.  The beta-blocker therapy was started just before surgery and continued for a total of one week postoperatively.  Patients enrolled were at the VA Hospital undergoing noncardiac surgery under general anesthesia.  (Subsequent studies have demonstrated a clear benefit of beta-blocker therapy in CAD patients undergoing major surgery, although the exact dose and duration of therapy is still uncertain.)

All inpatients at Bellflower Hospital who require major surgery and who either have evidence of CAD or are at significant risk of underlying CAD should be strongly considered for prophylactic beta-blocker therapy.  (If patient is already on a beta-blocker, it needs to be continued perioperatively.)

STATISTICAL BENEFIT FOR APPROPRIATE PATIENTS UNDERGOING MAJOR SURGERY:

·        50% relative reduction in overall mortality 1

·        65% relative reduction in cardiac mortality 1

·        90% relative reduction in combined nonfatal MI + cardiac death for high-risk cardiac patients 2

*Data from 1Mangano, NEJM Dec1996; 335:1713-20 and 

   2Poldermans, NEJM Dec1999; 341:1789-94

THE FOLLOWING PATIENT SELECTION AND EXCLUSION CRITERIA ARE SUGGESTED GUIDE-LINES ONLY.  USE YOUR DISCRETION.

SUGGESTED PATIENT SELECTION FOR PROPHYLACTIC BETA-BLOCKERS

Any patient with 1 (one) of the following:

Or any patient 65 or older with 2 (two) of the following:

*Age cutoff is unclear—should consider patients under 65.

SUGGESTED EXCLUSION CRITERIA FOR PROPHYLACTIC BETA-BLOCKERS

Known intolerance to beta-blockers

  SUGGESTED BETA-BLOCKER REGIMEN

Preoperatively:

Postoperatively:

NOTE:

·        I generally write hold orders for the beta-blocker, such as hold dose for HR <60 or SBP <110.

·        If you want to put someone on a prophylactic beta-blocker but you are concerned about the possibility of adverse reaction to the medication, you can order a test dose of metoprolol 2.5 mg IV ahead of surgery and then, if tolerated, order the beta-blocker as suggested above.

·        Patients already taking a beta-blocker prior to surgery must have it continued at the time of surgery and postoperatively (unless the drug is being held for hypotension, bradycardia, wheezing, etc.)

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THE USE OF A PULMONARY ARTERY CATHETER (SWAN-GANZ)  

*The role of a PA catheter for surgery even in very high-risk patients remains controversial.  There are no definitive studies that have proven benefit in the surgical setting.  More recently, one randomized controlled trial of PA catheters in high-risk surgical patients showed no survival benefit with PA catheters versus standard care.1   The ultimate decision regarding the need for a PA catheter intraoperatively must be made on a case-by-case basis and should involve input from the surgeon, the anesthesiologist, and the internist/cardiologist.  The current trend is away from the use of a PA catheter for surgery, except in very select cases.

Examples of conditions for which a PA catheter might be considered for major surgery include active CHF, severely depressed LV function, and critical aortic stenosis.  If a PA catheter is deemed necessary for surgery, then assistance from Cardiology is essential for patient management.

Reference 1Sandham JD, NEJM Jan 2003; 348: 5-14

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ANTIBIOTIC PROPHYLAXIS  

VALVE PROPHYLAXIS

*The details of what conditions to prophylax and which antibiotic to give change routinely per the American Heart Association guidelines.  In general, I simply recommend prophylaxis in patients with any significant valvular lesion, a prosthetic heart valve, or a history of endocarditis.  The procedures which require prophylaxis for these conditions are any major dental work or oral surgery, gastrointestinal/urologic/gynecologic surgeries or endoscopic procedures.  

USUAL REGIMEN (INPATIENTS):  Ampicillin 2.0 gm IV at the start of surgery as a single dose.  If patient is allergic to PCN, then Vancomycin 1.0 gm IV at the start of surgery as a single dose.

HIGH-RISK REGIMEN (INPATIENTS): *This applies to patients with a prosthetic heart valve or a history of endocarditis.  Ampicillin 2.0 gm + Gentamicin (1.5 mg/kg, not to exceed 120mg) IV at the start of surgery followed by one more dose of Ampicillin 1.0 gm IV 6 hours later.  If patient is allergic to PCN, then a single dose of Vancomycin 1.0 gm + Gentamicin IV at the start of surgery only. 

(Vancomycin is a restricted antibiotic but I.D. approval is not necessary for a single dose in the O.R.)

WOUND PROPHYLAXIS

*Surgical wound prophylaxis applies to prevention of local wound infection postoperatively in a previously uninfected site; it does not apply to treatment of already infected tissue or intraoperative spillage/contamination of potentially infectious material.

USUAL REGIMEN:  Ancef 1.0 gm IV q8 hours for 24 to 48 hours postop.  Alternative antibiotic for wound prophylaxis is Clindamycin if patient cannot take Ancef.  (Vancomycin is indicated for wound prophylaxis only if patient cannot take either Ancef or Clindamycin due to severe allergic reaction, such as anaphylaxis.)

For colorectal surgery, Flagyl 500 mg IV q8 hours for 24 to 48 hours postop may be added.  Preoperative oral Neomycin + Erythromycin along with bowel prep prior to colorectal surgery is also beneficial.

*Ideally a single preoperative dose of IV antibiotic should be given within one hour of surgery.  This preoperative dose is actually the most important one with regard to prophylactic benefit.

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DVT PROPHYLAXIS   

GENERAL RECOMMENDATIONS:

1)      SQ HEPARIN (5000 units q 8-12 hours)—adequate prophylaxis for most procedures (particularly in combination with pneumatic compression boots) but not effective for hip or knee surgeries.  Heparin should not be used in patients with active bleeding, significant thrombocytopenia, or after neurosurgical/ophthalmologic procedures.

2)      PNEUMATIC COMPRESSION BOOTS (flowtrons)—adequate prophylaxis alone or, even more effective, in combination with one of the other modalities.  It is the prophylaxis of choice for neurosurgical/ophthalmologic procedures.  Pneumatic compression boots should not be used in patients who have undergone lower extremity vascular surgery.

3)      ENOXAPARIN (30 mg SQ BID or 40mg SQ qD)—highly effective prophylaxis but more costly.  It is the prophylaxis of choice for hip surgery and other immobilizing major orthopedic procedures.  It should also be considered in high-DVT-risk patients who undergo major surgery with postoperative immobility.

(The dose for renal failure patients is not known. Unless essential, it is probably safer to avoid enoxaparin in this group due to increased bleeding complications.)

4)      ASPIRIN (325 mg daily)—previously deemed inadequate for DVT prophylaxis but there is data suggesting that it may be effective, specifically after orthopedic surgery.  It is currently listed on the Bellflower orthopedic protocol for DVT prophylaxis after knee replacement surgery in combination with pneumatic compression boots.

5)      COUMADIN—no longer a commonly used modality for prophylaxis but still employed on occasion for high DVT risk patients/procedures.  The usual strategy involves postoperative coumadin dosing to achieve a protime INR of 2-3 and then continue for 1 to 3 months, depending on the surgery and postoperative mobility.

NONPHARMOCOLOGIC INTERVENTIONS TO REDUCE DVT RISK:

1)      LEG ELEVATION (1 to 2 pillows beneath distal lower extremities while in bed)—this has been shown to decrease the incidence of PE in hospitalized patients, but the data is controversial with regard to DVT prophylaxis.  It is a simple, cheap, and well-tolerated intervention, although not recommended for patients with lower extremity vascular insufficiency.

2)      EARLY MOBILIZATION/AMBULATION—clearly decreases DVT risk in postop patients.

*WARNING REGARDING ENOXAPARIN:

There have been a number of case reports of spinal/epidural hematomas after spinal/epidural anesthesia in patients receiving enoxaparin, even at prophylactic doses.  The current recommendation is that the last preoperative dose of enoxaparin be given 24 hours or more before spinal/ epidural anesthesia and surgery in general (taking into account the 4.5 hour half-life).  Postoperative dosing of enoxaparin should not resume until 8-12 hours after spinal/epidural catheter is removed.

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HIGH-RISK WOUND INTERVENTIONS  

*Patients considered high risk for postoperative wound complications/wound infection would benefit from the following preventative interventions.  

1)       INTRA-OPERATIVE NORMOTHERMIA: Maintaining core temperature near 36.5 degrees C during surgery has been shown to decrease the incidence of surgical wound infection by a relative difference of about 70%.  This is achieved by intra-operative warming measures, such as a warming blanket and IV fluid warmer.  (Study group consisted of patients undergoing colorectal resection.1)  

NOTE that intra-operative normothermia has also been shown to improve perioperative cardiac morbidity and to decrease surgical bleeding.

 2)       PROPHYLACTIC ANTIBIOTICS: Essential but no demonstrable benefit beyond 24-48 hours post-operatively in the patient without clinical infection.  Most important dose is the initial preoperative dose within one hour prior to procedure.  (See Antibiotic Prophylaxis section.)

 3)       VITAMIN A SUPPLEMENTATION: Administration of Vitamin A (25,000 to 100,000 units daily) has been recommended for high-risk wound patients in general; however, the only reasonably good data is in steroid-treated patients, for whom the benefit is likely to be significant.2  Oral Vitamin A (6000 or 8000 units per tablet over-the-counter) is well-tolerated and inexpensive; the only contraindication is pregnancy.  Begin preoperatively if possible, and continue postop for  one to two weeks.  Injectable Vitamin A is no longer available.

 4)       GLYCEMIC CONTROL: Perioperative glycemic control in diabetics is proven to decrease the risk of infectious complications after surgery.  In general, the closer to normal blood sugars the better, although a cutoff range appears to be under 200-230.3  

(NOTE that intra-operative high flow oxygen is no longer a recommended intervention for high-risk wound patients.  Current data has shown no demonstrable benefit from this intervention, and it may actually be detrimental to some extent.4)  

REFERENCES

1Kurz, NEJM May 1996; 334:1209-15

2Anstead, Advances in Wound Care Oct 1998; 11:277-85

3Golden, Diabetes Care Sept 1999; 22:1408-14

4Pryor, JAMA Jan 2004; 291:79-87

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POSTOPERATIVE PAIN MANAGEMENT

PATIENT CONTROLLED ANALGESIC (PCA)

MEDICATIONS:

PARAMETERS:

INJECTABLE NARCOTIC MEDICATIONS (prn)

·        Morphine (MS) IV or SQ—2 to 10 mg q2h to q6h

·        Hydromorphone (Dilaudid) IM, IV, or SQ—0.5 to 2 mg q2h to q6h  (*Conversion: MS 10mg = 1.5mg Dilaudid)

·        Meperidine (Demerol) IM or SQ—50 to 150 mg q3h to q4h; IV dosing may be given if necessary but must be administered slowly (no greater than 25 mg per minute).

*Demerol is no longer considered a first-line agent for pain control due to risk of major adverse reactions such as seizures, hypotension, and delirium.  It should be given with extreme caution in elderly patients, in patients with renal failure, and patients with a seizure history.  It is contraindicated in patients on MAO inhibitors, most commonly Eldepryl (Selegiline) for Parkinson’s disease.

ORAL NARCOTIC MEDICATIONS (prn)

*In order of increasing strength:

·        Darvocet-N 100 (acetaminophen 650mg + propoxyphene 100mg)—1 tablet q4h

·        Tylenol with codeine (#3: acetaminophen 300mg + codeine 30mg; #4: acetaminophen 300mg + codeine 60mg)—1 to 2 tablets q4h to q6h

·        Vicodin (acetaminophen 500mg + hydrocodone 5mg)  — 1 to 2 tablets q4h to q6h

·        Percocet (acetaminophen 325mg + oxycodone 5mg) —1 to 2 tablets q4h to q6h

·        Morphine soluble tablets (sublingual) 10mg, 15mg, 30mg—used primarily for terminally ill patients; can be taken up to every 1 hour with immediate effect.

·        Oramorph SR (MS sustained release) 15mg, 30mg, 60mg, 100mg tablets—used primarily for chronic pain; 
dose should be titrated as BID or TID regimen (not prn).

NON-NARCOTIC MEDICATIONS

·        Acetaminophen (Tylenol) —well-tolerated for mild pain

·        Aspirin/NSAID’s—generally well-tolerated for mild pain but there are concerns regarding bleeding risk.

·        Toradol (Ketorolac) IM or IV—30mg IV initial then 15mg q6h, or 60mg IM initial then 30mg q6h for 24-48h (or as prn order); same bleeding concerns as NSAID’s.

·        Vioxx (Rofecoxib)—shown to be beneficial for added pain control perioperatively without increased bleeding, but no longer a stocked drug.  Celebrex (Celecoxib) can be tried instead, but results in studies have not been as good for postoperative analgesia and added pain control.

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NUTRITION/ FLUIDS/ ELECTROLYTES

Ideal Body Weight (IBW) based on height:

            Men = 106 lb for 5 feet + 6 lb for each added inch

            Women = 100 lb for 5 feet + 5 lb for each added inch

            (metric conversion: 2.2 lb = 1 kilogram)

ESTIMATED PROTEIN-CALORIE REQUIREMENT:

Normal caloric maintenance after mild-to-moderate stress surgery = 25-30 Cal/kg/day

For severe stress surgery, sepsis, major trauma, or malnourished patient = 35-40 Cal/kg/day

Protein requirement in normal patient after mild-to-moderate stress surgery = 1.0-1.5 gm/kg/day

For malnourished patient or severe stress surgery, protein requirement = 2.0 gm/kg/day

*Above calculations are based on actual weight   or IBW, whichever is the lower.

TOTAL PARENTERAL NUTRITION (TPN) SOLUTIONS   ( Bellflower stocks Clinimix brand)

1) Standard Formulations—need specify with or without standard electrolytes:

            Dextrose 10% with Amino Acid 4.25%

            Dextrose 25% with Amino Acid 4.25%*via central IV

            Dextrose 10% with Amino Acid 2.75%

            Dextrose 5% with Amino Acid 2.75%

            (Intralipid formulations are 10% and 20% in 500ml)

2) Standard electrolytes (per liter) = sodium 35mEq, potassium 30mEq, magnesium 5mEq, calcium 4.5mEq, phosphate 15mmol, chloride 39mEq

3) Nonprotein Calories:

            Dextrose 5% = 170 per liter

            Dextrose 10% = 340 per liter

            Dextrose 25% = 850 per liter

            Intralipid 10% = 550 per 500ml

            Intralipid 20% = 1000 per 500ml

4) Protein concentration:

            Amino Acid 2.75% = 27.5 grams per liter

            Amino Acid 4.25% = 42.5 grams per liter

5) Routine additives:   multivitamins 1 vial per day, vitamin K 1mg per 2 liter bag, trace elements

Example: For a 70kg patient, standard TPN solution of D10 with AA 4.25% @100ml/hr + 20%intralipid 500ml/d provides about 1800 Cal (nonprotein) and 100gm protein per day, which is sufficient for a non-malnourished patient.

A note regarding Preoperative TPN:  The most convincing study to date concluded that preoperative TPN should be reserved only for “severely” malnourished patients undergoing major surgery.  The study involved malnourished VA Hospital patients who required laparo-tomy or noncardiac thoracotomy.  TPN was administered for 1-2 weeks preop and 3 days postop (vs. no TPN).  Overall, major complications and mortality were not significantly different between the TPN vs. no-TPN groups, but the subgroup of severely malnourished patients who received TPN had fewer noninfectious complications without an increase in infectious complications (NEJM Aug 1991; 325:525-32).  In summary, preoperative TPN should be considered only in severely malnourished patients who require major abdominal or thoracic surgery as long as operative delay is not prohibited.  Patients with mild to moderate malnutrition do not benefit from preop TPN.

Complications of TPN include cholestasis, line sepsis, hyperglycemia, and hypertriglyceridemia.  There is also an overall increased risk of major infection.

ENTERAL TUBE FEEDS (TF) + SUPPLEMENTS (supp)

*If possible, enteral nutrition is preferred over parenteral.

·        NUTREN 1.0 TF: 1 Cal per ml, 40gm protein per liter

·        NUTREN 1.5 TF: 1.5 Cal per ml, 60gm protein per liter

·        NUTREN 2.0 TF: 2 Cal per ml, 80gm protein per liter

·        PEPTAMEN TF and supp: 1 Cal per ml, 40gm protein per liter, elemental (small peptide) for impaired GI fxn

·        VIVANEX (*more elemental than peptamen, so less diarrhea effect): 1 Cal per ml, 50gm protein per liter

·        GLYTROL TF and supp: 1 Cal per ml, 45gm protein per liter, decreased carbohydrate for diabetic patients

·        RENALCAL TF and supp: 2 Cal per ml, 35gm protein per liter, recommended for pre-dialysis renal patients

·        MAGNACAL RENAL TF and supp: 2 Cal per ml, 75gm protein per liter, recommended for dialysis patients

·        NUTRI-HEP TF and supp: 1.5 Cal per ml, 40gm protein per liter, amino acid formulation for liver failure patients

·        NUBASICS supp: 1 Cal per ml, 35gm protein per liter

·        NUBASICS VHP supp: 1 Cal per ml, 62gm protein per liter (high protein supplement)

FLUIDS

*Assuming normal renal function, the usual daily fluid requirement is approximately 25-35 ml/kg in adults.  For individual surgical patients, the recommended amount of fluid is dependent upon urine output, insensible water losses (skin, wound, respiratory tract), GI losses and drainage (such as NG tube and surgical drains), intra-vascular volume status and third-spacing of fluid.  

Common IV Fluid Solutions
IV Fluid Solutions   Osmolalitiy
mOsm/kg		 Glucose
gm/liter		 Na
mEq/liter		 Cl
mEq/liter
D5W 278 50 0 0
D10W 556 100 0 0
D50W 2778 500 0 0
1/2 NS 154 0 77 77
NS 308 0 154 154
3% NaCl 1026 0 513 513
Lactate Ringer 274 0 130 130

*½NS, NS, LR commonly given as D5½NS, D5NS, D5LR, in which case glucose content is 50 gm/liter.
*LR also contains potassium 4 mEq/liter, calcium 1.5 mmol/liter, lactate 28 mmol/liter.

NOTE: To prepare a bicarbonate IV fluid solution, order ½NS with 2 amps Sodium Bicarb per liter or D5W with 3 or 4 amps Sodium Bicarb per liter (1 amp Sodium Bicarb = 44mEq Sodium)

ELECTROLYTES

*The following are the most commonly encountered electrolyte disturbances in surgical patients.

1)       HYPONATREMIA:  Moderate (sodium <130) to severe (sodium <125) hyponatremia in the surgical patient can be successfully managed with combined saline (NS) infusion and IV furosemide to raise sodium level acutely but not overly rapid.  If more aggressive therapy is necessary for severe hyponatremia, 3% saline infusion can be administered with the goal of raising sodium level by 1 mEq per hour initially.  Calculation is Total Body Water (TBW) x 1 mEq/liter/hour = number of mEq per hour of infused sodium needed to raise serum sodium by 1 mEq per hour.  (TBW is 60% of kg weight in men, 50% of kg weight in females.)  3% saline contains about 500mEq sodium/liter, or 0.5mEq/ml. Table of infusion rates of 3% saline to raise serum sodium 1meq/hour:

Weight

  Male

 Female

 Weight

   Male

 Female

 40kg

48 ml/hr

40 ml/hr

    70kg

84 ml/hr

70 ml/hr

 50kg

60 ml/hr

50 ml/hr

    80kg

96 ml/hr

80 ml/hr

 60kg

72 ml/hr

60 ml/hr

    90kg

108ml/h

90 ml/hr

*Serum sodium should not be raised more than 8 mEq in a  24h period.  Lower rates of 3% saline infusion can be used to raise sodium more slowly.

*Patients who are volume depleted should have immediate repletion of intravascular volume first with NS before attempting to correct sodium level by other means.

*Check for hyperglycemia in patients with hyponatremia.   Correction is to add 1.6 to the measured sodium for each 100 of glucose over 100.

2)       HYPOKALEMIA:  Repletion of potassium is safest via the oral route.  KCl (tablets or elixir) is the preferred preparation and can be given in 20 to 40 mEq increments, with just 2 hours between doses.  If IV replacement is necessary acutely (due to NPO status), then K-rider 40 mEq over 4 hours can be ordered initially, with subsequent doses after re-check of potassium level.  (Generally, by the time the serum potassium drops below 3.0, a total of 100 mEq or more of potassium is required to achieve a normal level in patients with normal renal function.)

 3)       HYPOMAGNESEMIA:  Repletion of magnesium is most effective via the intravenous route.  Mildly low magnesium levels can be treated with Magnesium Sulfate 1 to 2 grams in 100 ml of D5W or NS.  More depleted levels (1.0 or less) should receive 4 grams in 250 ml, with subsequent doses if needed based on re-check of level.  Rate of infusion of magnesium should be 1 gram per hour.

 4)       HYPOCALCEMIA:  Mild hypocalcemia is common and generally well-tolerated in the surgical patient.  More depleted levels require replacement; acutely this is accomplished via the intravenous route.  Calcium Gluconate 1 to 2 grams in 100 ml D5W over 1 hour can be given to replete moderate hypocalcemia, with subsequent doses if needed based on re-check of level.  Severe or symptomatic hypocalcemia requires more aggressive therapy with 2 grams of Calcium Gluconate in 100 ml D5W over 15 minutes, followed by infusion of 6 grams Calcium Gluconate in 500 ml D5W over 4-6 hours and serial calcium levels every 6 hours.

*Remember to check albumin level in patients with hypocalcemia.  The correction is to add 0.8 to the measured serum calcium for each 1.0 albumin level below 4.0.

*Magnesium level needs to be checked and, if low, repleted in order to successfully correct hypocalcemia.  

5) HYPERKALEMIA:  *See Renal section.

       Peri-op  TOC  

Dunn AS and Turpie AGG. Perioperative management of patients receiving oral anticoagulants: A systematic review.
Arch Intern Med 2003 Apr 28; 163:901-8   [Abstract]
[Journal Watch May 20, 2003 Comment:
Multiple factors -- underlying indication for OAC, type of surgery, and chosen management strategy for perioperative anticoagulation -- affect perioperative risks for thromboembolism and bleeding among patients on long-term OAC. The authors support replacing OAC with unfractionated heparin or LMWH for major surgery in patients at high risk for thromboembolism (e.g., mechanical mitral valve, atrial fibrillation with prior stroke), and they recommend withholding OAC perioperatively for major surgery in patients with lower-risk indications for OAC. Minor procedures usually can be performed without changing OAC regimens. However, the generally poor quality of the literature suggests a need for additional rigorous studies before we draw firm conclusions. — Thomas L. Schwenk, MD ]

       Peri-op  TOC