Mr. Paul is a 39-year-old man who sustained a 30 The affected areas include his right arm and hand and sections of his anterior and posterior trunk and neck.
Mr. Paul was injured at 2:00 p.m. and rushed to the emergency room where intravenous therapy was begun at 3:00 p.m. If he is to receive 5,000 ml of lactated Ringer's in 24 hours, according to the Parkland formula how much solution should he receive by 10:00 p.m.

Choice A rationale

Endotracheal intubation is indicated for respiratory failure or an inability to protect the airway. This patient is currently breathing spontaneously with an oxygen saturation of 95 percent, which is within the normal range of 95 to 100 percent. Intubation is an invasive procedure with risks such as ventilator associated pneumonia. It is not the priority intervention when clinical signs suggest an immediate mechanical issue like a tension pneumothorax or hemothorax resulting from the rib fractures.

Choice B rationale

Lactated Ringer's solution is used for fluid resuscitation in hypovolemic shock. While rib fractures can cause internal bleeding, giving a liter wide open without assessing the cause of respiratory distress can worsen outcomes, especially if the patient has a pulmonary contusion. The priority is addressing the mechanical compromise of the chest wall and pleural space. Excessive fluid can lead to pulmonary edema, further decreasing the efficiency of gas exchange in a patient with thoracic trauma.

Choice C rationale

Rib fractures from blunt chest trauma significantly increase the risk of a tension pneumothorax or hemothorax. A tension pneumothorax is a life threatening emergency where air enters the pleural space but cannot exit, increasing intrathoracic pressure. This shifts mediastinal structures and compresses the heart and great vessels, leading to obstructive shock. Needle thoracostomy provides immediate decompression of the pleural space, followed by chest tube insertion to restore negative pressure and allow for lung re-expansion.

Choice D rationale

A chest x-ray is a valuable diagnostic tool to identify the extent of rib fractures, presence of a pneumothorax, or pulmonary contusions. However, in the setting of acute thoracic trauma and potential respiratory compromise, waiting for imaging can delay life saving treatment. If a tension pneumothorax is suspected clinically based on symptoms and mechanism of injury, immediate decompression is required before radiographic confirmation. Assessment and intervention for airway, breathing, and circulation must always precede diagnostic imaging studies.

Choice A rationale

The standard recommendation for crystalloid fluid resuscitation in hypovolemic shock is the 3 to 1 rule. This means that for every 1 liter of estimated blood or fluid volume lost, 3 liters of crystalloids such as normal saline or Lactated Ringer's should be administered. This ratio accounts for the fact that only about one fourth to one third of the infused isotonic crystalloid remains in the intravascular space, while the rest shifts into the interstitial compartment.

Choice B rationale

Replacing each liter of fluid loss with 5 liters of crystalloid is excessive and increases the risk of severe complications. Over-resuscitation can lead to pulmonary edema, abdominal compartment syndrome, and dilutional coagulopathy. While aggressive fluid therapy is necessary for severe volume loss, the 5 to 1 ratio exceeds standard clinical guidelines and can cause significant fluid overload, placing unnecessary stress on the cardiovascular and renal systems without providing additional benefit for maintaining the effective circulating volume.

Choice C rationale

A 2 to 1 replacement ratio is often insufficient to restore and maintain intravascular volume in the setting of severe fluid loss. Because crystalloids rapidly redistribute from the plasma into the interstitial fluid, a 2 liter infusion would likely result in less than 500 mL remaining in the vessels. This would fail to correct hypovolemia effectively and could lead to persistent tissue hypoxia and organ dysfunction. The 3 to 1 rule ensures more adequate plasma volume expansion.

Choice D rationale

Replacing fluid loss on a 1 to 1 basis with crystalloids is inadequate because crystalloids are not confined to the intravascular space. Unlike blood products or colloids, which have higher oncotic pressure, isotonic saline leaves the capillaries quickly. A 1 to 1 ratio would result in a significant net deficit in circulating volume, failing to stabilize the patient's blood pressure or heart rate. Clinical protocols require the higher 3 to 1 ratio to achieve hemodynamic stability.