Viva 4

A 65-year-old man with chronic obstructive pulmonary disease (COPD) and known chronic alcoholic liver disease has been in the ICU for 48 hrs with septic shock, due to an infective exacerbation of COPD. He has been treated with antibiotics, fluid therapy, initial catecholamine support for hypotension that has now been weaned off, mild renal impairment that did not require dialysis, and intermittent non-invasive ventilation. You are called by your registrar at 1am because the patient has just vomited 250ml of ‘coffee-ground vomit’

What is your approach to this problem, and what advice will you give the registrar?

The rest of the viva focussed on the management of upper GI bleeding. Historically, this issue has only appeared in Question 1a and Question 1b from the second paper of 2001, where the college offered us an exsanguinating alcoholic. 

(Warning! For this viva to be effective, you need an oesophageal tamponade device to show the trainees; if you do not have one, a picture is provided below).

Immediate management:

• Airway:
  • This patient is likely to have hematemesis again; the airway may need to be protected. Make the patient "nil by mouth" in the meantime.
• Breathing/ventilation
  • As the patient is vomiting, NIV is not an option. Place them on high flow nasal prongs, aiming for SpO₂ ~ 90-92% (COPD)
• Circulatory support
  • The inital stages of resuscitation will consist of replacement of blood and blood products
• Specific investigations
  • CXR to confirm/exclude aspiration and rule out GI perforation
  • FBC, G&H, coags, fibrinogen, EUC and CMP
  • Ultrasound of the abdomen to investigate the severity of liver disease or portal hypertension
• Specific management
  • This patient requires urgent gastroscopy and banding or sclerotherapy of the varices
  • A pantoprazole infusion should be commenced

The candidate may continue talking, but they need to be cut off at this stage, as they may spoil the rest of the viva for themselves.

What could be the cause of this bleeding?

UPPER GASTROINTESTINAL BLEEDING Oesophageal sources Oesophageal varices (90% of varices) Mallory-Weiss tears Oesophagitis Gastric sources Gastric varices (10% of varices) Peptic ulcers (75% of bleeding ulcers) Portal hypertensive gastropathy Gastritis Duodenal Duodenal ulcers (25% of bleeding ulcers) Duodenitis

LOWER GASTROINTESTINAL BLEEDING Intestinal sources Angiodysplasia Arteriovenous malformations Meckel's diverticulum Colonic sources Angiodysplasia Arteriovenous malformations Inflammatory bowel disease Diverticular disease Colonic polyps Malignancy Haemorrhoids

The patient continues to vomit coffee grounds. Haemoglobin has dropped from 110 g/L to 75 g/L over the last 4 hours. What are your management options?

What would be your indications for urgent endoscopy?

• Syncope (indicates hemodynamic instability)
• Ongoing haematemesis (indicates that the stomach is filling with blood)
• Hypotension
• Transfusion requirements in excess of 4 units of PRBCs over 12 hrs
• Age over 60
• Multiple comorbidities

(this is from the Oh's manual chapter)

An urgent endoscopy is performed. Bleeding gastic and oesophageal varices are discovered. What are options for controlling this bleeding?

• Haemostasis:
  • Sclerotherapy - easier in the oesophagus; may cause chest pain, fever and mediastinitis
  • Banding - no inflammatory reaction, and at least as effective as sclerotherapy

The patient is brought back to ICU following banding. Within one hour, he vomits again (200ml of frank blood). What are your management options?

• Balloon tamponade - for when sclerotherapy and banding has failed, as you wait for TIPS. It is generally said that optimal pharmacological therapy is better than inexperienced use of balloon tamponade.
• Reducing portal hypertension pharmacologically
  • Terlipressin is the drug of choice in decreasing portal venous congestion, and it has been shown to decrease mortality in variceal bleeding
  • Octreotide is the next best choice
  • Non-selective beta blockade might be helpful to prevent further re-bleeding, but the jury is still out.
• Reducing portal hypertension invasively
  • TIPS procedure - the redistribution of blood from the portal circulation certainly reduces the presure in oesophageal varices, and prevents rebleeding. TIPS decreases the chances of treatment failure in refractory variceal bleeding (in one study, the probability of remaining bleed-free was 97% in the TIPS group and 50% in the pharmacotherapy group). However, it is a risky undertaking. It is typically reserved for patients who have failed all the other therapeutic approaches. By commiting to this course of action, you exhange sanity for hemostasis, and condemn the patient to a greatly increased risk of hepatic encephalopathy.

• Surgical control - this means either the resection of the bleeding varices, or the construction of some sort of surgical shunt, eg. the Warren distal splenorenal shunt. This has never been demonstrated to improve survival, and certainly exposes the patient to a host of complications, most notable of which is the greatly increased difficulty of any future liver transplant procedures.

(At this stage, you pull out the SB tube, or your picture of the SB tube)

What is this device? How is it used?

What are the key features of this device which make it suitable for use?

This is a Minnesota tube.

• The SB tube has three ports- NG suction, oesophageal balloon and gastric balloon.
• The Minnesota tube has four ports at the end (one extra port for aspirating stuff from above the oesophageal balloon)
• The Linton-Nachlas tube has only has only two ports, and a single 500-600ml gastric balloon.

The total length of the tube is usually 85cm, and it comes in a series of sizes ranging from 14Fr to 21Fr.

Beyond oesophageal varices, what are the other possible uses of this device?

• Intrauterine tamponade of postpartum haemorrhage (Seror et al, 1999)
• Rectal tamponade of bleeding angiodysplasia (Roy et al, 1996)
• Removal of rectal foreign bodies (Hughes et al, 1976)
• Control of massive epistaxis by inflating the gastric balloon in the oropharynx (Morita et al, 2006)

What are the contraindications for the use of this device?

• Unprotected airway
• Oesophageal rupture (eg. Boerhaave syndrome)
• Oesophageal stricture
• Uncertainty regarding the source of bleeding (how do you know it is not duodenal?)
• Well-controlled variceal bleeding

How will you insert this device?

The college asked for this in Question 30 from the second paper of 2015. They gave us a suggested technique in their "model answer" which I have modified with some of the suggestions made at the LITFL page for this procedure, and the Nepean ICU protocol for handling this device.

1. Protect the airway.
   Ideally, the patient should be intubated.
   This prevents you from inserting the tube into the trachea accidentally, and prevents aspiration of pooling oesophageal blood or displaced gastric content.
2. Inspect the tube and check the balloons for leaks.
   LITFL also recommend to calculate the compliance of the balloon "by inflating the  balloon with incremental 100ml aliquots of air to maximal recommended volume (usually 250 -300ml for SBT, 450-500ml for Minnesota) and note the corresponding balloon pressure at each step". This is highly appealing to any person who enjoys graphs.
3. Lubricate the tube.
4. Position the patient sitting up to 45°
   This protects them from aspiration
5. Insert the tube into the mouth or nose.
   The college answer offers the nares as an option, but realistically everybody always uses the orogastric route because these patients are always coagulopathic and thrombocytopenic from their chronic liver disease. Moreover, the tube is huge and thick, with big balloons- they will shred the nasal mucosa on the way in regardless of how much lube you cake them in. The insertion should ideally be performed under direct laryngoscopy so that you can be sure you are in the oesophagus.
6. The tube should be advanced to 50cm. 
   The college answer prescribes a depth of 50cm, which is consistent with the classical technique for insertion (Bauer et al, 1974). The alternative is to measure from mouth to angle of the jaw, then suprasternal notch and xiphisternum. LITFL authors recommend the latter method, acknowledging that humans vary in the length of their oesophagus. 
7. Inflate the gastric balloon. Check position with a chest Xray.
   There seems to be some disagreement as to how much one might inflate. The college recommend 250ml; LITFL mention that the Minnesota tube should take 450-500ml. Locally, we are more cautions: we inflate with about 100ml and then check position with an AXR. If one has produced a compliance curve for their balloon, one may check the balloon pressure against their curve to see whether it has been inflated in the oesophagus (LITFL offer a 15mmHg increase in pressure as a rough guide: if the post-insertion pressure for a given volume is more than 15mmHg higher than the pre-insertion pressure, then the balloon needs to be repositioned as it is likely in the oesophagus. )
8. Withdraw the tube until resistance is felt (at 30-35cm)
   This is usually the depth to the gastro-oesophageal junction. Tension develops, which gives one the impression that the balloon is up against an obstacle of some sort. If one has not inflated with enough air there will be no resistance, and the balloon will come out of the mouth to theembarrassment of the operator. 
9. Aspirate the gastric and oesophageal ports.
   If there was vigorous bleeding, it should have stopped by balloon tension.
10. Decide whether or not to inflate the oesophageal balloon.
    If you already know where the varices are on the basis of a gastroscopy result, you may use your judgment (i.e. there is no point of inflating the oesophageal balloon for gastric varices). Otherwise, one is guided by blood loss.  If bleeding from oesophageal and gastric ports has ceased,  then you may leave oesophageal balloon deflated. Bauer et al (1974) recommend to irrigate the suction ports with warm saline, to assure oneself that the aspirate returns clear and that there is no new bleeding.
11. If appropriate, inflate the oesophageal balloon to 25-30 mmHg pressure.
    The maximum oesophageal pressure is 40mmHg. If the bleeding in the oesophagus has stopped, one should deflate the oesophageal balloon by 10mmHg every 2 hours.
12. Apply traction to the tubing
    The precise amount of traction is uncertain. Some centres specify 1kg, others 2kg. The college answer calls for a 500ml bag of fluid, suspended over a pulley.

What are the different methods to confirm that it is in the right position?

One can do this in a number of ways.

• One can inflate it with a safe 80-100mls of air, and look for its position on AXR.
• One can inflate it with radio-opaque contrast, and look for its position on AXR
• One can position it under direct vision during gastroscopy
• One can compare the balloon pressure pre and post insertion (as suggested by the college), observing a change of 15mmHg as a sign that it is in the oesophagus.
  • Some go so far as to actually plot a compliance curve for the balloon, inflating it with progressively larger volumes of air and observing the change in pressure. The argument for doing this is that the stomach has much greater compliance than the oesophagus, and the compliance curve of the stomach will be much more linear, whereas in the oseophagus the increase in pressure per unit volume will be rapid and steep.

What are the complications of insertion, and how will you prevent these?

This features in Question 30 from the second paper of 2015, Question 30from the first paper of 2013, and Question 18.3 from the first paper of 2008. The questions usually ask the candidate to come up with a list of complications, and then to give brief suggestions as to how one might avoid them.

Complications of Sengstaken-Blakemore Tube Insertion

Complication	Preventative measure
Aspiration	Use only in intubated patients Sit the patient up to 45° Aspirate all gastric content before inflating the gastric balloon
Oesophageal rupture	Ensure both balloons completely deflated prior to insertion Avoid inflation of oesophageal balloon Ensure gastric balloon is correctly positioned during inflation
Gastric balloon migration; upper airway obstruction	Only use in intubated patients An older paper recommends the tube be fixed in position to the face mask of a standard football helmet
Oesophageal necrosis	Dont inflate the oesophageal balloon Avoid using this device for longer than 24-36 hrs Avoid using traction for prolonged periods Deflate the balloon regularly to check for rebleeding Monitor the gastric/oesophageal pressure carefully - keep it under 15mmHg

How will you remove the Minnesota tube?

No specific literature exists to guide practice here. Generally speaking, one should only consider it if the bleeding has stopped. Locally, we manage this in steps:

1. Deflate the oesophageal balloon. Watch for bleeding for a few hours (4-6).
2. Remove the tension (and keep the balloon inflated). Watch for bleeding.
3. Deflate the gastric balloon (keeping the tube in situ). Again, watch for bleeding. Ensure gastric aspirates (or lavage samples) remain unbloodied.
4. Remove the tube and watch for bleeding.

Disclaimer: the viva stem above may be an original CICM stem, acquired from their publicly available past papers. Or, perhaps it is a slightly altered version of the original CICM stem. Or, it is a completely original viva stem, concocted by the monstrously amoral author of Deranged Physiology for nothing more than his own personal amusement. In either case, because the college do not make the main viva text or marking criteria available, almost everything here has been confabulated. It might sound like a plausible viva and it could be used for the purpose of practice, but all should be aware that it does not represent the "true" canonical CICM viva station.