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{{WBRQuestion
{{WBRQuestion
|QuestionAuthor={{Rim}}, {{AJL}} {{Alison}}
|QuestionAuthor={{Rim}}
|ExamType=USMLE Step 1
|ExamType=USMLE Step 1
|MainCategory=Pharmacology
|MainCategory=Pharmacology
Line 20: Line 20:
|MainCategory=Pharmacology
|MainCategory=Pharmacology
|SubCategory=Neurology
|SubCategory=Neurology
|Prompt=A researcher, studying the hemodynamic and respiratory effects of intravenous anesthetics, injects a mouse with intravenous ketamine infusion.  Several minutes later, he measures the mouse's heart rate (HR), blood pressure (BP), cerebral blood flow (CBF), and bronchial diameter (BDm) to assess the cardiovascular and respiratory roles of ketamine.  Which of the following hemodynamic and respiratory changes are most likely to occur following ketamine infusion in this experiment?
|Prompt=A researcher is studying the hemodynamic and respiratory effects of intravenous anesthetics.  In one experiment, he injects a mouse with intravenous ketamine infusion.  Several minutes later, he measures the mouse's heart rate (HR), blood pressure (BP), cerebral blood flow (CBF), and bronchial diameter (BDm) to assess the cardiovascular and respiratory roles of ketamine.  Which of the following hemodynamic and respiratory changes are most likely to occur following ketamine infusion in this experiment?
|Explanation=[[Ketamine]], a PCP analog used as an intravenous anesthetic drug, acts as a non-competitive NMDA receptor blocker.  A side effect of [[ketamine]] is dissociative anesthesia, a state of profound analgesia with only superficial sleep and spontaneous ventilation.  It does not usually suppress respiratory drive unless used at very high doses.   
|Explanation=Ketamine is a PCP analog used as an intravenous anesthetic drug.  Ketamine acts as a non-competitive NMDA receptor blocker.  Ketamine is known to cause dissociative anesthesia, a state of profound analgesia with only superficial sleep and spontaneous ventilation.  It does not usually suppress respiratory drive unless used at very high doses.   


Because [[ketamine]] increases intracranial pressure, it is contraindicated in patients with brain injury. Following [[ketamine]] administration, frequently there is an increase in heart rate, blood pressure, CVP, CO2 baroreceptor function, bronchodilation, respiratory rate, uterine tone, and salivation.
Because ketamine increases intracranial pressure, it is contraindicated in patients with brain injury.  Other systemic effects of ketamine are generally also increased. Following ketamine, there is an increased heart rate, blood pressure, CVP, CO2 baroreceptor function, bronchodilation, respiratory rate, uterine tone, salivation.


|EducationalObjectives= [[Ketamine]] administration may result in systemic effects by stimulating hemodynamic and respiratory systems.
Educational Objective: Ketamine causes systemic effects by stimulating hemodynamic and respiratory systems.
|References= Stevenson C. Ketamine: a review. Update in Anaesthesia. 2005;20:25-9.  


Reference: Stevenson C. Ketamine: a review. Update in Anaesthesia. 2005;20:25-9.
|AnswerA=Increased HR, increased BP, increased CBF, and increased BDm
|AnswerA=Increased HR, increased BP, increased CBF, and increased BDm
|AnswerAExp=See overall explanation.
|AnswerAExp=Ketamine increases hemodynamic and respiratory systems.
|AnswerB=Increased HR, decreased BP, increased CBF, and increased BDm
|AnswerB=Increased HR, decreased BP, increased CBF, and increased BDm
|AnswerBExp=BP frequently increases following [[ketamine]] infusion.
|AnswerBExp=BP increases following ketamine infusion.
|AnswerC=Increased HR, decreased BP, increased CBF, and decreased BDm
|AnswerC=Increased HR, decreased BP, increased CBF, and decreased BDm
|AnswerCExp=BP and BDm frequently increase following [[ketamine]] infusion.
|AnswerCExp=BP and BDm increase following ketamine infusion.
|AnswerD=Increased HR, decreased BP, decreased CBF, and decreased BDm
|AnswerD=Increased HR, decreased BP, decreased CBF, and decreased BDm
|AnswerDExp=BP, CBF, and BDm frequently increase following [[ketamine]] infusion.
|AnswerDExp=BP, CBF, and BDm increase following ketamine infusion.
|AnswerE=Decreased HR, increased BP, increased CBF, and increased BDm
|AnswerE=Decreased HR, increased BP, increased CBF, and increased BDm
|AnswerEExp=HR frequently increases following [[ketamine]] infusion.
|AnswerEExp=HR increases following ketamine infusion.
|RightAnswer=A
|RightAnswer=A
|WBRKeyword=ketamine, systemic effect, hemodynamic, respiratory, adverse drug reaction, dissociative analgesia, heart rate, cerebral blood flow, bronchial, side effects, intravenous, trial
|WBRKeyword=ketamine, systemic, effect, hemodynamic, respiratory, side, adverse, drug, reaction, dissociative, analgesia, heart, rate, heart rate, cerebral, blood, flow, cerebral blood flow, pressure, bronchodilation, bronchodilator, bronchial, diameter
|Approved=Yes
|Approved=No
}}
}}

Revision as of 22:55, 17 February 2015

 
Author [[PageAuthor::Rim Halaby, M.D. [1]]]
Exam Type ExamType::USMLE Step 1
Main Category MainCategory::Pharmacology
Sub Category SubCategory::Neurology
Prompt [[Prompt::A researcher is studying the hemodynamic and respiratory effects of intravenous anesthetics. In one experiment, he injects a mouse with intravenous ketamine infusion. Several minutes later, he measures the mouse's heart rate (HR), blood pressure (BP), cerebral blood flow (CBF), and bronchial diameter (BDm) to assess the cardiovascular and respiratory roles of ketamine. Which of the following hemodynamic and respiratory changes are most likely to occur following ketamine infusion in this experiment?]]
Answer A AnswerA::Increased HR, increased BP, increased CBF, and increased BDm
Answer A Explanation AnswerAExp::Ketamine increases hemodynamic and respiratory systems.
Answer B AnswerB::Increased HR, decreased BP, increased CBF, and increased BDm
Answer B Explanation AnswerBExp::BP increases following ketamine infusion.
Answer C AnswerC::Increased HR, decreased BP, increased CBF, and decreased BDm
Answer C Explanation AnswerCExp::BP and BDm increase following ketamine infusion.
Answer D AnswerD::Increased HR, decreased BP, decreased CBF, and decreased BDm
Answer D Explanation AnswerDExp::BP, CBF, and BDm increase following ketamine infusion.
Answer E AnswerE::Decreased HR, increased BP, increased CBF, and increased BDm
Answer E Explanation AnswerEExp::HR increases following ketamine infusion.
Right Answer RightAnswer::A
Explanation [[Explanation::Ketamine is a PCP analog used as an intravenous anesthetic drug. Ketamine acts as a non-competitive NMDA receptor blocker. Ketamine is known to cause dissociative anesthesia, a state of profound analgesia with only superficial sleep and spontaneous ventilation. It does not usually suppress respiratory drive unless used at very high doses.

Because ketamine increases intracranial pressure, it is contraindicated in patients with brain injury. Other systemic effects of ketamine are generally also increased. Following ketamine, there is an increased heart rate, blood pressure, CVP, CO2 baroreceptor function, bronchodilation, respiratory rate, uterine tone, salivation.

Educational Objective: Ketamine causes systemic effects by stimulating hemodynamic and respiratory systems.

Reference: Stevenson C. Ketamine: a review. Update in Anaesthesia. 2005;20:25-9.
Educational Objective:
References: ]]

Approved Approved::No
Keyword WBRKeyword::ketamine, WBRKeyword::systemic, WBRKeyword::effect, WBRKeyword::hemodynamic, WBRKeyword::respiratory, WBRKeyword::side, WBRKeyword::adverse, WBRKeyword::drug, WBRKeyword::reaction, WBRKeyword::dissociative, WBRKeyword::analgesia, WBRKeyword::heart, WBRKeyword::rate, WBRKeyword::heart rate, WBRKeyword::cerebral, WBRKeyword::blood, WBRKeyword::flow, WBRKeyword::cerebral blood flow, WBRKeyword::pressure, WBRKeyword::bronchodilation, WBRKeyword::bronchodilator, WBRKeyword::bronchial, WBRKeyword::diameter
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