Evaluation of a Nurse-Managed Insulin Infusion Protocol

Optimal Blood Glucose Monitoring Interval for Insulin Infusion in Critically Ill Non-Cardiothoracic Patients: A Pilot Study

Objective:

The American Diabetes Association and the Society of Critical Care Medicine recommend monitoring blood glucose (BG) every 1-2 hours in patients receiving insulin infusion to guide titration of insulin infusion to maintain serum glucose in the target range; however, this is based on weak evidence. We evaluated the compliance of hourly BG monitoring and relation of less frequent BG monitoring to glycemic status.

Materials and Methods:

Retrospective chart review performed on 56 consecutive adult patients who received intravenous insulin infusion for persistent hyperglycemia in the ICU at Saint Vincent Hospital, a tertiary care community hospital an urban setting in Northeast region of USA. The frequency of fingerstick blood glucose (FSBG) readings was reviewed for compliance with hourly FSBG monitoring per protocol and the impact of FSBG testing at different time intervals on the glycemic status. Depending on time interval of FSBG monitoring, the data was divided into three groups: Group A (<90 min), Group B (91-179 min) and Group C (≥180 min).

Results:

The mean age was 69 years (48% were males), 77% patients had preexisting type 2 diabetes mellitus (T2DM). The mean MPM II score was 41. Of the 1411 readings for BG monitoring on insulin infusion, 467 (33%) were in group A, 806 (57%) in group B and 138 (10%) in group C; hourly BG monitoring compliance was 12.6%. The overall glycemic status was similar among all groups. There were 14 (0.99%) hypoglycemic episodes observed. The rate of hypoglycemic episodes was similar in all three groups (p=0.55).

Conclusion:

In patients requiring insulin infusion for sustained hyperglycemia in ICU, the risk of hypoglycemic episodes was not significantly different with less frequent BG monitoring. The compliance to hourly blood glucose monitoring and ICU was variable, and hypoglycemic episodes were similar across the groups despite the variation in monitoring.

Significance of the Study:

The importance of glycemic control in ICU has been well established and it is a resource intensive venture. However, there are no major studies highlighting the most optimal time interval for blood glucose checks in critically ill patients on insulin infusion. With this study we hypothesize that time duration between blood glucose checks can be increased safely without any untoward effects. Our study provides evidence for effective resource management with reducing the time spent with every glucose check and directly translating into high value care.

Effectiveness of blood glucose control protocol for open heart surgery patients

AIMS

To evaluate the effectiveness of a tailored blood glucose control protocol for postoperative cardiac surgery patients treated in intensive care.

DESIGN

Retrospective study.

METHODS

Data for the control group (non-tailored protocol) were collected from medical records at a tertiary hospital in Seoul, Korea between April-July 2015. Data for the experimental group (tailored protocol) were obtained from medical records between April-July 2016. After adjusting the target blood glucose range, eliminating single-dose insulin administration and extending the blood glucose measurement time interval, data for blood glucose measurements, time for reaching and maintaining target blood glucose, mean number of daily blood glucose measurements and insulin dose adjustments for the experimental group were collected.

RESULTS

In the experimental group (where the target blood glucose rate was increased) the hypoglycaemia rate and the variation in blood glucose decreased significantly compared with the control group. In particular, the experimental group maintained relatively stable blood glucose levels by retaining a small variation range in glucose, regardless of the presence of diabetes. Time required for maintaining target blood glucose, mean number of daily blood glucose measurements and insulin dose adjustments per patient decreased.

CONCLUSION

The tailored protocol contributes to the safe and effective control of blood glucose in critical care patients after cardiac surgery and to the efficiency of nurses administering it.

IMPACT

This study has two significant impacts. The application of the tailored protocol has a positive impact on patients' blood glucose management, a critical component of treatment for postoperative cardiac patients in intensive care units. It also has a positive impact on the efficiency of nurses applying it. The results of this study are thus expected to facilitate successful implementation of clinical protocols for critical care after heart surgery.

Prospective evaluation of a dynamic insulin infusion algorithm for non critically-ill diabetic patients: A before-after study

INTRODUCTION

Insulin infusion is recommended during management of diabetic patients in critical care units to rapidly achieve glycaemic stability and reduce the mortality. The application of an easy-to-use standardized protocol, compatible with the workload is preferred. Glycaemic target must quickly be reached, therefore static algorithms should be replaced by dynamic ones. The dynamic algorithm seems closer to the physiological situation and appreciates insulin sensitivity. However, the protocol must meet both safety and efficiency requirements. Indeed, apprehension from hypoglycaemia is the main deadlock with the dynamic algorithms, thus their application remains limited. In contrary to the critical care units, to date, no prospective study evaluated a dynamic algorithm of insulin infusion in non-critically ill patients.

AIM

This study primarily aimed to evaluate the efficacy of a dynamic algorithm of intravenous insulin therapy in non-critically-ill patients, and addressed its safety and feasibility in different departments of our university hospital.

METHODS

A "before-after" study was conducted in five hospital departments (endocrinology and four "non-expert" units) comparing a dynamic algorithm (during the "after" period-P2) to the static protocol (the "before" period-P1). Static protocol is based on determining insulin infusion according to an instant blood glycaemia (BG) level at a given time. In the dynamic algorithm, insulin infusion rate is determined according to the rate of change of the BG (the previous and actual BG under a specific insulin infusion rate). Additionally, two distinct glycaemic targets were defined according to the patients' profile: 100-180 mg/dl (5.5-10 mmol/l) for vigorous patients and 140-220 mg/dl (7.8-12.2 mmol/l) for frail ones. Different BG measurements for each patient were collected and recorded in a specific database (e-CRF) in order to analyse the rates of hypo- and hyperglycaemia. A satisfaction survey was also performed. A study approval was obtained from the institutional revision board before starting the study.

RESULTS

Over 8 months, 72 and 66 patients during P1 and P2 were respectively included. The dynamic algorithm was more efficient, with reduced time to control hyperglycaemia (P1 vs P2:8.3 vs 5.3 hours; HR: 2.02 [1.27; 3.21]; p<0.01), increased the number of in-target BG measurements (P1 vs P2: 37.0% vs 41.8%; p<0.05), and reduced the glycaemic variability related to each patient (P1 vs P2, %CV: 40.9 vs 38.2;p<0.05, Index Correlation Class:0.30 vs 0.14; p<0.05). In patients after the first event of hypoglycemia after having started the infusion, new events were lower (P1 vs P2: 19.4 vs 11.4; p<0.001) thanks to an earlier reaction to hypoglycaemia (8.3% during P1 vs 44.3% during P2; p = 0.004). With the dynamic algorithm, the percentage of recurrence of mild hypoglycaemia was significantly lower in frail patients (20.5% vs 10.2%; p<0.001), and in patients managed in the non-expert units (18 vs 7.1%, p<0.001). The %CV was significantly improved in frail patients (36.9%). Mean BG measurements for each patient/day were 5.5±1.1 during P1 and 6.0±1.6 during P2 (p = 0.6). The threat from hypoglycaemia and the difficulty in using dynamic algorithm are barriers for nurses' adherence.

CONCLUSIONS

This dynamic algorithm for non-critically-ill patients is more efficient and safe than the static protocol, and adapted for frail patients and non-expert units.

Nurse-Directed Blood Glucose Management in a Medical Intensive Care Unit

BACKGROUND

Insulin-delivery algorithms for achieving glycemic control in the intensive care unit require frequent checks of blood glucose level and thus increase nursing workload. Hypoglycemia is a serious complication associated with intensive insulin therapy.

OBJECTIVES

To evaluate a nurse-directed protocol for blood glucose management that allows individualized insulin delivery within a predefined blood glucose corridor, intended to avoid hypoglycemia while maintaining adequate control of blood glucose level without increasing nursing workload.

METHODS

A nurse-directed protocol for blood glucose management was developed by an interprofessional team, and the protocol's performance was investigated in 175 patients compared with 384 historical controls.

RESULTS

With the nurse-directed protocol, hypoglycemia incidents declined significantly (31% vs 12%, P < .001), and minimum blood glucose levels increased significantly (80 mg/dL vs 93 mg/dL, P < .001). Mean and maximum blood glucose levels, the proportion of glucose readings within the target range (31% vs 26%, P = .06), and the number of blood glucose checks (59 vs 58, P = .85) remained unchanged with use of the protocol.

CONCLUSION

Implementation of the nurse-directed protocol for blood glucose management did not increase nursing workload but reduced hypoglycemia incidents significantly while maintaining adequate glycemic control.

Hypoglycemia Prevention by Algorithm Design During Intravenous Insulin Infusion

PURPOSE OF REVIEW

This review examines algorithm design features that may reduce risk for hypoglycemia while preserving glycemic control during intravenous insulin infusion. We focus principally upon algorithms in which the assignment of the insulin infusion rate (IR) depends upon maintenance rate of insulin infusion (MR) or a multiplier.

RECENT FINDINGS

Design features that may mitigate risk for hypoglycemia include use of a mid-protocol bolus feature and establishment of a low BG threshold for temporary interruption of infusion. Computer-guided dosing may improve target attainment without exacerbating risk for hypoglycemia. Column assignment (MR) within a tabular user-interpreted algorithm or multiplier may be specified initially according to patient characteristics and medical condition with revision during treatment based on patient response. We hypothesize that a strictly increasing sigmoidal relationship between MR-dependent IR and BG may reduce risk for hypoglycemia, in comparison to a linear relationship between multiplier-dependent IR and BG. Guidelines are needed that curb excessive up-titration of MR and recommend periodic pre-emptive trials of MR reduction. Future research should foster development of recommendations for "protocol maxima" of IR appropriate to patient condition.