1. Comma misuse. The comma is probably the most misused punctuation mark in the written English language. Misuse includes inserting too many commas, too few, or using them inappropriately so that the meaning of a sentence is unclear or may be misconstrued. In medicine, this can have serious consequences by changing medical meaning.
2. Commas and compound sentences. A compound sentence consists of two independent clauses joined most commonly by the conjunctions and, but, for, or, nor. If the two independent clauses-each a complete sentence-are short (only about four or five words long), a comma is not needed to separate them but may be used. If each independent clause is longer, a comma is generally used.
Before inserting a comma, check to be sure that the second part of the sentence is really an independent clause. Sometimes the second part of the sentence contains only a verb that agrees with the subject in the first part of the sentence. In that case, do not insert a comma because a comma should never separate a subject from its verb.
The patient is having chest pain, but she denies diaphoresis or dyspnea.
Both parts of the sentence are independent clauses and contain a subject and a verb. A comma is optional because the clauses are short.
The patient is having chest pain but denies diaphoresis and dyspnea.
No comma should be used because patient is the subject and the sentence has a compound verb, is having and denies.
3. Commas and adjectives. Commas are used with adjectives and nouns in a series according to the a, b, and c rule or the a, b and c rule. The use of the final comma before the word and or or in any list is optional if it does not distort medical meaning.
I have ordered a CBC, BUN, and creatinine.
I have ordered a CBC, BUN and creatinine.
4. Commas and adjectives in a series. Use a comma to separate adjectives or nouns in a series, but do not put a comma between the last adjective in a series and the noun that follows it.
The patient is a 60-year-old, frail, disoriented female.
5. Race. When the patient's race is given, consider it to be part of the noun and not an adjective.
The patient is a 70-year-old, frail, disoriented Caucasian female.
Tip: If you can substitute "and" for the comma in an adjective series, and the sentence sounds natural, it is usually safe to use the comma.
The patient was wearing a sleeveless black vest.
(No comma after sleeveless, because it sounds unnatural to say, "The patient was wearing a sleeveless and black vest.")
6. Commas and titles. Use a comma pair to set off a degree or title.
Marion Bartley, M.D., has agreed to see the patient in the emergency department.
Pamela K. Wear, RRA, and Vera Pyle, CMT, presented a seminar on confidentiality of health records.
7. Commas and appositives. Use a comma pair with an ap-positive if it provides information that is not essential to understanding the meaning of the sentence. (Note: An appositive is a phrase that immediately follows another word to identify or explain it.) If the appositive provides information that is essential to understanding the meaning of the sentence, do not use commas. Titles such as M.D. and CMT are treated as nonessential appositives, and thus a comma pair is used.
Dr. Dianna McElroy, the head of the department of cardiology, will provide us with a detailed follow-up evaluation on this patient.
Patient Ima N. Payne has asked me to write this letter to inquire about insurance coverage of this surgical procedure.
Linda Campbell, CMT, transcribed that particular report. The patient was referred to Carl Steward, M.D., for consultation and was asked to return to see me immediately after that visit.
8. Commas and diagnoses. Use a comma when the disease entity or condition is followed by its location in the body or when the term is followed by an adjective describing it.
Deep venous thrombosis, right leg.
9. Commas and introductory phrases and clauses. Use a comma to separate an introductory adverbial clause or prepositional phrase from the main independent clause of the sentence. If the introductory phrase or clause is short (less than five words), you can omit the comma if the meaning is clear.
When he experiences his typical chest pain, he always takes nitroglycerin sublingually.
On this occasion the patient is pleasant and cheerful.
10. Commas and introductory transitional words/phrases. Commas are often used to separate an introductory transitional word or phrase from the rest of the sentence. However, there is precedent in current usage for omitting the comma.
As a result, we felt that the patient was not a candidate for cardiac bypass.
As a result we felt that the patient was not a candidate for cardiac bypass.
Consequently, it was decided not to admit Mr. Smith at this time.
Consequently it was decided not to admit Mr. Smith at this time.
Otherwise, he will return to see me in a month.
Otherwise he will return to see me in a month.
11. Commas and semicolons. Use a comma to separate internal elements in sections that are already separated by semicolons.
HEART: Regular rate and rhythm; no murmur, gallop, or rub; S1 and S2 normal.
12. Commas with however. If the word however is in the middle of an independent clause, place commas around it.
The patient was, however, very tired.
The patient was very tired, however, complaining of weakness and fatigue.
13. If the word however separates two independent clauses, place a semicolon before however and a comma after it.
The patient was very tired; however, he did not complain of weakness.
14. Comma pair with phrases. Use a comma pair to set off nonessential phrases within a sentence. Omitting one of the commas in a comma pair is termed a comma fault.
Her condition, in my opinion, is critical.
15. Comma pair in dates. Use a comma pair to set off the year within a sentence when the date is presented in the month/day/year format. When the date is presented in the day/month/year format, a comma is not needed. Do not use a comma pair when only the month and year are given.
The patient is scheduled for surgery on June 15, 1995, at Valley General Hospital.
The patient is scheduled for surgery on 15 June 1995 at Valley General Hospital.
She had open heart surgery in June 1995 at Valley General Hospital.