UWorld Review 1 Flashcards
Describe the clinical presentation of salicylate toxicity. What would the ABG show?
- the hallmark is tinnitus accompanied by fever, tachypnea, nausea, and GI upset
- it leads to a respiratory alkalosis by stimulating tachypnea and an anion gap metabolic acidosis by uncoupling oxidative phosphorylation, which promotes anaerobic metabolism
- this mixed respiratory alkalosis and metabolic acidosis leads to a near-normal pH
What is winter’s formula?
- PaCO2 = 1.5(serum bicarb) + 8 +/- 2
- it predicts the appropriate respiratory compensation for a metabolic acidosis; a PaCO2 below this range suggests a respiratory alkalosis also exists
How does paranoid personality disorder differ from delusional disorder, paranoid type?
time course and intensity: those with a paranoid personality disorder have a pattern of distrust and suspicion of others throughout their entire lives and their beliefs do not have the same intensity as those with delusional disorder
What is the most common etiology for small bowel obstruction?
adhesions, which may be post-operative, post-inflammation, or congenital (known as Ladd’s bands)
Describe the presentation, diagnosis, and management of small-bowel obstruction.
- presents with colicky abdominal pain, vomiting, an inability to pass flatus or stool, hyperactive and later absent bowel sounds, and a distended or tympanic abdomen
- diagnosis is supported by the presence of dilated bowel or air-fluid levels on plain film or CT
- it should be initially managed with bed rest, NPO status, placement of an NG, and IV fluids
- if patients show signs of a complicated SBO (fever, hemodynamic instability, peritoneal signs, leukocytosis, or metabolic acidosis), surgical exploration is needed
Describe the pathogenesis of exercise-induced hypothalamic amenorrhea.
- prolonged caloric deficiency leads to diminished GnRH
- low GnRH leads to low FSH/LH levels
- this results in low estrogen levels and thus amenorrhea
Describe the pathogenesis, presentation, diagnosis, and management of Ashermann syndrome.
- suction and sharp curettage may inadvertently remove the basalts layer of the endometrium, promoting the formation of intrauterine adhesions and endometrial cavity obliteration
- presents with abnormal uterine bleeding or amenorrhea, infertility, cyclic pelvic pain, and recurrent pregnancy loss
- hysteroscopy with lysis of adhesions confirms the diagnosis and serves as treatment
How is familial adenomatous polyposis managed?
- screen with annual signoidoscopies and then colonoscopies beginning at age 10-12
- urgent proctocolectomy is indicated for patients who initially present with CRC or adenomas with high-grade dysplasia or have a significant increase in polyp number during the screening interval
- otherwise, proctocolectomy can be delayed until patients are in their 20s
Describe the presentation of HELLP syndrome. How is it treated?
- hypertension, elevated liver enzymes, and low platelet count are the hallmark features
- usually this is accompanied by RUQ pain from stretch of the hepatic capsule, microangiopathic hemolytic anemia, nausea, and vomiting
- pulmonary edema may complicate the course due to generalized arterial vasospasm, diminished albumin, poor renal function, and an increase in vascular permeability
- treat with magnesium for seizure prophylaxis, antihypertensive medications, and delivery of the baby
Describe magnesium toxicity?
patients typically have neuromuscular depression including decreased respiratory effort, muscle paralysis, somnolence, visual disturbance, and diminished reflexes
Describe the presentation and treatment of bacterial vaginosis.
- patients report thin, off-white discharge with a fishy odor and no vulvovaginal inflammation (no erythema or prutitis)
- the diagnosis is supported by a vaginal pH greater than 4.5, a positive whiff test, and the presence of clue cells on wet mount
- treat with metronidazole
Describe the presentation, labs, potential complications, and management of cholesasis of pregnancy.
- develops in the third trimester as generalized pruritus with RUQ pain and without rash
- labs show elevated bile acids, transaminases, and bilirubin
- may lead to intrauterine fetal demise, preterm delivery, meconium-stained amniotic fluid, or neonatal respiratory distress
- treat with ursodeoxycholic acid, antihistamines, and delivery at 37 weeks
Describe the presentation and management of ITP.
- it presents as petechiae, ecchymosis, and mucosal bleeding with isolated thrombocytopenia
- treatment is a progression of steroids, IVIG, and splenectomy
Describe the management of pediatric constipation.
- begin with dietary modifications including increased fiber, increased water intake, and decreased milk
- add laxatives and stool softeners
- use suppositories and enemas if oral laxatives are unsuccessful
- plain films are only necessary for severe constipation with abdominal pain and vomiting
Describe the pathogenesis, presentation, and management of methemoglobinemia.
- it is a complication of exposure to oxidizing substances, namely dapsone, nitrites, and local anesthetics
- this exposure causes a transition from ferrous (2+) to ferric (3+) iron which increase oxygen affinity and reduces release to peripheral tissues
- presents with cyanosis, chocolate-colored blood, respiratory depression, and lethargy
- pulse ox is always approximately 85% because the methemoglobin absorbs different frequencies of light, ABG shows a normal PaO2 since it measures only unbound oxygen, and patients don’t respond to oxygen therapy
- treat with methylene blue, a reducing agent
What are the diagnostic criteria for schizophrenia?
more than 2 of the following (with 1 being the first three) for at least six months, causing functional decline
- hallucinations
- delusions
- disorganized speech
- disorganized or catatonic behavior
- negative symptoms
Name six circumstances or health issues that allow minors to provide their own consent.
- emergency care
- mental health and substance abuse treatment
- management of STIs, contraceptive care, and pregnancy care
What is the triad of symptoms seen in those with heat stroke?
- temperature greater than 104F
- CNS dysfunction
- additional organ or tissue damage
How does the management of exertional and nonexertional heat stroke differ?
- for exertion, ice water immersion for rapid cooling is preferred
- for non-exertional, which is more common in the elderly, evaporative cooling is preferred because it has lower mortality
How do cardiac index, systemic vascular resistance, and left-ventricular end-diastolic volume change in those with HFrEF?
- cardiac index declines
- systemic vascular resistance increases to maintain blood pressure and organ perfusion
- LVEDV increases due to increased blood volume and chronically reduced EF
Describe the typical presentation for TMJ dysfunction.
pain which localizes to the ear and is exacerbated by chewing, often in patients with a history of nocturnal teeth grinding
Describe the presentation and treatment of bronchial mucus plugs.
- they most often form in post-op patients and smokers
- they cause distal air trapping and eventual atelectasis, presenting with dyspnea, hypoxemia, and absent breath sounds on the affected side
- CXR reveals opacification of the affected lung with ipsilateral mediastinal shift
- physiotherapy is first-line treatment but bronchoscopy may be required
Define the following types of bias:
- ascertainment bias
- Berkson bias
- Neyman bias
- ascertainment: also known as sampling bias, it is when the study population differs from the target population due to non-random selection methods
- Berkson: studies using only hospital-based patients may lead to results not applicable to the target population
- Neyman: also known as prevalence bias, exposures that happen long before disease assessment can miss diseased patients that die early or recover
Describe the pathogenesis, presentation, diagnosis, and treatment of porphyria cutanea tarda.
- it is due to uroporphyrinogen decarboxylase deficiency
- as a cutaneous porphyria, it presents with painless blisters that heal with scarring and hyperpigmentation of sun exposed skin
- diagnosis is based on elevated plasma and urinary porphyrin levels as well as labs consistent with iron overload
- treat with phlebotomy for iron overload