Category: Critical Care Nursing In its final stages, uncontrolled intracranial hypertension will result in downward herniation of the cerebellar tonsils through the foramen magnum, thereby compressing critical cardiorespiratory centers in the medulla.
Category: Critical Care Nursing Adaptation to increased intracranial volume is initially accomplished by shifting CSF from the intracranial to spinal subarachnoid compartment. Approximately two-thirds of cerebral blood volume is contained in the cerebral veins and dural sinuses.
Category: Critical Care Nursing In septic shock related to an abscess, aggressive infection (eg, necrotizing fasciitis) or wound (eg, toxic shock syndrome), removal of the infectious stimulus through surgical intervention should proceed as soon as practical.
Category: Critical Care Nursing Controlling hemorrhage remains the cornerstone of treating hemorrhagic shock and evidence supports immediate surgery when direct vascular control cannot otherwise be obtained. Gastrointestinal bleeding may require urgent endoscopy.
Category: Critical Care Nursing Intubation reduces the work of breathing, which, in the patient with hypoperfusion, further exacerbates lactic acidemia. Strenuous use of accessory respiratory muscles can increase oxygen consumption and decrease cerebral blood flow.
Category: Critical Care Nursing Rapid sequence intubation is the preferred method of airway control in most patients with refractory shock. Tissue hypoperfusion leads to increasing fatigue and respiratory failure commonly supervenes in patients with persistent shock.
Category: Critical Care Nursing Mixed venous oxygen saturation (SvO2) measurements reflect the balance between oxygen delivery and oxygen consumption. The SvO2 can be used as a surrogate for cardiac index.
Category: Critical Care Nursing If the lactate concentration has not decreased by 10-20% two hours after resuscitation has begun, steps should be taken to improve systemic perfusion. Resuscitation should continue until the lactate concentration drops below 2 mM/L.
Category: Critical Care Nursing Lactate clearance has been shown to be equivalent to central venous oxygen saturation as an endpoint of early septic shock resuscitation. Lactate clearance measurements are the preferred endpoint of resuscitation.
Category: Critical Care Nursing Muffled heart sounds with jugular venous distention suggest cardiac tamponade, whereas a loud, machine-like, systolic murmur indicates acute rupture of a papillary muscle or interventricular septum.
Category: Critical Care Nursing A rising lactate concentration (or refractory hypotension, with worsening base deficit), despite ongoing resuscitation, calls for more intensive measures. Once shock has been discovered, the next step is to consider the cause of the shock.
Category: Critical Care Nursing A downward trend of the serum lactate concentration or upward trend of the base deficit, with correspondingly improving vital signs and urine output, reliably gauge the adequacy of resuscitation and prognosis in shock from any cause.
Category: Critical Care Nursing Arterial or venous lactate concentration and the base deficit provide accurate assessment of global perfusion status. A lactate concentration greater than 4.0 mM or base deficit more negative than -4 mEq/L indicates circulatory insufficiency.
Category: Critical Care Nursing Neurogenic shock results from interrupted sympathetic and parasympathetic input from the spinal cord to the heart and peripheral vasculature, typically resulting from acute traumatic injury.
Category: Critical Care Nursing Cardiogenic shock results when more than 40% of the myocardium becomes dysfunctional from ischemia, inflammation, toxins or immune injury. Impaired baseline cardiac function can contribute to the development of circulatory shock.