WBR0797
| Author | [[PageAuthor::Rim Halaby, M.D. [1]]] |
|---|---|
| Exam Type | ExamType::USMLE Step 1 |
| Main Category | MainCategory::Physiology |
| Sub Category | SubCategory::Renal |
| Prompt | [[Prompt::A 52 year old patient presents to the physician's office complaining of headache and blurry vision. Past medical history is insignificant. The physician suspects the patient's blood pressure is elevated. In the clinic, the patient's blood pressure measures 150/70 mmHg in the right arm in sitting position. His other vital signs are as follows: Temperature 36.8 degrees C (98.2 degrees F), heart rate is 80 bpm, and respiratory rate is 14/min. What is the patient's approximate mean blood pressure?]] |
| Answer A | AnswerA::110 mmHg |
| Answer A Explanation | AnswerAExp::The mean blood pressure (MBP) is not measured by simply adding the systolic blood pressure (SBP) and diastolic blood pressure (DBP) and dividing by 2. |
| Answer B | AnswerB::123 mmHg |
| Answer B Explanation | [[AnswerBExp::This option corresponds to the following wrong equation: [2SBP+DBP]/3. It is important to remember that DBP is multiplied by 2, not the SBP.]] |
| Answer C | AnswerC::97 mmHg |
| Answer C Explanation | [[AnswerCExp::MBP = [SBP + 2DBP]/3 = 97 mmHg.]] |
| Answer D | AnswerD::73 mmHg |
| Answer D Explanation | [[AnswerDExp::This option corresponds to the following wrong equation: [SBP+DBP]/3. It is important to remember that DBP is multiplied by 2.]] |
| Answer E | AnswerE::Cannot be calculated |
| Answer E Explanation | AnswerEExp::MBP can be calculated by simply having the SBP and DBP. No additional values are needed for the equation. Other vital signs are not required either. |
| Right Answer | RightAnswer::C |
| Explanation | [[Explanation::The patient's mean blood pressure is measured as [SBP + 2DBP]/3, where SBP is the systolic blood pressure and DBP is the diastolic blood pressure. Accordingly, the patient's mean blood pressure (MBP) is [150 + (2x70)]/3 = [150+140]/3 = 97mmHg.
To calculate MBP, other vital signs are not required. Educational Objective: MBP = [SBP + 2DBP]/3 |
| Approved | Approved::No |
| Keyword | WBRKeyword::mean, WBRKeyword::blood, WBRKeyword::pressure, WBRKeyword::systolic, WBRKeyword::diastolic, WBRKeyword::systole, WBRKeyword::diastole, WBRKeyword::MBP, WBRKeyword::SBP, WBRKeyword::DBP, WBRKeyword::equation, WBRKeyword::hypertension, WBRKeyword::high |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |