Blood glucose response to rescue dextrose in hypoglycemic, critically ill patients receiving an insulin infusion

BACKGROUND

There is inadequate guidance for clinicians on selection of the optimal dextrose 50% (D50W) dose for hypoglycemia correction in critically ill patients.

OBJECTIVE

The purpose of this study was to determine the blood glucose (BG) response to D50W in critically ill patients.

METHODS

A retrospective analysis was conducted of critically ill patients who received D50W for hypoglycemia (BG < 70 mg/dL) while on an insulin infusion. The primary objective of this study was to determine the BG response to D50W. The relationship between participant characteristics and the dose-adjusted change in BG following D50W was analyzed using simple and multiple linear mixed-effects models.

RESULTS

There were 470 hypoglycemic events (BG < 70 mg/dL) corrected with D50W. The overall median BG response was 4.0 (2.53, 6.08) mg/dL per gram of D50W administered. Administration of D50W per protocol resulted in 32 episodes of hyperglycemia (BG > 150 mg/dL), resulting in a 6.8% rate of overcorrection; 49% of hypoglycemic episodes (230/470) corrected to a BG >100 mg/dL. A multivariable GEE analysis showed a significantly higher BG response in participants with diabetes (0.002) but a lower response in those with recurrent hypoglycemia (P = 0.049). The response to D50W increased with increasinginsulin infusion rate (P = 0.022). Burn patients experienced a significantly larger BG response compared with cardiac, medical, neurosurgical, or surgical patients.

CONCLUSIONS

The observed median effect of D50W on BG was approximately 4 mg/dL per gram of D50W administered. Application of these data may aid in rescue protocol development that may reduce glucose variability associated with hypoglycemic episodes and the correction.

Arm Vein as a Last Autogenous Option for Infrainguinal Bypass Surgery: It is Worth the Effort

OBJECTIVES

Considerable evidence exists for the use of arm vein conduit in lower limb bypass surgery. The use of arm vein in preference to synthetic conduit as a last autogenous option was assessed for patency and limb salvage outcomes.

MATERIALS AND METHODS

A prospective database was interrogated and checked against TQEH operating theatre database to detect all infrainguinal arm vein bypasses performed between 1997 and 2005. Patency, limb salvage and survival data for 37 arm vein bypasses was calculated using the Kaplan-Meier survival estimate method.

RESULTS

There were no perioperative deaths. 30 day patency rates were 89% primary, 95% secondary and 95% limb salvage. 12 month patency rates were 56% primary, 79% secondary and 91% limb salvage. 5 year patency rates were 37% primary, 76% secondary and 91% limb salvage. There was no significant patency advantage for primary vs. "redo" grafts (p=0.54), single vessel vs. spliced conduits (p=0.33) or popliteal vs tibial outflow (p=0.80). Patient survival rate was 92% and 65% at 1 and 5 years respectively.

CONCLUSION

Lower limb bypasses using arm vein can be performed with favourable patency and limb salvage compared to synthetic conduits. However, secondary interventions are frequently required to maintain patency. We recommend a vigilant surveillance program for early identification of patency threatening disease.

Aortic aneurysm repair with a functioning renal transplant: therapeutic options

BACKGROUND

Aortic aneurysm repair in the presence of a functioning renal transplant carries significant risks of renal ischaemia. We describe the management of patients undergoing this treatment by using a temporary, externally sited axillofemoral bypass and discuss other treatment options.

METHODS

Three patients underwent a temporary, externally sited axillary artery to common femoral artery bypass. The aneurysm was then dissected via a transperitoneal incision. When the aneurysm was clamped, the axillofemoral graft was opened allowing retrograde perfusion to the renal transplant.

RESULTS

All three patients made a good recovery without postoperative deterioration of renal function.

CONCLUSION

Numerous methods of protecting the transplanted kidney have been described, including expeditious surgery with no renal protection or some form of temporary shunt to perfuse the donor iliac artery. Temporary insertion of an axillofemoral bypass adds 45-60 min of extra operating time if two surgeons are present. However, this technique should completely avoid transplant ischaemia and is an excellent technique for dealing with abdominal aneurysms in patients with functioning transplants.

Up-regulation of MMP-2 and MMP-9 leads to degradation of type IV collagen during skeletal muscle reperfusion injury; protection by the MMP inhibitor, doxycycline

OBJECTIVES

to determine the role of matrix metalloproteinases, MMP-2 and MMP-9, in reperfusion injury following skeletal muscle ischaemia and whether inhibition of MMPs by doxycycline protects against tissue damage.

METHODS

rats were anaesthetised and a tourniquet applied to the proximal thigh to occlude blood flow. Four hours of ischaemia was followed by reperfusion for 0, 4, 24 or 72 h. Two further groups received doxycycline for 7 days prior to bilateral ischaemia and 24 h reperfusion. Skeletal muscle from both limbs, kidneys and lungs were harvested for zymography and immunohistochemical staining for type IV collagen.

RESULTS

upregulation of MMP-2 and MMP-9 was detected by zymography in the ischaemic leg and lung but not in the kidney. Quantitative immunohistochemical analysis showed marked degradation of type IV collagen in reperfused muscle, lung and kidney. Doxycycline-treated rats showed significant preservation of type IV collagen in skeletal muscle and a trend towards preservation in kidney and lung.

CONCLUSIONS

MMP-2 and MMP-9 are strongly upregulated in skeletal muscle ischaemia/reperfusion injury and are also upregulated in remote organs, leading to degradation of basement membranes. Inhibition of MMP activity may therefore be potentially therapeutically useful in reducing the severity of reperfusion injury.