DDX by Symptoms

Altered Mental Status

Structural: brain mass, mets, SZRs, NCSE, postictal state, Hydrocephalus 

  

Vascular: Ischemic/hemorrhagic stroke, SAH, TBI(EDH/SDH/DAI/diffuse cerebral swelling/Contusions/SAH/IVH), AVM, CVT, Aneurysym, TIA 

  

Infectious: Meningitis, aseptic meningitis, encephalititis, sepsis, GBS 

  

Metabollic: Delirium, electrolyte disturbance(glucose, sodium,calcium, magnesium, phosphate), Hypercarbia, Headache(cluster/migraine/tension), septic/hepatic/metabollic/hypoxemic/hypertensive/uremic/Wernicke encephalopathy, severe hypothyroidism (myexedema coma)

  

Toxins: Drugs(current meds too much or missed), illicit drug use, poly-pharmacy, withdrawal or overdose 

  

Other: Re-accumulation of SDH/EDH, herniation from cerebral edema/hematoma, anoxic injury, dehydration, drug overdose/rxn, missed medication, slow metabolism of analgesics, etoh withdrawal, dementias, primary psychiatric illness. Vitamin deficiency, prion’s disease(CJD)


Delirium ddx: dementia, primary psychiatric illnesses, NCSE, focal syndromes(Wernicke's aphasia/RMCA stroke, brain tumor/trauma, anton syndrome), sundowning, metabolic encephalopathy 

  

UNRESPONSIVE/COMA ddx: structural(neoplasm, mets)/vascular(stroke), CNS infection/autoimmune encephalitits, Acute disseminated encephalomyelitis, sepsis, metabollic, toxin/OD, vitamin deficiency/nutritional deficiency, SZR/NCSE, mechanical fall, MI, arrythmia, shock, aortic trauma, hypoxia, CO poisoning, PE, PNA, PTX, GI bleed, fx, suicide attempt, HIE(Hypoxic ischemic encephalopathy), PRES 


Seizure ddx: alcohol withdrawal, lowered seizure threshold (meds), medication noncompliance, PNES, Medications (opioids [meperidine, tramadol], anticancer drugs, ABXs [carbapenems, Csporins 4th gen, Quinolones, Isoniazid, PCNs], hypoglycemic agents, immunosuppresants, antipsychotics/antidepressants, stimulants[adderall], sympathomimetics, decongestants), infection, syncope, TIA, Migraine, Panic attack and Anxiety, transient global amnesia, narcolepsy with cataplexy, paroxysmal movement disorder. 

Headache ddx: migraine, hypoglycemia, hunger, tension headache, CVA, CV sinusT, CSF leak, idiopathic intracranial hypertension, giant cell arteritis.

Syncope ddx: Hemorrhage, PE, SAH, vasovagal syncope(MCC), orthostasis, medications (CCBs, BBs, alpha blockers, nitrates, diuretics, QTc prolongers antipsychs, antiemetics)


Shortness Of Breath/Dyspnea

Infectious: Pna(bacterial, fungal, atypical, viral, Tb, covid), bronchiolitis, bronchitis, Flu, Croup, epiglotittis, pneumonitis 

Obstructive: COPDAE, AsthmaAE, mass/nodule, carcinoid tumors, foreign body 

Restrictive: ILDs, autoimmune disease

Vascular: cor pulmonale/chf, PE, pHTN 

Pleural: pEffusion, PTX 

Other: sleep apnea, Obesity hypoventilation syndrome, ARDS, angioedema, anaphylaxis, pulmonary contusions, neurogenic pulmonary edema(from SAH)

Cardiac: ACS, CHF, arrhythmias, Valvular dz, Endocarditis 

  

Parenchymal(COPD, pulmonary tumor, pneumonitis, bronchiectasis, pulmonary contusion, ILD, sarcoidosis),  

Airway(asthma, bronchitis, laryngitis, pharyngitis, OSA, angioedema, foreign body aspiration, trachea bronchial tumor, vocal cord dysfunction),  

Pulmonary vascular disease(PE,pHTN, pulmonary AV malformations, hepatopulmonary syndrome) 

Pleural disease(pEffusion,  PTX, pneumomediastinum, mesothelioma, pleuritis, HTX), Anemia, CO poisoning, methemoglobinemia, pulmonary leukostasis, GERD, ascites, thyroid disease, Cushing, pheochromocytoma, kyphoscoliosis, pectus excavatum, shock, and relaxes, stroke, botulism, ALS, tetanus, polio, PNS infection, GBS, MG, paraneoplastic my Stanek syndrome, respiratory muscle deficiency, anxiety, panic attack, aging, obesity.  

  

Airspace disease ddx: blood(hemorrhage), water (edema), tumor, pus(pneumonia)


HEMOPTYSIS DDX 

PE, coagulopathy, Acute or chronic bronchitis, airway trauma, bronchiectasis, bronchovascular fistula, dieulafoy lesion(superficial, sub epithelial bronchial artery), foreign body, neoplasm. TB, PNA, lung abscess, Wegener disease, Goodpasture syndrome, idiopathic pulmonary hemosideroosis, lupus pneumonitis. 

Chest Pain

Pleuritic chest pain/non traumatic: PE, PTX, PNA, pleurisy, pericarditis 

Traumatic: Tamponade, Contusion, PTX 

Reproducible: muscle strain(from activity/coughing), costochondritis, Rib/sternal fx, infenction, Zoster 

Substernal: MI/Angina, Sikcle cell crisis, Dissecting TAA/AAA, GI ulcer/perf, pneumomediastinum, mediastinitis 


Cardiac: ACS, tachyarrhythmias, htn emergency, Takotsubo CM, uremic pericarditis, PE(post ortho surgery, malignacy)

GI: esophagitis, GERD, gastritis, 

Other: panic attack, anxiety

Leg Swelling

Acute: HF exacerbation, Nephrotic syndrome, Venous thrombosis, Acute worsening of chronic causes, PAD, compartment syndrome 

Chronic: Venous insufficiency, HF history, pHTN (including sleep apnea), Restrictive pericarditis, Restrictive cardiomyopathy, Liver disease (early cirrhosis), Premenstrual edema, Pregnancy, 

Pelvic compression (including tumor or lymphoma), Dependent edema 

Sodium or fluid overload (including parenteral fluids, antibiotics and other drugs with large amounts of sodium), Refeeding edema, Idiopathic edema, Inflammation (including sepsis), Medications 

Lymph related: Primary lymphedema (presenting in childhood), Secondary lymphedema (including lymph node dissection), Thyroid disease (myxedema)

Abdominal Pain

Esophageal disorders(esophagitis, MW tear, GERD, motility disorder, stricture/varices) 

Gastric disorders(gastritis, PUD, pyloric stenosis) 

Hepatic(acute/chronic hepatitis, cirrhosis) 

Biliary(acute/chronic cholecystitis, cholangitis, cholelithiasis) 

Pancreatic disorder(acute/chronic pancreatitis, pancreatic cyst/necrosis/fistula, pancCA) 

Small intestine disorders(appendicitis, celiac disea, intussusception, obstruction, polyps) 

Colorectal disorders(Ischemic bowel disease, abscess/fistula, diverticulitis, Obstruction, TOXIC megacolon, fecal impaction, fissures/hemorrhoids, constipation, IBD/IBS) 

Neoplasm 

Food allergies, hernia, diarrhea, toxic ingestion 

Metabollic disorder 

Nutritional/vitamin disorders 


RUQ/Epigastric: Cholecystitis, cholangitis, Hepatitis, Ulcer(gastric/duodenal), Renal (pyelonephritis/kidney stone), esophagitis, gerd, 

LUQ/Epigastric: gastritis/PUD, pancreatitis, splenic rupture/infarct/sequestration, Mono, kidney dz 

RLQ: Appendicitis, Ovarian (rupture, cyst, torsion, abscess, PID), Testicular (torsion/hernia/epididymitis) 

LLQ: Diverticulitis, Proctitis, Prostatitis, Ischemic colitis, ulcerative colitis

Generalized: Mesenteric ischemia, AAA, Constipation, SBO, IBS, Colitis, Toxic megacolon, Cdiff, Gastroenteritis, perforation, DKA, volvulus, GI bleed, Hernias, cancers 

Other: Lower lobe pneumonia, ACS, UTI, tumor, urinary retention/obstruction, thyrotoxicosis, hypercalcemia 

Rash

Emergencies: SJS, TENs, DRESS syndrome (Drug reaction with eosinophilia and systemic symptoms), Acute generalized exanthematous pustulosis, Necrotizing fasciitis, staphylococcal scalded skin syndrome 

Bacterial: cellulitis, impetigo 

Fungal: candidiasis, esophagitis 

Viral: HSV, Molluscum, Varicella-zoster 

Other: contact dermatitis, drug eruption, 

OLIGURIA/ANURIA

AKI 

Pre-Renal: hypovolemic, hypervolemic states with low effective circulating volume (HF with reduced EF (cardiorenal), decompensated liver disease with portal HTN (HRS), alterations in renal vascular auto regulation (medications: NSAIDS - prevent prostaglandin release, ACEinhibitors - prevents renin release) 

- Prerenal most often leads to Intrinsic. (Atn) if not corrected. 

- may also be a combined effect of afferent arterial constriction, (I.e nsaids, IV contrast) + efferent arterial dilation, (I. eACEI, ARBS) 

-Labs: Scr increase slower than 0.3/day, uNa <20, FENA <1%, UA normal, High specific gravity(elevated Uosm), rapid SCr improvement to IV fluids, BUN:CR ratio >20:1. 

- TX is volume repletion. To restore volume and renal perfusion. Rapidly response to treatment. 


Intrinsic(ATN, AIN, AGN, Vascular)- nephrotoxic, cytotoxic, prolonged ischemic, inflammatory insults to the kidney. 

ATN 

Causes: 

-ischemic: from prolonged prerenal, hypotension., hypovolemia or post op. 

- nephrotoxic: exogenous(drugs, contrast), endogenous(gout, myoglobinuria/rhabdo, lymphoma/leukemia,MM, What can be nephrotoxic? From drugs, dye, medications. 

- muddy brown casts, epithelial casts, low specific gravity, hyperK,hyperPhos 

-Labs: Scr increase >0.3/day, uNa>40, FENa>2%, low specific gravity, UA with epithelial cells/granular casts, SCr doesn’t improve with fluids, BUN:SCr ration 10-15:1. 

- consider diuretics, Iv fluids, stop offending meds 

- Most patients return to baseline in seven dash 21 days. 


AIN- Inflammatory or allergic response in interstitium with sparing of Glomeruli and blood vessels. 

- Causes: Drugs, infections, autoimmune. Idiopathic. 

-sx: Fever, eosinophilia, Maculopapular rash, anthralgias, WBC casts, elevated serum IgE 

- creat bumps 7-10 days after drug exposure 

- pyuria with or without WBCs or hematuria (no red cell casts) 

- Tx is withdraw offending medications. Recovery in 1 year 

- can use corticosteroids - Prednisone 1mg/kg per day 

Abx: cephalosporins, ampicillin, amoxicillin, penicillin G, sulfa, rifampin, tetracycline 

Diuretics: Lasix, Thiazidees 

NSAIDS 

 

AGN 

- Hematuria (RBC casts), Azotemia, proteinuria. Management is high dose corticosteroids, cytotoxic agents. 

  

FENA 

Urine Na should be < 20mEq/L in hypovolemia 

Urine Na is high in ATN due to impaired tubular function 

<1% in pre renal, >2% in ATN 

  

Diuretics: Use FeUrea - Prerenal is <35%, ATN is >35% 


Post renal: Obstruction from stone or BPH. Tx Is removal of obstruction.  

FEVER

ICU related causes: Sinusitis, blood transfusions, drug fever, catheter infection, surgical site infection, pneumonia, PE, MI, endocarditis, Acalculous cholecystitis, Bowel translocation, bowel infarction, Cdiff, UTI, DVT 

Bacterial: chlamydia, gonorrhea, MRSA, rheumatic fever, shigella, tetanus, atypical mycobacterial disease, Tuberculosis 

Viral: CMV, EBV, HSV, HIV, Influenza, VZV 

Other: Lyme disease, syphilis, toxoplasmosis, infective thrombophlebitis, fistula infection 

VAP ddxs: staph aureus, PSA, aerobic GNBs(E.coli, Kleb pna, enterobacter), early vap mcc’s are***, PSA(MCC of VAP), mdro Acenitobactar baumanni