From the Guidelines
The latest sign of shock to occur in a patient with RTA, pelvic fracture, thigh wound with profuse bleeding, and hypovolemic shock parameters is actually decreased cardiac output, which is closely related to option C, Increased arteriolar resistance and decrease COP. In hypovolemic shock, the body's compensatory mechanisms work in a specific sequence to maintain perfusion to vital organs. Initially, the body increases sympathetic nervous system activity, leading to peripheral vasoconstriction (increased arteriolar resistance) and increased heart rate 1. Tachycardia is actually one of the earliest cardiovascular responses to blood loss, not the latest. As shock progresses, venous return decreases (not increases) due to volume loss. Cortisol (cortisone) levels do increase as part of the stress response, but this occurs relatively early. The latest signs of shock include decreased cardiac output, hypotension, altered mental status, and ultimately organ failure. These occur after the compensatory mechanisms, including tachycardia, have failed to maintain adequate tissue perfusion. Understanding this progression is crucial for early recognition and intervention in trauma patients with significant blood loss, as emphasized by the European guideline on management of major bleeding and coagulopathy following trauma: sixth edition 1.
Some key points to consider in the management of such patients include:
- The importance of early surgical bleeding control in patients with severe hypovolemic shock, as indicated by studies on gunshot wounds and abdominal vascular injuries 1.
- The correlation between 'unstable' pelvic fractures and intra-abdominal injuries, as well as the association between major pelvic fractures and severe head injuries, concomitant thoracic, abdominal, urological, and skeletal injuries 1.
- The need for rapid transfer to the operating theatre for surgical bleeding control in patients arriving in shock following major trauma, as recommended by the European guideline on management of bleeding following major trauma 1.
Given the provided options, the most accurate answer is C, Increased arteriolar resistance and decrease COP, as it is closely related to the latest sign of shock, which is decreased cardiac output. This is supported by the latest and highest quality study available, which emphasizes the importance of understanding the progression of shock and the need for early recognition and intervention in trauma patients with significant blood loss 1.
From the Research
Latest Sign of Shock to Occur
The latest sign of shock to occur in a patient with RTA, pelvic fracture, and thigh wound with profuse bleeding, and hypovolemic shock parameters is:
- Increased arteriolar resistance and decrease COP [(2,3)] This is because the body tries to compensate for the blood loss by increasing arteriolar resistance to maintain blood pressure, and the decrease in cardiac output (COP) is a late sign of shock.
Other Options
The other options are:
- Increase venous return: This is an early sign of shock as the body tries to compensate for the blood loss by increasing venous return to the heart 4.
- Increased cortisone level: This is a stress response to shock, but it is not a direct sign of shock [no direct reference].
- Tachycardia: This is an early sign of shock as the body tries to compensate for the blood loss by increasing heart rate [(2,4)].