Dr Rafaat, can you do one CT guided Biopsy before you go
home?
Slide 2
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
Slide 3
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
Slide 4
What I Discovered: 11 x 7 x 11cm Anterior mediastinal mass
Slide 5
Look at it, gently covering the trachea and SVC.
Slide 6
Slide 7
Normal Structures in CT
Slide 8
Marked compression of SVC with obstruction Mild compression of
branch PAs without obstruction Right Pleural effusion
Slide 9
Compression, without occlusion of bilateral mainstem
bronchi
Slide 10
Compression, right bronchus
Slide 11
Mediastinal Compartments
Slide 12
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 Ts: Teratoma Terrible
Lymphoma Thyroid Thymoma From Lerman, J Anterior Mediastinal Masses
in Children, Semin Anes, Peri Pain, (26) 2007
Slide 13
EKG
Slide 14
Guesses?
Slide 15
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)
Slide 16
Echo Echocardiogram showing SVC occlusion by the mass. RV was
under filled. Echo otherwise showed preserved LV function and
findings consistent with CT.
Slide 17
What I Discovered Pt severely orthopneic, has to sleep on many
pillows. Becomes dyspneic on exam at 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.
Slide 18
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 Im alone and
far away from help
Slide 19
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
Slide 20
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
Slide 21
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
Slide 22
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
Slide 23
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]
Slide 24
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.
Slide 25
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: Anesthesias a goddamned luxury. If they make it
back to complain to you in a couple years, youve 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.
Slide 26
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 wasnt giving her any medication
Proceeded with 20mg Ketamine, preceded by 0.6mg Glycopyrollate
Slide 27
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.
Slide 28
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
Slide 29
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
Slide 30
........... 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
Couldnt paralyze, and didnt 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
Slide 31
........ 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.
Slide 32
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