Chapter 18. Neurocritical Care
A 22-year-old man presented with traumatic brain injury and was admitted to the neurocritical care unit. Given his poor neurological examination and a Glasgow coma scale (GCS) <8, an intracranial pressure (ICP) monitor was placed. Over a period of 1 hour, the ICP increased, and results of the monitor are shown in Figure 18-1.
Figure 18-1 Intracranial pressure (ICP) waves. (Reproduced with permission from Lee K. The NeuroICU Book. New York: McGraw-Hill Education; 2012.)
Which of the following statements is correct regarding this ICP waveform?
(A) This represents a Lundberg A wave.
(B) This waveform typically lasts between 5 and 20 minutes.
(C) This is a pathological finding.
(D) This finding is associated with decreased cerebral compliance.
(E) All of the above statements are correct.
(E) The ICP waveform shown in the graph is the Lundberg A wave. Lundberg A waves (plateau waves) represent a sustained elevation in ICP with an amplitude of 50 to 100 mm Hg, which is higher than that for Lundberg B and C waves. Typical duration of a Lundberg A wave is 5 to 20 minutes. Lundberg A waves are always pathological, as they represent reduced cerebral compliance and increase intracranial pressure.
Lundberg B waves are short elevation of ICP with an amplitude of 5 to 20 mm Hg at a frequency of 0.5 to 2 waves/min, with a duration of 1 to 5 minutes. Lundeberg B waves are thought to be normal with probable association with unstable ICP and vasospasm.
Lundberg C waves are rapid oscillations of 4 to 8 waves/min with low amplitude of <20 mm Hg. Lundberg C waves are normal waves with cardiac and respiratory cycle–related changes (Figure 18-7). (Beaumont, 109–114)
Figure 18-7 Intracranial compliance and intracranial pressure (ICP) waveforms. A. Normal ICP waves: higher P1, lower P2. B. Abnormal ICP waves: P1 and P2 with similar amplitudes. C. Abnormal ICP waves: P2 with higher amplitude than P1. (Reproduced with permission from Lee K. The NeuroICU Book. New York: McGraw-Hill Education; 2012.)
Beaumont A. Intracranial pressure and cerebral blood flow monitoring. Neuromonitoring. In: Torbey M, ed. Neurocritical Care. New York, NY: Cambridge University Press; 2009:109–114.
A 59-year-old man with a history of hyperlipidemia, diabetes mellitus type 2, and hypertension presented with an alteration in mental status and left-sided hemiplegia. The patient was last seen normal the night before. In the emergency room, he was not following commands. Cranial nerve examination revealed a dense right gaze deviation. The right pupil was 6 mm in size and poorly reactive to light. Corneal reflex was absent on the right, but cough reflex was present. Vital signs evaluation revealed a blood pressure of 200/105, a heart rate of 45 beats per ...