Continuous Subcutaneous Insulin Infusion (CSII) in Inpatient Setting: Unmet Needs and the Proposal of a CSII Unit

H ere, we report the results of the Lazio Region Continuous Subcutaneous Insulin Infusion (CSII) Group, which took place on December 4, 2010, under the auspices of the Italian Society of Diabetology and the Diabetes Specialists Association. Each topic was introduced by the report of major literature data, selected by systematic review of the literature. The members of the Group then held an open discussion, with the report of personal experiences. Finally, consensus was reached on the basis of both literature and personal experience contribution.

CSII, commonly referred to as the insulin pump, is an increasingly used treatment within the population with diabetes and has been shown to improve metabolic control and reduce hypoglycemic episodes, at least in type 1 diabetes.

On the other hand, it is well known that hospitalization represents a common event ¹ in the diabetes population, due to both acute and chronic complications. However, hospitalization tremendously increases the risk of hyperglycemia, through various mechanisms, and numerous data indicate that inpatient hyperglycemia results in poorer outcomes. ² Therefore, every effort should be made to warrant euglycemia in the hospital setting. Quality improvement organizations are developing standards for inpatient diabetes management and are working to disseminate guidelines for inpatient diabetes care.

As the popularity of CSII increases, it becomes very likely that hospital healthcare providers may face the need for managing the inpatient care of patients under insulin pump therapy. On the other hand, these patients could be eager to continue their treatment while hospitalized since they are generally well trained on diabetes self-management and invest considerable time in mastering the technology. ³

However, literature data on the role and application of CSII inside the hospital are lacking, and insulin pump manufacturers provide only limited indications for use.

Therefore, although a wide agreement exists that insulin pump therapy during hospitalization should be regarded as a fundamental tool in patients already receiving insulin pump therapy, several issues about inpatient management of diabetes with CSII are still unresolved.

As previously stated, patients treated with CSII are generally well trained in self-management of diabetes and invest considerable time and money in the technology. Thus, they could feel uncomfortable in transferring responsibility and control of their own diabetes care to staff members perceived as less knowledgeable about the disease and pump technology. ⁴ The need for hospital personnel trained in the use of insulin pump technology clearly suggests that insulin pump policy should be implemented in the hospital setting. Nevertheless, because of the infrequency of seeing patients using this technology, the rapid improvement of the devices, and the different insulin pump models available, inpatient practitioners often do not have experience on the assessment and management of CSII. Moreover, some facilities may not have any expertise available for consultation on the use of insulin pumps.

Recently, some units have published their own guidelines to assist practitioners in the management of CSII in their hospital and to implement inpatient insulin pump policy. In 2005 an interinstitutional task force reviewed current available literature regarding the use of insulin pump in the hospital setting ³ and proposed guidelines in a formal written policy. The primary objective was to promote patients' independence in the use of their insulin pump during hospitalization, maximizing patient safety. The document included contraindications for continuing pump use (e.g., altered state of consciousness, critically ill patients, radiological procedure), a patient consent form, and also a set of rules to guide medical staff about pump management, and, finally, some measures used to assess effectiveness of an inpatient insulin pump policy are outlined. As the authors themselves admitted, this protocol has some limits: it was not developed for pediatric population and is not specific for intra- and perioperative use of CSII. ³ A retrospective review of only 25 admissions, using this protocol, a too small sample to assess the efficacy of CSII in controlling glucose levels in the acute care setting, ⁵ showed that to use a successful inpatient insulin pump policy, it is mandatory to address some specific issues, in particular, identification of patients at admission and assessment for their candidacy for continued CSII use. This analysis also provided with specific information about the characteristics of the inpatient population that receives CSII and showed no adverse events with the use of CSII in properly selected patients.

Bailon et al. ⁶ analyzed data from 50 hospitalizations with insulin pump therapy between 2005 and 2008, using the same protocol. They found that proportion of hypoglycemic events was lower among insulin pump users (P<0.01) than among nonusers. Even if most patients using insulin pumps can safely have their therapy transitioned when hospitalized, further study is needed to determine how to optimize glycemic control when pumps are allowed during hospitalization. ⁷

Noschese et al. ⁸ determined the safety and the metabolic effects of using an inpatient insulin pump protocol in 50 consecutive patients admitted to the hospital using CSII. They concluded that, although a standard protocol is useful to provide a safe approach to the use of CSII in the hospital setting, overall impact on the management of these patients is strictly related to the experience of the hospital staff nurses and to the patient's self-management ability.

On this basis, our proposal is to identify those hospitals where a CSII unit can be created. We believe that in our region, most hospitals are entitled to have a CSII unit, because a diabetes facility is often present in the Lazio Region hospitals. It should be staffed with an endocrinologist, a diabetes educator, a nutritionist, and a nurse, and, first of all, it should assess patient competency in self-administration of CSII therapy. The CSII unit should assist with ongoing evaluation about the advisability of continuing CSII therapy and also help with adjustments of insulin basal rates and boluses in order to promote patient independence in the use of the insulin pump during hospitalization while maximizing patient safety in accordance with established guidelines for patient self-management. Consistent contact between the pump user and the healthcare team is required for the successful use of insulin pump therapy. Nurses play a fundamental role in the diabetes team, as demonstrated by the significant improvement of many medical outcomes observed in patients with complicated diabetes, following a nurse-care management program. ⁹ Well-trained nurses may not only help well-educated patients with the use of CSII, but also facilitate patient education, when needed, thus allowing the pump user to achieve tighter glycemic control. We propose that the nurse of the CSII unit may also act as a consultant for all the facilities inside the hospital. This could significantly reduce costs because the same nurse could be employed in numerous facilities, thus promoting the spreading of a standard protocol and reducing the number of consultancies asked of the diabetologist.

In those hospitals where no expertise is available on CSII, patients on CSII should be transferred to insulin injections, according to a standardized protocol (Table 1).

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Table 1.

Protocol to Transfer Patients on Continuous Subcutaneous Insulin Infusion Treatment to Insulin Injections

• Calculate the total amount of overall basal insulin and administer it as basal injections, if using slow-acting analog (one injection of insulin glargine or two injections of insulin detemir with the total dosage calculated administered in two injections every 12 h).

• Increase it by about 30%, if using NPH insulin (with the total dosage calculated administered in two injections every 12 h: 30% of the dosage in the morning and 70% at bedtime).

• Unchange boluses. In well-trained patients, continue CHO counting and the algorithm to calculate bolus, according to preprandial glycemia. In patients not adequately trained, give the patient a form, indicating CHO content of the meals, and provide the algorithm to calculate bolus, according to preprandial glycemia.

• Besides meal bolus, give a bolus of rapid-acting insulin every 3–4 h (or regular insulin every 5–6 h), until the first basal insulin injection is administered, to replace 80% of the basal insulin not administered.

CHO, carbohydrate; NPH, neutral protamine Hagedorn.

The other option of utilization of CSII in a hospital setting, from our point of view, is for critical ill patients ¹⁰ or special circumstances. Intensive insulin therapy has become a standard of care for diabetes patients in intensive care units. Whatever method is used for delivering insulin, it should be able to control hyperglycemia, hypoglycemia, and insulin delivery errors, and therefore an ideal insulin protocol should be adaptable to the individual's response to insulin and should balance stability and responsiveness. In particular, hypoglycemia during intensive insulin therapy has been associated with increased cardiovascular morbility and mortality. It is important that CSII has been shown to decrease the frequency of hypoglycemic episodes in diabetes patients, and this seems particularly valuable in critical conditions. ¹¹

During the perioperative period, CSII has shown short-term benefits in glycemic control, reducing the risk of hyperglycemia or hypoglycemia and thus simplifying anesthesiological procedures, improving wound healing, and reducing the incidence of surgical wound infections. ¹² However, all these observations have been made in small groups of patients, and therefore the role of CSII during and after surgery remains unclear. The subcutaneous continuous glucose monitoring system appears to be reliable for use in critically ill patients and showed glucose values with a strong correlation to arterial reference blood glucose levels, determined by a blood gas analyzer. ¹³ Finally, although all guidelines recommend optimizing glycemic control in women with diabetes, not only during pregnancy, but also during labor, only limited evidence that CSII might be at least as effective as, for example, insulin infusion is available, at the moment. ¹⁴

However, although a strong rationale exists behind CSII, because a continuous, controllable baseline insulin infusion with intermittent larger boluses at mealtimes more closely mirrors physiologic secretion of insulin by the pancreas, little information is available in the medical literature to compare protocols for intravenous insulin infusion with CSII in the critical care setting.

Here, we propose a protocol for minor surgery interventions, under local or general anesthesia, no longer than 1 h (Table 2). This protocol, already utilized by some of us, will be now experimented with by all the members of the Study Group.

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Table 2.

Continuous Subcutaneous Insulin Infusion Protocol for Minor Surgery Interventions

• 5% glucose solution, at 100 mL/h

• Temporary basal=average basal

• Every hour, check blood glucose:

∘ If < 100 mg/dL, stop basal infusion (and check blood glucose every 30 min).

∘ If > 100 to <140 mg/dL, decrease basal of 30%.

∘ If > 140 to <180 mg/dL, maintain basal infusion.

∘ If > 180 to <200 mg/dL, increase basal of 50%.

∘ If > 200 mg/dL, administer 2–3 units, as a bolus.

It should be clearly stated that insulin pump therapy is not considered appropriate in patients with an altered state of consciousness, at risk of suicide, and during radiology procedures and major surgery, in accordance with most guidelines.

In summary, insulin pump therapy can be safely continued in the hospital setting. However, the implementation of standardized protocols, possibly through the action of a CSII unit, is needed.

Appendix

The institutions and participants composing the CSII Study Group of Lazio Region, Italy, are: Bambin Gesù Hospital, Rome, Marco Cappa and Ippolita Patrizia Patera; University Campus Biomedico, Rome, Silvia Manfrini; Diabetes Center (Viale D. Cambellotti), Rome, Daniela Bracaglia, Giuseppina Ciampittiello, and Elena Cicconetti; Israelitic Hospital, Rome, Claudio Ventura; Hospital of Marino, Rome, Donatella Bloise and Patrizio Tatti; Pertini Hospital, Rome, Sergio Leotta and Natalia Visalli; Policlinico Gemelli, Catholic University of Rome, Salvatore Caputo, Giovanni Ghirlanda, and Andrea Giaccari; Policlinico Umberto I, University of Rome “La Sapienza,” Maria Gisella Cavallo and Frida Leonetti; Policlinico Tor Vergata, University of Rome “Tor Vergata,” Davide Lauro, Maria Luisa Mancabitti, Maria Adelaide Marini, and Vincenza Spallone; Sant'Andrea Hospital, University of Rome “La Sapienza,” Angela Napoli and Giuseppe Pugliese; San Camillo-Forlanini Hospital, Rome, Maria Rosaria Nardone and Claudio Tubili; S. Eugenio Hospital, Rome, Maria Giuliano; San Giovanni Hospital, Rome, Danila Fava and Fabio Piergiovanni; Diabetes Center, Fondi, Latina, Elisa Forte; Azienda Unità Sanitaria Locale Latina, Presidio Ospedaliero of Gaeta, Latina, Franco Tuccinardi; S. Spirito Hospital, Rome, Francesco Chiaramonte; and University of Rome “La Sapienza,” Latina, Rome, Raffaella Buzzetti and Gaetano Leto.