Case of the Month: Case 1

Read printer friendly
 Subscribe in a reader

Share with others

 

Related Articles

• Triage Of Fire Smoke Intoxicated Victims In A Disaster Situation
• Reflections of "The Flood": Will the Rain Never End?
• Obitulogy: Pasquale Ciaglia, M.D., F.A.C.S.; Feb. 18, 1912 - May 23, 2000
• Cardiac Tamponade Secondary To Suppurative Pericarditis. A Case Report And Review Of The Literature
• Treatment Of Severe Hypothermia Utilizing A Veno-venous Continuous Renal Replacement System With A Counter Current Blood Warmer.

Joseph L Nates MD*
Assistant Professor
Departments of Neurosurgery and Anesthesiology
Health Science Center Medical School
The University of Texas-Houston

Address:

Ioannis Christou MD
Visiting Clinician Scientist
Departments of Neurosurgery and Anesthesiology
Health Science Center Medical School
The University of Texas-Houston

Address:

Andrei Alexandrov MD, RVT
Assistant professor
Departments of Neurosurgery and Anesthesiology
Health Science Center Medical School
The University of Texas-Houston

Address:

Citation: J. L. Nates, I. Christou & A. Alexandrov : Case of the Month: Case 1 . The Internet Journal of Emergency and Intensive Care Medicine. 2000 Volume 4 Number 1

Keywords: emergency medicine | critical care | intensive care medicine | medicine | education | patient care | ventilation | cardiac | neuro | pediatric | cardio-pulmonary support | ards | respiratory failure | multiorgan failure | hemodynamics | intensivecare unit | surgical i

History

A white female, 71 y.o., was admitted to the neurological ICU due to subarachnoid hemorrhage secondary to a ruptured cerebral aneurysm. Patient developed hydrocephalus which was managed with a ventriculostomy after the clipping and her intracranial pressure (ICP) was continuously monitored.

The patient developed severe cerebral vasospasm with deterioration of her mental status requiring endotracheal intubation. This complication was followed by sepsis with ARD’S. After spasm resolution, patient developed systemic infection. The following hemodynamic and Transcranial Doppler (TCD) parameters were recorded (patient was sedated, paralyzed and on controlled mechanical ventilation):

Monitor Screen with Hemodynamic Changes

TCD waveforms correspond to the segment between dotted arrows on the monitor screen above. The white arrows indicate waveforms with pulsatility index 1.4 (left) and 1.0 (right).

Questions

What is your diagnosis?Why is there a variation in all pressure waveforms of more than 15 mmHg?What is your explanation for the cyclic variations in ICP?What is your explanation for corresponding changes in TCD recordings?

Answers

1. The diagnosis is intracranial hypertension. Note that the ICP raises from approximately 10 mmHg up to 25 mmHg. These ICP changes occurred along with hypovolemia, CVP 5 mmHg and wedge pressure 4 to 6 mmHg.

2. The variations are due to intravascular volume depletion. In this case, the “systolic pressure variation”, or SPV (SPV is the difference between the maximal and minimal systolic blood pressure during one ventilation cycle), is greater than 15 mmHg. On the monitor screen, the dDown is easily seen during the inspiratory phase on the ventilation cycle.

3. The ICP variations correspond to the blood pressure and cardiac output changes following the intra-thoracic pressure pattern during mechanical ventilation. Elevated ICP and cyclic ICP changes were present in a patient who had brain infarctions, hydrocephalus and hypovolemia showing systemic pressure dependency of the ICP.

4. Pulsatility index (Gosling PI = Peak systolic – end diastolic / mean flow velocities) shows resistance to blood flow in the intracranial cavity in relationship to systemic blood pressure. When ICP increases (or CPP decreases), PI increases to 1.4 and then decreases to 1.0 with ICP drops to less than 14 mm Hg. TCD showed time corresponding changes from high resistance to low resistance flow waveforms during meachanical ventilation. Note that mean flow velocity measurements can be affected by these factors (see the following figure).

References

(s)

(s)

(s)

This article was last modified on Fri, 13 Feb 09 13:25:29 -0600

This page was generated on Wed, 17 Mar 10 23:30:27 -0500, and may be cached.