Nursing care
Insulin pump client with high glucose and ketones: troubleshooting priorities
Written and reviewed by Dana Whitfield, RN, MSN · 4 min read · Updated October 2026
Short answer
A pump client with unexplained high glucose and ketones may have lost insulin delivery, and because pumps hold only rapid-acting insulin, ketoacidosis can develop within hours. The nurse first assesses for signs of DKA, then checks the site, cannula and tubing, arranges backup insulin by injection or infusion as ordered, and notifies the prescriber or diabetes team.
First, decide whether the client is already in DKA
Start with the client, not the device. Assess level of consciousness, breathing pattern, nausea, vomiting, abdominal pain and signs of dehydration, and confirm the blood ketone and glucose results. A client who is drowsy, vomiting or breathing deeply needs urgent escalation as possible DKA, and the pump becomes a secondary issue.
Inpatient technology guidance advises that an acutely unwell or confused pump user should not manage their own pump, and that a client in DKA is treated with intravenous insulin under the DKA pathway. In that case the pump is usually removed, labelled and stored according to policy, and the decision is made with the prescriber.
Troubleshoot delivery in a set order: site, cannula, tubing, pump
If the client is alert and stable, look for the reason insulin is not reaching them. Inspect the insertion site for redness, swelling, leakage or a dislodged cannula. Check the tubing for kinks, air bubbles or a disconnection, and ask when the set was last changed. Then check the pump screen for alarms, suspend mode or an empty reservoir.
Do not assume the pump is working because it is switched on and quiet. Clients may not notice a slipped cannula after showering or sweating. Ask about insulin storage and heat exposure as well. Documenting what was found helps the diabetes team decide whether the problem was the set, the insulin or the pump itself.
Give backup insulin without delay, then change the set
Pumps deliver only rapid-acting insulin, so there is no long-acting insulin in reserve when delivery stops. Guidance for inpatients states that when pump delivery is disrupted, an alternative insulin source must start immediately, by subcutaneous injection or intravenous infusion. The nurse obtains and gives this according to the order rather than waiting to see if glucose improves.
Patient troubleshooting guidance commonly pairs a correction injection by pen or syringe with replacing the whole infusion set, cannula and reservoir, followed by repeat glucose and ketone checks. A correction given through a pump that may not be delivering is a weaker choice. Recheck within the interval the protocol sets and escalate if values are not improving.
What can wait, what can be delegated, and why distractors fail
Calling the pump manufacturer, reviewing carbohydrate ratios and teaching about set change frequency can wait until insulin is restored and the client is safe. Encouraging sugar-free fluids is helpful but does not replace insulin. Assistive staff can record intake and output and report vomiting or drowsiness, while assessment and insulin decisions stay with the nurse.
Tempting distractors include giving a larger bolus through the existing set, restricting fluids, or telling the client to sleep it off and recheck in the morning. Each delays effective insulin. Troubleshooting advice warns against sleeping with unresolved unexplained high glucose, because ketones can keep rising overnight.
Study the priorities in a hypothetical case
Imagine a hypothetical alert adult on an insulin pump with glucose well above target on two readings and moderate blood ketones. The cannula site looks wet. Options are to give a correction bolus through the pump, give a correction by injection as ordered and change the set, increase oral fluids only, or wait two hours and recheck.
Giving the correction by injection and changing the set is the strongest answer because the wet site suggests a leak and insulin must reach the client now. The pump bolus may never arrive, fluids alone do not stop ketone production, and waiting risks DKA. This original case is a study example, not a real exam item.
Sources and further reading
JBDS-IP and DTN: Using technology to support diabetes care in hospital (JBDS 20, 2024). No long-acting insulin on pumps, rapid DKA after delivery interruption, immediate alternative insulin, pump removal when acutely unwell.
Chelsea and Westminster Hospital NHS: Troubleshooting CSII. Correction by pen or syringe, set and reservoir change, checklist of site and tubing causes, avoiding sleep with unresolved high glucose.
The next step on this is the same as on everything else here: answer questions and read the rationales. Our endocrine practice questions are the closest set to what this page covers.
Common questions
Why can DKA develop quickly when an insulin pump fails?
Pumps hold rapid-acting insulin only and the client usually takes no long-acting insulin, so an interruption leaves almost no insulin on board. Glucose rises and ketones can form within hours.
Should the nurse remove the insulin pump?
Removal is usually part of the plan when the client is in DKA, acutely unwell or confused, and intravenous or injected insulin replaces it. Follow the prescriber's order and policy, and label and store the device.
Is a correction bolus through the pump acceptable?
When delivery failure is suspected, a correction by pen or syringe is safer because the pump may not be delivering. The set is then changed and glucose and ketones are rechecked.