Indocyanine green clearance as an outcome prediction tool in cardiac surgery: a prospective study

PURPOSE

To evaluate the role of plasma disappearance rate of indocyanine green (PDR-ICG) as an outcome prediction tool in cardiac surgery.

PATIENTS AND METHODS

One hundred ninety patients undergoing coronary artery bypass grafting, valve surgery or combined procedures were enrolled. PDR-ICG measurements along with standard lab values were performed preoperative and on postoperative days 1, 2, and on discharge from the intensive care unit. Adverse outcomes were defined as prolonged length of stay in the intensive care unit and/or mortality. Two groups were defined according to length of stay in the intensive care unit (≤ 3 days vs >3 days).

RESULTS

PDR-ICG values differed significantly for all time points between the groups. In a multivariate model, in patients over 65 years with a EuroSCORE below 8.5, a preoperative PDR-ICG value below 12.85%/min was the strongest independent predictor for prolonged intensive care unit stay (>3 days). A preoperative PDR-ICG value below 8.2%/min was the strongest independent predictor for mortality in a multivariate analysis including age, cardiac function, and EuroSCORE.

CONCLUSIONS

In addition to the established scores, PDR-ICG may provide valuable information for the assessment of perioperative morbidity and mortality in cardiac surgery. Pre- and early postoperative measurements may help to identify patients at risk for developing perioperative complications.

Intestinale Perfusionsstörungen beim Intensivpatienten

Due to the bowel's poor tolerance of hypoxia, intestinal malperfusion presents as a grave disease with high mortality. The intensivist is confronted with this condition in association with other underlying diseases, in the course of surgery, during application of medication or associated with invasive therapy. In a critical care setting, the non-occlusive mesenteric ischemia (NOMI) is of increasing importance. Since critical care patients often lack clinical symptoms, special attention is required and one main factor of the patient's prognosis is early diagnosis. This review summarizes pathophysiology and diagnostic aspects and the range of therapeutic and preventive measures.

Dopamine under α1-blockade, but not dopamine alone or fenoldopam, increases depressed gastric mucosal oxygenation*

OBJECTIVE

To compare the effects of dopamine, both in the presence and absence of alpha1-blockade, and fenoldopam on microvascular gastric mucosal oxygenation and systemic oxygen transport under compromised circulatory conditions, both without and with fluid resuscitation.

DESIGN

Randomized controlled animal study.

SETTING

University department of anesthesiology.

SUBJECTS

Eight anesthetized dogs with chronically implanted ultrasound flow probes around the pulmonary artery for continuous measurement of cardiac output.

INTERVENTIONS

On different days, the dogs received in random order either dopamine (2.5 and 5.0 microg.kg(-1).min(-1), with or without alpha1-blocker pretreatment), the selective DA1-agonist fenoldopam (0.1 and 1.0 microg.kg(-1).min(-1), with and without DA1-blocker pretreatment), or saline (control). These interventions were performed under compromised cardiocirculatory conditions (induced by ventilation with positive end-expiratory pressure [PEEP] of 10 cm H2O), both without and with fluid resuscitation.

MEASUREMENTS AND MAIN RESULTS

We continuously measured regional microvascular hemoglobin saturation (microHbO2) in gastric mucosa by reflectance spectrophotometry and systemic oxygen transport ([U1E0A]O2). Ventilation with PEEP significantly decreased [U1E0A]O2 (from 19 +/- 2 to 9 +/- 1 mL.kg(-1).min(-1), mean +/- sem) and gastric mucosal microHbO2 (from 57 +/- 2% to 37 +/- 3%). Fluid resuscitation restored [U1E0A]O2 back to baseline (from 9 +/- 1 to 19 +/- 2 mL.kg(-1).min(-1)) but only partially restored microHbO2 (from 37 +/- 3% to 50 +/- 4%). Under both conditions, dopamine with and without alpha1-blockade significantly increased [U1E0A]O2 (by about 5 mL.kg-1.min-1 in the nonresuscitated state and 10 mL.kg-1.min-1 in the fluid resuscitated state, respectively), but only dopamine in the presence of alpha1-blockade also significantly increased gastric mucosal microHbO2 (by 5 +/- 1% and 7 +/- 2% in the nonresuscitated and fluid resuscitated states, respectively). Fenoldopam under all study conditions did not significantly affect [U1E0A]O2 or microHbO2, either in the presence or absence of DA1-blockade.

CONCLUSIONS

During compromised cardiocirculatory conditions, alpha1-receptor activation during dopamine infusion prevented an increase in gastric mucosal oxygenation. Furthermore, selective DA1-stimulation (by fenoldopam) was insufficient to overcome the PEEP-induced depression of microHbO2. The responses of gastric mucosal oxygenation did not parallel changes in systemic oxygen transport. These findings were independent of fluid resuscitation.

Candesartan cilexetil: an update of its use in essential hypertension

Candesartan cilexetil is converted to the angiotensin II receptor antagonist candesartan during absorption from the gastrointestinal tract. The selective and competitive binding of candesartan to the angiotensin II type 1 (AT(1)) receptor prevents binding of angiotensin II, a key mediator in the renin-angiotensin system. Significant reductions in systolic BP and diastolic BP are achieved with a once-daily dosage of candesartan cilexetil 2 to 32 mg/day in patients with mild to moderate hypertension. In randomised studies, candesartan cilexetil 8 to 16 mg/day was at least as effective as therapeutic dosages of losartan or other angiotensin II receptor antagonists. At a dosage of up to 32 mg/day candesartan cilexetil demonstrated greater antihypertensive efficacy than losartan 50 or 100 mg/day. In comparative trials, candesartan cilexetil demonstrated similar or greater antihypertensive efficacy compared with enalapril or hydrochlorothiazide and equivalent efficacy compared with amlodipine. The efficacy of candesartan cilexetil is not affected by age, and the drug provided significant BP reductions in Black patients and in those with severe hypertension. Long-term clinical studies to assess the effects of treatment with candesartan cilexetil on cardiovascular morbidity and mortality are ongoing. Regression of left ventricular hypertrophy has been seen with candesartan cilexetil treatment in patients with hypertension. Furthermore, the drug has favourable effects on renal function in patients with hypertension with or without coexisting diabetes mellitus. Renal vascular resistance and albumin excretion were reduced following treatment with candesartan cilexetil. Glucose homeostasis and lipid metabolism were not affected by treatment in patients with type 2 diabetes mellitus. Candesartan cilexetil is well tolerated and is not associated with cough, a common adverse effect of angiotensin converting enzyme inhibitor treatment. A pooled analysis of clinical trials found that the tolerability profile of candesartan cilexetil is not significantly different from that of placebo. Adverse events are not dose-related and are generally of mild to moderate severity.

CONCLUSIONS

Candesartan cilexetil is an effective antihypertensive agent with a tolerability profile similar to that of placebo. Comparative data indicate that candesartan cilexetil has antihypertensive efficacy equivalent to that of other major classes of antihypertensive agents and has a long duration of action. Therefore, candesartan cilexetil is a useful therapeutic option in the management of patients with hypertension.