ORIGINAL ARTICLES

Guidelines for Preoperative Administration ofPatients’ Home Medications

Waseem Ashraf, MDDavid T. Wong, MD

Michael Ronayne, FCARCSIDonna Williams, BScN(c), RN

Currently, there are no agreed upon guidelines for the administra-tion of preoperative medications. Institutional guidelines were for-mulated after a review of the literature, recommendations by experts,and a consensus among anesthesiologists, surgeons, pharmacists,and nursing educators. These guidelines were then provided to thepreadmission staff to instruct patients regarding preoperative medi-cations. These guidelines will have to be reassessed periodically asnew medications and medical evidence emerge.

© 2004 by American Society of PeriAnesthesia Nurses.

idtgttiuRrgOacs

M

AeiW

OFTEN ANESTHESIOLOGISTS are asked, asperioperative consultants, to advise patients ap-proaching surgery on the necessary and safe useof long-term medications in the perioperativeperiod. In one study, Kluger et al showed that44% of surgical patients took medications priorto surgery, with an average of 2.1 drugs perpatient.1 The chances of an adverse drug inter-action increases as the number of drugs taken

Waseem Ashraf, MD, is a Clinical Fellow, Department ofAnesthesia; David T. Wong, MD, is an Assistant Professor,Department of Anesthesia; Michael Ronayne, FCARCSI, is aClinical Fellow, Department of Anesthesia; and Donna Wil-liams, BScN(c), RN, is a Clinical Educator, Ambulatory Surgery/PACU, at Toronto Western Hospital, Toronto, ON, Canada.

Supported by the Department of Anesthesiology, TorontoWestern Hospital, University of Toronto, Toronto, Canada.

Address correspondence to David T. Wong, MD, Depart-ment of Anesthesiology, Toronto Western Hospital, Universityof Toronto, 399 Bathurst St EC 2-046, Toronto, Ontario M5T2S8 Canada; e-mail address: david.wong@uhn.on.ca.

© 2004 by American Society of PeriAnesthesia Nurses.1089-9472/04/1904-0002$30.00/0

pdoi:10.1016/j.jopan.2004.04.002

Jo228

ncreases. To decrease the potential of adverserug interactions, the majority of experts agreeo stop unnecessary medications prior to sur-ery. However, only a small number of long-erm medications are subjected to controlledrials in the perioperative period. Another limit-ng factor is inadequate data to support contin-ation or stopping of long-term medications.ecommendations are usually drawn from caseeports, experimental data, manufacturer’s sug-estions and/or consensus among the experts.ur institution has developed a protocol to

ssist in determining whether some of the mostommon groups of medications prior to theurgery should be continued or stopped.

ethods

fter reviewing the literature, a panel of 3 an-sthesiologists with research experience andnterest in ambulatory anesthesia from Toronto

estern Hospital drafted a set of guidelines for

reoperative medications. Those recommenda-

urnal of PeriAnesthesia Nursing, Vol 19, No 4 (August), 2004: pp 228-233

bdppdtau

A

Htscat

anti-in

PREOPERATIVE MEDICATIONS GUIDELINES 229

tions were then circulated to staff anesthesiolo-gists, surgeons, pharmacists, and nursing educa-tors for comments and feedback. After a3-month process of comments and feedback, allparties involved approved a final version ofrecommendations (Table 1). In-services wereprovided for the preanesthesia nurses, whichincluded using the guidelines to instruct thepatients regarding their medications during thepreanesthesia visit.

Discussion on Most CommonlyUsed DrugsCardiovascular Medications

Antianginals

The most common groups of antianginals are

Table 1. Re

Patients presenting for surgeryshould be asked to take theseregularly prescribedmedications on the morning ofsurgery with a sip of water.

Hypertensiomedicatio

Cardiac med

BronchodilaGastroesoph

reflux medAnticonvulsAnalgesics/o

Recommendations for Coumadin(Bristol-Myers Squibb,Princeton, NJ) andASA/NSAIDs for days priorto surgery

For eye pati

For non-eye

Abbreviations: ASA, aspirin; NSAIDs, nonsteroidal

nitrates, beta-blockers, and calcium channel b

lockers. There is consensus that all antianginalrugs should be continued in the perioperativeeriod.2 Mangano et al demonstrated that inatients with significant risk of coronary arteryisease (CAD) undergoing noncardiac surgery,reatment with beta-blockers reduced mortalitynd the incidence of cardiac complications forp to 2 years after surgery.3

ntihypertensive

ypertension is a risk factor for CAD. Pa-ients with uncontrolled high blood pres-ures are likely to experience considerablehanges in blood pressure intraoperativelynd related morbidity.4 Therefore, satisfac-ory blood pressure control is necessary

endations

Thiazide diuretics, beta-blockers, calciumchannel blockers, ACE inhibitors,angiotensin receptor blockers, alpha-blockers (exceptions: furosemide and/or ethacrynic acid)

ns: Nitrates, beta-blockers, calcium channelblockers, digoxin

Inhalants

ns:H2 blockers, proton pump inhibitors

ASA, NSAIDs, and Coumadin should becontinued as usual for eye cases.

ts: Coumadin should be stopped 5 daysprior to the surgery. Discuss withanesthesiologist/internist regardingneed for low molecular weightheparin.

NSAIDs, ASA, clopidrogel (Plavix,Bristol-Myers Squibb) should bestopped 7 days preoperatively.

COX-2 inhibitors should be continuedas usual.

flammatory drugs.

comm

nns:

icatio

tors:agealicatio

antspioids

ents:

patien

efore elective surgery. The following are

emfuwvws

A

Aednitdhhasctewltrii

D

Dcplftdtspp

P

I

ASHRAF ET AL230

the most commonly used medications totreat high blood pressure.

Beta-Blockers. There is evidence that periop-erative beta-blockade reduces cardiac eventsand mortality.3 In addition to controlling bloodpressure, beta-blockers can also help to treatdysrhythmias intraoperatively and prevent car-diac ischemia.3 It is recommended that beta-blockers should be continued throughout theperioperative period, and abrupt discontinua-tion of these drugs should be avoided in hyper-tensive patients to prevent sudden rebound hy-pertension.5

Calcium Channel Blockers. Calcium chan-nel blockers should be continued throughoutthe perioperative period to maintain controlof hypertension, angina, or cardiac dysrhyth-mia.2,6 Intravenous formulation is also avail-able, which can be used as antidysrhythmicintraoperatively. Calcium channel blockersmay be withheld for significant preoperativehypotension or bradycardia without causingrebound hypertension.

Angiotensin Converting Enzyme Inhibitorsand Angiotensin II Receptor Blockers. Indi-cation for continuing or withholding angio-tensin converting enzyme (ACE) inhibitorsand angiotensin II receptor blockers (ARBs) islimited.7 Hypertensive patients on ACE inhib-itors may have a higher possibility of hypo-tension during anesthetic induction.8 Becausethere is no clear evidence for stopping ACEinhibitors or ARBs, we suggest that ACE in-hibitors and ARBs should be continued peri-operatively.

Diuretics. Most authorities recommend with-holding diuretics at least the morning of sur-gery because diuretics can be given intrave-nously in response to undesired volumeoverload. The rationale behind stopping di-uretics is to prevent hypokalemia and to avoidintravascular volume depletion.5 In our in-stitution, the consensus is that patientsshould take their thiazide diuretics on the day

of surgery and withhold furosemide and p

thacrynic acid. The rationale for this recom-endation was that loop diuretics such as

urosemide frequently induce a significant di-resis and intravascular volume depletion,hich may be associated with blood pressure

ariations. Patients taking thiazide diureticsere rarely associated with significant diure-

is and intravascular volume depletion.

ntidysrhythmics

ntidysrhythmics should be continued periop-ratively if they are prescribed to treat cardiacysrhythmias that are associated with hemody-amic changes or myocardial ischemia.9 It is

mportant to understand that medications usedo suppress rhythm abnormalities can provokeysrhythmias themselves. This effect is en-anced by hypokalemia, hypomagnesemia, andypocalcemia. Some antidysrhythmics are notvailable in intravenous formulation. Patients onuch antidysrhythmics should be advised toontinue their medications until the morning ofhe surgery. Primary rhythm abnormalities, ifncountered intraoperatively, should be treatedith other drugs available in intravenous formu-

ations. Alternatively, if prolonged fasting is an-icipated after the surgery, the patient may beeferred to the cardiologist to change the med-cation to a form available in both oral (PO) andntravenous formulations prior to the surgery.

igoxin

igoxin is often prescribed for the treatment ofongestive heart failure and to control su-raventicular dysrhythmias such as atrial fibril-

ation. Digoxin has a long half-life, an advantageor maintaining therapeutic plasma concentra-ions should a patient fail to receive severaloses.10 Because digoxin also has a narrowherapeutic range, we recommend that ithould be continued during the perioperativeeriod and a serum level may be measuredreoperatively.

ulmonary Drugs

t is recommended that all those drugs that

atients are taking for the stability of the respi-

EMT

Ataemtwos

D

OhsbhPtahigttitr

C

Eadpemcidst

OR

O

PREOPERATIVE MEDICATIONS GUIDELINES 231

ratory system should be continued during theperioperative period.

Inhaled Medications

Inhaled beta-agonists, anticholinergics, andcorticosteroids are routinely used for thetreatment of asthma and chronic obstruc-tive lung disease. Patients are advised tocontinue taking their inhalers and encour-aged to bring the inhalers with them on theday of surgery. Immediately prior to thesurgery, the use of nebulized albuterol orsimilar medication enhances delivery of themedication to the airway and is desirablefor the accurate delivery of the agent whenpatients are unable to use their inhalersproperly.

Theophyllines

Theophyllines are usually reserved for patientswith chronic obstructive lung disease resistantto other forms of treatment. Although it haslimited bronchodilatory effects, theophyllineaugments central respiratory drive and lessensthe overall work of breathing.11 For this veryreason, despite its narrow therapeutic ratio anddrug-to-drug interactions, it is reasonable thattheophylline should be continued for the peri-operative stability of the chronic lung disease.5

Serum levels of theophylline should be checkedbefore surgery, and if required, the dose shouldbe adjusted accordingly.9

Gastroesophageal RefluxMedications

Most commonly prescribed gastroesophagealreflux (GER) medications include H2 receptorblockers and proton pump inhibitors. Aspira-tion of gastric contents may contribute to chem-ical pneumonitis. Studies suggest that thosewho are at risk of aspiration should take theirGER medications on the day of surgery.12 Tominimize the potential complications associ-ated with aspiration during the perioperativeperiod, we recommend continuation of GER

medications. l

ndocrine and Hormonaledications

hyroid Medications

thyroid replacement hormone, such as levo-hyroxine, has a long half-life. Patients may beble to omit them on the day of surgery.4 How-ver, those patients who are taking thyroidedications for hyperthyroidism should take

heir medications according to their scheduleith minimal interruption. Maintaining controlf the overactive thyroid is essential for safeurgery and recovery.9

iabetic Medications

ral diabetic medications with a shorteralf-life should be withheld on the day ofurgery. Longer acting sulphonylureas shoulde stopped up to 48 hours preoperatively toelp prevent perioperative hypoglycemia.13

atients on regular insulin are asked to missheir morning dose and doses of intermediatecting insulin are usually reduced by aboutalf for the preoperative dose with close mon-

toring of serum glucose during and after sur-ery. For example, NPH or Lente is adminis-ered in half reduced dose on the morning ofhe surgery.13 We recommend stopping allnsulin and all subcutaneous insulin pumps onhe morning of the surgery to start infusion ofegular insulin with dextrose.

orticosteroids

xperts suggest that patients who present withhistory of steroid use greater than 1 week

uring the year prior to surgery should receiveerioperative supplement of steroids. In gen-ral, doses equivalent to prednisone 20 to 30g per day for less than 1 week probably do not

ause clinically important hypothalamic-pitu-tary-adrenocortical axis suppression.14 Theose and duration of supplemental steroidshould be guided according to the magnitude ofhe perioperative stress.

ral Contraceptives and Hormonaleplacement Therapy

ral contraceptives pills should be stopped at

east 4 weeks in advance for women scheduled

cbapppbsotr

Conttisphn

L

Tdsives

S

Cflcatrais

ASHRAF ET AL232

for surgery associated with higher risk of peri-operative venous thromboembolism.15 Thosepatients may be referred for counseling on al-ternate methods of contraception to minimizethe risk of unwanted pregnancy. For those un-dergoing low-risk surgeries, who will ambulatequickly, the medical risks of unanticipated preg-nancy may outweigh the increased risk of ve-nous thromboembolism. Withholding hormonereplacement therapy (HRT) for postmeno-pausal symptoms is associated with lesser med-ical risks than a higher risk of thromboembo-lism. It may be wise to stop HRT 4 or moreweeks before any major surgery.16

Anticonvulsants

Antiepileptic medications should be continuedin the perioperative period. Serum levels maybe measured if seizures are not under controlpreoperatively or in certain patient populationsthat do not provide reliable history. However,the literature also suggests that it may not benecessary to measure serum levels of anticon-vulsants if control of seizures has been adequateduring the year before surgery.4

Analgesics

Opioids

Opioid analgesics and anti-anxiety drugs shouldbe continued during the perioperative period.Sudden discontinuation of these types of medi-cations may result in withdrawal syndrome.2

Opioids and benzodiazepines are also com-monly used as premedications and anxiolysisduring the perioperative period.

Nonsteroidal Anti-Inflammatory Drugs

Nonselective Cyclooxygenase Inhibitors. As-pirin can cause increased surgical bleedingdue to irreversible inhibition of platelet cyclo-oxygenase.17 This can result in increasedtransfusion requirements. Aspirin may be

d1

ontinued for patients with a history of unsta-le angina. However, it is reasonable to stopspirin 7 to 9 days before high-risk surgicalrocedures such as vascular or neurosurgicalrocedures. Most non-aspirin NSAIDs inhibitlatelet cyclooxygenase reversibly.17 On theasis of the duration of action, they can betopped 3 to 7 days before the surgery. An-ther reason to stop these medications prioro the surgery is due to their potential forenal failure especially during hypovolemia.

yclooxygenase-2 Inhibitors. The cyclo-xygenase-2 (COX-2)-specific inhibitors haveo antiplatelet effect and bleeding complica-ions are minimized. Recent studies showedhat similar to other NSAIDs, these agentsnhibit renal prostaglandin synthesis andhould be avoided in patients with renal im-airment.18 We recommend that COX-2 in-ibitors should be continued if the patient hasormal renal functions.

imitations

he guidelines are only institutional recommen-ations and do not represent nationwide con-ensus among the experts. They are not primar-ly based on clinical trials. Experts’ opinion mayary from institution to institution (e.g., somexperts hold all diuretics on the morning of theurgery).

ummary

urrently, there are no agreed upon guidelinesor preoperative medications. Until the guide-ines are formulated with clinical trials, clini-ians will continue to apply their knowledgend experience to advise patients for their long-erm medications during the perioperative pe-iod. These guidelines were one institution’snswer to the ambiguity in dealing with admin-stration of patients’ home medications prior tourgery.

References

1. Kluger MT, Gale S: Perioperative drug prescribing pat-

tern. Anesthesia 46:456-459, 19912. Smith MS, Muir H, Hall R: Perioperative management of

rug therapy, clinical considerations. Drugs 51:238-259,9963. Mangano DT, Layug EL, Wallace A, et al: Effect of atenolol

hA

rS1

t2

eL

t

t1

t

cdk

PREOPERATIVE MEDICATIONS GUIDELINES 233

on mortality and cardiovascular morbidity after noncardiacsurgery. N Engl J Med 335:1713-1720, 1996

4. Nafisa KK, Reddy R: Perioperative medication manage-ment. Available at: http://www.emedicine.com AccessedAugust 10, 2002

5. Kelly RA, Smith TW: Drugs used in the treatment of heartfailure, in Braunwald E: Heart Disease (ed 5). Philadelphia, PA,Saunders, 1997, pp 471-491

6. Chui PT, Chung DCW: Medications to withhold or con-tinue in the preoperative consultation. Curr Anesth Crit Care9:302-306, 1998

7. Ryckwaert F, Colson P: Hemodynamic effects of anesthe-sia in patients with ischemic heart failure chronically treatedwith agiotensin-converting enzyme inhibitors. Anesth Analg84:945-949, 1997

8. Brabant S, Eyraud D, Bertrand M, et al: Refractory hypo-tension after induction of anesthesia in a patient chronicallytreated with angiotensin receptor antagonists. Anesth Analg89:887-888, 1999

9. Spell NO III: Stopping and restarting medications in theperioperative period. Med Clin North Am 85:1117-1128, 2001

10. Stoelting RK: Pharmacology and Physiology in Anesthe-sia Practice (ed 3). Philadelphia, PA, Lippincott-Raven, 1999,pp 280-282

11. Zoidis DJ: Chronic obstructive disease. Available atttp://www.rtmagazine.com/Articles.ASP?articleid�R0010A05ccessed August 10, 200212. Agnew N, Kendall J, Akrofi M, et al: Gastroesophageal

eflux and tracheal aspiration in the thoracotomy position:hould ranitidine premedication be routine? Anasth Analg 95:645-1649, 200213. Augetini G, Ketzler JT, Coursin DB: Perioperative care of

he diabetic. ASA Refresher Courses in Anesthesiology 29:1-9,00114. Wall TR: Updates on the anesthetic management of

ndocrine problems. ASA Annual Meeting Refresher Courseectures 293:1-6, 200315. Drugs in the perioperative period: 1-Stopping or con-

inuing drugs around surgery. Drug Ther Bull 37:62-64, 199916. Grady D: Postmenopausal hormone therapy increases

he risk for venous thromboembolic disease. Ann Intern Med32:689-696, 200017. Schafer AI: Effects of nonsteroidal anti-inflammatory

herapy on platelets. Am J Med 106:25S-36S, 199918. Lelorier J, Bombardier C, Burgess E, et al: Practical

onsiderations for the use of nonsteroidal anti-inflammatoryrugs and cyclo-oxygenase-2 inhibitors in hypertension andidney disease. Can J Cardiol 18:1301-1308, 2002