Real-time image-guided nasogastric feeding tube placement: A case series using Kangaroo with IRIS Technology in an ICU.

OBJECTIVE: Pulmonary misplacement during the blind insertion of enteral feeding tubes is frequent, particularly in ventilated and neurologically impaired patients. This is probably the first clinical study using the Kangaroo Feeding Tube with IRIS technology (IRIS) which incorporates a camera designed to provide anatomic landmark visualization during insertion. The study aim was to evaluate IRIS performance during bedside gastric placement. METHODS: This is the first prospective study to collect data on the use of IRIS. Twenty consecutive unconscious patients requiring enteral nutrition were recruited at a single center. IRIS placement was considered complete when a clear image of the gastric mucosa appeared. Correct placement was confirmed using a contrast-enhanced abdominal X-ray. To evaluate the device performance over time, the camera was activated every other day up to 17 d postplacement. RESULTS: In 7 (35%) patients, the trachea was initially visualized, requiring a second placement attempt with the same tube. The IRIS camera allowed recognition of the gastric mucosa in 18 (90%) patients. The esophagogastric junction was identified in one patient, while in a second patient the quality of visualization was poor. Contrast-enhanced X-ray confirmed the gastric placement of IRIS in all patients. IRIS allowed identification of gastric mucosa in 14 (70%) patients 3 d after placement. Performance progressively declined with time (P = 0.006, chi-square for trend). CONCLUSION: IRIS placement could have spared X-ray confirmation in almost all patients and prevented misplacement into the airway in about one third. Visualization quality needs to be improved, particularly after the first week.

Preoperative endogenous ouabain predicts acute kidney injury in cardiac surgery patients.

OBJECTIVES: Acute kidney injury is a frequent complication of cardiac surgery and increases morbidity and mortality. As preoperative biomarkers predicting the development of acute kidney injury are not available, we have tested the hypothesis that preoperative plasma levels of endogenous ouabain may function as this type of biomarker. RATIONALE AND DESIGN: Endogenous ouabain is an adrenal stress hormone associated with adverse cardiovascular outcomes. Its involvement in acute kidney injury is unknown. With studies in patients and animal settings, including isolated podocytes, we tested the above mentioned hypothesis. PATIENTS: Preoperative endogenous ouabain was measured in 407 patients admitted for elective cardiac surgery and in a validation population of 219 other patients. We also studied the effect of prolonged elevations of circulating exogenous ouabain on renal parameters in rats and the influence of ouabain on podocyte proteins both "in vivo" and "in vitro." MAIN RESULTS: In the first group of patients, acute kidney injury (2.8%, 8.3%, 20.3%, p < 0.001) and ICU stay (1.4±0.38, 1.7±0.41, 2.4±0.59 days, p = 0.014) increased with each incremental preoperative endogenous ouabain tertile. In a linear regression analysis, the circulating endogenous ouabain value before surgery was the strongest predictor of acute kidney injury. In the validation cohort, acute kidney injury (0%, 5.9%, 8.2%, p < 0.0001) and ICU stay (1.2±0.09, 1.4±0.23, 2.2±0.77 days, p = 0.003) increased with the preoperative endogenous ouabain tertile. Values for preoperative endogenous ouabain significantly improved (area under curve: 0.85) risk prediction over the clinical score alone as measured by integrate discrimination improvement and net reclassification improvement. Finally, in the rat model, elevated circulating ouabain reduced creatinine clearance (-18%, p < 0.05), increased urinary protein excretion (+ 54%, p < 0.05), and reduced expression of podocyte nephrin (-29%, p < 0.01). This last finding was replicated ex vivo by incubating podocyte primary cell cultures with low-dose ouabain. CONCLUSIONS: Preoperative plasma endogenous ouabain levels are powerful biomarkers of acute kidney injury and postoperative complications and may be a direct cause of podocyte damage.

Amiodarone supplants lidocaine in ACLS and CPR protocols.

Amiodarone is an antiarrhythmic medication used to treat and prevent certain types of serious, life-threatening ventricular arrhythmias. Amiodarone gained slow acceptance outside the specialized field of cardiac antiarrhythmic surgery because the side-effects are significant. Recent adoption of amiodarone in the ACLS (Advanced Cardiac Life Support) protocol has somewhat popularized this class of antiarrhythmics. Its use is slowly expanding in the acute medicine setting of anesthetics. This article summarizes the use of Amiodarone by anesthesiologists in the operating room and during cardiopulmonary resuscitation.

Voluven, a new colloid solution.

Hydroxyethyl starch (HES) 130/0.4 (Voluven, Fresenius/Hospira, Germany) is indicated for the treatment and prophylaxis of hypovolemia. As the Voluven molecule is smaller than those of other available hydroxyethyl starch products, it is associated with less plasma accumulation and can be safely used in patients with renal impairment. Previous studies have demonstrated that Voluven has comparable effects on volume expansion and hemodynamics as other available HES products. Voluven is also associated with fewer effects on coagulation and may be an acceptable alternative to albumin for volume expansion in situations in which other starches are contraindicated secondary to risk of coagulopathy.

Reducing mortality in cardiac surgery with levosimendan: a meta-analysis of randomized controlled trials.

OBJECTIVES: The authors performed a meta-analysis to evaluate whether levosimendan is associated with improved survival in patients undergoing cardiac surgery. DESIGN: A meta-analysis. SETTING: Hospitals. PARTICIPANTS: A total of 440 patients from 10 randomized controlled studies were included in the analysis. INTERVENTIONS: None. MEASURMENTS AND MAIN RESULTS: Four investigators independently searched BioMedCentral and PubMed. Inclusion criteria were random allocation to treatment, comparison of levosimendan versus control, and cardiac surgery patients. Exclusion criteria were duplicate publications, nonhuman experimental studies, and no mortality data. The primary endpoint was postoperative mortality. Levosimendan was associated with a significant reduction in postoperative mortality (11/235 [4.7%] in the levosimendan group v 26/205 [12.7%] in the control arm, odds ratio = 0.35 [0.18-0.71], p for effect = 0.003, p for heterogeneity = 0.22, I(2) = 27.4% with 440 patients included), cardiac troponin release, and atrial fibrillation. No difference was found in terms of myocardial infarction, acute renal failure, time on mechanical ventilation, intensive care unit, and hospital stay. CONCLUSIONS: Levosimendan has cardioprotective effects that could result in a reduced postoperative mortality. A large randomized controlled study is warranted in this setting.

Levosimendan reduces cardiac troponin release after cardiac surgery: a meta-analysis of randomized controlled studies.

OBJECTIVES: The authors performed a meta-analysis to investigate the effects of levosimendan in cardiac surgery. Inotropic drugs have never shown beneficial effects on outcome in randomized controlled studies, with the possible exception of levosimendan. DESIGN: A meta-analysis. SETTING: Hospitals. PARTICIPANTS: A total of 139 patients from 5 randomized controlled studies were included in the analysis. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Four investigators independently searched BioMedCentral and PubMed. Inclusion criteria were random allocation to treatment, and comparison of levosimendan versus control performed on cardiac surgery patients. Exclusion criteria were duplicate publications, nonhuman experimental studies, and no outcome data. The endpoint was postoperative cardiac troponin release. Levosimendan was associated with a significant reduction in cardiac troponin peak release (weighted mean difference = 2.5 ng/dL [-3.86, -1.14], p = 0.0003) and in time to hospital discharge (weighted mean difference = -1.38 days [-2.78, 0.03], p = 0.05). No other relevant outcome (mortality, myocardial infarction, atrial fibrillation, time on mechanical ventilation, and intensive care unit stay) was improved in those patients receiving levosimendan. CONCLUSIONS: Levosimendan has cardioprotective effects, resulting in reduced postoperative cardiac troponin release.

Recombinant activated factor VII in cardiac surgery: a meta-analysis.

OBJECTIVE: Perioperative microvascular bleeding is associated with increased morbidity and mortality and could be reduced by hemostatic drugs such as recombinant activated factor VII (rFVIIa). Few trials have investigated rFVIIa and each individually lacked power to detect a beneficial effect on transfusion of blood products or thromboembolic side effects. DESIGN: Meta-analysis. SETTING: Hospitals. PARTICIPANTS: The authors performed a meta-analysis of 5 clinical trials (1 randomized, 3 propensity matched, and 1 case matched) that included 298 patients and indicated major clinical outcome (survival and thromboembolic events). INTERVENTIONS: Four of the 5 studies used rFVII in refractory blood loss. Doses varied between 17 and 70 microg/kg (repeatable) and 90 microg/kg for a single dose. MEASUREMENTS AND MAIN RESULTS: The authors observed a nonsignificant reduction in the rate of surgical re-exploration (10/76 [13%] in the rFVIIa group v 42/74 [57%] in the control group, odds ratio [OR] = 0.25 [0.01-7.01], p for effect = 0.42), with a trend toward an increase in the rate of perioperative stroke (8/150 [5%] in the rFVIIa v 2/148 [1.4%] in the control arm, OR = 3.17 [0.83-12.10], p = 0.09) and no effect on mortality that was similar in the 2 groups (22/150 [15%] in the rFVIIa group and 22/148 [15%] in the control group [OR = 0.96 (0.50-1.86), p for effect=0.90]). CONCLUSIONS: This analysis suggests that the hemostatic properties of rFVIIa could reduce the rate of surgical reexploration after cardiac surgery even if an increase of hazardous side effects (eg, perioperative stroke) could not be excluded. Because meta-analyses are hypothesis generating, this issue should be investigated further in large randomized controlled trials.

How to explain a PaO2 of 140 mmHg in a venous line?

Metformin is a commonly used oral antidiabetic drug which can cause lactic acidosis. Although rare, this condition carries a high mortality risk. Correction of metabolic acidaemia is essential for treatment and dialysis with bicarbonate replacement is the gold standard approach. A 53-year-old man with diabetes on metformin therapy was admitted to the intensive care unit with severe lactic acidosis and acute renal failure suggesting metformin intoxication. The lactic acidosis was treated with bicarbonate haemodialysis and his pH normalized after 10 hours, but he died because of myocardial infarction due to severe hypotension. At ICU admission an aortic dissection was also hypothesized but TEE did not evidence aortic dissection. The dilemma in this patient was represented by the abnormal PaO2 value (140 mmHg) in the venous blood gas analysis. Considering that metformin acts on mitochondrial respiration, the dilemma may be explained by hypothesizing a cellular respiration block caused by metformin or severe acidosis. (www.actabiomedica.it)