Ten pitfalls in the proper management of patients with hyponatremia

Hyponatremia (serum sodium <135 mEq/L) is a common electrolyte disorder in community or hospitalized patients. Serum sodium levels should be corrected at a proper rate in patients with hyponatremia, since overcorrection of serum sodium levels is related to devastating neurologic consequences, such as the osmotic demyelination syndrome (ODS). However, a number of pitfalls, which could lead to undercorrection or overcorrection of hyponatremia, are common during the treatment of hyponatremic patients. Hereby, we describe ten common pitfalls that are observed during the correction of serum sodium concentration in hyponatremic patients. These refer to pitfalls in the goals and limits of the correction rate of serum sodium, pitfalls in the means (e.g. solutions but also drugs) and formulas used for achieving the desired correction rate and pitfalls associated with inadequate management or overcorrection. The knowledge of these common-in-clinical-practice pitfalls could assist clinicians in the proper management of patients with hyponatremia.     

Safety considerations with fenofibrate/simvastatin combination

Introduction: Fenofibrate/simvastatin combination is useful for patients with mixed dyslipidemia. Aim of this review is to critically present the safety aspects of the fenofibrate/simvastatin combination.

Areas covered: Current evidence regarding the adverse effects of fenofibrate/simvastatin combination is critically presented based on the results of large randomized controlled trials and other relevant studies. Additionally, clinical pharmacology, drug interactions and the effects of fenofibrate and simvastatin on metabolic variables and cardiovascular risk are briefly described.

Expert opinion: Large randomized clinical trials show that the combined administration of fenofibrate with simvastatin is not associated with significantly increased incidence of serious adverse events compared with simvastatin monotherapy. The incidence of rhabdomyolysis is slightly increased with fibrate/statin combination compared with monotherapy but the actual risk is very low. Although fenofibrate increases creatinine and homocysteine serum levels, the incidence of diabetic nephropathy and thrombotic events was not significantly increased with fenofibrate/simvastatin combination compared with simvastatin monotherapy in the Action to Control Cardiovascular Risk in Diabetes (ACCORD) Lipid trial. Furthermore, a decrease in albuminuria was observed with fenofibrate in the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) and ACCORD Lipid trials. Overall, the combined administration of fenofibrate with simvastatin appears to be safe, unless clinicians give fenofibrate/simvastatin combination to patients with predisposing risk factors for the occurrence of adverse events.     

Adverse Effects of GLP-1 Receptor Agonists

Glucagon-like peptide-1 (GLP-1) receptor agonists are a class of injective anti-diabetic drugs that improve glycemic control and many other atherosclerosis-related parameters in patients with type 2 diabetes (T2D). However, the use of this relatively new class of drugs may be associated with certain adverse effects. Concerns have been expressed regarding the effects of these drugs on pancreatic and thyroid tissue, since animal studies and analyses of drug databases indicate an association of GLP-1 receptor agonists with pancreatitis, pancreatic cancer, and thyroid cancer. However, several meta-analyses failed to confirm a cause-effect relation between GLP-1 receptor agonists and the development of these adverse effects. One benefit of GLP-1 receptor agonists is that they do not cause hypoglycemia when combined with metformin or thiazolidinediones, but the dose of concomitant sulphonylurea or insulin may have to be decreased to reduce the risk of hypoglycemic episodes. On the other hand, several case reports have linked the use of these drugs, mainly exenatide, with the occurrence of acute kidney injury, primarily through hemodynamic derangement due to nausea, vomiting, and diarrhea. The most common symptoms associated with the use of GLP-1 receptor agonists are gastrointestinal symptoms, mainly nausea. Other common adverse effects include injection site reactions, headache, and nasopharyngitis, but these effects do not usually result in discontinuation of the drug. Current evidence shows that GLP-1 receptor agonists have no negative effects on the cardiovascular risk of patients with T2D. Thus, GLP-1 receptor agonists appear to have a favorable safety profile, but ongoing trials will further assess their cardiovascular effects. The aim of this review is to analyze critically the available data regarding adverse events of GLP-1 receptor agonists in different anatomic systems published in Pubmed and Scopus. Whenever possible, certain differences between GLP-1 receptor agonists are described. The review also provides the reader with structured data that compare the rates of the most common adverse effects for each of the various GLP-1 receptor agonists.     

(14)C-lidocaine disposition in serum and tissues of normal and liver diseased rats.

PURPOSE: This study was designed to investigate the disposition of (14)C-lidocaine in serum and tissues in rats with liver dysfunction. MATERIALS AND METHODS: Eighteen male rats were randomly divided into 2 groups. Group A was considered as control while group B underwent liver damage by administrating CCl(4) 0.4 mg/kg twice a week for 6 weeks. Both groups received 5 doses of 2.5 mg/kg lidocaine mixture (labeled (14)C-lidocaine and nonlabeled). The rats were killed 2 hours after the last dose. Total lidocaine levels ((14)C-lidocaine and (14)C-lidocaine metabolite concentrations) as well as the percent of total lidocaine-bound fractions in tissues were measured. RESULTS: (14)C-lidocaine concentrations were significantly increased in the serum (9.4+/-0.4 microg/mL), heart (7.8+/-2 microg/gL), and mandible (0.97+/-0.01 microg/g) in diseased rats as compared with normal rats (serum, 5.3+/-1.7 microg/mL; heart, 4.2+/-0.9 microg/g; mandible, 0.68+/-0.02 microg/g, respectively). (14)C-lidocaine bound fractions in the mandible and heart did not show any significant differences between the 2 groups. Instead, (14)C-lidocaine bound fractions in serum were significantly reduced in diseased animals as opposed to normal ones. CONCLUSION: We concluded that liver dysfunction can modify (14)C-lidocaine concentrations in the serum and tissues without altering the lidocaine binding properties in the mandible and heart.     

Intraoperative TTE inferior vena cava monitoring in elderly orthopaedic patients with cardiac disease and spinal-induced hypotension

Objective To address the role of transthoracic echocardiography in inferior vena cava (IVC) monitoring in the management of haemodynamically unstable elderly patients subjected to lower limb orthopaedic surgery under spinal anesthesia. Possible implications in the postoperative care unit (PACU) length of stay (LOS) are investigated. Methods 41 elderly patients with cardiac diseases were recruited. Patients experiencing intraoperative haemodynamic instability (diastolic blood pressure ≤ 60 mmHg) were divided into two groups according to right atrial pressure (RAP), (RAP < 5 mmHg and RAP between 5 and 10 mmHg) as measured by inferior vena cava collapsibility index (IVCCI). Haemodynamic instability was treated with normal saline infused at a constant rate supplemented by phenylephrine (PHE) infusions titrated to normal blood pressure values. Intraoperatively comparisons of peak PHE infusion rates and all episodes of hypotension, including in the PACU, were recorded among groups. The patients’ PACU LOS and associated factors were assessed. Results The intraoperative peak PHE infusion rate and the incidence of haemodynamic instability in the postoperative period were significantly higher in patients with RAP < 5 mmHg. The total PHE consumption was also higher in patients with RAP < 5 mmHg postoperatively. The primary risk factor for a prolonged stay in PACU, as determined by multiple regression analysis was RAP. Conclusions Patients with high dynamic collapsibility of the IVC may require aggressive treatment to restore their haemodynamic status. Additionally, intraoperative levels of RAP, as measured by IVCCI, can act as a predictor for increased LOS in the PACU.     

1-Year All-Comers Analysis of the Eluvia Drug-Eluting Stent for Long Femoropopliteal Lesions After Suboptimal Angioplasty

Objectives

The aim of this study was to assess the performance of the fluoropolymer-based paclitaxel-eluting stent (PES) in long femoropopliteal lesions.

PEDICLED MYOCUTANEOUS AND MUSCLE FLAPS IN THE MANAGEMENT OF COMPLICATED CARDIOTHORACIC PROBLEMS

The purpose of this study was to review our experience with the management of patients with complicated cardiothoracic problems by the use of pedicled myocutaneous or muscle flaps, and discuss the various methods of reconstruction. Over the last 11 years, we have treated 54 patients with complicated cardiothoracic problems by reconstruction with pedicled myocutaneous or muscle flaps. The underlying causes were chest wall tumours (n?=?13), radionecrosis of the chest wall (n?=?12), deep or chronic sternal infections (n?=?25), and bronchopleural fistulas (n?=?4). The most commonly used muscles for reconstruction were pectoralis major and the rectus abdominis. Our results compare favourably with those reported elsewhere. We conclude that although the use of pedicled myocutaneous or muscle flaps is not free of complications, it is an effective and reliable method for the management of patients with complicated cardiothoracic problems.     

High density lipoprotein and cardiovascular diseases

Several epidemiological studies have clearly shown that low plasma levels of high density lipoprotein cholesterol (HDL-C) represent a cardiovascular disease (CVD) risk factor. However, it is unclear if there is a causal association between HDL-C concentration and CVD. A recent study published in the Lancet, which performed two Mendelian randomization analyses, showed that increased HDL-C levels were not associated with a decreased risk of myocardial infarction. These findings, together with the termination of the niacin-based AIM-HIGH trial and the discontinuation of cholesteryl ester transfer protein inhibitor dalcetrapib, challenge the concept that raising of plasma HDL-C will uniformly translate into reductions in CVD risk. HDL particles exhibit several anti-atherosclerotic properties, such as anti-inflammatory and anti-oxidative activities and cellular cholesterol efflux activity. Furthermore, HDL particles are very heterogeneous in terms of size, structure, composition and metabolism. HDL functionality may be associated more strongly with CVD risk than the traditional HDL-C levels. More research is needed to assess the association of the structure of HDL particle with its functionality and metabolism.     

Ultrasound anatomy of the cervical paravertebral space: a preliminary study

Purpose  

The aim of the study was to examine the ultrasound anatomy of the cervical paravertebral space in order to facilitate the implementation of sonographically guided regional anesthesia techniques for this region.