ICU Fellowship Vivas – Post-heart Transplant, Tracheostomy Complication & ICC Insertion

Answers Written by Dr Madhuri Anupindi

1. You are the intensivist in charge of a 12 bed regional ICU. A 50F presents 5 months after heart transplant for dilated cardiomyopathy. She has been short of breath for several days. She has a temperature of 37.8, AF with ventricular rate of 126, BP 80/50mmHg, sats on room air of 88%, GCS 15. Her current medications are tacrolimus, mycophenolate and prednisone. What are the two most important causes of this presentation to consider? How would you distinguish between them?

The two most important causes of this presentation to consider are infection in an immunosuppressed patient or transplant rejection. Distinguishing between these two would involve a thorough assessment including history, examination and investigations.

History: important aspects to distinguish between infection and rejection would involve exploring presenting symptoms and risk factors:

• Presenting symptoms:
  • Infection
    • Identifying any localising symptoms of infection although maybe non-specific or atypical due to immunosuppression
      • Fevers, cough, sore throat, rhinorrhea, nausea, vomiting, dysuria, headache, night sweats, rigors, myalgia, diarrhoea
  • Rejection
    • Symptoms of rejection are generally those of heart failure
      • Shortness of breath, orthopnoea, paroxysmal nocturnal dyspnoea, pre-syncope, palpitations, fatigue, decreased exercise tolerance, anorexia, weight gain
      • May have gastrointestinal symptoms secondary to hepatic congestion: nausea, abdominal pain
• Risk factors:
  • Infection: highest risk of opportunistic infections in the 1-6 months post-transplant
    • Net state of immunosuppression
      • Compliance with antimicrobial prophylaxis
      • Type, dose and duration of immunosuppressants
      • Nutritional status and exercise
      • Previous vaccinations: influenza, hepatitis B, pneumococcal vaccine
      • Presence of invasive devices
      • Co-morbidities: diabetes, coronary artery disease (more common post-transplant)
    • Epidemiological exposure
      • TB, Strongyloides, HIV
      • Travel to or residence to areas of the world with unique endemic infections
      • Unwell contacts
      • Exposure to contaminated food/water (listeria, cryptosporidium, salmonella), soil (aspergillus, Nocardia), animals (Cryptococcus)
    • Nosocomial exposure
      • Prolonged hospitalisation
      • Use of broad-spectrum antimicrobials
    • Latent infections – whether testing was done pre-transplant
      • CMV status of patient and donor (highest risk if a seronegative patient and seropositive donor)
      • TB
      • Strongyloides
  • Rejection
    • Timing: risk is greatest during the first 6 months post-transplant
    • More HLA mismatches between recipient and donor
    • Compliance with immunosuppression and follow up appointments
      • Blood tests to monitor levels
    • Any evidence of rejection: whether surveillance biopsies have been done

Examination

• Infection
  • Localising signs of infection
    • Meningism, bronchial breath sounds, localised abdominal tenderness, cellulitis
  • Increased risk of infection
    • Nutritional status
    • Dental health
• Rejection
  • Signs of heart failure: arrhythmias, raised JVP, peripheral oedema, bilateral crepitations

Investigations

• Infection
  • Bedside
    • Urinalysis and MCS – septic screen, ECG, ABG  – lactate/acid-base balance/glucose, sputum MCS
  • Bloods
    • Peripheral blood cultures and paired vascular access cultures if present, evaluation of organ function – UEC, LFT, coags, FBC
    • Immunosuppressant levels – tacrolimus
    • Quantitative PCR for CMV DNA, EBV antibodies and DNA, HIV, hepatitis B and C antibodies, serum galactomannan
    • Inflammatory markers: CRP, PCT
  • Imaging
    • CXR, consider CT
  • Other: stool MCS if diarrhoea, bronchoscopy and BAL with fungal cultures and galactomannan if respiratory signs, consider LP/cryptococcal antigen if CNS signs
• Rejection
  • Bedside: TTE – systolic/diastolic dysfunction, ECG
  • Bloods: troponin
  • Gold standard: cardiac biopsy showing a mononuclear inflammatory response with myocyte damage – however, this would be done in a transplant unit

What are the important principles of managing this patient in your unit?

The important principles are:

• Resuscitation
  • Supplemental oxygen
  • Full monitoring, large-bore IV access, arterial line, IDC
  • Assess fluid status, cautious fluid boluses, early vasopressors aiming MAP => 65
  • Broad-spectrum antimicrobials: can use Taz + vanc – individualise depending on patient e.g. MROs, presence of vascular devices
• Evaluation
  • As outlined above: history, exam, investigations including septic screen and evaluation of organ function aiming to identify the cause of deterioration
    • Other differentials include PE, side effects of immunosuppression, malignancy
• Early liaison and transfer to a transplant unit
  • Includes discussion of the immunosuppressive regime and how to manage:
    • If the low risk of rejection then sometimes mycophenolate ceased, prednisone changed to hydrocortisone at an increased dose
• Specific management
  • Source control and targeted antimicrobials if infection
  • Specific management of rejection will involve transfer to a specialised unit
    • Management generally involves high dose steroids, increased doses or change in immunosuppressant regime and in acute antibody-mediated rejection plasmapheresis, IVIG, or monoclonal antibody treatment
• Supportive management
  • Optimise organ function: sats > 92%, adequate MAP – vasopressors/inotropes, consider cardiac output monitoring, monitor for drug toxicities and interactions
  • The heart has no autonomic innervation (agents such as digoxin and atropine will have no effect): use direct acting agents such as NORAD, isoprenaline, adrenaline 
  • Nutrition and PPI
  • Update and reassure patient and family

2. 25M with isolated traumatic brain injury who has had a percutaneous tracheostomy inserted within the last 30minutes to facilitate ventilatory weaning. The bedside nurse is concerned about bleeding from the tracheostomy tube. He has the following observations sats 88% on fio2 80% (increased from fio2 40%), SIMV + VC mode TV 400ml, PEEP 5cmH20, normal peak and plateau pressure, HR 120/min and BP 180/110mmHg, sedated and paralysed. Discuss your initial approach to the management of this patient.

This is a potentially life-threatening situation that requires urgent simultaneous resuscitation and assessment. I would want to call for further assistance, confirm the tracheostomy is in the correct place, optimise his oxygenation and circulatory status, and assess for and treat the cause and contributors of his deterioration.

Call for help: likely to need more assistance to optimally manage this patient, initially from rest of ICU team, consider anaesthetics/ENT if major concerns re airway/difficulty

Get airway and arrest trolley

Allocate one person to review file – grade of the airway, any difficulties with insertion of tracheostomy, previous ventilator settings, allergies, recent CXR, anticoagulants/antiplatelets, recent blood results, any previous bleeding from ETT, recent infections

Airway: First increase fio2 to 100% and ensure tracheostomy is in the correct place

• Quick assessment as to whether ETCO2 trace is present and trace looks normal
• Pass suction catheter ?easily passes ?clots
• Bronchoscope should be readily available as tracheostomy just inserted  can insert down trache and see if correctly positioned and any significant bleeding
  • Generally too early for tracheoinominate fistula but may have an injury to the vessel  may need urgent IR/surgery
• If dislodged then remove, cover site, pre-oxygenate orally and intubate orally

If an airway is in place

• Disconnect from the ventilator and see if easy to bag and equal chest rise, look for subcut emphysema
  • Bagging easy when disconnected and sats improve  ventilator issues, look at the circuit, change ventilator
  • If bagging is more difficult: multiple potential causes
    • Assess breath sounds, chest movement ? equal, amount of bleeding, train of four for paralysis, amount of sedation, signs of an allergic reaction, obtain urgent CXR/ABG
      • If pneumothorax  decompress
      • ?bronchospasm  If allergic reaction  adrenaline, steroids, bronchodilators
      • Atelectasis, de-recruited  increase PEEP, increase TV
      • Blood clots: assess with bronchoscopy, can suction if blocking part of the airway
      • Dysynchrony: increase sedation and paralysis

Simultaneously assess circulation and optimise same:

• IV access, ABG, G+H, coags, ROTEM
• Assess site of bleeding (?from around trache, in lungs, nose, mouth – consider bronch), amount of bleeding – some bleeding post insertion of tracheostomy is normal, presence of haematoma, pulsation of the cannula
• Adequate sedation and paralysis
• If significant bleeding:
  • 100% fio2 via trache and face mask
  • Nebulised TXA
  • IV access, MTP, correct medical coagulopathy
  • Optimise tracheostomy tube position and inflate the balloon to max volume
  • Urgent ENT assistance +/- CTx +/- angiography depending on the stability

What are the risk factors for a tracheo-innominate fistula?

Tracheo-innominate fistula is a life-threatening complication of tracheostomy and is an abnormal connection between the trachea and the innominate artery.

Risk factors:

• Anatomical: innominate artery usually traverses the trachea between the 6^th – 0^th cartilage ring  increased risk if this distance is reduced
  • Tracheostomy below 3^rd tracheal ring
  • Hyperextension of neck
  • Anomalous/High location of the innominate artery
  • Neck/chest deformity
  • Paediatric patients
• Increased friability of tissue
  • High-pressure cuff
  • Prolonged tracheostomy
  • Excessive dissection of tissues for tracheostomy
  • Prolonged use of steroids or immunosuppressants
  • Localised infection
  • Malnutrition
  • Localised radiotherapy
  • Recurrent episodes of hypotension

What are the clinical features of a TOF?

• Sentinel bleed occurs in about 50% of patients: may be pulsatile
• Timing: often > 48 hours since tracheostomy insertion
• Bloodstained secretions, massive haemoptysis, haemorrhagic shock
• Bronchoscopy: may have direct visualisation of active bleeding from the anterior wall of the trachea around 6^th-7^th tracheal rings
• Angiography/CTA: blush from the innominate artery into the trachea

How do you manage a trachea-innominate fistula?

• Call for senior assistance including ENT/Ctx
• General resuscitation: Activate MTP, ensure large-bore IV access, 100% fio2 via mask and tracheostomy, airway trolley in case requires oral intubation, correct medical contributors to coagulopathy, adequate sedation and paralysis, haemodynamic support
• Aim to compress the innominate artery
  • Overinflate tracheostomy cuff
  • Try position tracheostomy cuff over bleeding point with bronchoscopy or replace tracheostomy with ETT and place the cuff over the bleeding point
  • If unable to compress then: place ETT distal to the bleeding site and use Utley manoeuvre where the finger is placed through tracheostomy opening and digital pressure applied on the artery against the posterior sternum
• Definitive management
  • Endovascular stenting or surgical ligation

3. 60M who has been trampled by a bull. He has a history of right-sided pneumonia complicated by empyema 10 years ago but is otherwise well. CT shows a significant right-sided haemopneumothorax, but nil other injuries. RR 30, sats 94% 15L NRBM, HR 100, BP 140/90. What technique would you use to decompress this patient’s chest and why?

I would use a formal intercostal catheter as:

• Pigtail drain more likely to be blocked with blood from the haemothorax
• The patient may have unusual anatomy, residual fibrin from the previous empyema

Potentially complicated  loculated  discussed with cardiothoracic/surgeons

• Look at CT and see if chronic pathology present

Technique

• Prepare patient: explain the procedure, consent, full monitoring including sats/ECG/BP ideally invasive or BP cuff cycling, oxygen, nasal etco2 detector, ensure not coagulopathic and nil allergies, fasting status, IV access, G+H
  • Position: 30-degree head up, arm abducted and elbow flexed
• Prepare staff: assistant or anaesthetics to provide analgesia and help if required, cardiothoracics/surg if difficulties anticipated
• Prepare equipment
  • Anaesthetic drugs and emergency drugs, pump set, vasopressors, fluids
  • Airway trolley, BVM, adjuncts, suction, ETT, etco2
  • Chest drain: sterile field, lignocaine, drapes, chlorhex, long needle, scalpel, curved forceps, > 24Fr drain (36Fr), suture material, UWSD, dressing
• Insertion
  • Analgesia in small increments for the patient and small dose midaz
  • Gown, glove after sterile wash
  • Chlorhex, prep and drape
  • Triangle of safety: anterior to mid-axillary line, posterior to pectoral groove, above 5^th intercostal space on the right
  • Infiltrate lignocaine 1% to skin and subcut tissue, above the rib, infiltrate down to parietal pleura, aspiration of the needle should reveal blood once in pleural space
  • Make incision following line of ribs with scalpel 1 – 2cm long
  • Blunt dissection with the finger or blunt forceps
  • Once the parietal pleura is breeched there should be a rush of blood  dilate with finger
  • Load chest drain onto curved forceps, oriented towards the apex and use forceps to allow clamped drain to follow tract  insert drain
  • The suture in place and dress with a sterile dressing
  • Connect to UWSD
  • CXR to confirm the position

What are the complications of intercostal catheters?

Complications

• Anaesthetic complications:
  • Allergic reaction, aspiration, hypoxia, hypotension
• Insertion
  • Pain
  • Damage to surrounding structures: pneumothorax, pulmonary injury, liver injury, mediastinal perforation, injury to diaphragm, cardiac penetration, vascular injury
  • Bleeding, haemothorax
  • Malposition – too shallow (subcutaneous), too far, wrong structure
  • Surgical emphysema
• Use:
  • Tube blockage or displacement or dislodgement – tension pneumothorax
  • Infection
  • Pain  poor respiratory effort – atelectasis, hypoxia
  • Re-expansion pulmonary oedema