How a Cannula-Related Infection Expert Witness Reviewed a Hospital-Acquired Cellulitis Claim

In the fast-paced environment of a busy hospital ward, a peripheral intravenous (IV) cannula is perhaps the most common medical intervention. It is a routine task, performed thousands of times a day across the NHS. However, as any experienced clinician knows, there is no such thing as a "minor" procedure when it comes to patient safety.

This case review explores a scenario where a simple IV cannula led to a chain of events including cellulitis, sepsis, and a significantly extended hospital admission. We look at the role of the Nursing Expert Witness in determining whether this outcome was a dedicated "unfortunate complication" or a result of a breach in the standard of care.

The Case Background: A Routine Admission Gone Wrong

The patient in this case was admitted to an acute ward following a traumatic fall at home. Upon admission, a peripheral cannula was inserted into the patient’s arm to facilitate the administration of fluids and any necessary intravenous medications.

For the first few days, the patient’s recovery from the fall was progressing well. However, the situation took a sharp turn for the worse when the patient began complaining of intense pain, swelling, and heat around the cannula site. What began as a routine admission for a fall transformed into a life-threatening battle with cellulitis and sepsis.

The patient required an escalated antibiotic regime, suffered significant distress, and remained in hospital for several days longer than originally anticipated. The family, concerned that something had been missed, sought legal advice. Apex Experts were subsequently instructed to provide a nursing expert witness to determine if the care provided was defensible.

What the Expert Witness Identified

When an expert witness reviews a case involving a cannula-related infection, they don't just look at the infection itself; they look at the process and the policy.

The expert established a very specific timeline that became the focal point of the legal claim.

1. The 72-Hour Threshold: Most NHS Trusts have a robust policy regarding "dwell time" - the amount of time a cannula is allowed to remain in a patient's vein. In this specific Trust, the policy was clear: cannulas were to be removed or replaced every 72 hours.

   The expert noted that at the 72-hour mark, the patient’s cannula was actually performing well. The nursing notes showed a VIP (Visual Infusion Phlebitis) Score of 0, meaning there were no signs of redness, pain, or swelling at that time.

2. The Breach of Policy: Despite the 72-hour policy, the cannula was not removed. It remained in situ for approximately 96 hours. It was during this "overtime" period - the window between 72 and 96 hours - that the patient first began to report symptoms of discomfort.

3. The Clinical Escalation: Shortly after the 96-hour mark, the site showed classic signs of infection: redness, heat, and suspected discharge. The patient was quickly moved onto the sepsis pathway. While the hospital's response to the sepsis was clinical and prompt, the expert's focus was on the cause: why was the cannula still there?

"Cannula care must be guided by both policy and clinical indication. When both align and removal is still delayed, the risk becomes indefensible." — Apex Nursing Expert Witness

What is Expected in Hospital-Based IV Care?

To determine if a breach of duty has occurred, an expert witness compares the care given against what would be expected from a "reasonable body" of nursing staff. In the context of IV therapy, there are several gold standards:

1. Strict Adherence to Dwell Time: Trust policies are not "suggestions"; they are evidence-based protocols designed to minimise the risk of Staphylococcus aureus and other bloodstream infections. If a policy states 72 hours, the nurse is expected to act on that deadline unless there is a documented clinical reason to keep the cannula (such as extremely difficult venous access where no alternative exists).

2. The Role of VIP Scores: The VIP score is a vital tool for preventing infection. Nurses are expected to document this score at least once per shift. A score of 0 means the site is healthy, while a score of 2 or more usually demands immediate removal. In this case, the nurse correctly documented a score of 0, but failed to recognise that the time limit for the device had expired regardless of the score.

3. Clear Documentation: A nursing expert looks for a clear "paper trail." This includes the date and time of insertion, the size and batch number of the cannula, regular VIP score entries and a clear record of when the cannula was removed and the condition of the site at that moment.

The Expert’s Conclusion: Was it Preventable?

The expert clarified that this was not a case of broad systemic failure or "bad nursing" in a general sense. Instead, it was a specific procedural breach.

The Trust’s position might have been stronger if they had a "clinically indicated" removal policy (where cannulas only come out if they show signs of trouble). However, because this Trust had a written 72-hour replacement rule, the failure to follow it constituted a breach of duty.

The expert concluded that, on the balance of probabilities, the infection would likely have been avoided had the cannula been removed at the 72-hour mark as per the Trust's own safety guidelines. The "dwell time" provided a window for bacteria to colonise the site, leading directly to the cellulitis and subsequent sepsis.

Why This Matters for Legal Teams

This case highlights how a seemingly minor oversight - missing a deadline by 24 hours - can lead to a significant "Quantum" (the value of the claim). The patient didn't just have a sore arm; they suffered a systemic infection that required intensive treatment and caused lasting psychological distress.

For legal teams, this case demonstrates the importance of:

• Securing the Trust Policy: Always obtain the specific IV therapy policy in place at the time of the incident.

• The VIP Score Review: Look for gaps in documentation. A missing VIP score is often the first sign of sub-standard monitoring.

• Causation: It isn't enough to show a breach; you must show the breach caused the injury. Here, the timing of the symptoms shortly after the 72-hour mark provided a strong link.

Final Thoughts: Learning from the Breach and Cannula Infection

At Apex Experts, we believe that every case review is an opportunity for learning. For healthcare providers, this case is a reminder that documentation and policy adherence are the best defences against both infection and litigation. For legal professionals, it underscores the need for a nursing expert who can look past the medical charts to find the specific procedural failures that change the course of a case.

A cannula is a small device, but the responsibilities that come with it are vast. When those responsibilities are overlooked, the consequences for the patient and the Trust can be profound.