Technology

Trauma cases such as fractures, crush injuries, and severe burns often present in Accident & Emergency (A&E) and require to be treated by Trauma & Orthopaedics surgeons, Plastic surgeons, and Accident & Emergency staff. These cases carry a well-recognised risk of Acute Compartment Syndrome (ACS), where swelling of the injured limb restricts the blood supply, leading to the development of ischaemia, since the flow of adequately oxygenated blood is insufficient to keep the tissues/organs within the limb alive. SentinelpH® provides real-time, continuous pH monitoring that can detect developing ischaemia, that will alert clinicians, and permit them to intervene promptly and potentially prevent, or limit irreversible muscle and nerve damage, infection, amputation, and other severe outcomes. On occasions, the sequelae of missed ACS can result in Multiorgan failure, and potentially death.  Real-time pH monitoring also seems logical for guiding the management of patients who have been subjected to significant chest injuries and/or blood loss.

Orthopaedic surgeons regularly use tourniquets to minimise blood loss during procedures such as joint replacements, and to improve visibility during key-hole surgery or complex surgery to the forearm, hand or foot (trauma or elective surgery).  It is increasingly recognised that the potential for complications through using tourniquets for too long or with excessive tourniquet inflation pressures can results in permanent damage to the limb.  Unfortunately, there is no simple algorithm that informs the treating clinician as to which patients are more susceptible to tourniquet induced ischaemia.  Through adopting real-time pH monitoring of the limb, it seems logical that excessive ischaemia could be avoided, permitting timely periods of limb re-perfusion to be included where necessary, prior to re-inflating the tourniquet.

During cardiac procedures involving prolonged cardiopulmonary bypass (CPB), or through the use of invasive mechanical heart support systems, or ECMO (extracorporeal membrane oxygenation), maintaining optimal tissue/organ pH is critical. SentinelpH® offers real-time pH monitoring to detect the development of ischaemia early, helping clinicians to optimise heart or generalised bodily perfusion/oxygenation, reducing the risk of complications associated with impaired blood flow or reduced oxygen delivery.

SentinelpH® has the potential to offer real-time pH monitoring of patients who have sustained traumatic head injuries.  Accurate monitoring of patients who have sustained brain injuries is crucial to maximising recovery, and pH monitoring would logically add a new dimension, that should enable neurosurgeons make better informed decisions.  For patients who have aggressive brain tumours, it seems likely that pH monitoring will provide valuable insights into tumour and surrounding brain tissue metabolism. By comparing pH levels with advanced imaging and microdialysis data, SentinelpH® aims to improve surgical outcomes and rationalise drug usage, to optimise clinical outcomes.

Maintaining organ viability during organ transport is essential for successful transplantation. SentinelpH® monitors tissue pH in real time, potentially providing critical insights into organ health during storage and immediately before transplantation. By helping to optimise storage conditions, it reduces the risk of ischaemic damage and improves the likelihood of transplant success.  It is likely that tissue pH measurements will also enable clinicians to choose which organs are suitable for transplantation, rationalising this extremely expensive form of treatment.

Critically ill patients in the ICU are vulnerable to tissue/organ and generalised body ischaemia, as a result of injury or disease. In particular, generalised sepsis (septicaemia) is a real concern for ICU patients, especially for those requiring active organ support. SentinelpH® provides continuous tissue/organ pH monitoring, that enables the early detection of ischaemia developing in response to a number of conditions, including metabolic changes and organ dysfunction.  It seems highly likely that pH monitoring of tissues/organs will provide clinicians with sensitive real-time data that will guide decision making and enhance patient management and outcomes.

General surgical procedures commonly involve joining one structure onto another (anastomosis), and usually involve the bowel, liver and pancreas. Unfortunately, as a result of surgery, the blood supply present at the anastomotic junctions can become critical as a result of developing ischaemia, resulting in leakage resulting in infection (peritonitis), organ death and other life-threatening complications. SentinelpH® has the potential to provide real-time pH monitoring of anastomotic sites to detect the early onset of ischaemia, enabling timely intervention to rectify the impending complication.  Another very topical clinical problem is ‘abdominal’ compartment syndrome, which results from blunt abdominal trauma. Following injury, intra-abdominal organs such as the liver, pancreas, bowel and kidneys can become swollen, and subsequently ischaemic, as the abdominal cavity prevents further organ swelling.  A simple method, such as using pH monitoring to assess the pH of peritoneal fluid, seems logical and has the potential to detect the onset of abdominal compartment syndrome at a time when surgical intervention is likely to be successful.

SentinelpH® aims to aid vascular surgeons by offering real-time pH monitoring to assess limb viability, diagnose arterial insufficiency, and evaluate the effectiveness of arterial bypass procedures. It could help determine the best level for limb amputation, assess the need for temporary shunts during prolonged vascular procedures, and monitor the success of stent placements, ultimately improving surgical outcomes.

During reconstructive procedures involving muscle and skin flaps, maintaining tissue viability at the time of surgery and in the postoperative period is crucial. SentinelpH® has the potential to provide continuous pH monitoring, assessing that the blood supply is adequate by monitoring for any signs of developing ischaemia. This could help prevent flap failure by enabling surgeons to intervene in a timely fashion rectifying the clinical emergency.

WLS is a variant of ACS but results from reduced blood supply to patients’ legs due to the combined effects of surgery, patient positioning, and systemic effects of anaesthetic agents.  Unlike trauma related ACS, patients’ limbs are initially healthy at the start of the procedure but can become grossly ischaemic without clinicians being able to detect its development. Surgical specialities that are particularly susceptible to WLS include General Surgery, Gynaecology and Urology.  WLS is a condition that could potentially be completely avoided through using real-time pH monitoring.

Brain ischaemia in unborn children can lead to cerebral palsy and other neurological disorders. SentinelpH® has the potential to provide continuous pH monitoring for at-risk children, around the time of delivery, enabling early detection of reduced blood flow to the unborn child. This could support timely interventions (e.g. the decision to undertake an emergency Caesarean Section) to prevent or minimise brain injury to the newborn, and also improve neonatal care, especially for premature babies who are especially prone to infection.

In oncology, SentinelpH® has the potential to monitor tumour pH levels in real time, providing insights into tumour aggressiveness and treatment efficacy. This could support personalised treatment strategies and allow for timely adjustments to the treatments provided, improving patient outcomes and enhancing the overall effectiveness of cancer care.