Severe hypophosphataemia induced by glucose-insulin-potassium therapy. A case report and proposal for altered protocol

Refeeding in the ICU: an adult and pediatric problem

PURPOSE OF REVIEW

To describe the etiology and complications of the refeeding syndrome.

RECENT FINDINGS

Complications of the refeeding syndrome can include electrolyte abnormalities, heart failure, respiratory failure, and death. This syndrome is of particular importance to critically ill patients, who can be moved from the starved state to the fed state rapidly via enteral or parenteral nutrition. There are a variety of risk factors for the development of the refeeding syndrome. All of these risk factors are tied together by starvation physiology. Case reports and case series continue to be reported, suggesting that this entity continues to exist in critically ill patients. Initiation of enteral nutrition to patients with starvation physiology should be gradual and careful monitoring of electrolytes and organ function is critical during the early stages of refeeding.

SUMMARY

The refeeding syndrome remains a significant issue in critically ill patients. Knowledge of the risk factors and the clinical signs of the refeeding syndrome is important to optimize outcomes.

Tight glucose control in intensive care units: an update with an emphasis on nutritional issues

PURPOSE OF REVIEW

Tight glucose control in ICU patients is now regarded as a goal of successful care. Some challenge this on the basis that it produces no benefit and may cause harm. We review the recent literature with an emphasis on nutritional aspects.

RECENT FINDINGS

Since 2001, several randomized controlled trials have examined the effect of tight glucose control in ICU patients, but only one showed an overall survival benefit. Glucose potassium insulin infusions have also produced variable results, and sometimes cause falls in plasma phosphate with potential consequences. Several studies have shown tight glucose control is labour-intensive and increases the incidence of hypoglycaemia, which could have profound effects, especially if cerebral perfusion is poor. Nutritional intake during tight glucose control has generally been poorly defined. Unintentional cessation of nutrition has been identified as a risk factor for hypoglycaemia. No difference in glucose control has been found between parenteral and enteral feeding.

SUMMARY

Without knowledge of nutrition provision in terms of carbohydrate, total energy intake and route of administration, some studies are difficult to interpret. It is currently difficult to recommend routine use of tight glucose control in the ICU. Many clinicians have adopted regimes to control glucose between 5.0-9.0 mmol/l.

Safety, tolerability, and efficacy of a glucose-insulin-potassium-magnesium-carnitine solution in acute myocardial infarction

Fifty-four patients with AMI were treated with a front-loaded 15-hour infusion of hypertonic glucose, insulin, potassium, magnesium, and L-carnitine in addition to usual therapy. This metabolic solution was well tolerated, free of serious side effects, and reduced the incidence of morbid events.

Prebypass glucose-insulin-potassium infusion in elective nondiabetic coronary artery surgery patients

Perioperative GIK therapy has been advocated to ensure adequate energy substrate levels during cardiac surgery. However, hyperglycemia should be avoided because it may worsen neurologic outcome after cerebral ischemia. A prospective, randomized, clinical comparison was performed between two prebypass infusion regimens in 32 elective nondiabetic CABG patients. Sixteen patients (GIK group) received glucose, 0.6 g/kg/h, insulin, 0.12 U/kg/h, and KCl, 0.12 mmol/kg/h, from the induction of anesthesia to the start of CPB; while the remaining 16 patients (R group) received only Ringer's acetate. The pump prime was glucose free and a blood cardioplegia technique was used in both groups. No differences were found between the groups with regard to myocardial injury; the CK-MB enzyme fractions were elevated to a similar degree and the frequency of postoperative ECG changes were similar in both groups. Likewise, there were no differences in hemodynamic changes, need for inotropic support, arrhythmia frequency, or duration of ICU stay. The GIK patients had higher blood glucose (P < 0.05) and insulin levels (P < 0.01); blood glucose increased to 12.4 +/- 5.4 mmol/L (mean +/- SD) at cannulation, with a drop after starting bypass. Interindividual variation in GIK patients was great, with glucose values ranging between 20.1 mmol/L at cannulation to 2.0 mmol/L after starting CPB. A hyperglycemic response was seen in both groups during rewarming: 15.0 +/- 4.2 and 15.0 +/- 3.1 mmol/L in GIK and R patients, respectively. It is concluded that prebypass GIK infusion had no clinical benefits for elective CABG patients as compared to Ringer's acetate.(ABSTRACT TRUNCATED AT 250 WORDS)

Antianginal and cardiac metabolic effects of low-dose glucose infusion during pacing in patients with and without coronary artery disease

Anginal threshold and cardiac metabolism during infusion of glucose, 350 mg/min, were compared with control values before, during, and after pacing in nine patients with coronary artery disease (CAD) and nine patients without coronary artery disease (non-CAD). Pacing induced no ischemia in non-CAD patients; in CAD patients, intolerable angina developed in less than 5 minutes. However, glucose infusion in the latter group increased the time to onset of angina (110 +/- 24 seconds before infusion versus 140 +/- 24 seconds following infusion) and decreased the extent of ST segment depression (1.8 +/- 0.3 mm before infusion versus 0.9 +/- 0.2 mm following infusion, p less than 0.01) following pacing. In all subjects, arterial levels and cardiac uptake of glucose rose by 100% (p less than 0.001) and those of free fatty acids fell by 50% (p less than 0.01). Arterial lactate and uptake of lactate by nonischemic myocardium increased by 30% (p less than 0.05). During pacing in CAD patients, this elevated uptake was outweighed by similar increases of lactate release from ischemic areas, leaving mean negative global exchanges unaltered. In CAD patients solely, rebuilding of cardiac glycogen after pacing was suggested from augmented citrate efflux in the control period but not during glucose infusion, suggesting a glycogen-sparing effect. Arterial concentrations and net cardiac fluxes of oxygen, glutamate, and alanine remained unaltered. In conclusion, beneficial effects of glucose during ischemia are associated with increased aerobic and anaerobic glycolysis, saving of glycogen, and decreased lipolysis.