Download Dr Rafaat, can you do one CT guided Biopsy before you go home?

Dr Rafaat, can you
do one CT guided
Biopsy before you
go home?
What I knew:
HPI: 15 year old, 60kg female, presenting to outside
hospital with a 10 day history of fatigue, dyspnea and cough
Additionally, had HA, night sweats and weight loss
PMHx: ex 26wk preemie, some “EKG abnormality”, recent
hx of recurrent PNA
SurgHx: s/p PDA ligation
Something was going to be biopsied.
CT scan was from outside hospital, and was not in EPIC
What I knew:
It was 5pm, most of ASMG had gone
home, and CT is FAR AWAY from the
OR
AND I sent the resident home, because
this was “just a biopsy”
What I Discovered:
11 x 7 x 11cm Anterior mediastinal mass
Look at it, gently
covering the trachea and
SVC.
Normal Structures in CT
• Marked
compression
of SVC with
obstruction
• Mild
compression
of branch PAs
without
obstruction
• Right Pleural
effusion
Compression, without occlusion of
bilateral mainstem bronchi
Compression, right bronchus
Mediastinal Compartments
Mediastinal Masses
Of all mediastinal masses, 35%-55% arise in the
anterior mediastinum
The most common types of tumor in the anterior
mediastinum are known by the Four “T”s:
Teratoma
Terrible Lymphoma
Thyroid
Thymoma
From Lerman, J Anterior Mediastinal Masses in Children, Semin Anes, Peri Pain, (26)
2007
EKG
Guesses?
Wolff-Parkinson-White
Syndrome
Due to an accessory pathway that bypasses AV node allowing reentry
tachyarrhythmias
Pts at risk for PSVT and AF
Anesthetic management involves avoiding increases in sympathetic tone
Treat anxiety and pain
Maintain adequate intravascular volume
Avoid medications that may precipitate tachycardia (Ketamine, Glyco, Epi)
Neostigmine, by slowing conduction through the AV node, may encourage
conduction through accessory pathway
Treatment is with Calcium channel blockers, beta blockers
NOT ADENOSINE ( can induce VF)
Echo
Echocardiogram showing SVC occlusion by the mass. RV was under filled.
Echo otherwise showed preserved LV function and findings consistent with CT.
What I Discovered
Pt severely orthopneic, has to sleep on many pillows.
Becomes dyspneic on exam at <45 degree head-up
Exam:
HEENT: slightly plethoric, some head/neck swelling.
Airway: MP 2, good mouth opening, TM distance and prognath
Resp: Bilateral crackles R>L, wheezes primarily on right
CV: RRR, no m/r/g, strong radial pulses
Abd: soft, NT
Neuro: Intact
During exam, pt experienced several long bouts of coughing that
seemed to make not just her lips, but her entire head and neck
blue.
Problems
Anterior mediastinal mass
With SVC obstruction, branch PA occlusion, and some
tracheal and mainstem bronchus compression
Resulting in:
SVC Syndrome
Dyspnea and orthopnea
WPW
I’m alone and far away from help
SVC Syndrome
Mediastinal tumors are the primary natural cause of
SVCS in children and adolescents
50% of these are primary mediastinal tumors
Symptoms are secondary to impaired venous drainage
of the head, neck and upper extremities
Worsen when supine, improve when upright
Can include dyspnea, facial and neck swelling, venous
distention of neck and chest, wheezing and stridor
SVC Syndrome: Brief Anesthetic
Considerations
Neuro: Obstructed venous drainage may also lead to increased
ICP
Important to maintain MAP to ensure CPP
Airway: Increased edema may increase risk of difficult intubation
Pulm: Positive pressure ventilation, by increasing intrathoracic
pressure, may further decrease venous return
CV: Preload augmentation may be necessary to ensure adequate
ventricular filling and maintenance of CO
Access: Obstructed upper extremity venous drainage necessitates
lower body intravenous access
Anterior Mediastinal Mass:
Forces at Work
In the supine position, two opposing forces maintain the
position of the tumor:
Negative Intrathoracic pressure – pulls the tumor up
Gravity – pulls tumor down
If the intrathoracic pressure is made less negative, gravity
will win, and the tumor will compress underlying structures
Positive pressure ventilation
Cessation of spontaneous respiratory efforts
Sitting, lateral decubitus or prone positions direct force of
mass towards abdomen, left chest or sternum
Instead of aorta, SVC and trachea
Anterior Mediastinal Mass:
Important Studies
EKG, Labs, etc…
Echocardiogram
Assess presence and degree of vascular or cardiac
compression
SVC, RA, pulmonary arteries and pulmonary veins
susceptible to compression due to low internal pressure
Function and pericardial involvement
CAT Scan
Assess size and position of mass
Effect on adjacent structures
Anterior Mediastinal Mass:
PFTs?
Several authors advocate routine measurement of PFTs
Dynamic measurement of presence and degree of obstruction
Can be done both seated and supine to assess functional changes
PFTs do little to help predict intraoperative morbidity and mortality
in this population
No study to date has predicted perioperative airway
complications from spirometry alone prospectively
Although, PFTs can help predict postoperative respiratory
complications
Tracheal compression >50% on CT and Peak Expiratory Flow
Rate < 40%
[Bechard P et al, Perioperative respiratory complications in adults with anterior mediastinal mass,
Anesthesiology 2004]
AMM: Basic Anesthetic
Considerations
Maintain spontaneous ventilation
Awake/sedated FOB intubation if ETT necessary
Consider a partial left lateral decubitus position
Have a rigid bronchoscope ready
If tracheal compression occurs despite precautions and/or if ETT unable
to be easily advanced in trachea
Lower extremity access
Have a quick way to flip pt prone
Consider CPB
In cases of severe vascular compression, cannulate for CPB while pt still
awake.
The Plan
Created a ramp on the CT scanner, ~30degrees
Plan to use local and nothing
In the words of one of my PICU attendings, Dr. Brad Peterson:
“Anesthesia’s a goddamned luxury. If they make it back to complain to you in a
couple years, you’ve done a good job.”
Placed lower extremity IV
Small dose ketamine (0.25mg/kg) and glyco if sedation was necessary
I know, I know….. Fentanyl and Midaz would potentially lead to respiratory
depression (especially in doses sufficient to allow pt to remain still), and propofol
may increase venous capacitance, leading to even poorer venous return.
I chose the Devil I knew
Prepare for war
Epi, code drugs, LMA, etc.
What Happened
Pt extremely anxious, almost hyperventilating
Could not lay on 30 degree ramp without significant
dyspnea
Anxiety was definitely contributing to difficulties
Sat pt up, and explained again, carefully, why I wasn’t
giving her any medication
Proceeded with 20mg Ketamine, preceded by 0.6mg
Glycopyrollate
What Happened
Pt was still, breathing comfortably with no evidence of
obstruction, and laying on ramp.
Started coughing
Airway free of oral secretions
Improved with another 20mg ketamine.
And Then.....
Pt began coughing again, and did not stop.
Sats started to drop.
Attempted to assist ventilation with bag and mask and
100% O2
No appreciable help
Sats continued to drop..now in 70s and pt still
coughing
Pts BP, which, up to this point was ~110/60, was
dropping to 80/40
And Then......
Attempted to place LMA and deepen anesthesia with more
ketamine
LMA 4 and 80mg ketamine
Ketamine administered with 10mcg EPI, given risk of circulatory
collapse
LMA did not help, sats in 50% range, BP steady, HR in 130s
Copious frank blood began to come from pts nose and mouth
LMA insertion easy and atraumatic
Most likely secondary to increased venous pressure coupled with
acutely elevated and sustained increase in intrathoracic pressure
...........
The patient required control of her airway and 100% O2
For oxygenation, ventilation and protection from what
seemed to be only upper airway blood
But was possibly on the verge of circulatory collapse
secondary to mass compression of vasculature
Couldn’t paralyze, and didn’t want to give any further
narcotics or sedatives
Waited until she took a breath in between bouts of
coughing, saw where the bubbles were coming from, and
slipped an ETT in
........
Frank blood from ETT after placement
100% O2 with GENTLE positive pressure and ~0.5 MAC
of Sevoflurane
Sats returned, BP required continued boluses of Ephedrine
and Epi, plus 1.5L Crystalloid.
Biopsies obtained
Left intubated, taken to PICU
Extubated next day without issue. Pt with no memory of
event.
What I learned
Better safe than sorry
a late, non emergent case, with a patient with this many
issues, can be put off until there are a lot more hands
around
Perhaps tried a slight decubitus position as well?
Especially in the face of the coughing.
Preparation is key