What is the management of hypovolemic shock?

Management of Hypovolemic Shock

Begin immediate fluid resuscitation with crystalloid isotonic solutions (balanced crystalloids or 0.9% saline) using initial boluses of 20 ml/kg administered over 5-10 minutes, while simultaneously controlling any obvious bleeding source. 1

Immediate Priorities

Bleeding Control

• Patients with obvious bleeding or hemorrhagic shock in extremis require immediate bleeding control procedures before or concurrent with resuscitation. 1
• Do not delay definitive hemorrhage control while waiting for diagnostic confirmation—this is a critical pitfall that worsens outcomes. 1

Vascular Access and Initial Assessment

• Establish large-bore intravenous access (preferably two lines) as quickly as possible. 1
• Collect blood immediately for complete blood count, coagulation profile, and cross-matching. 1
• Use the shock index (heart rate/systolic blood pressure) and narrow pulse pressure to assess severity and transfusion requirements. 1
• Measure blood lactate levels to estimate the extent of bleeding and tissue hypoperfusion; use base deficit as an alternative if lactate is unavailable. 1

Fluid Resuscitation Strategy

Initial Fluid Administration

• Start with crystalloid isotonic solutions (balanced crystalloids preferred over 0.9% saline) or albumin with boluses of 20 ml/kg for crystalloids administered over 5-10 minutes. 1
• For adults with signs of shock, administer boluses of 500-1000 ml of crystalloids over 30 minutes. 1
• For children, use boluses of 20 ml/kg of colloid or 0.9% saline. 1

Fluid Titration

• Titrate fluid administration according to clinical response: normalization of heart rate, blood pressure, capillary refill time (<2 seconds), mental status, and urine output (>1 ml/kg/hour). 1
• Continue fluid administration while hemodynamic factors keep improving (fluid challenge technique). 2
• Monitor continuously for signs of fluid overload: hepatomegaly, pulmonary rales, and increased jugular venous pressure. 1

Albumin Considerations

• Albumin 25% is hyperoncotic and expands plasma volume by 3-4 times the volume administered by withdrawing fluid from interstitial spaces. 3
• If the patient is dehydrated, additional crystalloids must be given with albumin 25%, or alternatively use albumin 5%. 3
• The total albumin dose should not exceed 2 g per kg body weight in the absence of active bleeding. 3

Vasopressor Support

Initiate norepinephrine as the first-choice vasopressor to achieve a target mean arterial pressure (MAP) of 65 mmHg if hypotension persists despite adequate fluid resuscitation. 1, 2

• Vasopressors may be transiently required to sustain life and maintain tissue perfusion even when fluid expansion is in progress and hypovolemia has not yet been corrected. 4
• Norepinephrine induces both arterial vasoconstriction and venoconstriction at the splanchnic circulation level, actively shifting blood volume to systemic circulation. 4
• Consider inotropic agents in the presence of myocardial dysfunction. 4

Important Caveat

• Early use of vasopressors for hemodynamic support after hemorrhagic shock may be deleterious compared to aggressive volume resuscitation and should be used cautiously—only when fluid resuscitation is inadequate. 4

Blood Product Administration

Maintain hemoglobin at a minimum of 10 g/dL in patients with ongoing hemorrhage. 1

• A hemoglobin target of 7-9 g/dL is generally recommended for stable patients. 5
• In cases requiring massive transfusion, use a ratio of red blood cells, plasma, and pooled platelets of 4:4:1. 5

Hypertonic Saline: Not Recommended

Hypertonic saline solutions are safe but do not improve survival or neurological outcomes compared to normal 0.9% saline. 4

• Two large prospective randomized multi-center studies with 2,184 patients found no advantage of hypertonic fluids over normal saline for traumatic hypovolemic shock. 4
• Meta-analysis of eight trials with 1,283 participants showed no beneficial effects (pooled RR 1.24,95% CI 0.94 to 1.65). 4
• While hypertonic saline acutely expands plasma volume by 24% and reduces crystalloid requirements, it does not affect mortality rates. 6

Ongoing Monitoring

• Continuously monitor vital signs, urine output, mental status, and peripheral perfusion. 1
• Perform repeated hemoglobin/hematocrit measurements to detect ongoing bleeding. 1
• Consider central venous pressure monitoring in complex cases to guide fluid management. 1
• Avoid hyperventilation in severely hypovolemic patients, as it may decrease cardiac output. 1

Special Considerations

Traumatic Brain Injury

• Avoid excessive volume resuscitation to prevent increasing intracranial pressure in patients with traumatic brain injury or altered consciousness. 1

Severe Refractory Shock

• Consider rapid sequence intubation and mechanical ventilation in cases of severe shock not responding to 40 ml/kg of fluid resuscitation. 1

Coagulation Management

• Maintain normothermia, pH above 7.2, and normocalcemia. 5
• Early goal-directed administration of tranexamic acid and fibrinogen is recommended to stabilize coagulation. 5

Critical Pitfalls to Avoid

• Do not rely solely on blood pressure as an indicator of shock resolution—use multiple perfusion parameters including capillary refill, mental status, urine output, and lactate levels. 1
• Excessive fluid administration without evaluating response leads to volume overload and pulmonary edema. 1
• Do not use etomidate for intubation in septic shock due to its inhibitory effects on adrenal corticosteroid biosynthesis. 1