Oligoarticular arthritis, 1012 Oligomenorrhea associated with hyperandrogenism, 344 caloric intake and, 344 definition, 341 differential diagnosis, 342 t evaluation and decision, 343 f approach to diagnosis, 345 examination, 341 history, 341 of nonpregnant patients, 342 –343 pregnancy, 341 –342 vital signs, 341 psychosocial stressors and, 345 Omental cysts, 1307 Ominous signs, 1410 Omphalitis, 337 Omphalomesenteric duct, 1310 , 1353 Omphalomesenteric remnants, 1311 f Oncologic emergencies bone tumors, 918 –919 care of patients with advanced cancer, 932 –934 central nervous system, tumors of, 907 –909 chemotherapy-induced nausea and vomiting (CINV), management, 929 , 930 t complications associated with cancer and cancer therapy, management of acute alteration in mental status, 928 t acute complications of selected drugs, 921 t cardiovascular, 928 t–929 t of CAR-T cell therapy, 924 –925 , 932 genitourinary, 931 hematologic, 920 –922 hematopoietic stem cell transplantation, 932 , 933 t hepatic and gastrointestinal, 929 –931 infectious, 922 –924 metabolic, 925 –926 neurologic, 927 –928 pain, 926 –927 renal, 931 skin, 931 –932 emergency therapy, goals of, 901 gastrointestinal tract tumors, 914 –915 gastrointestinal (GI) tract tumors, 914 –915 gonadal tumors, 917 –918 head and neck tumors, 909 –910 hepatobiliary tree tumors, 912 –915 histiocytic diseases, 906 –907 historical data needed for evaluation, 902 t initial care of child with new or recurrent cancer, 901 kidney tumors, 915 –917 leukemia, 901 –906 lower genitourinary tract tumors, 917 neuroblastoma, 915 pancreas tumors, 914 skin cancers, 920 soft tissues tumors, 919 –920 symptoms and signs of pediatric cancer, 903 t thorax tumors, 910 –912 tumors in and around spinal cord, 918 Ondansetron (Zofran), 149 , 149 t, 191 , 193 , 887 Ophthalmic emergencies chalazion, chronic, 1402 f conjunctivitis, differential diagnosis of, 1397 t dacryocystitis, 1402 f Desmarres lid retractors, 1394 f emergency care, goals of, 1392 epidemic keratoconjunctivitis infection, 1398 f examinations and administration, 1392 –1395 eye drops, instillation of, 1394 –1395 ocular positioning assessment, 1392 swollen eye, 1394 visual acuity testing, 1392 –1394 eye emergencies, 1395 –1402 chalazions, 1401 –1402 chemical injury, 683 See also Ocular chemical injury conjunctivitis, 1396 –1400 See also Conjunctivitis hordeolums, 1401 –1402 nasolacrimal duct (NLD) obstruction, 1402 periorbital cellulitis, 1395 , 1395 f See also Periorbital/orbital cellulitis HOTV visual acuity chart, 1393 , 1393 f left nasolacrimal duct obstruction, 1402 f multiple chalazions, 1401 f neonatal gonorrheal conjunctivitis, 1397 f ocular lavage, irrigation setup, 1401 f orbital cellulitis, CT scan of, 1396 f periorbital cellulitis, 1395 , 1395 f stye, acute, 1401 f vision obstruction, in eye, 1394 f Ophthalmology, consultation, 1401 Ophthalmoplegic migraine, 191 Opioid abuse, 1078 Opportunistic fungal infections, 444 Oppositional defiant disorder, 97 Opsoclonus-myoclonus syndrome, 108 Optic nerve gliomas, 190 Optic neuritis, 193 , 898 Oral antihistamines, 586 t Oral cavity and pharynx trauma, 1117 –1118 caustic injuries, 1118 clinical recognition, 1117 evidences, 1117 initial assessment, 1117 lateral neck radiograph, 1118 f management, 1117 –1118 treatment goals, 1117 triage, 1117 Oral lesions, 348 f associated with systemic disease, 351 –352 causes common, 349 t life-threatening, 349 t differential diagnosis, 347 –352 , 349 t evaluation and decision, 352 –353 pathophysiology, 347 Oral mucosal soft tissue pathology, 1316 –1318 aphthous stomatitis, 1317 eruption cysts, 1317 , 1317 f mucocele, 1317 neonatal cysts, 1318 pyogenic granuloma, 1317 –1318 Riga–Fede disease, 1318 treatment goals, 1316 Oral phosphosoda, 132 Oral rehydration therapy (ORT), 149 –150 , 150 f Orbital blowout fractures, defined, 1124 , 1125 f Orbital cellulitis, 179 –180 See also Periorbital/orbital cellulitis Orbital dystopia, 1122 Orbital fracture, 1124 –1126 , 1124 f Orbital tumors, 175 , 180 Orbital wall fractures, 176 Orchiopexy, 257 Orchitis, 411 Order set, –11 Organic acidemias, 874 Organic psychosis, 95 t Organophosphates, 1065 Orifice odors, 338 Oropharyngeal airways (OPA), 48 , 48 f Oropharyngeal injuries, 625 –627 Oropharyngeal tumors, 909 Orthostatic hypotension, 492 , 518 , 520 , 522 , 524 , 539 Orthostatic intolerance, 520 –521 Oseltamivir, 81 t Osgood–Schlatter disease, 279 –280 , 301 –302 , 1367 , 1367 f Osler–Weber–Rendu disease, 166 Os odontoideum, 330 ...neurologic, 927 –928 pain, 926 –927 renal, 931 skin, 931 –932 emergency therapy, goals of, 901 gastrointestinal tract tumors, 914 –915 gastrointestinal (GI) tract... 915 pancreas tumors, 914 skin cancers, 920 soft tissues tumors, 919 –920 symptoms and signs of pediatric cancer, 903 t thorax tumors, 910 –912 tumors in and around spinal cord, 918 Ondansetron... conjunctivitis, differential diagnosis of, 1397 t dacryocystitis, 1402 f Desmarres lid retractors, 1394 f emergency care, goals of, 1392 epidemic keratoconjunctivitis infection, 1398 f examinations and