16th May 2019:
- Please describe the provided CT abdomen
image of an 83 year old gentleman with severe left sided back pain. - Vitals are as follows: HR 120 BPM | BP 188/ 98 mm Hg | Sats 99% RA| GCS 15. What are the immediate treatment considerations for this condition?
Please enter your answers in the comments section below. Further images are given below.
1. The Coronal image demonstrates a large infra renal dilated and elongated AAA with luminal contrast and mural thrombus. There appears to be extravasation of contrast into the retroperitoneum with associated haematoma. Difficult to tell from the images but there is likely extension into one or more of the common Iliac arteries. There is also extensive calcification of the abdominal aorta. There is also note of previous internal fixation of the lumbar spine apparent on the sagittal image. The presumably ruptured AAA is the likely cause of the patient’s abdominal pain.
2. Management: ABCs as a first step. IV access (2x large bore cannulas or IO if required). Blood pressure control, aiming for a systolic pressure of 50-100 (permissive hypotension, avoiding large volumes of crystalloid and using vasopressors if required). Bloods including Cross match, VBG, FBE, EUC, CMP, Coags. Contact blood bank for consideration of massive transfusion protocol. Analgesia (IV/IO). Discuss with Surgical team (Vascular/General plus Anaesthetics + ICU) for consideration of immediate transfer for OT for definitive management (Endovascular or open) or Transfer to major centre if not available onsite and Pt stable enough. Above referral made giving consideration to Patient/Family regarding wishes (Advanced care directive etc).
Great response Guy! Sorry for the really long delay in replying.
1. The provided coronal CTA image slice demonstrates a large ruptured uncontained (leak into intra peritoneal cavity) AAA. You are right; the images are single slices hence hard to interpret completely. This was a suprarenal AAA and the Iliac arteries are not visualised on provided images. Your comments on the metalwork, calcification etc are spot on.
2. A ruptured AAA has 100% mortality if not repaired. Your comments on definitive care with either EVAR or open repair are perfect. Palliative care is probably the only non-surgical option, depending on factors such as severity, extent of organ failure, medical premorbid state, patient choices etc. For example, in this specific case, the patient had a palliative approach.
Regarding management, as you have rightly said, ABCs come first. In this case, C is bound to be hardest to manage.
Patients can present in 3 haemodynamic states: Hypertensive, hypotensive or normotensive. Hence a little elaboration on the variations in management based on haemodynamic state.
A. You would have noticed that in the given scenario, this patient was significantly hypertensive and tachycardic. Both high heart rate and high blood pressure are detrimental in the context of vascular accidents like dissections or leaks. In a pre-rupture phase, elevated AAA wall tension is a significant predictor of impending rupture and worsens the likelihood of extending size of an existing tear or dislodgement of a temporary clot. This principle applies strongly to vascular dissection scenarios.
Accordingly, it is important to achieve acute heart rate and blood pressure control in patients with AAA and elevated blood pressure; agents commonly used include antihypertensive agents and analgesics. Regarding shearing stress on the vessel walls, it is important to control heart rate (to about 60 BPM) before, or in addition to controlling the systolic pressure.
Initial therapeutic goals in such situations include elimination of pain, control of tachycardia and reduction of systolic blood pressure to 100-120 mm Hg or to the lowest level consistent with adequate vital organ (cardiac, cerebral, or renal) perfusion. Whenever systolic hypertension is present, beta blockers can be used to reduce the rate of rise of the aortic pressure (dP/dt). GTN may not be a good initial agent due to reflex tachycardia. Once rate control is achieved with a Beta blocker (e.g. Esmolol, Metoprolol), other antihypertensive agents (e.g. Hydralazine, Sod. Nitroprusside, GTN etc) can be used. If beta blockers are contraindicated, a CCB could be considered. To prevent exacerbations in tachycardia and hypertension, patients should be treated with opiates such as IV Morphine. This reduces the force of cardiac contraction and the dP/dt and may thus delay rupture.
B. Haemorrhagic shock, if present is managed by means of cautious fluid resuscitation, blood transfusion, and immediate surgical intervention. The concept of permissive hypotension, whereby aggressive fluid resuscitation is avoided so as not to aggravate bleeding by raising the blood pressure, is recommended. In the setting of hypotension, reduction of blood pressure may be contraindicated. If shock ensues, morbidity and mortality increase dramatically. Perfusion of vital organs including the spinal cord will be heavily compromised with every passing second of unmanaged shock state. The minimum systolic BP target is debatable in such a context. 90 mmHg is generally considered an acceptable SBP for a permissive hypotension approach of this condition, particularly due to the high risk of spinal ischaemia and due to physiology resembling penetrating abdominal trauma
C. Patients with leaking AAAs, if normotensive, do not require pharmacotherapy.
Other considerations:
Like you have said, disposition considerations include organising inter hospital transfer and local consultations.
Treatment for coagulopathy may be initiated in the ED for patients who are receiving warfarin, heparin or NOACs.
Other measures would be supportive.
Long overdue, Guy you have won the prize for your answer.