When Do I Order What?

Bucky Boaz, ARNP-C

Criteria for Detecting Electrolyte Abnormalities in ED Patients

• Poor oral intake• Vomiting• Hypertension, diuretic use• Age > 65• Recent Seizure• Muscle Weakness• Alcohol abuse • Altered mental status• Recent abnormal

electrolytes

Electrolyte Disorders

• Calcium

• Magnesium

• Potassium

• Sodium

Calcium

• Normal range:٭ 8.5-10.5 mg/dL

• Panic!٭ <6.5 or >13.5 mg/dL

• Marbled top

• Serum calcium is the sum of ionized calcium plus complexed calcium and calcium bound to proteins (albumin)

• Level of ionized calcium is regulated by parathyroid hormone and vit D.

Calcium

Hypocalcemia

• Hypoparathyroidism• Vitamin D deficiency• Renal insufficiency• Pseudohypo-

parathyroidism• Magnesium deficiency

• Hypophosphatemia• Massive transfusion• hypoalbuminemia

Calcium

Hypercalcemia

• Hyperparathyroidism• Malignancies secreting

parathyroid hormone-related protein (PTHrP)٭ squamous cell of lung٭ Renal cell carcinoma٭ Leukemia

• Vitamin D excess• Multiple myeloma

• Paget’s disease• Sarcoidosis• Vitamin A intoxication• Thyrotoxicosis• Addison’s disease• Drugs

٭ Antacids, Calcium salts, Diuretic use, Lithium

Calcium

Calcium

• Need to know serum albumin to know corrected calcium level.

• For every decrease in albumin by 1 md.dl, calcium should be corrected upward by 0.8mg/dL.

• Serum PTH level should be measured at initial presentation of all hypercalcemic patients

Magnesium

• Normal range:٭ 1.8-3.0 mg/dL

• Panic!٭ <0.5 or 4.5 mg/dL

• Marbled top

• Concentration is determined by intestinal absorption, renal excretion, and exchange with bone and intracellular fluid

Hypomagnesium

• Chronic diarrhea• Enteric fistula• Starvation• Chronic alcholism• Hypoparathyroidism• Acute pancreatitis• Chronic

glomerulonephritis

• Diabetic ketoacidosis• Drugs

٭ Albuterol

٭ Amphotericin B

٭ Calcium salts

٭ Cisplatin

٭ Cyclosporin

٭ Diuretics

Hypomagnesemia

• (<1.5 mEq/L) • Due to diuretics, aminoglycosides, cyclosporine. • Clinical features:

٭ Irritable muscle,tetany,seizure,arrhythmia.• Treat:

٭ MgSO4 25-50 mg/kg IV over 20 min.

Hypermagnesium

• Dehydration• Tissue trauma• Renal failure• Hypothyroidism

Drugs٭ Aspirin (prolonged

use)

٭ Lithium

٭ Magnesium salts

٭ Progesterone

٭ Triamterene

Hypermagnesemia

• (>2.2 mEq/L) • Due to renal failure, excess maternal Mg

supplement, or overuse of Mg-containing medicine.

• Clinical features: ٭ weakness, hyporeflexia, paralysis, and ECG with AV block &

QT prolongation. • Treat:

٭ CaCl (10%) 0.2-0.3 ml/kg (max 5 ml) IV.

Potassium

• Normal range:٭ 3.5-5.0 mg/dL

• Panic!٭ <3.0 or >6.0 mg/dL

• Marbled top

• Predominately an intracellular cation whose plasma level is regulated by renal excretion.

• Plasma concentration determines neuromuscular irritability

Potassium

Hypokalemia

• Clinical Features of Hypokalemia٭ Lethargy, confusion, weakness٭ Areflexia, difficult respirations٭ Autonomic instability, Low BP

• ECG findings in Hypokalemia٭ K+ < 3.0 mEq/L: low voltage QRS,٭ flat T waves, ST segment,٭ prominent P and U waves.٭ K+ = 2.5 mEq/L: prominent U wave٭ K+ = 2.0 mEq/L: widened QRS

Hyperkalemia

• Causes of Hyperkalemia٭ Exogenous:

• blood • Salt substitutes• K+ containing drugs (e.g. penicillinderivatives)• Acute digoxin toxicity• Beta blockers, ACE inhibitors• Succinylcholine• Non-steroidals

Hyperkalemia

٭ Endogenous:• Acidemia• Trauma• Burns• Rhabdomyolysis• DIC• Sickle cell crisis • GI bleed • Chemotherapy (destroying tumor mass) • Mineralocorticoid deficiency • Congenital defects (21 hydroxylase deficiency)

Hyperkalemia

• K+ 5-6.0: peak T waves• K+ 6-6.5: PR and QT intervals• K+ 6.5-7: P, ST segments• K+ 7-7.5: intraventricular conduction• K+ 7.5-8: QRS widens, ST and T waves merge• K+ > 10: sine wave appearance

Sodium

• Normal range:٭ 135-145 mg/dL

• Panic!٭ <125 or >155 mg/dL

• Marbled top

• Predominately an extracellular cation.

• Serum sodium level is primarily determined by the volume status of the individual.

Hyponatremia

• Symptoms٭ Lethargy, apathy٭ Depressed reflexes ٭ Muscle cramps٭ Pseudobulbar palsies٭ Cerebral edema٭ Seizures٭ Hypothermia

Hyponatremia

• CHF• Cirrhosis• Vomiting• Diarrhea• Excessive sweating

(replacing water, but not salt)

• Salt-loss nephropathy

• Adrenal insufficiency• Water intoxication• SIADH• Drugs

٭ Thiazides٭ Diuretics٭ ACE Inhibitors٭ Chlorpropamide٭ Carbamazepine

Hyponatremia

Hypernatremia

• Symptoms٭ Lethargy, irritability, coma٭ Seizures٭ Spasticity, hyperreflexia٭ Doughy skin٭ Late preservation of intravascular٭ volume (and vital signs)

Hypernatremia

• Dehydration (excessive sweating, vomiting, diarrhea)

• Polyuria (diabetes mellitus, diabetes insipidus)

• Hyperaldosteronism

• Inadequate water intake (coma, hypothalmic disease)

• Drugs٭ Steroids

٭ Licorice

٭ Oral contraceptives

Hypernatremia

Endocrine Disorders

• Hyperthyroidism/

Thyroid Storm

• Hypothyroidism/

Myxedema Coma

Hyperthyroidism/Thyroid Storm

• Underlying Thyroid Disease٭ Grave’s Disease (#1)

٭ Toxic nodular goiter

٭ Toxic adenoma

٭ Factitious thyrotoxicosis

٭ Excess TSH

• Precipitants ٭ Infection (#1)

٭ Pulmonary embolus

٭ DKA or HHNC

٭ Thyroid hormone excess

٭ Iodine therapy/dye

٭ Stroke, surgery

٭ Childbirth, D&C

Clinical Features of Hyperthyroidism/Thyroid Storm

• Hyperkinesis

• Palpable goiter

• Proptosis, lid lag

• Exopthalmus, palsy

• Temp > 101 F HR + Pulse pressure

• Arrhythmia (new onset)

• Weight Loss

• Palpitations

• Dyspnea

• Psychosis

• Apathy

• Coma

• Tremor

• Hyperreflexia

• Diarrhea

• Jaundice

Laboratory Findings Hyperthyroidism/Thyroid Storm

free T4

T3

TSH T4RIA FT4I Glucose Ca+2

WBC Hb Cholesterol

• Lab test can diagnose hyperthyroid, but Thyroid Storm (Thyrotixicosis) is a clinical diagnosis

Hypothyroidism/Myxedema Coma

• Precipitants٭ Pneumonia٭ GI bleed٭ CHF٭ Cold exposure٭ Stroke٭ Trauma pO2

CO2

Na+

• Drugs٭ Phenothiazides

٭ Narcotics

٭ Sedatives

٭ Phenytoin

٭ propanolol

Clinical Features of Hypothyroidism/Myxedema Coma

Vitals Temp is ofter < 90 F, 50% have BP < 100/60

Cardiac HR, heart block, low voltage, ST-T changes, effusion

Pulmonary Hypoventilation, pCO2, O2, pleural effusions

Metabolic Hypoglycemia, hyponatremia

Neurologic coma, seizures, tremors, ataxia, nystagmus, psychiatric disturbances, depressed reflexes

GI/GU Ileus, ascites, fecal impaction, megacolon, urinary retention

Skin Alopecia, loss of lateral 1/3 of eyebrow, nonpitting puffiness around eyes, hands, and pretibial region

ENT Tongue enlarges, voice deepens and becomes hoarse

Laboratory Findings of Hypothyroidism/Myxedema Coma• Serum TSH > 60

U/ml Total & free T4

or total & free T3

Liver Disease

Laboratory Findings in Liver DiseaseDisease AST/SGOT ALT/SGPT Alk Phos Bilirubin Albumin

Abscess 1-4 X 1-4 X 1-3 X 1-4 X Normal

Acetomenophren 50-100 X 50-100 X 1-2 X 1-5 X Normal

Alcohol Hepatitis AST>ALT 2:1

AST>ALT 2:1

10 X 1-5 X Chronic

Biliary Chirrosis 1-2 X 1-2 X 1-4 X 1-2 X

Chronic Hepatitis 1-20 X 1-20 X 1-3 X 1-3 X

Viral Hepatitis 5-50 X 5-50 X 1-3 X 1-3 X Normal

Stroke, TIA, and Subarachnoid Hemorrhage

• CT Scan abnormal > 95% if onset < 12h

• CT Scan abnormal 77% if onset > 12h

• CSF > 100,000 RBCs/mm3 (mean) although any # can be seen

• Xanthochromia

• ECG = peaked, deep, or inverted T waves, QT, or large U wave

Imaging Low Back Pain

• Acute neuro deficit consistent• Acute significant trauma• Age > 70, or minor trauma > 50 years• History of prolonged steroid use OR osteoperosis• History of cancer OR unexplained wt loss• History of recent infection OR fever > 100 F OR

parental drug abuse• LBP worse at rest OR disability due to LBP > 4

weeks

Fever in Children

Clinically Significant CXR Abnormalities

S Saturation < 90%

O Older than 59 years

B Breath sounds diminished

R Rales or Respiratory rate > 24 bpm

E Embolic disease (prior DVT or PE)

A Alcohol abuse

T Tuberculosis or Temp > 100.4

H Hemoptysis

95% sensitive, 40% specificity

SOBreath Criteria

Pulmonary EmbolismDIAGNOSTIC STUDIES ECG Findings

CXR – abnormal in 60-84% Nonspecific ST-T changes 50%

Art blood gas – 92% A-a gradient T wave inversion 42%

Ventilation perfusion scan V/Q - below

New right bundle branch 15%

D-Dimer – 95% sen, 50% spec S in 1, Q in 3, T in 3 12%

Angiography - > 98% sen/spec Right axis deviation 7%

Echo – detects 90% causing BP Shift in transition to V5 7%

CT – 90% sen for central PE Right ventricle hypertrophy 6%

MRI - >90% sen for PE P pulmonale 6%

Abdominal Pain

Abdominal Pain

In first 24 hours, WBC count > 11,000 20-40%

After 24 hours, WBC > 11,000 70-90%

Urinalysis with > 5 WBC or RBC/hpf 15-30%

Ultrasound sensitivity 78-94%

Ultrasound specificity 89-100%

CT scan sensitivity 92-100%

CT scan specificity >95%

Diagnostic Studies in Appendicitis

Abdominal Pain

Abdominal Pain

Abdominal Pain

Biliary Tract Disease

• Clinical Features of Biliary Colic٭ Pain usually begins 30-60 min after meal٭ Pain duration < 6-8 hrs٭ Absence of fever٭ WBC < 11,000 cell/mm3 in most٭ Normal liver function tests in 98%٭ Absence of pancreatitis٭ US is 98% sensitive for gallstones

Biliary Tract Disease

Clinical Features Acute Cholecystitis

Pain duration > 6-8 hrs > 90%

Temp > 100.4 F 25%

WBC > 11,000 cell/mm3 in most >95%

Murphy’s sign 65%

Elevated liver function tests 55%

Pancreatitis 15%

Ultrasound sensitivity 85%

Pancreatitis

• Suspect abscess, hemorrhage, or pseudocyst if fever, persistent amylase, bilirubin, WBC.

• US – 60-80% sensitive, 95% specific

• CT – 90% sensitive, 100% specific

• Obtain CT or US if suspected pseudocyst, abscess, gallstones, or trauma

Painful Scrotum

Trauma

Accidental vs Non-accidental

Head Trauma

Head Trauma

Head Trauma

Cervical Spine

Cervical Spine

Thoracolumbar Spine

Back pain or tenderness Ejection from motorcycle/vehicle

Neurologic deficit Motor vehicle crash > 50 mph

Glasgow coma scale < 14 Major distracting injury

Drug intoxication •Pelvic fracture

Alcohol intoxication •Long bone fracture

•Blood alcohol > 100 mg/dl Intrathoracic injury

Fall > 10 feet Intraabdominal injury

Indications for Thoracolumbar Spine Radiographs in Blunt Trauma

Shoulder

Shoulder deformity History of fall (with age > 43.5 years)

Shoulder swelling Abnormal range of motion

High-Yield Criteria for Shoulder Xrays in the Emergency Department

Blunt Real Trauma

Pelvis

Disoriented, Glasgow coma scale < 14 Groin or suprapubic swelling

Intoxication with drugs or alcohol Pain, swelling, eccymosis of medial thigh, genitalia, or lumbosacral area

Hypotension or gross hematuria Instability of pelvis to anterior-posterior or lateral-medial presure

Lower extremity neurologic deficit Pain with abduction, adduction, rotation, or flexion of either hip

Femur pain

Pain or tenderness of pelvic girdle, symphysis pubis, or iliac spine

Criteria for Pelvic Radiography Following Blunt Trauma

Abdominal Trauma

Abdominal Trauma

Ottawa Knee

Age > 55 Unable to flex 900

Unable to walk immediately after injury or 4 steps in the ED

Isolated fibular head tenderness

Isolated patellar tenderness

Pittsburgh Knee

Foot and Ankle