Fluid resuscitation principles — MCQs

10 questions

A 27-year-old man with a past medical history of type I diabetes mellitus presents to the emergency department with altered mental status. The patient was noted as becoming more lethargic and confused over the past day, prompting his roommates to bring him in. His temperature is 99.0°F (37.2°C), blood pressure is 107/68 mmHg, pulse is 120/min, respirations are 17/min, and oxygen saturation is 98% on room air. Laboratory values are ordered as seen below. Serum: Na+: 144 mEq/L Cl-: 100 mEq/L K+: 6.3 mEq/L HCO3-: 16 mEq/L BUN: 20 mg/dL Glucose: 599 mg/dL Creatinine: 1.4 mg/dL Ca2+: 10.2 mg/dL Which of the following is the appropriate endpoint of treatment for this patient?

A 17-year-old male presents to your office complaining of polyuria, polydipsia, and unintentional weight loss of 12 pounds over the past 3 months. On physical examination, the patient is tachypneic with labored breathing. Which of the following electrolyte abnormalities would you most likely observe in this patient?

A 19-year-old man with a history of type 1 diabetes presents to the emergency department for the evaluation of a blood glucose level of 492 mg/dL. Laboratory examination revealed a serum bicarbonate level of 13 mEq/L, serum sodium level of 122 mEq/L, and ketonuria. Arterial blood gas demonstrated a pH of 6.9. He is admitted to the hospital and given bicarbonate and then started on an insulin drip and intravenous fluid. Seven hours later when his nurse is making rounds, he is confused and complaining of a severe headache. Repeat sodium levels are unchanged, although his glucose level has improved. His vital signs include a temperature of 36.6°C (98.0°F), pulse 50/min, respiratory rate 13/min and irregular, and blood pressure 177/95 mm Hg. What other examination findings would be expected in this patient?

A 16-year-old woman presents to the emergency department for evaluation of acute vomiting and abdominal pain. Onset was roughly 3 hours ago while she was sleeping. She has no known past medical history. Her family history is positive for hypothyroidism and diabetes mellitus in her maternal grandmother. On examination, she is found to have fruity breath and poor skin turgor. She appears fatigued and her consciousness is slightly altered. Laboratory results show a blood glucose level of 691 mg/dL, sodium of 125 mg/dL, and elevated serum ketones. Of the following, which is the next best step in patient management?

A 14-year-old female with no past medical history presents to the emergency department with nausea and abdominal pain. On physical examination, her blood pressure is 78/65, her respiratory rate is 30, her breath has a fruity odor, and capillary refill is > 3 seconds. Serum glucose is 820 mg/dL. After starting IV fluids, what is the next best step in the management of this patient?

A 22-year-old woman with a history of type I diabetes mellitus presents to the emergency department with nausea, vomiting, and drowsiness for the past day. Her temperature is 98.3°F (36.8°C), blood pressure is 114/74 mmHg, pulse is 120/min, respirations are 27/min, and oxygen saturation is 100% on room air. Physical exam is notable for a confused and lethargic young woman. Initial laboratory values are notable for the findings below. Serum: Na+: 139 mEq/L Cl-: 100 mEq/L K+: 2.9 mEq/L HCO3-: 9 mEq/L BUN: 20 mg/dL Glucose: 599 mg/dL Creatinine: 1.1 mg/dL Ca2+: 10.2 mg/dL AST: 12 U/L ALT: 10 U/L An initial ECG is notable for sinus tachycardia. Which of the following is the best initial step in management for this patient?

An 8-year old boy is brought to the emergency department because he has been lethargic and has had several episodes of nausea and vomiting for the past day. He has also had increased thirst over the past two months. He has lost 5.4 kg (11.9 lbs) during this time. He is otherwise healthy and has no history of serious illness. His temperature is 37.5 °C (99.5 °F), blood pressure is 95/68 mm Hg, pulse is 110/min, and respirations are 30/min. He is somnolent and slightly confused. His mucous membranes are dry. Laboratory studies show: Hemoglobin 16.2 g/dL Leukocyte count 9,500/mm3 Platelet count 380,000/mm3 Serum Na+ 130 mEq/L K+ 5.5 mEq/L Cl- 99 mEq/L HCO3- 16 mEq/L Creatinine 1.2 mg/dL Glucose 570 mg/dL Ketones positive Blood gases, arterial pH 7.25 pCO2 21 mm Hg Which of the following is the most appropriate next step in management?

A 57-year-old man is admitted to the burn unit after he was brought to the emergency room following an accidental fire in his house. His past medical history is unknown due to his current clinical condition. Currently, his blood pressure is 75/40 mmHg, pulse rate is 140/min, and respiratory rate is 17/min. The patient is subsequently intubated and started on aggressive fluid resuscitation. A Swan-Ganz catheter is inserted to clarify his volume status. Which of the following hemodynamic parameters would you expect to see in this patient?

A 56-year-old man is brought to the emergency department after falling 16 feet from a ladder. He has severe pain in both his legs and his right arm. He appears pale and diaphoretic. His temperature is 37.5°C (99.5°F), pulse is 120/min and weak, respirations are 26/min, and blood pressure is 80/50 mm Hg. He opens his eyes and withdraws in response to painful stimuli and makes incomprehensible sounds. The abdomen is soft and nontender. All extremities are cold, with 1+ pulses distally. Arterial blood gas analysis on room air shows: pH 7.29 PCO2 33 mm Hg PO2 65 mm Hg HCO3- 15 mEq/L A CT scan shows displaced fractures of the pelvic ring, as well as fractures of both tibiae, the right distal radius, and right proximal humerus. The patient undergoes emergent open reduction and is admitted to the intensive care unit. Which of the following best indicates inadequate fluid resuscitation?

Q10

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?

Fluid resuscitation principles US Medical PG Practice Questions and MCQs

Question 1: A 27-year-old man with a past medical history of type I diabetes mellitus presents to the emergency department with altered mental status. The patient was noted as becoming more lethargic and confused over the past day, prompting his roommates to bring him in. His temperature is 99.0°F (37.2°C), blood pressure is 107/68 mmHg, pulse is 120/min, respirations are 17/min, and oxygen saturation is 98% on room air. Laboratory values are ordered as seen below. Serum: Na+: 144 mEq/L Cl-: 100 mEq/L K+: 6.3 mEq/L HCO3-: 16 mEq/L BUN: 20 mg/dL Glucose: 599 mg/dL Creatinine: 1.4 mg/dL Ca2+: 10.2 mg/dL Which of the following is the appropriate endpoint of treatment for this patient?

A. Clinically asymptomatic
B. Normal anion gap (Correct Answer)
C. Normal glucose
D. Vitals stable
E. Normal potassium

Explanation: ***Normal anion gap*** - A **normal anion gap** (approximately 8-12 mEq/L) indicates resolution of the **metabolic acidosis** characteristic of diabetic ketoacidosis (DKA). The current anion gap is high (Na - (Cl + HCO3) = 144 - (100 + 16) = 28 mEq/L). - The patient's presentation with **type 1 diabetes** and **altered mental status**, coupled with **hyperglycemia** (599 mg/dL) and **low bicarbonate** (16 mEq/L), is highly suggestive of DKA, for which anion gap normalization is a key treatment endpoint. *Clinically asymptomatic* - While a desirable outcome, resolution of symptoms occurs gradually and is not the primary biochemical endpoint for DKA treatment. - Patients may have residual symptoms even after metabolic derangements have significantly improved. *Normal glucose* - In DKA treatment, glucose is allowed to drop to a level (e.g., <200 mg/dL) but not necessarily to normal range, before initiating **dextrose-containing intravenous fluids** to prevent hypoglycemia while continuing insulin. - **Normal glucose** alone does not guarantee resolution of ketoacidosis, which is the main life-threatening aspect of DKA. *Vitals stable* - **Stable vital signs** indicate hemodynamic stability, which is crucial but does not confirm the resolution of the underlying DKA metabolic derangements. - Vitals can stabilize or worsen independently of acidosis resolution, especially if complications arise. *Normal potassium* - **Potassium levels** are critical to monitor and correct during DKA treatment, as insulin administration drives potassium into cells, potentially causing **hypokalemia**. - While important for patient safety, achieving a normal potassium level is part of supportive care and not the primary endpoint for resolving the ketoacidotic state itself.

Question 2: A 17-year-old male presents to your office complaining of polyuria, polydipsia, and unintentional weight loss of 12 pounds over the past 3 months. On physical examination, the patient is tachypneic with labored breathing. Which of the following electrolyte abnormalities would you most likely observe in this patient?

A. Hypophosphatemia
B. Hypermagnesemia
C. Hyperkalemia
D. Hyponatremia (Correct Answer)
E. Hyperphosphatemia

Explanation: ***Hyponatremia*** - This patient's symptoms of polyuria, polydipsia, and weight loss, along with **tachypnea and labored breathing**, are highly suggestive of **diabetic ketoacidosis (DKA)**. - **Hyponatremia** is the **most consistently observed** electrolyte abnormality in DKA, present in nearly all cases at initial presentation. - This is typically **pseudohyponatremia** caused by the osmotic effect of severe hyperglycemia—glucose pulls water into the extracellular space, diluting the measured sodium concentration. - The **corrected sodium** can be calculated using: Corrected Na = Measured Na + 0.016 × (Glucose - 100), which typically reveals a more normal sodium level. - True hyponatremia from sodium loss via **osmotic diuresis** can also occur but is usually masked by the dilutional effect. *Hyperkalemia* - While serum potassium may appear normal or even elevated initially due to **transcellular shifts** (acidosis causes potassium to move from intracellular to extracellular space in exchange for hydrogen ions), this is not the most consistently observed abnormality. - **Total body potassium is always depleted** in DKA due to osmotic diuresis and vomiting. - Many patients present with normal or even low potassium levels despite acidosis. - Potassium levels require careful monitoring during treatment as insulin therapy drives potassium back into cells, potentially causing life-threatening hypokalemia. *Hypophosphatemia* - While **phosphate levels** can fluctuate in DKA due to osmotic diuresis, initial presentation often involves normal or even elevated phosphate levels due to cellular shifts. - Significant **hypophosphatemia** is more typically observed during treatment as insulin drives phosphate back into the cells, similar to potassium. *Hypermagnesemia* - **Hypermagnesemia** is uncommon in DKA and is usually associated with impaired renal excretion or excessive magnesium intake. - The symptoms described do not point towards magnesium imbalance. *Hyperphosphatemia* - Although cellular shifts can initially raise serum phosphate, sustained **hyperphosphatemia** is not a characteristic or common electrolyte abnormality seen in the acute presentation of DKA. - More typically, total body phosphate is depleted due to **osmotic diuresis**.

Question 3: A 19-year-old man with a history of type 1 diabetes presents to the emergency department for the evaluation of a blood glucose level of 492 mg/dL. Laboratory examination revealed a serum bicarbonate level of 13 mEq/L, serum sodium level of 122 mEq/L, and ketonuria. Arterial blood gas demonstrated a pH of 6.9. He is admitted to the hospital and given bicarbonate and then started on an insulin drip and intravenous fluid. Seven hours later when his nurse is making rounds, he is confused and complaining of a severe headache. Repeat sodium levels are unchanged, although his glucose level has improved. His vital signs include a temperature of 36.6°C (98.0°F), pulse 50/min, respiratory rate 13/min and irregular, and blood pressure 177/95 mm Hg. What other examination findings would be expected in this patient?

A. Hypoglycemia
B. Pupillary constriction
C. Papilledema (Correct Answer)
D. Pancreatitis
E. Peripheral edema

Explanation: ***Papilledema*** - This patient's symptoms (confusion, severe headache, bradycardia, irregular respiration, hypertension) following treatment for **diabetic ketoacidosis (DKA)** are highly suggestive of **cerebral edema**. - **Papilledema** is a retinal finding resulting from increased intracranial pressure (ICP), which is a characteristic sign of cerebral edema. *Hypoglycemia* - While the patient's glucose level has improved, it is not described as being low enough to cause hypoglycemia, and the symptoms are more consistent with **increased ICP**. - Symptoms of hypoglycemia (e.g., tremors, sweating, hunger, anxiety) are different from the patient's current presentation of confusion and severe headache. *Pupillary constriction* - **Pupillary constriction** (miosis) is typically not associated with cerebral edema; instead, **pupillary dilation** (mydriasis) can occur with severe increase in ICP due to uncal herniation. - The combination of bradycardia, irregular respiration, and hypertension (Cushing's triad) is indicative of increased ICP, which would likely cause pupillary changes related to brainstem compression. *Pancreatitis* - Pancreatitis is a known complication of DKA, but it typically presents with **severe abdominal pain**, nausea, and vomiting, rather than cerebral symptoms. - Although the patient had DKA, the current neurological symptoms point directly to an intracranial process rather than an abdominal issue. *Peripheral edema* - **Peripheral edema** results from fluid accumulation in peripheral tissues and is not a direct consequence or expected finding in cerebral edema. - While fluid administration can cause some peripheral fluid retention, it typically does not lead to the acute neurological deterioration seen in this patient.

Question 4: A 16-year-old woman presents to the emergency department for evaluation of acute vomiting and abdominal pain. Onset was roughly 3 hours ago while she was sleeping. She has no known past medical history. Her family history is positive for hypothyroidism and diabetes mellitus in her maternal grandmother. On examination, she is found to have fruity breath and poor skin turgor. She appears fatigued and her consciousness is slightly altered. Laboratory results show a blood glucose level of 691 mg/dL, sodium of 125 mg/dL, and elevated serum ketones. Of the following, which is the next best step in patient management?

A. Administer IV fluids and insulin (Correct Answer)
B. Initiate basal-bolus insulin regimen
C. Initiate insulin glargine 10 units at bedtime only
D. Initiate oral antidiabetic medications
E. Initiate insulin aspart at mealtimes only

Explanation: ***Administer IV fluids and insulin*** - The patient presents with **fruity breath**, **altered consciousness**, **hyperglycemia (691 mg/dL)**, **hyponatremia**, and **elevated serum ketones**, which are classic signs of **diabetic ketoacidosis (DKA)**. - The immediate management for DKA involves aggressive **intravenous fluid resuscitation** to correct dehydration and hypovolemia, followed by a continuous **intravenous insulin infusion** to lower blood glucose and suppress ketogenesis. *Initiate basal-bolus insulin regimen* - A **basal-bolus insulin regimen** is appropriate for long-term management of diabetes but is not the immediate treatment for acute DKA, which requires continuous intravenous insulin. - This approach does not address the severe dehydration and electrolyte imbalances seen in DKA, which need urgent fluid replacement. *Initiate insulin glargine 10 units at bedtime only* - **Insulin glargine** is a long-acting insulin used for basal insulin coverage, typically in the chronic management of diabetes. - This dose is insufficient to manage acute DKA, and it also fails to address the critical need for fluid resuscitation. *Initiate oral antidiabetic medications* - **Oral antidiabetic medications** are suitable for individuals with type 2 diabetes or milder forms of insulin resistance, not for acute DKA. - They are ineffective in severe hyperglycemia and metabolic acidosis characteristic of DKA, and do not address dehydration. *Initiate insulin aspart at mealtimes only* - **Insulin aspart** is a rapid-acting insulin used to cover mealtime glucose excursions. - Administering it only at mealtimes is inadequate for acute DKA, which requires continuous insulin infusion and aggressive fluid management.

Question 5: A 14-year-old female with no past medical history presents to the emergency department with nausea and abdominal pain. On physical examination, her blood pressure is 78/65, her respiratory rate is 30, her breath has a fruity odor, and capillary refill is > 3 seconds. Serum glucose is 820 mg/dL. After starting IV fluids, what is the next best step in the management of this patient?

A. Intravenous Dextrose in water
B. Subcutaneous insulin glargine
C. Intravenous regular insulin (Correct Answer)
D. Intravenous glucagon
E. Subcutaneous insulin lispro

Explanation: ***Intravenous regular insulin*** - The patient presents with **diabetic ketoacidosis (DKA)**, characterized by **hyperglycemia**, **fruity breath** (due to ketones), and **hypotension**. Prompt administration of **intravenous regular insulin** is crucial to lower blood glucose and resolve ketoacidosis. - **Regular insulin** is preferred intravenously due to its **rapid onset** and short duration of action, allowing for precise titration and continuous adjustment based on glucose levels. *Intravenous Dextrose in water* - **Dextrose** would further increase the already severely elevated blood glucose level in a patient with DKA, worsening the metabolic derangements. - Dextrose is typically initiated only after blood glucose drops to safe levels (<200 mg/dL) to prevent **hypoglycemia** during insulin infusion. *Subcutaneous insulin glargine* - **Insulin glargine** is a **long-acting insulin** designed for basal insulin coverage, not for acute management of severe hyperglycemia or DKA. - Its **slow onset of action** and prolonged effect make it unsuitable for the urgent and rapid glucose reduction required in DKA. *Intravenous glucagon* - **Glucagon** is a hormone that **raises blood glucose levels**, counteracting the effects of insulin. - Administering glucagon would exacerbate the severe hyperglycemia present in DKA and is used only in cases of severe hypoglycemia. *Subcutaneous insulin lispro* - **Insulin lispro** is a **rapid-acting insulin analog** but is typically given subcutaneously. - While faster than regular insulin subcutaneously, the **subcutaneous route** has variable absorption in critically ill patients, and the immediate and precisely controllable effect of intravenous regular insulin is needed in DKA.

Question 6: A 22-year-old woman with a history of type I diabetes mellitus presents to the emergency department with nausea, vomiting, and drowsiness for the past day. Her temperature is 98.3°F (36.8°C), blood pressure is 114/74 mmHg, pulse is 120/min, respirations are 27/min, and oxygen saturation is 100% on room air. Physical exam is notable for a confused and lethargic young woman. Initial laboratory values are notable for the findings below. Serum: Na+: 139 mEq/L Cl-: 100 mEq/L K+: 2.9 mEq/L HCO3-: 9 mEq/L BUN: 20 mg/dL Glucose: 599 mg/dL Creatinine: 1.1 mg/dL Ca2+: 10.2 mg/dL AST: 12 U/L ALT: 10 U/L An initial ECG is notable for sinus tachycardia. Which of the following is the best initial step in management for this patient?

A. Normal saline and insulin
B. Insulin and potassium
C. Normal saline and potassium
D. Normal saline, insulin, and potassium (Correct Answer)
E. Normal saline, insulin, potassium, and sodium bicarbonate

Explanation: ***Normal saline, insulin, and potassium*** - This patient presents with signs and symptoms consistent with **diabetic ketoacidosis (DKA)**, including hyperglycemia (glucose 599 mg/dL), metabolic acidosis (HCO3- 9 mEq/L, respiratory compensation with elevated respiratory rate), and altered mental status. The initial management of DKA involves aggressive **intravenous fluid resuscitation** (normal saline), **insulin administration** to correct hyperglycemia and acidosis, and **potassium replacement** due to total body potassium depletion and anticipated further drop with insulin therapy. - Her **hypokalemia (2.9 mEq/L)**, even before insulin administration, necessitates immediate potassium repletion as insulin drives potassium intracellularly, which could worsen hypokalemia and lead to arrhythmias. *Normal saline and insulin* - While fluid resuscitation and insulin are crucial for DKA management, omitting **potassium replacement** in a patient with initial hypokalemia (K+ 2.9 mEq/L) would be inappropriate and potentially dangerous. - Failure to correct hypokalemia before or with insulin administration can precipitate life-threatening **cardiac arrhythmias**. *Normal saline, insulin, potassium, and sodium bicarbonate* - **Sodium bicarbonate** is generally not recommended for DKA unless pH is extremely low (typically <6.9), as it can worsen cerebral edema and hypokalemia. The patient's bicarbonate of 9 mEq/L and presumably higher pH does not warrant bicarbonate administration. - While fluids, insulin, and potassium are essential, the addition of sodium bicarbonate is usually reserved for severe, life-threatening acidosis (pH < 6.9). *Normal saline and potassium* - Administering only normal saline and potassium would address dehydration and hypokalemia but would fail to correct the underlying **hyperglycemia** and **ketoacidosis**, which are the core pathologies of DKA. - **Insulin** is critical to stop ketogenesis and lower blood glucose. *Insulin and potassium* - Administering insulin and potassium without **fluid resuscitation** would be inadequate. The patient is likely significantly dehydrated due to osmotic diuresis from hyperglycemia and vomiting. - **Fluid administration** is paramount in restoring circulating volume, improving renal perfusion, and reducing hyperglycemia by enhancing glucose excretion.

Question 7: An 8-year old boy is brought to the emergency department because he has been lethargic and has had several episodes of nausea and vomiting for the past day. He has also had increased thirst over the past two months. He has lost 5.4 kg (11.9 lbs) during this time. He is otherwise healthy and has no history of serious illness. His temperature is 37.5 °C (99.5 °F), blood pressure is 95/68 mm Hg, pulse is 110/min, and respirations are 30/min. He is somnolent and slightly confused. His mucous membranes are dry. Laboratory studies show: Hemoglobin 16.2 g/dL Leukocyte count 9,500/mm3 Platelet count 380,000/mm3 Serum Na+ 130 mEq/L K+ 5.5 mEq/L Cl- 99 mEq/L HCO3- 16 mEq/L Creatinine 1.2 mg/dL Glucose 570 mg/dL Ketones positive Blood gases, arterial pH 7.25 pCO2 21 mm Hg Which of the following is the most appropriate next step in management?

A. Intravenous hydration with 0.45% normal saline and insulin
B. Intravenous hydration with 5% dextrose solution and 0.45% normal saline
C. Intravenous sodium bicarbonate
D. Intravenous hydration with 0.9% normal saline and insulin (Correct Answer)
E. Intravenous hydration with 0.9% normal saline and potassium chloride

Explanation: ***Intravenous hydration with 0.9% normal saline and insulin*** - This patient presents with **diabetic ketoacidosis (DKA)**, characterized by hyperglycemia (glucose 570 mg/dL), metabolic acidosis (pH 7.25, HCO3- 16 mEq/L, ketones positive), and dehydration (dry mucous membranes, increased thirst, weight loss). - Initial management of DKA involves aggressive **volume expansion** with **0.9% normal saline** to restore perfusion and reduce hyperglycemia; subsequently, **insulin infusion** is started to correct hyperglycemia and halt ketogenesis. *Intravenous hydration with 0.45% normal saline and insulin* - While insulin is crucial, **0.45% normal saline (hypotonic saline)** is generally not the initial fluid of choice for DKA due to the risk of exacerbating cerebral edema, especially in children. - **Isotonic saline (0.9% normal saline)** is preferred for initial resuscitation to rapidly restore extracellular fluid volume. *Intravenous hydration with 5% dextrose solution and 0.45% normal saline* - **5% dextrose solution** should only be added to intravenous fluids when the blood glucose level falls to around 200-250 mg/dL, to prevent hypoglycemia while continuing insulin to resolve ketosis. - Administering dextrose initially would worsen the existing severe hyperglycemia. *Intravenous sodium bicarbonate* - **Sodium bicarbonate** is generally not recommended for mild to moderate DKA due to potential risks like cerebral edema and metabolic alkalosis, and potential paradoxical worsening of CNS acidosis. - Bicarbonate therapy is reserved for **severe acidosis (pH < 6.9 or 7.0)** with hemodynamic instability or impaired cardiac contractility, which is not the case here. *Intravenous hydration with 0.9% normal saline and potassium chloride* - While **0.9% normal saline** is appropriate, this option lacks **insulin therapy**, which is essential for treating DKA by halting ketogenesis and correcting hyperglycemia. - Although potassium supplementation will be necessary during DKA treatment (as insulin drives K+ into cells and can cause hypokalemia), the most appropriate **next step** is to initiate both fluid resuscitation and insulin therapy together. - The patient's current potassium level of 5.5 mEq/L is at the upper limit of normal, but reflects total body potassium depletion; potassium should be added to maintenance fluids once adequate urine output is established.

Question 8: A 57-year-old man is admitted to the burn unit after he was brought to the emergency room following an accidental fire in his house. His past medical history is unknown due to his current clinical condition. Currently, his blood pressure is 75/40 mmHg, pulse rate is 140/min, and respiratory rate is 17/min. The patient is subsequently intubated and started on aggressive fluid resuscitation. A Swan-Ganz catheter is inserted to clarify his volume status. Which of the following hemodynamic parameters would you expect to see in this patient?

A. Cardiac output: ↓, systemic vascular resistance: ↔, pulmonary artery wedge pressure: ↔
B. Cardiac output: ↑, systemic vascular resistance: ↑, pulmonary artery wedge pressure: ↔
C. Cardiac output: ↑, systemic vascular resistance: ↓, pulmonary artery wedge pressure: ↔
D. Cardiac output: ↓, systemic vascular resistance: ↑, pulmonary artery wedge pressure: ↓ (Correct Answer)
E. Cardiac output: ↔, systemic vascular resistance: ↔, pulmonary artery wedge pressure: ↔

Explanation: ***Cardiac output: ↓, systemic vascular resistance: ↑, pulmonary artery wedge pressure: ↓*** - The patient's **hypotension (75/40 mmHg)** and **tachycardia (140/min)**, combined with severe burns, indicate **hypovolemic shock** due to massive fluid loss from damaged capillaries. - In response to decreased cardiac output and hypovolemia, the body compensates by increasing **systemic vascular resistance (SVR)** to maintain perfusion to vital organs, and **pulmonary artery wedge pressure (PAWP)** will be low due to reduced intravascular volume. *Cardiac output: ↓, systemic vascular resistance: ↔, pulmonary artery wedge pressure: ↔* - This option incorrectly suggests that systemic vascular resistance and pulmonary artery wedge pressure would be normal, which is inconsistent with **hypovolemic shock**. - In shock, the body's compensatory mechanisms would lead to significant changes in SVR and PAWP, not maintain them at baseline. *Cardiac output: ↑, systemic vascular resistance: ↑, pulmonary artery wedge pressure: ↔* - Increased cardiac output is usually seen in **distributive shock** (e.g., septic shock) where vasodilation leads to reduced SVR, not increased SVR as suggested here. - An elevated SVR coupled with an increased cardiac output would typically result in a higher blood pressure unless there is a compensatory drop in other parameters. *Cardiac output: ↑, systemic vascular resistance: ↓, pulmonary artery wedge pressure: ↔* - This pattern (high cardiac output, low SVR) is characteristic of **distributive shock**, such as **septic shock** or anaphylactic shock, rather than the hypovolemic shock expected in a burn patient. - Severe burns primarily cause massive fluid shifts, leading to hypovolemia and a reduced cardiac output, not an elevated one. *Cardiac output: ↔, systemic vascular resistance: ↔, pulmonary artery wedge pressure: ↔* - This scenario represents **normal hemodynamic parameters**, which would not be expected in a patient experiencing severe shock from extensive burns. - The patient's clinical presentation (hypotension, tachycardia) clearly indicates a state of hemodynamic instability.

Question 9: A 56-year-old man is brought to the emergency department after falling 16 feet from a ladder. He has severe pain in both his legs and his right arm. He appears pale and diaphoretic. His temperature is 37.5°C (99.5°F), pulse is 120/min and weak, respirations are 26/min, and blood pressure is 80/50 mm Hg. He opens his eyes and withdraws in response to painful stimuli and makes incomprehensible sounds. The abdomen is soft and nontender. All extremities are cold, with 1+ pulses distally. Arterial blood gas analysis on room air shows: pH 7.29 PCO2 33 mm Hg PO2 65 mm Hg HCO3- 15 mEq/L A CT scan shows displaced fractures of the pelvic ring, as well as fractures of both tibiae, the right distal radius, and right proximal humerus. The patient undergoes emergent open reduction and is admitted to the intensive care unit. Which of the following best indicates inadequate fluid resuscitation?

A. Urine output of 25 mL in 3 hours (Correct Answer)
B. Capillary refill time of 3 seconds
C. Base deficit of 1 mmol/L
D. Glasgow coma score of 8
E. High pulse pressure

Explanation: ***Urine output of 25 mL in 3 hours*** - A critically low urine output of **less than 0.5 mL/kg/hr** (or <30 mL/hr in an adult) over several hours is a direct and sensitive indicator of **renal hypoperfusion** due to inadequate fluid resuscitation, especially in the context of traumatic shock. - Oliguria suggests that the kidneys are not receiving sufficient blood flow to maintain normal function, indicating persistent systemic hypovolemia despite initial interventions. *Capillary refill time of 3 seconds* - A capillary refill time of 3 seconds, while slightly prolonged (normal <2 seconds), is less definitive for **severe ongoing hypovolemia** compared to oliguria. - It can be influenced by factors like **ambient temperature** and peripheral vasoconstriction, which are common in trauma but may not solely reflect inadequate fluid volume. *Base deficit of 1 mmol/L* - A base deficit of 1 mmol/L is essentially **within the normal range** (typically -2 to +2 mmol/L). - A normal or low base deficit suggests that **tissue perfusion is adequate** and there's no significant ongoing metabolic acidosis due to anaerobic metabolism, making it an indicator of *adequate* rather than *inadequate* resuscitation. *Glasgow coma score of 8* - A Glasgow Coma Scale (GCS) score of 8 (Eyes: 2, Verbal: 2, Motor: 4 from the stem) indicates **moderate head injury** or altered mental status. - While hypovolemic shock can affect mentation, a GCS of 8 is more indicative of **neurological damage** (e.g., from head trauma sustained in the fall) or other systemic issues rather than being a primary measure of fluid resuscitation status. *High pulse pressure* - A high pulse pressure (the difference between systolic and diastolic blood pressure) is typically seen in conditions like **sepsis** or **aortic regurgitation**. - In a patient with hypovolemic shock, **pulse pressure is usually narrowed** due to increased peripheral vascular resistance and decreased stroke volume.

Question 10: 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. Administer 4 liters of intravenous colloids over the next 8 hours
B. Administer 5 liters of intravenous colloids over the next 6 hours
C. Administer 5 liters of intravenous crystalloids over the next 6 hours
D. Administer 8 liters of intravenous colloids over the next 12 hours
E. Administer 6 liters of intravenous crystalloids over the next 24 hours (Correct Answer)

Explanation: ***Administer 6 liters of intravenous crystalloids over the next 24 hours*** - The **Parkland formula** is 4 mL × weight (kg) × %TBSA burn. The patient's weight is 55 kg. The burns cover the anterior chest (9%), anterior abdomen (9%), and anterior surfaces of both upper extremities (4.5% + 4.5% = 9%), totaling **27% TBSA**. - Calculation: 4 mL × 55 kg × 27% = **5,940 mL ≈ 6 liters**. Half is given in the first 8 hours (approximately 3 L), and the remaining half over the next 16 hours (approximately 3 L). Total fluid in 24 hours is approximately **6 liters of crystalloids**. *Administer 4 liters of intravenous colloids over the next 8 hours* - The Parkland formula primarily uses **crystalloids** (lactated Ringer's solution) for initial fluid resuscitation in burn patients, not colloids. - Administering only 4 liters would be insufficient given the patient's 27% TBSA burn, and colloids are not first-line. *Administer 5 liters of intravenous colloids over the next 6 hours* - **Colloids** are not the first-line fluid for initial burn resuscitation under the Parkland formula; crystalloids are used. - The timing of 6 hours does not align with the Parkland formula's 24-hour resuscitation period (half in first 8 hours, half in next 16 hours). *Administer 5 liters of intravenous crystalloids over the next 6 hours* - While **crystalloids** are appropriate, 5 liters over 6 hours represents an inappropriately rapid infusion rate that does not follow the Parkland formula timing. - The first 8 hours should receive approximately 3 liters, not 5 liters over 6 hours, which could lead to complications such as **pulmonary edema or compartment syndrome**. *Administer 8 liters of intravenous colloids over the next 12 hours* - This option incorrectly specifies **colloids** instead of crystalloids as the primary fluid for burn resuscitation according to the Parkland formula. - The volume of 8 liters exceeds the calculated requirement of 6 liters for this patient's 27% TBSA burn.

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