Synchrony relationships between the left ventricle and a left ventricular assist device: an experimental study in pigs

Background: Synchronization between the left ventricle and a left ventricular assist device (LVAD) may be important for ventricular unloading and coronary perfusion. We assessed the synchrony between cardiac and LVAD cycles by increasing delays in steps of 100 msec throughout the cycle, under conditions of total and partial left ventricular support. Methods: We studied 7 healthy minipigs weighing 30-40 kg. A 60-cc Berlin Heart Excor LVAD was implanted and connected to a BCM 1200 console, making it possible to synchronize the LVAD systole and the EKG signal with a prefixed delay. We recorded hemodynamic parameters (including aortic, pulmonary, and left ventricular pressure) and LVAD flow for each delay. Results: Intraventricular pressure during LVAD systole was minimized with delays of around 40-80% of one cycle. In addition, total flow was higher under these conditions. Conclusions: This study shows that the synchronous mode of LVAD operation is feasible. Moreover, a delay in device contraction until the second half of the cardiac cycle optimizes ventricular unloading and may eventually improve myocardial recovery.     

Consensus Report of the XI Congress of the Spanish Society of Odontology for the Handicapped and Special Patients

This article summarizes the findings of consensus of the XI congress of the SEOEME. All of these conclusions are referring to the review articles responsible to the general rapporteurs in order to bringing up to date knowledge with regard to the use of implants in patients medically compromised and with special needs and, in the dental management of autism and cerebral palsy, in the dental treatment of patients with genetic and adquired haematological disorders, the dental implications of cardiovascular disease and hospital dentistry. Key words:Autism, cardiovascular diseases, cerebral palsy, dental implants, disabled patients, haematological disorders, hospital dentistry.     

Cannabinoid hyperemesis syndrome: potential mechanisms for the benefit of capsaicin and hot water hydrotherapy in treatment

Introduction: Cannabinoid hyperemesis syndrome is a clinical disorder that has become more prevalent with increasing use of cannabis and synthetic cannabinoids, and which is difficult to treat. Standard antiemetics commonly fail to alleviate the severe nausea and vomiting characteristic of the syndrome. Curiously, cannabinoid hyperemesis syndrome patients often report dramatic relief of symptoms with hot showers and baths, and topical capsaicin.

Objectives: In this review, we detail the pharmacokinetics and pharmacodynamics of capsaicin and explore possible mechanisms for its beneficial effect, including activation of transient receptor potential vanilloid 1 and neurohumoral regulation. Putative mechanisms responsible for the benefit of hot water hydrotherapy are also investigated.

Methods: An extensive search of PubMed, OpenGrey, and Google Scholar from inception to April 2017 was performed to identify known and theoretical thermoregulatory mechanisms associated with the endocannabinoid system. The searches resulted in 2417 articles. These articles were screened for relevant mechanisms behind capsaicin and heat activation having potential antiemetic effects. References from the selected articles were also hand-searched. A total of 137 articles were considered relevant and included.

Capsaicin: Topical capsaicin is primarily used for treatment of neuropathic pain, but it has also been used successfully in some 20 cases of cannabinoid hyperemesis syndrome. The pharmacokinetics and pharmacodynamics of capsaicin as a transient receptor potential vanilloid 1 agonist may explain this effect. Topical capsaicin has a longer half-life than oral administration, thus its potential duration of benefit is longer.

Capsaicin and transient receptor potential vanilloid 1: Topical capsaicin binds and activates the transient receptor potential vanilloid 1 receptor, triggering influx of calcium and sodium, as well as release of inflammatory neuropeptides leading to transient burning, stinging, and itching. This elicits a novel type of desensitization analgesia. Transient receptor potential vanilloid 1 receptors also respond to noxious stimuli, such as heat (>43?°C), acids (pH <6), pain, change in osmolarity, and endovanilloids. The action of topical capsaicin may mimic the effect of heat-activation of transient receptor potential vanilloid 1.

Endocannabinoid system and transient receptor potential vanilloid 1: Cannabinoid hyperemesis syndrome may result from a derangement in the endocannabinoid system secondary to chronic exogenous stimulation. The relief of cannabinoid hyperemesis syndrome symptoms from heat and use of transient receptor potential vanilloid 1 agonists suggests a complex interrelation between the endocannabinoid system and transient receptor potential vanilloid 1.

Temperature regulation: Hot water hydrotherapy is a mainstay of self-treatment for cannabinoid hyperemesis syndrome patients. This may be explained by heat-induced transient receptor potential vanilloid 1 activation.

“Sensocrine” antiemetic effects: Transient receptor potential vanilloid 1 activation by heat or capsaicin results in modulation of tachykinins, somatostatin, pituitary adenylate-cyclase activating polypeptide, and calcitonin gene-related peptide as well as histaminergic, cholinergic, and serotonergic transmission. These downstream effects represent further possible explanations for transient receptor potential vanilloid 1-associated antiemesis.

Conclusions: These complex interactions between the endocannabinoid systems and transient receptor potential vanilloid 1, in the setting of cannabinoid receptor desensitization, may yield important clues into the pathophysiology and treatment of cannabinoid hyperemesis syndrome. This knowledge can provide clinicians caring for these patients with additional treatment options that may reduce length of stay, avoid unnecessary imaging and laboratory testing, and decrease the use of potentially harmful medications such as opioids.     

Preoperative factors influencing success in pterygium surgery

ABSTRACT: BACKGROUND: To identify preoperative, perioperative and postoperative risk factors that influence the success of pterygium surgery. METHODS: This is a prospective study of thirty-six patients with primary or recurrent pterygia. A detailed anamnesis and an ophthalmological examination were performed looking for the following factors: age, race, latitude and altitude of the main place of residence, hours of exposure to the sun, use of protective measures against UV-radiation, classification of pterygium, width of the pterygium at limbus, surgical technique (conjunctival autograft plus suturing versus tissue glue), graft alterations (misapposition, granuloma, haemorrhage, oedema, retraction or necrosis), and postoperative symptoms (foreign-body sensation, pain). The examinations were performed 2 and 7 days and 2, 6 and 12 months after surgery. In addition, recurrence was defined as any growth of conjunctiva into the cornea. RESULTS: A Logistic regression and a survival analysis have been used to perform data analysis. A total number of 36 patients completed a one year follow-up. A total of 13 patients were born and lived in Spain, and 26 came from other countries, mostly Latin America. A total number of 8 males (no women) presented a recurrence, mainly between 2 and 6 months. The hours of sun exposure throught their life was independently related to surgical success. Pterygia of less than 5 mm of base width showed a weak positive correlation with recurrence. None of the other factors considered were significantly related to recurrence. CONCLUSIONS: Male gender and high sun exposure are strongly and independently related to surgical success after the removal of pterygia. KEYWORDS: risk factors, sunlight exposure, pterygium surgery, conjunctival autograft .