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 coughAdditionally, had HA, night sweats and weight lossPMHx: ex 26wk preemie, some EKG abnormality, recent hx of recurrent PNASurgHx: s/p PDA ligationSomething 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 bronchusMediastinal Compartments

Mediastinal MassesOf all mediastinal masses, 35%-55% arise in the anterior mediastinumThe most common types of tumor in the anterior mediastinum are known by the Four Ts:TeratomaTerrible LymphomaThyroidThymoma

From Lerman, J Anterior Mediastinal Masses in Children, Semin Anes, Peri Pain, (26) 2007EKG

Guesses?

Wolff-Parkinson-White SyndromeDue to an accessory pathway that bypasses AV node allowing reentry tachyarrhythmiasPts at risk for PSVT and AFAnesthetic management involves avoiding increases in sympathetic toneTreat anxiety and painMaintain adequate intravascular volumeAvoid medications that may precipitate tachycardia (Ketamine, Glyco, Epi)Neostigmine, by slowing conduction through the AV node, may encourage conduction through accessory pathwayTreatment is with Calcium channel blockers, beta blockersNOT 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 DiscoveredPt severely orthopneic, has to sleep on many pillows. Becomes dyspneic on exam at L, wheezes primarily on rightCV: RRR, no m/r/g, strong radial pulsesAbd: soft, NTNeuro: IntactDuring exam, pt experienced several long bouts of coughing that seemed to make not just her lips, but her entire head and neck blue.ProblemsAnterior mediastinal massWith SVC obstruction, branch PA occlusion, and some tracheal and mainstem bronchus compressionResulting in:SVC SyndromeDyspnea and orthopneaWPWIm alone and far away from helpSVC SyndromeMediastinal tumors are the primary natural cause of SVCS in children and adolescents50% of these are primary mediastinal tumorsSymptoms are secondary to impaired venous drainage of the head, neck and upper extremitiesWorsen when supine, improve when uprightCan include dyspnea, facial and neck swelling, venous distention of neck and chest, wheezing and stridor

SVC Syndrome: Brief Anesthetic ConsiderationsNeuro: Obstructed venous drainage may also lead to increased ICPImportant to maintain MAP to ensure CPPAirway: Increased edema may increase risk of difficult intubationPulm: Positive pressure ventilation, by increasing intrathoracic pressure, may further decrease venous returnCV: Preload augmentation may be necessary to ensure adequate ventricular filling and maintenance of COAccess: Obstructed upper extremity venous drainage necessitates lower body intravenous accessAnterior Mediastinal Mass:Forces at WorkIn the supine position, two opposing forces maintain the position of the tumor:Negative Intrathoracic pressure pulls the tumor upGravity pulls tumor downIf the intrathoracic pressure is made less negative, gravity will win, and the tumor will compress underlying structuresPositive pressure ventilationCessation of spontaneous respiratory effortsSitting, lateral decubitus or prone positions direct force of mass towards abdomen, left chest or sternumInstead of aorta, SVC and tracheaAnterior Mediastinal Mass:Important StudiesEKG, Labs, etcEchocardiogramAssess presence and degree of vascular or cardiac compressionSVC, RA, pulmonary arteries and pulmonary veins susceptible to compression due to low internal pressureFunction and pericardial involvementCAT ScanAssess size and position of massEffect on adjacent structures

Anterior Mediastinal Mass: PFTs?Several authors advocate routine measurement of PFTsDynamic measurement of presence and degree of obstructionCan be done both seated and supine to assess functional changesPFTs do little to help predict intraoperative morbidity and mortality in this populationNo study to date has predicted perioperative airway complications from spirometry alone prospectivelyAlthough, PFTs can help predict postoperative respiratory complicationsTracheal 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 ConsiderationsMaintain spontaneous ventilationAwake/sedated FOB intubation if ETT necessaryConsider a partial left lateral decubitus position Have a rigid bronchoscope readyIf tracheal compression occurs despite precautions and/or if ETT unable to be easily advanced in tracheaLower extremity accessHave a quick way to flip pt prone Consider CPB In cases of severe vascular compression, cannulate for CPB while pt still awake.The PlanCreated a ramp on the CT scanner, ~30degreesPlan to use local and nothingIn 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 IVSmall dose ketamine (0.25mg/kg) and glyco if sedation was necessaryI 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 knewPrepare for warEpi, code drugs, LMA, etc.What HappenedPt extremely anxious, almost hyperventilatingCould not lay on 30 degree ramp without significant dyspneaAnxiety was definitely contributing to difficultiesSat pt up, and explained again, carefully, why I wasnt giving her any medicationProceeded with 20mg Ketamine, preceded by 0.6mg GlycopyrollateWhat HappenedPt was still, breathing comfortably with no evidence of obstruction, and laying on ramp.Started coughingAirway free of oral secretionsImproved 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% O2No appreciable helpSats continued to drop..now in 70s and pt still coughingPts BP, which, up to this point was ~110/60, was dropping to 80/40And Then......Attempted to place LMA and deepen anesthesia with more ketamineLMA 4 and 80mg ketamineKetamine administered with 10mcg EPI, given risk of circulatory collapseLMA did not help, sats in 50% range, BP steady, HR in 130sCopious frank blood began to come from pts nose and mouthLMA insertion easy and atraumaticMost 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 bloodBut was possibly on the verge of circulatory collapse secondary to mass compression of vasculatureCouldnt paralyze, and didnt want to give any further narcotics or sedativesWaited 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 placement100% O2 with GENTLE positive pressure and ~0.5 MAC of SevofluraneSats returned, BP required continued boluses of Ephedrine and Epi, plus 1.5L Crystalloid.Biopsies obtainedLeft intubated, taken to PICUExtubated next day without issue. Pt with no memory of event.What I learnedBetter safe than sorrya late, non emergent case, with a patient with this many issues, can be put off until there are a lot more hands aroundPerhaps tried a slight decubitus position as well?Especially in the face of the coughing.Preparation is key