Lynn Schallom

Guidelines for the use of an insulin infusion for the management of hyperglycemia in critically ill patients.

Objective:To evaluate the literature and identify important aspects of insulin therapy that facilitate safe and effective infusion therapy for a defined glycemic end point. Methods:Where available, the literature was evaluated using Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) methodology to assess the impact of insulin infusions on outcome for general intensive care unit patients and those in specific subsets of neurologic injury, traumatic injury, and cardiovascular surgery. Elements that contribute to safe and effective insulin infusion therapy were determined through literature review and expert opinion. The majority of the literature supporting the use of insulin infusion therapy for critically ill patients lacks adequate strength to support more than weak recommendations, termed suggestions, such that the difference between desirable and undesirable effect of a given intervention is not always clear. Recommendations:The article is focused on a suggested glycemic control end point such that a blood glucose ≥150 mg/dL triggers interventions to maintain blood glucose below that level and absolutely <180 mg/dL. There is a slight reduction in mortality with this treatment end point for general intensive care unit patients and reductions in morbidity for perioperative patients, postoperative cardiac surgery patients, post-traumatic injury patients, and neurologic injury patients. We suggest that the insulin regimen and monitoring system be designed to avoid and detect hypoglycemia (blood glucose ⩽70 mg/dL) and to minimize glycemic variability.Important processes of care for insulin therapy include use of a reliable insulin infusion protocol, frequent blood glucose monitoring, and avoidance of finger-stick glucose testing through the use of arterial or venous glucose samples. The essential components of an insulin infusion system include use of a validated insulin titration program, availability of appropriate staffing resources, accurate monitoring technology, and standardized approaches to infusion preparation, provision of consistent carbohydrate calories and nutritional support, and dextrose replacement for hypoglycemia prevention and treatment. Quality improvement of glycemic management programs should include analysis of hypoglycemia rates, run charts of glucose values <150 and 180 mg/dL. The literature is inadequate to support recommendations regarding glycemic control in pediatric patients. Conclusions:While the benefits of tight glycemic control have not been definitive, there are patients who will receive insulin infusion therapy, and the suggestions in this article provide the structure for safe and effective use of this therapy.

Improved Extubation Rates and Earlier Liberation from Mechanical Ventilation with Implementation of a Daily Spontaneous-Breathing Trial Protocol

BACKGROUND Daily spontaneous-breathing trials (SBTs) are promulgated as the best method for assessing readiness for discontinuation of mechanical ventilation. SBT protocols have also been shown to improve outcomes as opposed to wild-type implementation of daily SBT recommendations. Here we determine whether implementation of a mandatory, protocol-driven daily SBT on all ventilated patients in the ICU improves extubation rates and accelerates liberation from mechanical ventilation. STUDY DESIGN A daily 30-minute SBT protocol was introduced into an academic surgical ICU in July 2005 and followed through September 2006. Decisions about next steps (continued mechanical support versus liberation) after each trial were recorded. Owing to the low liberation rate, physicians began (in January 2006) recording the reasons for continuing mechanical ventilation after a passing SBT. Differences in patient outcomes were compared for the first and last 8 weeks of the study period, corresponding to similar times in the academic and calendar years. RESULTS Four hundred eighty-eight patients experienced 547 mechanical ventilation episodes from July 2005 to September 2006. A total of 2,835 safety evaluations for SBTs were completed. Rate of extubations of passing patients after the first 8 weeks of implementation (n = 73 patients) was 27% (35 extubations of 131 passed trials). This rate improved in the last 8 weeks to 42% (42 of 101) (p < 0.02) (n = 57 patients). Reintubation rate was similar at 6% for the first 8 weeks and 8% for the final 8 weeks (p = 0.65), including self-extubations. CONCLUSIONS Implementation of a daily SBT protocol resulted in improvement of extubation rates during the year of implementation without a change in the reintubation rate. Requesting that physicians enumerate reasons for continuing mechanical ventilation in the face of a passing breathing trial was associated with a sustained improvement in extubation rate.

Bedside Small Bowel Feeding Tube Placement in Critically III Patients Utilizing a Dietitian/Nurse Team Approach

Background: To determine if a previously described protocol for small bowel feeding tube (SBFT) placement would be feasible for use in surgical/trauma/burn intensive care population; if limiting the number of a professionals placing the tubes would achieve a sufficient success rate for cost effectiveness; and to determine the effectiveness of a certified nutrition support dietitian (CNSD)/clinical nurse specialist (CNS) team approach to tube placement. Method: Prospective trial of bedside small bowel feeding tube placement by a CNS/CNSD team. The setting was an university-affiliated surgical/trauma/burn intensive care unit. A total of 74 patients were included in the study. Results: We successfully placed 64 of 74 (86.4%) SBFTs in our intensive care unit. The CNS successfully placed 32 of 38 tubes and the CNSD placed 32 of 36 tubes. Of the successfully placed tubes 41 (64%) were at or beyond the ligament of Treitz. Of the other 23 (36%), 6 were in the second portion of the duodenum, 12 were in the third p...

National Survey of Central Venous Catheter Flushing in the Intensive Care Unit

BACKGROUND Evidence is needed on the best solution for flushing central venous catheters. OBJECTIVE To understand current flushing practices for short-term central venous catheters among critical care nurses before implementation of a randomized, controlled trial comparing physiological saline with heparin solution for flushing to maintain catheter patency. METHODS A 6-item survey including demographic data was mailed to 2000 practicing critical care nurses in the United States. An additional 316 surveys were completed at the annual conference of the American Association of Critical-Care Nurses. RESULTS Most (71.5%) of the 632 respondents who completed the survey were staff nurses. Most respondents (64.6%; 95% CI, 60.86%-68.34%) reported using physiological saline exclusively to flush central venous catheters and maintain patency. For heparin-containing solutions, the concentration and volume used varied. The most commonly reported volumes for flushing were 10 mL for saline (63%; 95% CI, 59.18%-66.82%) and 3 mL for heparin (50.2%; 95% CI, 43.5%-56.9%). CONCLUSION Flushing practices for central venous catheters vary widely. A randomized controlled trial is needed to determine the optimal flushing solution to maintain short-term patency.

Hemodynamic applications of capnography.

The measurement of the pressure of exhaled carbon dioxide (PetCO2) via capnography has several useful hemodynamic applications. This article discusses integrating PetCO2 values with hemodynamic assessment. Capnography can be applied to hemodynamic assessment in three key ways: (1) identification of end-expiration during pulmonary artery and central venous pressure measurements, (2) assessment of pulmonary perfusion and alveolar deadspace, (3) assessment of cardiopulmonary resuscitative efforts. The article presents research, sample waveforms for end-expiration identification, and case examples.

Systems biology in critical-care nursing.

Systems biology applies advances in technology and new fields of study including genomics, transcriptomics, proteomics, and metabolomics to the development of new treatments and approaches of care for the critically ill and injured patient. An understanding of systems biology enhances a nurses ability to implement evidence-based practice and to educate patients and families on novel testing and therapies. Systems biology is an integrated and holistic view of humans in relationship with the environment. Biomarkers are used to measure the presence and severity of disease and are rapidly expanding in systems biology endeavors. A systems biology approach using predictive, preventive, and participatory involvement is being utilized in a plethora of conditions of critical illness and injury including sepsis, cancer, pulmonary disease, and traumatic injuries.

Clinical Application: Using Oxygenation Profiles to Manage Patients

Cellular oxygenation is dependent on both tissue oxygenation and pulmonary oxygenation. The use of profiles can help to make the assessment of tissue and pulmonary oxygenation more thorough. Although oxygenation profiles have limitations, an understanding of them can provide useful information to the critical care nurse. Oxygenation profiles enable the nurse to trend a patients progress and response to nursing and medical interventions. A sophisticated assessment relies not merely on physical assessment alone but incorporates continuous mixed venous oxygenation and oxygenation profiles to assess a patients tissue and pulmonary oxygenation status.