Long-chain versus medium-chain lipids in acute pancreatitis complicated by acute respiratory distress syndrome: effects on pulmonary hemodynamics and gas exchange.

BACKGROUND AND AIMS: In order to assess the effects of fat emulsions in patients with acute pancreatitis and acute respiratory distress syndrome (ARDS) before the pancreatic injury was complicated by infection, pulmonary hemodynamics and gas exchange were investigated during the administration of long-(LCTs) or medium-chain triacylglycerols (MCTs). METHODS: This prospective trial included nine patients with acute pancreatitis and ARDS; each patient was used as his/her own control. In all cases, the needle aspiration culture of the pancreas was negative. Fat emulsion provided 50% of the energy expenditure. The patients were infused, in random order, with pure LCTs and a 1:1 mixture of LCTs/MCTs on days 1 and 2, over an 8 h period. RESULTS: LCT infusion increased the mean pulmonary artery pressure (MPAP) from 28+/-5 to 35+/-3 mmHg, pulmonary venous admixture (Qva/Qt) from 26+/-5% to 36+/-5% and decreased arterial PO2(PaO2)/fractional inspired oxygen (FIO2) from 210+/-20 to 170+/-20 (P<0.05). The infusion of LCT/MCT 1:1 emulsions increased oxygen consumption (VO2) from 340+/-10 to 398+/-15 ml/min, cardiac output (CO) from 8.8+/-0.2 to 9.5+/-0.5 L/min and CO2 production (VCO2) from 247+/-12 to 282+/-14 mL/min (P<0.05). CONCLUSION: LCT/MCT 1:1 mixtures are recommended in cases of acute pancreatitis and ARDS, even though infusion over a short period increases the metabolic demand.

Comparative results of staged and simultaneous bilateral carotid endarterectomy: a clinical study and surgical treatment.

OBJECTIVE: Bilateral carotid stenoses are actually managed by staged endarterectomy. The present study compares the results of the above surgical procedure with simultaneous bilateral carotid endarterectomy. METHODS: Sixty-four carotid endarterectomies were carried out on two groups of thirty-two patients with bilateral carotid stenoses. Fifteen patients (group A) were subjected to staged and 17 patients (group B) who were subjected to simultaneous bilateral carotid endarterectomies. RESULTS: The mortality rate was zero in both groups; no statistically significant difference was found concerning complications related to the heart, neurological deficit and postoperative hypertension. CONCLUSIONS: Simultaneous carotid endarterectomy is a challenging and technically demanding operation but with limited indications in strictly selected patients. The development of methods of more effective monitoring and protection of the cerebral cells might broaden the indications of such a surgical tactic in the future. Staged carotid endarterectomy, however, remains the method of choice for the management of bilateral carotid occlusive disease.

Incidence of vein thrombosis in peripheral intravenous nutrition: effect of fat emulsions.

The relative risk of thrombophlebitis induced by either Long-chain Triglycerides (LCTs) or Medium-chain Triglycerides (MCTs) during peripheral i.v. nutrition (PIN) was evaluated. A total of 76 patients were randomly assigned into group A (n=40) and group B (n=36). The nutritional requirements in both groups were covered by a standardized regime of osmolality 1130 mOsm and pH 5.2, which provided 14 kg/day(-1) nitrogen, 600 kcal/day(-1) of carbohydrates and 1000 kcal/day(-1) of lipids. Group A received the lipids as pure LCTs while group B received a mixture of LCTs/MCTs at a ratio 1:1. The infused nutritional volume was 2000 ml and was delivered via a suitable vein in a proximal forearm, using a fine bore polyurethane 22G catheter. The two standardized regimes were evaluated over a 10 day period regarding the incidence of thrombophlebitis. The cumulative risk of thrombophlebitis was documented to be significantly lower in group A compared to group B (17.5% versus 44.4%, P < 0.05). LCTs appear to prolong peripheral vein feeding by lessening the reaction of venous endothelium to the irritating nutritional infusate.

Postcarotid endarterectomy symptoms. Pre- and postoperative clinical and MRI findings.

BACKGROUND: The hyperperfusion syndrome represents a highly debated clinical entity, without having yet any clinically identifiable limits. The correlation of clinical with pre- and postoperative magnetic resonance imaging (MRI) findings following carotid endarterectomy in patients with a possible hyperperfusion syndrome was investigated. DESIGN: Prospective clinical and laboratory study. SETTING: At the Aretaieio University Hospital. MEASURES: Comparison to the postoperative clinical symptomatic and MRI findings. Patients. We studied 30 patients (mean age 66.6) of whom 14 (46.6%) were asymptomatic, 16 (53.4%) were symptomatic, 17 (56.6%) were hypertensive, 18 (60%) hyperlipidaemic, 5 (16.6%) diabetic and 17 (56.6%) had coronary artery disease. RESULTS: Twenty-one patients (70%) exhibited disturbances such as ipsilateral headache, seizures, vomiting or facial pain; immediate postoperative MRI scans revealed new ischaemic foci in 4 (19%) without any objective neurological findings. Lesions displayed in postoperative MRI scans did not always cause symptoms and normal findings on MRI did not exclude the presence of symptoms. Hypertension favoured the presence of subjective disturbances, without necessarily any change in the MRI appearances. Preoperative MRI and clinical findings did not contribute to the identification of patients who might have exhibited postoperative symptoms. Thus, the symptomatology remains unclear and open to debate, as a variety of other conditions may produce the same clinical picture postoperatively. CONCLUSIONS: Subjective disturbances, objective neurological findings and MRI abnormalities with or without hypertension may appear independently after carotid endarterectomy, a fact which makes the pathogenesis of the hyperperfusion syndrome more difficult to elucidate.