Bottom Line:

NMS (neuroleptic malignant syndrome) is a potentially life threatening condition thought to be caused by blockade of the dopamine D2 receptor pathway. SS (serotonin syndrome) is also a potentially life threatening condition associated with increased serotonergic activity. Both conditions result in mental status changes, fever, dysautonomia (autonomic dysfunction), leukocytosis, and neuromuscular symptoms. Both conditions have a wide array of possible presentations, and both conditions are clinical diagnoses (lab tests do not confirm the diagnosis).

Generally speaking, SS has a more rapid onset (symptoms present within 24 hours of starting a drug or changing a dose) whereas NMS takes several days or weeks to appear. SS involves neuromuscular hyperactivity (e.g. clonus, hyperreflexia) whereas NMS involves bradykinesia (typically “lead-pipe” rigidity). In SS the clonus can involve the eyes and pupils can be dilated, neither of which occur in NMS. Both NMS and SS cause hyperthermia, but shivering is apparently unique to SS.

Treatment is similar for both conditions. Remove the offending agent and provide supportive care to normalize vital signs and prevent renal damage. Sedation with benzodiazepines may be considered. Resolution of the syndrome with treatment occurs over hours with SS, but can take days to weeks with NMS.

Memory Aids:


F – Fever

A – Autonomic instability

L – Leukocytosis

T – Tremor

E – Elevated enzymes (CPK, LDH, AST, ALT)

R – Rigidity


(this is taken from an article by Christensen in Current Psychiatry)

S – Shivering (is apparently one symptom that distinguishes SS from other hyperthermic conditions)

H – Hyperreflexia (especially in lower extremities)

I – Increased temperature

V – Vital sign instability

E – Encephalopathy

R – Restlessness

S – Sweating (anticholinergic toxicity, in contrast, has a similar presentation, but with hot, dry skin) Continue reading “NMS VS SS”

Rh Factor VS RhD Factor

Bottom Line:

They are the same thing! D is the most common antigen in the Rh blood group system so people keep things simple by just saying “Rh” instead of RhD. Note that RhD can also be denoted as RhO (sometimes using a subscript letter O or number 0). So Rh, RhD, RhO, RhoD, RhO or Rh0 can all refer to the D antigen of the Rh blood group system.

Memory Aids:

When in doubt, it’s the Rh D antigen. Continue reading “Rh Factor VS RhD Factor”

Exudate VS Transudate

Bottom Line:

Fluid that collects in extracellular, extravascular spaces can be either exudative or transudative. Exudative fluid arises from inflammatory processes that make vessel walls more permeable to both fluid and proteins which allow them to exit the vessels and collect in the extravascular spaces. Transudative fluid exits the vessels due to a pressure differential between the intra and extravascular space (either hydrostatic or oncotic), but typically does not contain proteins since they are too large to squeeze out of the vessels. A fluid sample can be tested according to Light’s criteria to determine if it is exudative or transudative.

Memory Aids:

Exudates are from Enflammation (inflammation)

Light’s criteria – protein 5, LDH 6

(fluid protein:serum protein >0.5, fluid LDH:serum LDH>0.6) Continue reading “Exudate VS Transudate”


Bottom Line:

ADLs (activities of daily living) are the basic necessary daily self-care tasks people are required to perform such as bathing, dressing, toileting, grooming, and self-feeding. They are sometimes called Basic Activities of Daily Living (BADLs) to differentiate them from IADLs (instrumental activities of daily living) which are slightly more complex tasks that people are required to perform in order to live independently in society. These include shopping, banking, housework, and cooking among others.

Memory Aids:


D – dressing

E – eating (specifically feeding oneself, but not necessarily cooking or chewing or swallowing)

A – ambulation (walking and transferring)

T – toileting (including cleaning oneself afterwards)

H – hygiene (showering, grooming, combing/styling hair)


S – shopping

H – housekeeping

A – accounting (including banking, management of finances)

F – food preparation

T – telephone use (or another communication device) and transportation (driving or using the bus or calling a taxi) Continue reading “ADLs VS IADLs”

Fever VS Hyperthermia

Bottom Line:

Fever is a kind of hyperthermia where the physiological “set point” in the brain has been increased and the body attempts to maintain a high temperature (>38.3°C or 101°F) as though it were normal body temperature. Other kinds of hyperthermia i.e. heat stroke, malignant hyperthermia, etc. are increases in body temperature despite efforts by the thermoregulatory centres of the body trying to cool it down.

Memory Aids:

Fever is a kind of hyperthermia characterized by an increase in the “set point”. Continue reading “Fever VS Hyperthermia”

Creatinine VS Creatine

Bottom Line:

CreaTINE is converted in the body to phosphocreatine which is used to make ATP in high energy requiring tissues like the brain and skeletal muscle. CreaTININE is the breakdown product of creatine and is used as a biomarker of kidney function.

Memory Aids:

CreaTINE turns into creaTININE. Continue reading “Creatinine VS Creatine”

Direct Coombs Test VS Indirect Coombs Test

Bottom Line:

With the direct Coombs test you just add the anti-Ig antibodies (Coombs reagent) to your test solution and watch for agglutination. With the indirect Coombs test you have to add RBCs first, then you add the anti-Ig antibodies, and then watch for agglutination. So there is an extra step with the indirect Coombs test.

Direct Coombs is also called DAT (direct antiglobulin test).

Memory Aids:

Indirect has an extra step. Direct lets you go directly to the result. Continue reading “Direct Coombs Test VS Indirect Coombs Test”

GDM (Gestational Diabetes Mellitus) VS DM (Diabetes Mellitus)


Bottom Line:

GDM (Gestational Diabetes Mellitus) is a carbohydrate intolerance with onset OR first recognition during the present pregnancy. It does not matter if insulin is used as treatment, it does not matter if the intolerance continues post-pregnancy, and it does not preclude that the intolerance may have existed prior to the pregnancy. However, it would not be appropriate to label women with KNOWN pre-existing diabetes as having GDM. They would be said to have pre-gestational DM.

Memory Aids:

GDM is diabetes mellitus discovered during pregnancy. Continue reading “GDM (Gestational Diabetes Mellitus) VS DM (Diabetes Mellitus)”

Hepatitis B: HBsAg VS Anti-HBs

Bottom Line:

HBsAg (Hepatitis B surface antigen) is the one you are most likely to see on routine screening bloodwork for Hep B. If it is positive the person is likely actively infected with Hep B either chronically or acutely.

Memory Aids:

Surface Antigen is the one you want to remember. Continue reading “Hepatitis B: HBsAg VS Anti-HBs”