David Lopez; 22 5/04/1988
Author: Steve McLaughlin, MD
Reviewer: Deepi Goyal
Case Title: Acute Aspirin Overdose
Target Audience: Emergency Medicine Residents
Primary Learning Objectives:
1. Recognize signs and symptoms of ASA toxicity
2. Perform appropriate gastric decontamination
3. Describe technique for alkalinizing urine
4. Recognize indications for hemodialysis in ASA overdose
5. Order appropriate laboratory and radiology studies in ASA overdose
Secondary Learning Objectives: detailed technical goals, behavioral goals, didactic points
1. Obtain psychiatric evaluation for suicidal patients
2. Develop independent differential diagnosis in setting of leading information from RN
3. Describe importance of K replacement during urinary alkalinization
4. Describe role of repeated ASA levels
5. Describe role of WBI and MDAC in gastric decontamination of ASA ingestion
Critical actions checklist:
1. Perform gastric decontamination with AC – (Lavage or WBI are optional)
2. Order ASA level and Chemistry panel
3. Volume resuscitate with NS
4. Alkalinize urine using appropriate formula including K replacement
5. Consult Poison Control Center and arrange for dialysis
6. Obtain head CT to evaluate for trauma
Environment:
1.
Room Set Up – ED non-critical care area
a. Manikin Set Up – Mid or high fidelity simulator, simulated sweat, abrasion to
forehead, vomit on chest
b. Props – Standard ED equipment
2.
Distracters – ED noise, ED nurse #2 who insists this patient needs to “sleep it off”
Actors:
1.
2.
3.
4.
5.
Physician (played by resident learner)
Nurse #1 (can be learner or confederate)
Nurse #2 (confederate/insists patient needs to “sleep it off”)
ED technician (optional, can be learner)
Patient’s friend (confederate/provides history)
1
David Lopez; 22 5/04/1988
For Examiner Only
Author: Steve McLaughlin, MD
Reviewer: Deepi Goyal
Case Title: Acute Aspirin Overdose
CASE SUMMARY
CORE CONTENT AREA
Toxicology
SYNOPSIS OF HISTORY/ Scenario Background
The setting is an urban emergency department.
Patient is David Lopez who is a 22 year old male. He was found at the bottom of the
stairs leading up to his apartment by a friend. He has recently been depressed and has
been drinking alcohol. The friend is not aware of any suicidal ideations.
PMHx: Appendectomy
Medications: None
Allergies: NKDA
SocHx: Binge ETOH use, occasional tobacco, lives alone in apartment
[Patient is intoxicated and has an aspirin overdose. He fell down the stairs due to
intoxication but has no significant injuries.]
SYNOPSIS OF PHYSICAL
Patient is initially tachycardic and tachypneic.
Airway is intact. C-collar in place.
Abrasion to his forehead.
Neurologic exam is non focal. Mental status is altered – moaning/cursing/appears
intoxicated.
Skin is diaphoretic.
He has vomited and has vomit on chest.
2
David Lopez; 22 5/04/1988
For Examiner Only
CRITICAL ACTIONS
1. GI Decontamination
Perform gastric decontamination with activated charcoal (Lavage or whole bowel irrigation
are optional)
Cueing Guideline:
Nurse can ask if the doctor would like to place and NGT.
Nurse can ask if the doctor would like anything done with the NGT.
2. Appropriate Labs
Order salicylate level, acetaminophen level and chemistry panel
Cueing Guideline: The nurse or unit secretary can ask the doctor if they would like any labs
or any levels on the patient.
3. Volume Resuscitation
Give 1 to 2 liters of NS for volume resuscitation.
Cueing Guideline: The nurse may say “we have a line in place would you like any fluids?” If
that does not work the nurse can point out the tachycardia and ask if the doctor would like to
do anything. If not done the patient will become more tachycardic and may drop blood
pressure to 90/53.
4. Alkalinize Urine
Alkalinize urine using appropriate formula including K replacement
Cueing Guideline: Patient will have worsening acidosis and dropped K (see second
chemistry panel) if not treated. Even if the patient is treated the ASA will continue to climb
and the patient will need dialysis.
Ok to ask for details such as rate and target urine pH.
5. Poison Control Center (PCC) and Dialysis
Consult PCC and arrange for dialysis
Cueing Guideline: The PCC can call the ED and ask for the doctor if the resident does not
call. If the resident does not consider dialysis then the actor playing the PCC on the phone
can suggest dialysis for patient with major SxS and level over 140 which is climbing.
3
David Lopez; 22 5/04/1988
6. Critical Action
Obtain Head CT
Cueing Guideline: Nurse can ask “Do you want to go to CT before we go up to the floor?”
Nurse can say “Are you worried about trauma with his fall?”
SCORING GUIDELINES
1. Full credit given for placing NGT and giving 50 grams of AC with cathartic. Full credit also
given if lavage done in addition to AC. Full credit also given if WBI done in addition to AC.
Partial credit for AC in wrong dose or without cathartic. No credit if attempt to have this
drowsy patient drink AC. No credit if AC not given.
2. Full credit for electrolytes, glucose, BUN, Cr and ASA and APAP levels. No credit if any or
all of these critical labs are omitted.
3. Full credit for volume resuscitation with any amount between 1 and 2 L. LR is an acceptable
alternative. Partial credit if volume of resuscitation is between 500 cc and I L. No credit if
only maintenance fluids given, if less than 500 cc of if initial resuscitation fluid is no NS or
LR.
4. Full credit if: Single IV bolus of NaHCO 3 at 1-2 mEq/kg. Follow this with a constant infusion
of D5W with NaHCO 3 100-150 mEq/L and KCl 20-40 mEq/L at 1.5-2.5 mL/kg/h to produce a
urine flow of 0.5-1 mL/kg/h. Closely monitor the serum electrolytes and urine pH, and
maintain the urinary pH between 7.5-8. Partial credit for other formulas or if missing some
details. No credit if potassium is omitted or no drip started or no attempt to alkalinize.
5. Full credit for calling the PCC and providing patient information. Partial credit for asking for
a “toxicology consult.” No credit if participant refuses to talk to PCC on phone. Full credit
for calling the nephrologist and describing indications for dialysis in ASA OD. Partial credit
for asking for a nephrology consult or if unable to give indications. No credit if participant
refuses to follow PCC advice.
6. Full credit for ordering head CT. Partial credit if CT done with prompting. No credit if
refuses CT even after prompting.
4
David Lopez; 22 5/04/1988
For Examiner Only
HISTORY
Onset of Symptoms:
Today
Background Info:
“Mr. Lopez has been drinking all evening. It looks like he fell down
the stairs at his apartment. He was found by his friend who called
911. His friend states that he has been depressed recently and
drinking a lot of alcohol.”
Additional History
From EMS: If asked about the scene in the apartment they will
describe a cluttered, small apartment. There were multiple empty
bottles of “Jack Daniels” as well as an empty bottle of penicillin, a half
empty bottle of “Vicodin” and a large half empty bottle of aspirin. He
has been vomiting during transport.
From Friend: He states that Mr. Lopez has been very depressed. He
recently broke up with his girlfriend.
Chief Complaint:
Fall
Past Medical Hx:
None
Past Surgical Hx:
Appendectomy
Habits:
Smoking: Occasional
ETOH: Heavy binge drinking
Drugs: None
Family Med Hx:
Unknown
Social Hx:
Marital Status:
Children:
Education:
Employment:
ROS:
Patient is unable to answer.
5
Single
None
High School
Unemployed food service worker
David Lopez; 22 5/04/1988
For Examiner Only
PHYSICAL EXAM
Patient Name: David Lopez
Age & Sex: 22 year old male
General Appearance: Well-developed, well-nourished male in moderate distress. Vomit noted
on front of clothing.
Vital Signs:
BP: 108/64
P: 131
R: 40
T : 38.0
Head: Abrasion/contusion to forehead.
Eyes: PERRLA, pupils 4 mm B, lateral nystagmus
Ears: TM’s are normal
Mouth: Smells of ETOH beverages, no trauma
Neck: C-collar and on a long spine board. No tenderness or deformity on exam.
Skin: Moist skin/slightly sweaty, no rashes
Chest: Increased respiratory rate without any signs of distress (no retractions, etc)
Lungs: Clear and equal
Heart: Tachycardic, S1S2, no murmurs
Back: Normal
Abdomen: Mild LUQ TTP, no signs of trauma, no rebound, no guarding, decreased bowel
sounds
Extremities: No signs of trauma, no edema, pulses are present
Rectal: Normal tone, guiac negative
Neurological: Non focal exam
Mental Status: Patient is drowsy, opens eyes only to pain, confused and slurred speech, he is
not oriented. He is not able to provide any history. His airway appears to be intact with
preserved gag and cough reflex.
6
David Lopez; 22 5/04/1988
For Examiner Only
STIMULUS INVENTORY
#1
Emergency Admitting Form
#2
CBC
#3
BMP/LFTs
#4
U/A
#5
ABG
#6
Cardiac Enzymes
#7
Toxicology Labs
#8
CXR
#9
CT Head
#10
CT C-spine
#11
Abdominal XR
#12
Repeat Toxicology Labs
#13
Repeat BMP
#14
ECG
#15
Debriefing materials
7
David Lopez; 22 5/04/1988
For Examiner Only
LAB DATA & IMAGING RESULTS
Stimulus #2
Complete Blood Count (CBC)
WBC
14,500 /mm3
Hgb
13.2 g/dL
Hct
40 %
Platelets
239,000 /mm3
Differential
PNM
45%
Bands
1%
Lymphs
55%
Monos
2%
Eos
1%
Stimulus #5
Arterial Blood Gas
pH
7.47
pCO2
19 mm Hg
pO2
123 mm Hg
HCO3
14
O2 Sat
100%
Stimulus #3
Basic Metabolic Profile (BMP)
Na+
145
mEq/L
K+
3.6
mEq/L
CO2
16
mEq/L
Cl
109
mEq/L
Glucose
73
mg/dL
BUN
17
mg/dL
Creatinine
1.1
mg/dL
Stimulus #7
Toxicology
Salicylate
Acetaminophen
ETOH
AST
ALT
Br
D-Br
ALP
Albumin
49
32
1.2
0.2
110
4.3
Stimulus #4
Urinalysis (U/A)
Color
Sp gravity
Glucose
Protein
Ketone
Leuk. Est.
Nitrite
WBC
RBC
8
yellow
1.017
neg
neg
trace
neg
neg
3/hpf
2/hpf
U/L
U/L
mg/dl
mg/dl
U/L
U/L
Stimulus #6
Cardiac Enzymes
CK
98 ng/ml
CKMB
1 ng/ml
Troponin
0.025 ng/ml
86
mg/dl
Non detectable
112
mg/%
Diagnostic Imaging
Stimulus #8
CXR:
Normal
Stimulus #9
Head CT:
Normal
Stimulus #10
CT C-Spine
Normal
Stimulus #11
Abdominal XR
Normal
David Lopez; 22 5/04/1988
For Examiner Only
LAB DATA & IMAGING RESULTS (cont)
Stimulus #12
Repeat Toxicology
Salicylate
141
Stimulus #13
Repeat BMP
Na+
K+
CO2
ClGlucose
BUN
Creatinine
146
3.2
12
111
68
12
1.0
Stimulus #14
ECG
Sinus tachycardia
9
mEq/L
mEq/L
mEq/L
mEq/L
mg/dL
mg/dL
mg/dL
mg/dl
David Lopez; 22 5/04/1988
Learner Stimulus #1
CORD General Hospital
Emergency Admitting Form
Name:
David Lopez
Age:
22 years
Sex:
Male
Method of Transportation:
Ambulance
Person giving information:
Friend and EMS
Presenting complaint:
Fell down stairs
Background: Mr. Lopez has been drinking all evening. It looks like he fell down the stairs at
his apartment. He was found by his friend who called 911. His friend states that he has been
depressed recently and drinking a lot of alcohol.
Initial Vital Signs
BP:
108/64
P:
131
R:
40
T:
38.0
10
David Lopez; 22 5/04/1988
Learner Stimulus #2
Complete Blood Count (CBC)
WBC
14,500 /mm3
Hgb
13.2
g/dL
Hct
40
%
Platelets
239,000 /mm3
Differential
PNM
45%
Bands
1%
Lymphs
55%
Monos
2%
Eos
1%
11
David Lopez; 22 5/04/1988
Learner Stimulus #3
Basic Metabolic Profile (BMP)
Na+
145
mEq/L
+
K
3.6
mEq/L
CO2
16
mEq/L
Cl109
mEq/L
Glucose
73
mg/dL
BUN
17
mg/dL
Creatinine
1.1
mg/dL
AST
ALT
Br
D-Br
ALP
Albumin
49
32
1.2
0.2
110
4.3
12
U/L
U/L
mg/dL
mg/dL
U/L
U/L
David Lopez; 22 5/04/1988
Learner Stimulus #4
Urinalysis (U/A)
Color
Yellow
Sp gravity
1.017
Glucose
neg
Protein
neg
Ketone
trace
Leuk. Est.
neg
Nitrite
neg
WBC
3/hpf
RBC
2/hpf
13
David Lopez; 22 5/04/1988
Learner Stimulus #5
Arterial Blood Gas
pH
7.47
pCO2
19
pO2
123
HCO3
14
O2 Sat
100%
14
David Lopez; 22 5/04/1988
Learner Stimulus #6
Cardiac Enzymes
CK
CKMB
Troponin I
15
98
ng/ml
1
ng/ml
0.025 ng/ml
David Lopez; 22 5/04/1988
Learner Stimulus #7
Toxicology
Salicylate
Acetaminophen
ETOH
16
86
mg/dL
Non detectable
112
mg/%
David Lopez; 22 5/04/1988
Learner Stimulus #8
CXR
Normal
17
David Lopez; 22 5/04/1988
Learner Stimulus #9
Head CT
Normal
18
David Lopez; 22 5/04/1988
Learner Stimulus #10
C-spine CT
19
Normal
David Lopez; 22 5/04/1988
Learner Stimulus #11
Abdominal XR
20
Normal
David Lopez; 22 5/04/1988
Learner Stimulus #12
Repeat Toxicology
Salicylate
141 mg/dL
21
David Lopez; 22 5/04/1988
Learner Stimulus #13
Repeat Basic Metabolic Profile (BMP)
Na+
146
mEq/L
+
K
3.2
mEq/L
CO2
12
mEq/L
Cl111
mEq/L
Glucose
68
mg/dL
BUN
12
mg/dL
Creatinine
1.0
mg/dL
22
David Lopez; 22 5/04/1988
Learner Stimulus #14
ECG
Sinus tachycardia
23
David Lopez; 22 5/04/1988
For Examiner
Date:
Examiner:
Examinee(s):
Scoring: In accordance with the Standardized Direct Observational Tool (SDOT)
The learner should be scored (based on level of training) for each item above with one
of the following:
NI = Needs Improvement
ME = Meets Expectations
AE = Above Expectations
NA= Not Assessed
Critical Actions
1. Perform gastric decontamination
with AC
2. Order ASA level and Chemistry
panel
3. Volume resuscitate with NS
4. Alkalinize urine using appropriate
formula including K replacement
5. Consult PCC and arrange for
dialysis
6. Obtain head CT to evaluate for
trauma
NI
ME
AE
NA
Category
PC, MK
PC, MK
PC, MK
PC, MK
ICS, PBL, SBP
PBL, PC, SBP
The score sheet may be used for a variety of learners. For example, in using the case
for 4th year medical students, the key teaching points of the case may be the recognition
of shock and treatment with appropriate fluid resuscitation. Other items may be marked
N/A= not assessed.
24
David Lopez; 22 5/04/1988
Category: One or more of the ACGME Core Competencies as defined in the SDOT
PC=
Patient Care
Compassionate, appropriate, and effective for the treatment of health problems and the promotion
of health
MK= Medical Knowledge
Residents are expected to formulate an appropriate differential diagnosis with special attention to
life-threatening conditions, demonstrate the ability to utilize available medical resources effectively,
and apply this knowledge to clinical decision making
PBL= Practice Based Learning & Improvement
Involves investigation and evaluation of their own patient care, appraisal and assimilation of
scientific evidence, and improvements in patient care
ICS= Interpersonal Communication Skills
Results in effective information exchange and teaming with patients, their families, and other health
professionals
P=
Professionalism
Manifested through a commitment to carrying out professional responsibilities, adherence to ethical
principles, and sensitivity to a diverse patient population
SBP= Systems Based Practice
Manifested by actions that demonstrate an awareness of and responsiveness to the larger context
and system of health care and the ability to effectively call on system resources to provide care that
is of optimal value
25
David Lopez; 22 5/04/1988
Keywords for future searching functions
Salicylates
Aspirin
Overdose
Treatment
Toxicology
References:
Emedicine: http://emedicine.medscape.com/article/818242-overview. Accessed 11/8/2010.
Dargan PI, Wallace CI, Jones AL. An evidence based flowchart to guide the management of
acute salicylate (aspirin) overdose. Emerg Med J. 2002 May;19(3):206-9.
O'Malley GF.Emergency department management of the salicylate-poisoned patient.
Emerg Med Clin North Am. 2007 May;25(2):333-46.
Has this work been previously published?
No
26
David Lopez; 22 5/04/1988
Debriefing Materials - Salicylate Toxicity
Sources of Exposure:
 Salicylates are found in hundreds of over-the-counter (OTC) medications and in
numerous prescription drugs.
 Pepto-Bismol, a common antidiarrheal agent, contains 131 mg of salicylate per
tablespoon
 Aspirin or aspirin-equivalent preparations include children's aspirin (80-mg tablets), adult
aspirin (325-mg tablets)
 Methyl salicylate (eg, oil of wintergreen) (One teaspoon of 98% methyl salicylate
contains 7000 mg of salicylate - more than 4 times the potentially toxic dose for a child
who weighs 10 kg)
Pathophysiology:
 Salicylates stimulate the respiratory center, leading to hyperventilation and respiratory
alkalosis.
 Salicylates also interfere with the Krebs cycle, limit production of ATP, and increase
lactate production, leading to ketosis and a wide anion-gap metabolic acidosis.
Severity of Ingestion:
 A 16% morbidity rate and a 1% mortality rate are associated with patients presenting
with an acute overdose.
 Prognosis is worse for chronic overdose/exposure.
 The following 4 categories are helpful for assessing the potential severity and morbidity
of an acute, single event, nonenteric-coated, salicylate ingestion:
o Less than 150 mg/kg - Spectrum ranges from no toxicity to mild toxicity
o From 150-300 mg/kg - Mild-to-moderate toxicity
o From 301-500 mg/kg - Serious toxicity
o Greater than 500 mg/kg - Potentially lethal toxicity
Organ System Effects:
 Psychiatric:
o The chronic ingestion of salicylates may produce the appearance of anxiety with
its associated tachypnea, difficulty concentrating, and hallucinations. Patients
with underlying psychiatric illness may present with symptoms suggestive of an
exacerbation of their underlying psychiatric illness (eg, mania, psychosis)
 Pulmonary:
o Salicylates cause both direct and indirect stimulation of respiration. A salicylate
level of 35 mg/dL or higher causes increases in both rate (tachypnea) and depth
(hyperpnea) of respiration. Salicylate poisoning may rarely cause noncardiogenic
pulmonary edema (NCPE) and acute lung injury in pediatric patients.
 Cardiovascular:
o Tachycardia, Hypotension
 Neurologic:
o Salicylates are neurotoxic; this initially manifests as tinnitus. CNS toxicity is
related to the amount of drug bound to CNS tissue. It is more common with
chronic than acute toxicity. Acidosis worsens CNS toxicity by increasing the
27
David Lopez; 22 5/04/1988


amount of salicylate that crosses the blood brain barrier and increases CNS
tissue levels. Other signs and symptoms of CNS toxicity include nausea,
vomiting, hyperpnea, and lethargy. Severe toxicity can progress to disorientation,
seizures, cerebral edema, hyperthermia, coma, cardiorespiratory depression,
and, eventually, death.
Gastrointestinal:
o Nausea and vomiting are the most common toxic effects. This can be caused by
CNS toxicity or by direct damage to the gastric mucosa.
Dermatologic:
o Diaphoresis is a common sign in patients with salicylate toxicity.
Diagnostic Testing:
 Chemistry panel
o Repeat as needed
 Serum salicylate level
o Every 2 hours until the salicylate level falls.
o Avoid the use of the Done nomogram
o Serum levels determined less than 6 hours postingestion (acute overdose) do not
rule out impending toxicity because salicylates are in the absorption-distribution
phase.
o In cases of chronic salicylism, measured toxic levels may be only 30-40 mg/d.
o Acute overdoses are often symptomatic at salicylate concentrations higher than
40-50 mg/dL.
o Patients with salicylate concentrations approaching or exceeding 100 mg/dL
usually have serious or life-threatening toxicity.
 Urinalysis: Monitor and maintain an alkaline urine pH every 2 hours during alkalinization
therapy. Maintain a urine pH of 7.5-8
 Monitor glucose levels closely. Initial hyperglycemia may give way to hypoglycemia.
 Obtain hepatic, hematologic, and coagulation profiles for patients with clinical evidence
of moderate-to-severe toxicity.
 Chest x-ray is indicated if evidence of severe intoxication, pulmonary edema, or
hypoxemia is present.
 Consider an abdominal x-ray if an aspirin concretion is suspected.
Treatment:
 Decontamination
o Gastric lavage may be beneficial
o Oral activated charcoal, especially if the patient presents within one hour of
ingestion.
o Repeated doses of charcoal may enhance salicylate elimination and may shorten
the serum half-life.11 Most experts strongly recommend this for patients with a
serious ingestion.
o When enteric-coated aspirin has been ingested or when salicylate levels do not
decrease despite treatment with charcoal, WBI should be used in addition to
charcoal therapy.
 Administer lactated Ringer or isotonic sodium chloride solution for volume expansion at
10-20 cc/kg/h until a 1-1.5-cc/kg/h urine flow is established.
28
David Lopez; 22 5/04/1988

Alkalinization of blood and urine keeps salicylates away from brain tissue and in the
blood, in addition to enhancing urinary excretion.
o When the urine pH increases to 8 from 5, renal clearance of salicylate increases
10-20 times.
o Consider this treatment if the salicylate level is higher than 35 mg/dL.
o Single IV bolus of NaHCO 3 at 1-2 mEq/kg. Follow this with a constant infusion of
D5W with NaHCO 3 100-150 mEq/L and KCl 20-40 mEq/L at 1.5-2.5 mL/kg/h to
produce a urine flow of 0.5-1 mL/kg/h. Closely monitor the serum electrolytes and
urine pH, and maintain the urinary pH between 7.5-8.
o The urinary excretion of salicylic acid is dependent upon adequate serum
potassium.
Consultations:
 Consult with the regional poison control center or a local medical toxicologist for
additional information and patient care recommendations.
 Consultation with nephrology department personnel is required if hemodialysis is
indicated.
o Recommendations for hemodialysis include the following
 Severe manifestations of intoxication
 Refractory or profound acidosis
 Serum levels higher than 100 mg/dL after acute overdose or serum levels
higher than 40-50 mg/dL in chronic salicylism.
Disposition:
 Admit patients with major signs and symptoms to an intensive care unit
 Consult psychiatric service personnel for patients with intentional overdose.
 Patients with accidental ingestions of less than 150 mg/kg and no signs of toxicity can be
discharged after 6 hours postingestion.
Pitfalls:
 Failure to diagnose salicylate toxicity in a patient presenting with vague signs and
symptoms, such as anxiety, tachypnea, agitation, delirium, tinnitus, or a combined
respiratory alkalosis and metabolic acidosis
 Failure to initiate GI decontamination in a patient with acute salicylate ingestion who,
subsequently, has recurrent toxicity from a salicylate bezoar
 Failure to hyperventilate a patient with severe salicylate poisoning who has just been
intubated (when acid-base status had been maintained previously by the patient's own
hyperventilation) to prevent lethal acidemia
 Failure to diagnose and treat concomitant hypoglycemia in the salicylate-intoxicated
patient; more common in children than in adults
 Failure to confirm units of measurement may lead to confusion. Always confirm the units
of measurement.
 Immediately begin therapy in symptomatic patients. Do not wait for the salicylate levels
to return from the laboratory.
29