Download Perio-perative Medicine – “Nuggets” you will not find in the books

Peri-Operative Medicine
– “Nuggets” from the Consult Service
Guest Speaker – Glenn Newell M.D.
Presenter – Rinku Bhatia M.D.
Case 1
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63 year old Caucasian M with a long hx of osteoarthritis comes into
the hospital for bilateral knee replacements. He has a history of
hypertension on Norvasc, Lisinopril and Hydrochlorothiazide. On
post op day 1 while getting out of bed for physical therapy his blood
pressure falls to 70 /30 and he is tachycardic and lightheaded.
Case 2
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A 64 year old African American male is admitted to the hospital for
laparoscopic bowel surgery. He has a history of hard to control
blood pressure. Renal function is normal. On day one post op he is
npo and his blood pressure is 210/110 and has been resistant to
intravenous beta blockers, ace inhibitors and hydralazine
Management of HTN in Pre-Operative
patients
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Patients who are taking chronic antihypertensive medications
should continue taking their medication until the time of
surgery.
The ideal circumstance is to normalize blood pressure (eg, to
less than 140/90 mmHg) for several months prior to elective
surgery.
In a study published in JAMA that included 196 pts, with a BP
< 180/110 mmHg observed no difference in peri-operative
outcome and they may proceed to surgery safely
Studies have found that a diastolic pressure over 110 mmHg
immediately before surgery is associated with a number of
complications including dysrhythmias, myocardial ischemia
and infarction, neurologic complications, and renal failure
Management of HTN in Pre-Operative
patients
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B-blockers:
ACE/ARB:
Ca channel blockers:
Diuretics:
Central sympatholytics: Clonidine
Management of HTN in PostOperative patients
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Any patient who experiences a marked rise in blood pressure
following surgery should be treated.
Remedial causes of hypertension such as pain, agitation,
hypercarbia, hypoxia, hypervolemia, and bladder distention
should be excluded or treated.
Patients on chronic antihypertensive therapy should resume
their usual medications postoperatively as needed.
Those who cannot take oral medications should be given a
comparable alternative.
Management of HTN in NPO PostOperative patients
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Patients taking beta blockers may be given
parenteral propranolol, labetalol, or esmolol.
Patients taking an ACE inhibitor may be given
parenteral enalaprilat.
Patients taking centrally acting agents can be
given a clonidine patch.
Patients taking calcium channel blockers can be
given intravenous nicardipine
Patients taking diuretics may be given parenteral
furosemide or bumetanide
Case 3
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A 55 year old gentleman is admitted to the
hospital for elective hip replacement.He has well
controlled diabetes mellitus on Glimepiride and
Metformin (HgbA1C 6.4). He also takes Diovan
and Hydrochlorothiazide for hypertension. On
post op day 2 he is well and undergoing physical
therapy when the orthopedics nurse practitioner
calls you to say his creatinine is now 2.3 (was 0.8
pre operatively).
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What could be the cause of the patient’s
elevated Creatinine?
Effect of ACE-I & ARB on Renal
function
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ACE inhibitors and angiotensin II receptor blockers can theoretically blunt the
compensatory activation of the renin-angiotensin system during surgery and result in
prolonged hypotension.
In one study 51 patients undergoing peripheral vascular surgery were randomly
assigned to ACE inhibitor continuation or withdrawal. Patients continuing ACE
inhibitors through the morning of surgery had significantly more episodes of
hypotension requiring treatment compared with patients who stopped therapy at
least 12 hours captopril or 24 hours enalapril before surgery. No difference in the
incidence of hypertensive episodes was noted between the two groups.
A second study randomly assigned 40 patients with good left ventricular function
who were undergoing coronary artery bypass graft surgery to continue or omit ACE
inhibitors before surgery. Patients who omitted their ACE inhibitors required less
vasopressors during surgery but required more vasodilators to control hypertension
in the early postoperative period.
Angiotensin II receptor blockers (ARBs) have similar physiologic effects as ACE
inhibitors on hypertension and renal perfusion. It is not surprising then that a study in
vascular surgery patients found a statistically significant increase in the number of
hypotensive episodes in patients treated with ARBs prior to surgery compared with
those treated with beta blockers or calcium channel blockers
Management of ACE-I & ARB in
peri-operative period
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Findings suggest that continuing ACE inhibitors up to the time of
surgery increases perioperative hypotension, but possibly reduces
the incidence of postoperative hypertension.
While the data do not lead to clear recommendations, we
continuing ACE inhibitors in patients who are taking them for the
management of hypertension.
Substitution of shorter acting drugs (eg captopril) may allow more
flexibility for patients with postoperative labile blood pressure.
On the other hand, it would be reasonable to withhold ACE
inhibitors one dose interval before surgery in patients who are
taking them for heart failure, particularly if the baseline blood
pressure is low, to avoid significant hypotension during anesthesia
induction.
Case 4
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85 yr old M was climbing up a ladder when he slipped
and fell. CT Scan of his head revealed Subarachnoid
hemorrhage. As per neurosurgery no surgical
intervention was necessary. Pt is admitted under the
Trauma Service.
PMH is significant for HTN, HPL, DM which are wellcontrolled.
Patient’s started on Metoprolol 25 mg BID, Lipitor 20 mg
daily, Lantus 10 Units sq HS, Insulin Aspartate 6 Units
TID-AC and started on Famotidine 20mg iv q12hrs.
Nurse from trauma step down calls to inform you that
the patient has had a change in mental status.
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What could be the cause of patient’s
change in mental status and how would
you manage it?
Post-operative Delirium
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Delirium, or acute confusional state, is a
syndrome characterized by an acute change in
cognition with altered consciousness and
impaired attention that fluctuates over time.
It is a common problem associated with serious
complications and often goes unrecognized and
untreated. Delirium may be the sole indicator of a
serious underlying illness.
Post-op Delirium
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Delirium is associated with increased morbidity and mortality in
hospitalized patients.
Patients who develop delirium are at higher risk for falls, pressure
ulcers, and pneumonia. They have higher rates of functional
decline, loss of independence, and institutional care.
Delirium goes undetected in 33% to 66% of cases.
Etiology of delirium
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The etiology of delirium is usually multi factorial and involves a
complex interaction between a vulnerable patient with predisposing
risk factors and exposure to precipitating insults.
Etiology of delirium
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A patient with many predisposing risk factors is at high risk for
developing delirium from minor insults, such as a urinary tract
infection or a single dose of a medication with anticholinergic
activity.
Conversely, a patient with few predisposing risk factors will develop
delirium only when exposed to multiple or severe stressors, such as
critical illness and psychoactive medications.
Preventive measures
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Routine screening of cognitive functions and delirium (eg, Mini-Mental
Status Examination on admission and CAM during hospital stay)
Non pharmacologic, uninterrupted sleep promotion (eg, noise reduction
and lighting control)
Restoring visual and hearing aids
Fluid and electrolyte balance
Nutrition
Mobilization
Avoidance of bladder catheters and physical restraints
Elimination of unnecessary medications
Adequate pain control
Regulation of bowel/bladder function
Orientation (eg, use of clocks and calendars)
Management of Delirium
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Delirium is a medical urgency
Uncerlying cause should be identified and treated
Modify risk factors
Provide supportive care (eg, hydration, nutrition, and skin care)
Prevent complications (eg, infections, aspiration, falls, deep venous
thromboses, or pressure ulcers)
Treat the behavioral symptoms
Management of Delirium
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Initial evaluation should include a focused history and physical
examination and a search for reversible causes. Hypoglycemia,
hypoxia, hyperthermia, hypertensive encephalopathy, thiamine
deficiency, withdrawal states, and substance-induced delirium are
readily identifiable and treatable disorders.
Management of Delirium
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The history gathered should include baseline cognition level, the
acuity of the change in mental status, a careful assessment for
occult alcohol and benzodiazepine use, recent falls, last bowel
movement, and urinary output.
It is critical to review the home and in-hospital medication lists with
dosages, especially as-needed and over-the-counter drugs. All
potentially offending and unnecessary medications should be
discontinued if possible.
The physical examination should focus on vital signs, pulse
oximetry, volume and cardiopulmonary status, skin/wounds,
abdominal abnormalities, and the neurologic assessments. A blood
glucose value should be obtained upon initial evaluation.
Management of Delirium
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Initial testing should include:
 CBC, BMP, LFT, UA
 Chest radiography, ECG
Additional laboratory testing, if necessary, and may include:
 Serum osmolality
 Drug levels (eg, digoxin, lithium, carbamazepine, phenobarbital,
phenytoin, depakote, tricyclic antidepressants, and cyclosporine)
 Toxicology screen
 Arterial blood gas levels
 Cardiac enzymes
 Thyroid function tests
 Cortisol level
 Vitamin B12 levels
 Ammonia levels
 Blood cultures
Management of Delirium
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Neurologic imaging is indicated if there is a new focal neurologic
sign, a history of recent falls or head trauma. A lumbar puncture is
indicated if there are meningeal signs and fever and/or headache
(ie, concern for meningitis or encephalitis). An EEG has a limited
role in the diagnosis of delirium, but it can help to exclude
subclinical seizures and to confirm the presence of
encephalopathies.
Management of Behavioral symptoms
of Delirium
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Nonpharmacologic approaches to managing symptoms of delirium
should be instituted in all patients. These include: Creating a calm, comfortable environment
 Restoring sensory aids
 Using orientation strategies (eg, communication, clocks, and
calendars)
 Involving family members in supportive care
 Limiting room and staff changes
 Allowing uninterrupted sleep at night
 Encouraging wakefulness and mobility during the day
Management of Behavioral symptoms
of Delirium
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Pharmacologic therapy is indicated if the patient is a danger to himself,
staff, or others; the symptoms would interrupt essential therapy (eg,
intubation or pulling out IV lines); or the symptoms do not respond to
nonpharmacologic interventions
Antipsychotic medications are the agents of choice.
Haloperidol been studied and employed extensively to treat delirium, has
multiple routes of administration (oral, IM, and IV), a relatively rapid onset
of action with the IM and IV routes, and is inexpensive.
Benzodiazepines should not be used to treat delirium because they may
precipitate confusion, especially in the elderly, and are associated with
worsening of delirium. BZDs should be reserved for use in patients
undergoing sedative and alcohol withdrawal, those in whom there is a
contraindication to antipsychotics, or those with the neuroleptic malignant
syndrome
Physical restraint is an exceptional measure that may be indicated if other
less restrictive means have failed and the patient’s behavior puts the staff
and/or the patient at risk. Restraints can increase agitation in a delirious
patient. Reevaluation of their use should occur regularly.
Case 5
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38 yo F with pmh of Lupus, diagnosed 7 yrs ago, managed with
Prednisone 7.5mg po daily and Methotrexate 7.5mg qweekly. Her
last flare up which was manifested by arthralgias, fever and rash
was 8 months back. Pt is admitted at CUH for cholecystectomy.
Surgical service consults you to manage patient’s medications
perioperatively.
Management of steroids perioperatively
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Prolonged use of corticosteroids may suppress the normal increase
in endogenous cortisol that occurs in response to the stress of
surgery. Supplementation of corticosteroids may therefore be
needed to mimic the body's own response to stress.
Management of Methotrexate perioperatively
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There is little evidence to suggest that stopping methotrexate
preoperatively reduces the incidence of infection or improves
wound healing.
This was illustrated in a study of patients with RA having elective
orthopedic surgery; 388 patients were randomly assigned to
continue weekly methotrexate before and after surgery or to hold
methotrexate for two weeks before and after their operations.
Postoperative infections and other complications were significantly
less frequent in those who continued methotrexate than the others
(2 and 15 percent, respectively).
Postoperative flares of arthritis were not seen in those who
continued methotrexate but developed in 8 percent of those who
stopped the drug.