Luca Lorini

Epidural anesthesia and analgesia decrease the postoperative incidence of insulin resistance in preoperative insulin-resistant subjects only

BACKGROUND:Insulin resistance (IR) is a feature of the endocrine stress response to surgery. It is not known whether a preoperative state of IR would affect the postoperative endocrine response. We sought to characterize the preoperative state of IR in a group of patients undergoing elective hip and knee arthroplasty, and to determine to what extent perioperative epidural analgesia modifies the postoperative state of IR in those who are and are not insulin-resistant before surgery. METHODS:Sixty patients undergoing either hip or knee arthroplasty were screened by using the homeostatic model assessment (HOMA) in two populations: insulin-resistant patients and noninsulin-resistant patients, whereas HOMA is fasting insulin (&mgr;U/mL) × fasting glucose (mmol/L)/22.5. The patients belonging to each population were then randomly assigned to receive either intraoperative epidural blockade followed by postoperative epidural analgesia (epidural group) or general anesthesia followed by patient-controlled analgesia (control group). Analgesia was assessed with visual analog scale up to 48 h after surgery and HOMA was repeated at the end of surgery and 48 h after surgery to determine the postoperative state of IR. RESULTS:Epidural anesthesia and analgesia significantly influenced the postoperative HOMA score (smaller proportion of IR) in the postoperative period only in those patients who were insulin-resistant before surgery (P < 0.01). In contrast, noninsulin-resistant patients had a similar postoperative proportion of IR between the epidural and control groups (P > 0.05). At rest and during movement, visual analog scale scores were not different between groups at the end of surgery and in the first and second days after surgery. CONCLUSIONS:Epidural anesthesia and analgesia compared to general anesthesia followed by patient-controlled analgesia decreased the incidence of IR soon after surgery and 48 h after surgery only in patients who were insulin-resistant before surgery.

Preoperative insulin resistance and the impact of feeding on postoperative protein balance: a stable isotope study.

CONTEXT Major surgery induces a catabolic state resulting in a net loss of body protein. OBJECTIVES Our objective was to compare protein metabolism before and after surgery in nondiabetic patients with and without preoperative insulin resistance (IR). It was hypothesized that the anabolic response to feeding would be significantly impaired in those patients with preoperative insulin resistance. DESIGN A hyperinsulinemic-euglycemic clamp has been used to identify two groups of patients: IR and insulin sensitive (IS). A tracer kinetics technique has been used to evaluate the metabolic response to food intake in both groups. SETTING Patients undergoing cardiopulmonary bypass participated. PATIENTS OR OTHER PARTICIPANTS Ten IS patients and 10 IR patients were enrolled in the study. INTERVENTION After an overnight fasting, a 3-h infusion of a solution composed of 20% glucose and of amino acids at a rate of 0.67 and 0.44 kcal/kg · h, respectively, was started in each group. Phenylalanine kinetics were studied at the end of fasting and feeding. MAIN OUTCOME MEASURE Effect of feeding on protein balance before and after surgery was evaluated. Protein balance has been measured as the net difference of protein breakdown minus protein synthesis. RESULTS Protein balance increase after postoperative feeding was blunted only in the IR group. In contrast, in the IS group, the postoperative anabolic effect of feeding was the same as before surgery. CONCLUSIONS These findings propose a link between insulin resistance and protein metabolism. When non-IR patients are fed, a significant anabolic effect in the postoperative period is demonstrated. In contrast, IR patients are less able to use feeding for synthetic purposes.

Systolic anterior motion after mitral valve repair: myectomy as an alternative solution

by systolic anterior motion (SAM) of the mitral apparatus. 1 Correction of postrepair SAM is first medical: -blockers and calcium-channel blockers might be of some help in reducing left ventricular contractility. However, when a severe LVOT obstruction develops, a more aggressive approach is generally needed. In some cases obstruction of the LVOT disappears after removing the prosthetic ring; in other cases mitral valve replacement is necessary. When a hypertrophic septum is suspected to be a contributing factor leading to obstruction of the LVOT, a possible solution might be to perform a septal myectomy. Here we describe 2 cases of postrepair LVOT obstruction that were successfully treated by means of a transaortic septal myectomy in patients with no preoperative obstruction of the LVOT.

Twenty‐four hour hyperinsulinemic‐euglycemic clamp improves postoperative nitrogen balance only in low insulin sensitivity patients following cardiac surgery

Critically ill patients often suffer from a protein catabolic state. The aim of this study was to demonstrate that nitrogen balance (NB) in cardiac patients admitted to the intensive care unit (ICU) is related to their insulin sensitivity level and that supraphysiologic doses of insulin can restore anabolism.

Coronary pathology of inherited generalized arterial calcification of infancy: a case report

Generalized arterial calcification of infancy (GACI), or idiopathic infantile arterial calcification, is a rare autosomal-recessive disease recognized aAs an inherited disorder characterized by severe pathologic calcification of large- and medium-sized arteries accompanied by smooth muscle cell (SMC) hyperplasia leading to vascular obstruction [1]. The prognosis is extremely poor, with 85% of affected infants dying within the first 6 months of life. Loss-of-function mutations in the ectonucleotide pyrophosphatase phosphodiesterase 1 (ENPP1) gene is recognized as the main defect associated with GACI [1]. The underlying pathogenesis of osteogenic transition leading to calcification and severe stenosis in GACI, however, is poorly understood. Herein, we present a case of a GACI patient with cardiac complications who exhibited extensive vascular disease at autopsy.