|Home | About | Journals | Submit | Contact Us | Français|
Ruptured abdominal aortic aneurysm (RAAA) classically presents with sudden onset, severe ripping or tearing abdominal pain radiating through to the back. This case report describes features of an atypical presentation of a patient with RAAA and highlights the difficulties and uncertainties surrounding the prehospital assessment, appropriate treatment and management of these patients. All prehospital care educators and practitioners should be made aware of the wide spectrum of clinical manifestations for this condition.
An ambulance crew was requested to attend a 73‐year‐old male found collapsed in a motor vehicle. The patient was found slumped forwards over the steering wheel. There was no history or evidence of trauma. On examination the patient responded to voice, his airway was clear, respiratory rate was 36 with equal air entry bilaterally, and radial pulses were impalpable. He was diaphoretic, pale and had an obvious left sided hemiplegia. High‐flow oxygen was delivered via a non‐rebreathing face mask (fractional inspired oxygen (Fio2) 0.85) and the patient was rapidly extricated from the vehicle.
In the ambulance, lying supine, the hemiplegia unexpectedly resolved with the patient regaining power on his left side, Glasgow Coma Score improved to E4, M6, V2. Dysarthria resulted in the patient communicating non‐verbally with nods of the head. He denied head, chest or abdominal pain. Systolic blood pressure was 82 mm Hg; a three lead ECG displayed a broad complex tachycardia of 131 beats/min. A 12 lead ECG, performed en route to the emergency department (ED), revealed an atrial tachycardia with right bundle branch block. Oxygen saturation via pulse oximetry was 91% with ongoing administration of high flow oxygen. A standby was arranged with the local ED, intravenous access was established, and fluid resuscitation commenced en route. The total time from arrival at scene to arrival at hospital was 17 min.
In the ED the patient began vocalising, complaining of abdominal and back pain and loss of feeling in his legs, which had become notably pale. Assessment of the abdomen revealed a faintly palpable, pulsating mass in the epigastric region. Rapid infusion of 500 ml boli of colloids and O negative blood were administered in an attempt to maintain the blood pressure while awaiting definitive surgical intervention. Despite all efforts pulseless electrical activity ensued and the patient died.
In Scotland in 2005, ruptured abdominal aortic aneurysm (RAAA) caused the deaths of 313 patients, and in the period 2005–06 almost 2000 new patients were diagnosed with this potentially life‐threatening condition (J Quinn, ISD Scotland Healthcare Information Group, personal communication, 2007). Classically patients present with sudden onset, severe ripping or tearing abdominal pain radiating through to the back.1 Neurological complications occurring as part of the clinical picture have been described in the literature.2 One study suggests that diagnosis of aortic dissection in hospital is missed in up to 38% of patients on initial assessment with many, up to 28%, of diagnoses being made only at postmortem examination.2 It is therefore not surprising that difficulties are experienced when assessing and treating this condition in the prehospital environment. This case study demonstrates the rapidly changing clinical condition and varied neurological presentations of a patient with RAAA and how an atypical presentation can divert attention from the correct underlying diagnosis. The attending paramedics were influenced by two presenting features: firstly, the intermittent hemiplegia; and secondly, the lack of abdominal pain.
The hemiplegia on initial examination led the ambulance crew to believe the patient had suffered a cerebral vascular accident. However, neurological problems can be associated with aortic dissection, with an incidence of 18–30%,3 and are often caused by spinal artery involvement. In this case postmortem results excluded this as a cause but did identify significantly artheromatous vessels extending from the aortic arch. It is likely that this patient's intermittent hemiplegia was caused by cerebral hypoperfusion related to narrowed artheromatous carotid vessels and systemic hypotension. As a result, postural changes from the upright to supine position restored pressure in the cerebral vessels leading to the resolution of hemiplegia.
Severe abdominal pain is often the initial symptom of RAAA,1 but is reportedly absent in up to 15% of cases.2 The reasons behind these painless presentations are not yet fully understood.4 In this case, the absence of abdominal pain resulted in the ambulance crew focusing on the associated neurological problems. This highlights the need to educate ambulance staff to consider a differential diagnosis of RAAA in patients presenting in this or similar ways.
This atypical presentation of RAAA highlights the difficulties and uncertainties surrounding the prehospital assessment, appropriate treatment and management of these patients. Current prehospital care education in this subject is lacking, which results in reduced clinical awareness, possibly prolonged on scene and transportation times, and ultimately delayed definitive care. Fortunately, in this case, there was no delay in response, treatment or speed of transportation to the ED. If we are to reduce the mortality rates of patients' suffering from RAAA it is essential that all prehospital care educators and ambulance staff are made aware of the wide spectrum of clinical manifestations for this condition.
The authors would like to thank Dr Edward Duncan for his advice and editorial expertise during the writing of this paper and Ms Wendy Tait who assisted in the management of the case.
ED - emergency department
RAAA - ruptured abdominal aortic aneurysm
Competing interests: None declared.