Fluid management in special populations — MCQs

A 7-day-old male infant presents to the pediatrician for weight loss. There is no history of excessive crying, irritability, lethargy, or feeding difficulty. The parents deny any history of fast breathing, bluish discoloration of lips/nails, fever, vomiting, diarrhea, or seizures. He was born at full term by vaginal delivery without any perinatal complications and his birth weight was 3.6 kg (8 lb). Since birth he has been exclusively breastfed and passes urine six to eight times a day. His physical examination, including vital signs, is completely normal. His weight is 3.3 kg (7.3 lb); length and head circumference are normal for his age and sex. Which of the following is the next best step in the management of the infant?

A physician at an internal medicine ward notices that several of his patients have hyponatremia without any associated symptoms. Severe hyponatremia, often defined as < 120 mEq/L, is associated with altered mental status, coma, and seizures, and warrants treatment with hypertonic saline. Because some patients are chronically hyponatremic, with serum levels < 120 mEq/L, but remain asymptomatic, the physician is considering decreasing the cutoff for severe hyponatremia to < 115 mEq/L. Changing the cutoff to < 115 mEq/L would affect the validity of serum sodium in predicting severe hyponatremia requiring hypertonic saline in which of the following ways?

A 23-year-old man presents to the emergency department for altered mental status after a finishing a marathon. He has a past medical history of obesity and anxiety and is not currently taking any medications. His temperature is 104°F (40°C), blood pressure is 147/88 mmHg, pulse is 200/min, respirations are 33/min, and oxygen saturation is 99% on room air. Physical exam reveals dry mucous membranes, hot flushed skin, and inappropriate responses to the physician's questions. Laboratory values are ordered as seen below. Hemoglobin: 15 g/dL Hematocrit: 44% Leukocyte count: 8,500/mm^3 with normal differential Platelet count: 199,000/mm^3 Serum: Na+: 165 mEq/L Cl-: 100 mEq/L K+: 4.0 mEq/L HCO3-: 22 mEq/L BUN: 30 mg/dL Glucose: 133 mg/dL Creatinine: 1.5 mg/dL Ca2+: 10.2 mg/dL AST: 12 U/L ALT: 10 U/L Which of the following is the best next step in management?

The serum brain natriuretic peptide and N-terminal pro-BNP are elevated. A diagnosis of heart failure with preserved ejection fraction is made. In addition to supplemental oxygen therapy, which of the following is the most appropriate initial step in management?

An 81-year-old man is admitted to the hospital due to acute decompensated heart failure. He has type 2 diabetes mellitus, hypertension, coronary artery disease, and congestive heart failure. Current medications include lisinopril, metformin, and low-dose aspirin. He has smoked one pack of cigarettes daily for 45 years. His temperature is 37.6°C (99.7°F), pulse is 105/min and regular, respirations are 21/min, and blood pressure is 103/64 mm Hg. Laboratory studies show: Hemoglobin 13.7 g/dL Leukocyte count 8200/mm3 Serum Na+ 128 mEq/L Cl- 98 mEq/L K+ 4.9 mEq/L Urea nitrogen 58 mg/dL Glucose 200 mg/dL Creatinine 2.2 mg/dL Which of the following changes in the medication regimen is most appropriate in this patient at this time?

A 69-year-old male presents to the emergency department for slurred speech and an inability to use his right arm which occurred while he was eating dinner. The patient arrived at the emergency department within one hour. A CT scan was performed of the head and did not reveal any signs of hemorrhage. The patient is given thrombolytics and is then managed on the neurology floor. Three days later, the patient is recovering and is stable. He seems depressed but is doing well with his symptoms gradually improving as compared to his initial presentation. The patient complains of neck pain that has worsened slowly over the past few days for which he is being given ibuprofen. Laboratory values are ordered and return as indicated below: Serum: Na+: 130 mEq/L K+: 3.7 mEq/L Cl-: 100 mEq/L HCO3-: 24 mEq/L Urea nitrogen: 7 mg/dL Glucose: 70 mg/dL Creatinine: 0.9 mg/dL Ca2+: 9.7 mg/dL Urine: Appearance: dark Glucose: negative WBC: 0/hpf Bacterial: none Na+: 320 mEq/L/24 hours His temperature is 99.5°F (37.5°C), pulse is 95/min, blood pressure is 129/70 mmHg, respirations are 10/min, and oxygen saturation is 98% on room air. Which of the following is the best next step in management?

A 35-year-old woman is brought to the emergency department 45 minutes after being rescued from a house fire. On arrival, she appears confused and has shortness of breath. The patient is 165 cm (5 ft 5 in) tall and weighs 55 kg (121 lb); BMI is 20 kg/m2. Her pulse is 125/min, respirations are 29/min, and blood pressure is 105/65 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 97%. Examination shows second and third-degree burns over the anterior surfaces of the chest and abdomen, and the anterior surface of the upper extremities. There is black debris in the mouth and nose. There are coarse breath sounds over the lung bases. Cardiac examination shows no murmurs, rubs, or gallop. Femoral and pedal pulses are palpable bilaterally. Which of the following is the most appropriate fluid regimen for this patient according to the Parkland formula?

A 65-year-old woman is brought to the emergency department by her husband who found her lying unconscious at home. He says that the patient has been complaining of progressively worsening weakness and confusion for the past week. Her past medical history is significant for hypertension, systemic lupus erythematosus, and trigeminal neuralgia. Her medications include metoprolol, valsartan, prednisone, and carbamazepine. On admission, blood pressure is 130/70 mm Hg, pulse rate is 100 /min, respiratory rate is 17/min, and temperature is 36.5°C (97.7ºF). She regained consciousness while on the way to the hospital but is still drowsy and disoriented. Physical examination is normal. Finger-stick glucose level is 110 mg/dl. Other laboratory studies show: Na+ 120 mEq/L (136—145 mEq/L) K+ 3.5 mEq/L (3.5—5.0 mEq/L) CI- 107 mEq/L (95—105 mEq/L) Creatinine 0.8 mg/dL (0.6—1.2 mg/dL) Serum osmolality 250 mOsm/kg (275—295 mOsm/kg) Urine Na+ 70 mEq/L Urine osmolality 350 mOsm/kg She is admitted to the hospital for further management. Which of the following is the next best step in the management of this patient's condition?

A 25-year-old woman presents to the physician with a complaint of several episodes of headaches in the past 4 weeks that are affecting her school performance. These episodes are getting progressively worse, and over-the-counter medications do not seem to help. She also mentions having to raise her head each time to look at the board while taking notes; she cannot simply glance up with just her eyes. She has no significant past medical or family history and was otherwise well prior to this visit. Physical examination shows an upward gaze palsy and convergence-retraction nystagmus. What structure is most likely to be affected in this patient?

A 62-year-old man presents with multiple episodes of hemoptysis for a week. It is associated with generalized weakness, decreased appetite, and a 5.4 kg (12 lb) weight loss in 2 months. He has a smoking history of a pack a day for the last 47 years. Physical examination reveals pallor, while the rest of the results are within normal limits. Laboratory studies reveal decreased hemoglobin and a serum sodium value of 130 mEq/L. Chest X-ray shows a 3 cm rounded opaque shadow. Which of the following conditions is the patient most likely suffering from?