Aim
To remind clinicians at all levels that significant occult blood loss may be the cause of tachycardia and hypotension in the postoperative patient even when the haemoglobin level appears stable and there is little blood loss via drains.
Background
Delayed recognition of haemorrhage has been found to be the cause of several cases of mortality and significant morbidity reviewed by both the Anaesthetic and Surgical Subcommittees.
Factors implicated include:
- Delayed patient review in the post-anaesthesia care unit or surgical ward despite notification to treating clinicians of deterioration or failure to respond to therapy
- Delayed implementation of appropriate investigations
- Inter-hospital transfer with associated delays in assessment and treatment as well as lack of case familiarity
- Inter-specialty transfer, in particular from a surgical to a medical unit where different clinical perspectives may impact diagnosis
Whilst blood loss as a cause of tachycardia in the surgical patient is taught as a differential diagnosis in early clinical training, real world settings and experience can impact on decision making. Pain can be multifactorial as can hypotension in the setting of neuraxial blockade. In the younger, previously well patients, blood pressure may be stable despite significant blood loss, making hypotension a delayed sign. Similarly, a fall in haemoglobin may be a delayed sign in patients not receiving active adequate fluid resuscitation. Very occasionally, patients may demonstrate a limited tachycardic response to blood loss due to physiological and pharmacological factors.
Impaired cognition in the postoperative phase and language barriers can make assessment more challenging. Physical examination is always required when symptoms and signs persist despite therapy. In addition to laboratory tests, further timely investigations, such as imaging, may be required.
Body cavity surgery, specifically thoracic and abdominal cavity surgery, and vascular surgery, carry elevated risk of occult blood loss. Even when drains are used, clot occlusion or kinked drain can mask blood loss. Although laparoscopic and robotic surgeries involve limited incisions and may reduce surgical surfaces and organ manipulation, they can still result in blood loss if vascular or tissue injuries go unrecognised.
Recommendations
The VPCC recommends that:
- a timely clinical review must be undertaken when a patient fails to respond as expected to a prescribed therapy. This may entail out of hours in-person consultation.
- occult bleeding should be considered as a cause of tachycardia with or without hypotension, pain and a drop in haemoglobin. This is especially the case for any body cavity procedures, whether laparoscopic or open.
- the use of “minimally invasive” or robotic procedures does not eliminate the risk of concealed haemorrhage.