KNOW Medicine, Knowledge Needed On the Wards

Part 1/2 SINUS BRADYCARDIA: A DYSRHYTHMIA of slower than normal heart rate (Atrial & Ventricular rate of <60bpm) SINUS (node) RHYTHM requires regularly appearing P waves of similar morphology & MUST have a positive/ upright deflection in leads 1, 2 & aVF Remember that the function of the Atrioventricular−AV node is to slow the sinus impulse, as indicated by the PR interval which represents the time it takes for both Atrial depolarization & impulse passage through the AV node DIFFERENTIAL DIAGNOSIS •Athlete, due to enhanced cardiovascular efficiency •Sleep, as normal physiology •DECREASED Myocardial metabolism −Elderly −Hypothermia −Hypothyroidism •INCREASED Autonomic PARASYMPATHETIC TONE, via the Vagus nerve −Vasodepressor pre−syncope/ syncope −Autonomic neuropathy via ↓sympathetic tone −Carotid sinus stimulation −Inferior myocardial ischemia −↑Intracranial pressure •MEDICATIONS via DECREASED Autonomic SYMPATHETIC TONE −Amiodarone, β−receptor blockers, non−dihydropyridine Calcium channel blockers, Clonidine, Digoxin, Methyldopa, Sotalol, Sedative−hypnotics/ Anesthetics Visit our Website/ Medical wards app knowmedicine.net #medicalstudent #medicalresident #meded #medicalschool #internalmedicine #medicaleducation #medstudent #imresidency #medicalapp #foamed #hospitalist #hospitalmedicine #bradycardia

INDICATIONS FOR ACUTE BETA RECEPTOR BLOCKADE IN MYOCARDIAL INFARCTION WITHIN 24 HOURS for patients who are hemodynamically stable enough to tolerate the effects of β receptor blockade & of course, lack the contraindications The benefit is felt to be due to a reduction of myocardial demand (↓PULSE & BLOOD PRESSURE) & the ANTIDYSRHYTHMIC effects The concern lies within the use of IV β receptor blockers given in the acute setting, increasing the risk of CARDIOGENIC SHOCK (being a leading cause of death in MI) The goal is simply to be able to administer the medication @ a tolerable PO dose while maintaining normotension (SBP 90−130/ DBP 60−80) IV administration is based on clinical judgement & need to acutely control either blood pressure or pulse Use caution when administering β blockers to patients w/ acute Inferior infarctions, as they are often due to a lesion in the Right coronary artery−RCA, which also supplies both the Sinoatrial & Atrioventricular nodes, which may cause nodal dysfunction→bradycardia ± heart block Outcomes: DECREASE MORBIDITY & MORTALITY Visit our Website/ Medical wards app knowmedicine.net #medicalstudent #medicalresident #meded #medicalschool #internalmedicine #medicaleducation #medstudent #imresidency #medicalapp #foamed #hospitalist #hospitalmedicine #betablocker

MONITORING ORGAN PERFUSION STATUS DURING CPR CAPNOGRAPHY, being the monitoring of END TIDAL PCO2, is now considered the desired method for monitoring the intubated patient in cardiac arrest for the following parameters: •Correct endotracheal tube placement, as Esophageal intubation will show either no CO2 waveform, or small, transient waves •The quality of chest compressions •Determining when the patient has Return of spontaneous circulation−ROSC End tidal or end−expiratory partial pressure of CO2−ETPCO2 is usually <10mmHg in cardiac arrest patients (normal is 35−45mmHg, being nearly equivalent to arterial PCO2), being measured in real time, on a breath by breath basis via nasal cannula or endotracheal tube. Understand that normally, arterial, alveolar & ETPCO2 are generally considered to have the same value •A value <10mmHg during CPR indicates poor quality chest compressions •A value of 10−20mmHg indicates high quality chest compressions •A persistently low value of <10mmHg after 20minutes of CPR indicates unlikely successful resuscitation (almost no chance) •An abrupt increase to 35−45mmHg indicates ROSC Underlying PHYSIOLOGY: INCREASED Systemic perfusion pressure→ INCREASED Pulmonary CO2 delivery→ INCREASED End tidal CO2, indicating INCREASED organ perfusion & better prognosis Visit our Website/ Medical wards app knowmedicine.net #medicalstudent #medicalresident #meded #medicalschool #internalmedicine #medicaleducation #medstudent #imresidency #medicalapp #foamed #hospitalist #hospitalmedicine #capnography

Part 2/2 TOXIC ALCOHOLS ISOPROPYL ALCOHOL: The most commonly ingested Toxic alcohol in the U.S. Found in mouthwashes, rubbing alcohol, lotions, hand sanitizers… being metabolized to ACETONE→ KETONEMIA & KETONURIA. However, because Bicarbonate is not consumed during Acetone production, ACIDEMIA DOES NOT OCCUR METHANOL: Found in windshield wiper fluid, radiator antifreeze, paint removers & thinners, copy machine fluid, shellacs, varnishes, embalming fluid, automotive fluid additives (octane boosters) & contaminated moonshine… being metabolized to FORMIC ACID & LACTIC ACID. Formic acid has a propensity to cause Optic neuropathy, causing blurred vision & BLINDNESS ETHYLENE GLYCOL: Found in radiator antifreeze, de-greasing agents & metal cleaners… being metabolized to OXALIC ACID. Oxalic acid complexes w/ Calcium, precipitating as Calcium oxalate crystals in the renal tubules, causing RENAL FAILURE PROPYLENE GLYCOL: Seen mainly in the HOSPITALIZED setting, being a colorless, odorless nonpolar SOLVENT used to dissolve certain IV medications that do not readily dissolve in aqueous solutions, such as Diazepam, Digoxin, Esmolol, Etomidate, Hydralazine, Lorazepam, Nitroglycerin, Phenobarbital, Phenytoin & Trimethoprim− Sulfamethoxazole. Propylene glycol is metabolized to LACTIC ACID & PYRUVIC ACID. While it is generally considered safe in moderate amounts, excessive exposure, especially in those w/ impaired metabolism by the Kidneys & Liver, can lead to toxicity Visit our Website/ Medical wards app knowmedicine.net #medicalstudent #medicalresident #meded #medicalschool #internalmedicine #medicaleducation #medstudent #imresidency #medicalapp #foamed #hospitalist #hospitalmedicine #toxicalcohol

Part 1/2 DIAGNOSING TOXIC ALCOHOL OVERDOSES Any alcohol, when consumed in enough of a quantity, can be toxic. However, the classic “Toxic alcohols” include the following ‘non−drinking’ alcohols… being used industrially as solvents, being toxic via consumption, inhalation, or skin absorption. Referred to as ‘Toxic’ due to the toxic metabolites that are formed, causing ACIDEMIA & ORGAN DAMAGE All Toxic alcohols acutely cause intoxication, same as if drinking Ethanol. This is why Alcoholics may be led to drink them if they don’t have access to alcohol. The same enzymes involved in Ethanol metabolism, primarily Alcohol dehydrogenase & Aldehyde dehydrogenase, are involved in Toxic alcohol metabolism As alcohols are ingested, they are all initially osmotically active, creating an OSMOLAR GAP. Most Toxic alcohols are subsequently metabolized to acids, which create a concomitant ANION GAP METABOLIC ACIDEMIA. Late in the course, when the parent compunds have been metabolized, there is only an Anion gap metabolic acidemia, meaning: EARLY PRESENTERS may only have an OSMOLAR GAP, determined by taking the MEASURED osmolarity & subtracting it from the CALCULATED osmolarity, Normal value: ≤10 Calculated osmolarity: 2 [Na+] + (BUN/ 2.8)+ (Glucose/ 18), Normal value: 280−290 mOsm/ kg H2O LATE PRESENTERS may only have an ANION GAP METABOLIC ACIDEMIA, except Isopropyl alcohol, which is the only Toxic alcohol not to cause an Anion gap metabolic acidemia Visit our Website/ Medical wards app knowmedicine.net #medicalstudent #medicalresident #meded #medicalschool #internalmedicine #medicaleducation #medstudent #imresidency #medicalapp #foamed #hospitalist #hospitalmedicine #toxicalcohol

Part 4/4 CLASSIFICATION OF PSYCHOTIC DISORDERS BRIEF PSYCHOTIC DISORDER affecting <0.5% of the population Any psychotic symptom(s) LASTING up to 1month, w/ complete return to premorbid functioning SCHIZOPHRENIFORM DISORDER affecting <0.5% of the population Any psychotic symptom(s) LASTING 1−5months (not meeting the criteria for Delusional Disorder), w/ the potential for complete return to premorbid functioning SCHIZOPHRENIA affecting ~1% of the population Any psychotic symptom(s) LASTING 6months or more, indicating disease unlikely to allow for complete return to premorbid functioning SCHIZOAFFECTIVE DISORDER affecting <0.5% of the population Psychotic syndrome with Major depression ± mania, being INDEPENDENT OF EACH OTHER via the persistence of either for at least 2weeks after the resolution of the other DELUSIONAL DISORDER affecting <0.5% of the population Limited to NON−BIZARRE delusions without other psychotic symptoms, LASTING at least 1 month. Non−bizarre delusions are plausible & could conceivably occur in real life, even though they are false. They involve situations such as believing one is being followed, has a disease, or is under surveillance. This is distinct from bizarre delusions which are implausible, not being grounded in reality, such as believing that one has been abducted by aliens or that one has superpowers. The distinction speaks to the severity of the delusion & the patients overall mental state SHARED PSYCHOTIC DISORDER (aka Folie a deux, being French for ‘Madness/ Insanity of 2’)-very rare Delusion developing in the context of a close relationship w/ a person (or group) who has a previously established delusion. The delusions must be similar & not due to an underlying psychotic syndrome in the secondarily affected patient POSTPARTUM PSYCHOSIS affecting 0.2% of women who give birth (1 in 500) Any psychotic symptom(s) beginning within 2weeks postpartum, LASTING up to 3months Visit our Website/ Medical wards app knowmedicine.net #medicalstudent #medicalresident #meded #medicalschool #internalmedicine #medicaleducation #medstudent #imresidency #medicalapp #foamed #hospitalist #hospitalmedicine #psychosis

Part 3/4 TREATMENT OF PSYCHOSIS All antipsychotic medications are considered of equal efficacy for POSITIVE symptoms, w/ ATYPICAL ANTIPSYCHOTICS: •Being more effective in controlling NEGATIVE symptoms    •Having a lower incidence of Extrapyramidal symptoms    •Having a lower incidence of Neuroleptic malignant syndrome •Having a lower incidence of significant Prolactin elevation, as ↑Prolactin causes mood disturbances, decreased libido, erectile dysfunction, amenorrhea, gynecomastia (in men), galactorrhea (milk−like, persistent nipple discharge) or Osteopenia/ Osteoporosis However, Atypical antipsychotic medications have been found to ↑Mortality in Elderly patients w/ Dementia related psychosis & should be used with caution in this group - as sometimes there are no good alternatives A patient may need to try several medications within the same class in order to find the one that works best for their biology, w/ the least & most tolerable side effects   Syndrome improvement should occur within several days, w/ maximal effects @ 2months. Lack of improvement within 1month should prompt an increase in dose, followed by a change to another medication Visit our Website/ Medical wards app knowmedicine.net #medicalstudent #medicalresident #meded #medicalschool #internalmedicine #medicaleducation #medstudent #imresidency #medicalapp #foamed #hospitalist #hospitalmedicine #psychosis

Part 2/4 DIAGNOSIS OF PSYCHOSIS via any of the following NEGATIVE SYMPTOMS, indicating the reduction or absence of normal social & cognitive functions (mimicking Major Depression), important for understanding the impact of psychosis on an individual's functioning & quality of life Negative symptoms lead to ISOLATION & tend to be MORE DIFFICULT TO TREAT, compared to Positive symptoms, the reasoning of which is not fully understood These symptoms go beyond simply being ‘weird’ or ‘unusual’ - but rather, showing a bizarrely profound disconnection from society LACK OF MOTIVATION OR INTEREST in social activites, relationships, work & hobbies LACK OF ATTENTION, resulting in SHORT TERM MEMORY LOSS LACK OF EMOTIONAL EXPRESSION through voice tone & gestures LACK OF EYE CONTACT when communicating LACK OF VERBALIZATION, resulting in brief or limited responses in conversation LACK OF PHYSICAL ACTIVITY Visit our Website/ Medical wards app knowmedicine.net #medicalstudent #medicalresident #meded #medicalschool #internalmedicine #medicaleducation #medstudent #imresidency #medicalapp #foamed #hospitalist #hospitalmedicine #psychosis

Part 1/4 DIAGNOSIS OF PSYCHOSIS via any of the following POSITIVE SYMPTOMS, indicating the presence of BIZARRE thoughts, perceptions, emotions or behavior (Negative symptoms are discussed in the next post) These symptoms go beyond simply being ‘weird’ or ‘unusual’ - but rather, being bizarrely irrational & implausible, disconnected from reality DELUSIONS: A false belief, held w/ conviction despite incontrovertable evidence to the contrary, being unexpected given the patients cultural background •PARANOID delusions, being the most common: False belief that people are following or trying to hurt them •Delusions of GRANDEUR: False belief that they have special powers, abilities, importance or wealth •IDEAS OF REFERENCE: False belief that common nonpersonal elements of the environment, such as people, objects, events or media are directed toward them or have personal significance •SOMATIC delusions: False belief that they have a disease, being firmly held despite incontrovertable evidence to the contrary •THOUGHT BROADCASTING: Belief that ones thoughts are being broadcasted to others as they occur •THOUGHT INSERTION: Belief that thoughts are being placed in their minds •THOUGHT WITHDRAWAL: Belief that thoughts are being removed from their minds HALLUCINATIONS: Imaginary sensations (AUDITORY > taste=gustatory, smell=olfactory, touch=tactile, visual) BIZARRE BEHAVIOR/ AFFECT: Behaviors or emotions inappropriate or strange to others DISORGANIZED SPEECH: Illogical, nonsensical &/or incomprehensible speech ALTERED MOTOR FUNCTION: •CATATONIC via immobility •EXCESSIVE, PURPOSELESS motor activity •Maintenance of a rigid ECHOLALIA, being an involuntary parrot−like repetition of that just spoken by another person Visit our Website/ Medical wards app knowmedicine.net #medicalstudent #medicalresident #meded #medicalschool #internalmedicine #medicaleducation #medstudent #imresidency #medicalapp #foamed #hospitalist #hospitalmedicine #psychosis

Part 2/2 PROSTHETIC VALVE THROMBOEMBOLIC PROPHYLAXIS (BIOPROSTHETIC & MECHANICAL) Indications to ANTICOAGULATE: ALL MECHANICAL VALVES require lifelong WARFARIN, to an INR ranging from 2−4 (based on valve type & location)… w/ those @ HIGH RISK adding lifelong ASPIRIN (usually being preferred to Clopidogrel) Certain BIOPROSTHETIC VALVES: •PORCINE or BOVINE valves, termed HETEROGRAFTS, require WARFARIN to an INR of 2−3 X 3-6months, when the risk of thromboembolism is highest, w/ subsequent lifelong ASPIRIN (usually being preferred to Clopidogrel) •HUMAN cadaveric valves, termed HOMOGRAFTS, do not require anticoagulation or antiplatelet prophylaxis However, patients with bioprosthetic valves @ HIGH RISK should take lifelong WARFARIN to an INR of 2−3 HIGH RISK factors: •Atrial fibrillation •Mural thrombus •History of a thromboembolic event •Hypercoagulable state •Very decreased Left ventricular Ejection fraction •Dilated atrium •2 or more prosthetic valves Initially, anticoagulate w/ High molecular weight IV HEPARIN, being used to ‘bridge’ the patient, until they achieve an adequate INR via concomitant WARFARIN administration, which may require a week or more Low molecular weight heparins, such as SC Enoxaparin, are NOT recommended with Mechanical valves, as they have shown inferiority to Warfarin, w/ other anticoagulants not yet studied Antiplatelet medication & doses are inidvidualized to the particular patient, valve type, valve location & comorbidities/ risk factors Visit our Website/ Medical wards app knowmedicine.net #medicalstudent #medicalresident #meded #medicalschool #internalmedicine #medicaleducation #medstudent #imresidency #medicalapp #foamed #hospitalist #hospitalmedicine #prostheticvalve