--O--

O

oral

Ox3

oriented to person, place and time

O&P

ova and parasites

O.U.A.

off unit activities

O2

oxygen

OB

obstetrics

OB-GYN

obstetrics and gynecology

øbarb

phenobarbital

OBRR

Obstetric Recovery Room

OBS

organic brain syndrome

OBSU

Observation Unit

occ

occasional

OCT

oxytocin challenge test

OD

[L. oculus dexter] right eye; overdose

ODD

Oppositional Defiant Disorder

OG

orogastric

OHSD

Open Heart Step Down

oint

ointment

OM

Otitis Media

onco

oncology

OOB

out of bed

op

operation

OP or outpt

outpatient

OPC

outpatient clinic

OPD

outpatient department

Ophth

ophthalmologist/ophthalmology

OPV

oral poliovaccine

OR

operating room

ORIF

open reduction (with) internal fixation (fracture)

ortho

orthopedic

OS

[L. oculus sinister] left eye

Osm/mOsm

osmolality

OT

occupational therapy

OTC

over-the-counter (nonprescription drug)

OTP/L

Occupational Therapist Provisionally/Licensed

OTR/L

Occupational Therapist Registered/Licensed

OTS

Occupational Therapy Student

OU

[L. oculi unitas] both eyes (together)   [L oculi uterque] each eye

outpt

outpatient

ox

oximeter or oximetry

oz

ounce