FYS 4250Lecture 8

“Every patient is a mystery!” C Spiegel

Case 8

- A 35 year old man experience a three day progressive numbness in the right arm with weakness of the underarm and fingers and seeks his family doctor.

Footage.shutterstock.com

What is the most likely cause?

Case 8

- During examination, the patient describes a headache of gradual onset but no disturbance of visual function and no blind spots. There are small signs of impairment of consciousness, but no history of fainting or other blackouts. The patient was admitted to hospital for a thoroughly examination, at admission the blood pressure is 110/72 mmHg, the heart rate is 67 bpm, the temperature is 36.2 °C and the heart is regular without murmurs. His abdomen is mildly distended with hypoactive bowel sounds an marked left lower quadrate tenderness. The saturation is 99% and the HIV assay is negative. He does not smoke, nor is he drinking alcohol.

How will you examine this patient?

Case 8

- A CT-caput reveals a tumor located in the sulcus sentralis which can explain the paralysis. The patient is scheduled for a surgical tumor recession and starts the procedure with measuring the cardiac output.

Measuring the cardiac output

Swan-Ganz Catheter (Pulmonary artery catheter)

Image: Tormod Martinsen

Swan-Ganz Catheter (Pulmonary artery catheter)

Swan-Ganz Catheter (Pulmonary artery catheter)

http://www.google.no/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CCwQFjAA&url=http%3A%2F%2Fwww.bu.edu%2Fav%2Fcourses%2Fmed%2F05sprgmedanesthesiology%2F002%2FPulmonary%2520Artery%2520Catheter.ppt&ei=0YNEUuK4E8rbsgbF-YH4Dg&usg=AFQjCNFom3GiBoeCG1LM7SOWnaBhVIoV7Q&sig2=KGFSfzNK3XNrq-pwpiKFhA&bvm=bv.53217764,d.Yms&cad=rja

Fick’smethod,cardiacOutput(Continuous)

Indicator-dilution method

Measured hemodynamic parameters

• Central Venous Pressure (CVP)– The CVP is recorded from the proximal port of the PAC in the superior

vena cava or from the right atrium

• Pulmonary Artery Pressure (PAP) – The PAP is measured from the tip of the PAC with a deflated balloon

• Pulmonary Capillary Wedge Pressure (PCWP) – The PCWP is recorded from the tip of the PAC catheter with the balloon

inflated– PCWP ≈ LAP (Left Atrial Pressure)

• Cardiac Output (CO) – The CO is calculated using the thermodilution technique

Swan Ganz -Risks

• Accidental puncture of arteries• Bleeding• Air embolism• Pneumothorax• Thromboembolism• Valve injury• Infection• Pulmonary Artery Rupture

Measuring the blood flow, ultrasound

Ultrasonic doppler flowmeter

Transducer systems (transit time)

Doppler flowmeter, sinewave

Quadrature-phase detector

Directional flowmeter waveforms

Case 8

- Due to a sudden drop in saturation, cerebral oxygenation is measured. This is not routine for cerebral surgical procedures, but is more typical for heart surgery

Monitoring the cerebral oxygenation

Cerebral oximetry

http://www.perfusion.com/cgi-bin/absolutenm/articlefiles/chen2008/chen2008.pdf

http://www.perfusion.com/cgi-bin/absolutenm/articlefiles/chen2008/chen2008.pdf

Cerebral oximetry

http://www.perfusion.com/cgi-bin/absolutenm/articlefiles/chen2008/chen2008.pdf

Cerebral oximetry

http://www.perfusion.com/cgi-bin/absolutenm/articlefiles/chen2008/chen2008.pdf

Cerebral oximetry

http://www.perfusion.com/cgi-bin/absolutenm/articlefiles/chen2008/chen2008.pdf

Cerebral oximetry

http://www.perfusion.com/cgi-bin/absolutenm/articlefiles/chen2008/chen2008.pdf

Cerebral oximetry

http://www.perfusion.com/cgi-bin/absolutenm/articlefiles/chen2008/chen2008.pdf

Case 8

- The surgeon decides to use a harmonic scalpel for tumor recession

Ultrasoundsurgery

• An alternative to electrosurgery

Ultrasoundsurgery

Ultrasoundsurgery

Ultrasound ablation

CavitationMechanic abrasionThermal effect

Ultrasound ablation: CavitationPrinciple of operation: Cavitaion

Ultrasound ablationPrinciple of operation: Cavitaion

Ultrasound main advantage

Ultrasound main advantage

Electrosurgery vs Ultrasoundsurgery

Adv. Ultrasoundsurgery

1.Can cut through thicker tissue

2.Greater precision

3.Less toxic surgical smoke

4.Less lateral thermal damage

Disadv. Ultrasoundsurgery

1.Takes more time to cut and coagulate

2.Can only coagulate as it cuts

Neuro navigation

Intraoperative Navigation

• Utilization of preoperative scans – no navigation scan necessary

• No fiducials necessary

1st step: Preoperative Scan

Benefit: Reduction of radiation dose for patient

Source: Brainlab

Intraoperative Navigation

Non-invasive referencing with headband - generally used for sinus surgery in ENT

Minimal invasive referencing in bone structure - generally used for skull base surgery, lateral indications or CMF cases

2nd step: Intraoperative preparation – Patient reference star

Benefit: Referencing according to needs and indication.

Source: Brainlab

Intraoperative navigation

• Surface scanning with a laser

• No given registration points or registration routes

• Registration accomplished in one minute

• Registration possible in a sterile environment

3rd step: intraoperative registration

Benefit: Touchless registration saves sterile environment.

Source: Brainlab

Intraoperative Navigation

4th step: Navigation

Benefit: Time saving setup and workflow as well as advanced functionalities

Source: Brainlab

intraoperative Navigation

• Simple integration of all instruments

• Different geometries of stars and adapter clamps fit on every instrument

4th step: Instrument integration

Benefit: Fast integration of every rigid instrument available in the OR

Source: Brainlab

intraoperative Navigation

Image integration

Benefit: Video integration endoscope and micorscope as well as image injection in microscopes

Source: Brainlab

Case 8

- The patient recovers slowly, and after a convalescence of a couple of months, the strength in the right arm and fingers has been partly regained. The headache was cured the moment he woke up after the anesthesia, but he struggled to find the right words during regular conversation. All blood-tests and CT-scans after the surgery was negative, and after half a year he was able to return to his job as a carpenter. However, after almost a year, the same symptoms re-emerged and he experience a new progressive numbness in the right arm with weakness of the underarm and fingers.

Why?

Case 8

- An MRI-scan of the brain and spinal cord with contrast, a so called FLAIR MRI (fluid-attenuated inversion recovery) is carried out. In the axial T2-weighted image of a typical vascular brainstem involvement of transverse pontine fibers, there are obvious signs of some typical peripherally located white matter lesions close to the trigeminal tract.

What is the true diagnosis?http://www.radiologyassistant.nl/data/bin/w440/a519092a08bf88_1.jpg

Case 8

- The patient was diagnosed with multiple scleroris, treated with corticosterios (methylprednisolone) to reduce nerve inflammation and discharged from hospital. There is no cure for multiple sclerosis, but medication can slow down the progression of the disease and soften the symptoms

What is the true diagnosis?