Mallampati Class Zero airway: a narrative review.

INTRODUCTION: Mallampati Class Zero airway describes a visible epiglottis on pharyngoscopic view. It was first noted by Tobold A in 1869 and was proposed as a new class in modified Mallampati Classification by Ezri T. et al. We aim to summarize the current knowledge about Mallampati Class Zero airway and its implication on airway management. EVIDENCE ACQUISITION: We reviewed the reported studies about visible epiglottis on pharyngoscopy and 34 publications were selected. EVIDENCE SYNTHESIS: The diagnosis of Mallampati Class Zero airway is usually achieved as a casual finding during airway assessment of Mallampati Test, during a regular checkup at the dentist, or even after a medical consultation due to a suspected visualization of a foreign body at the back of the throat. Mallampati Class Zero airway has a low prevalence in the general population (prevalence of 0.7-1.7% of adults and 0.3-6% of children) and it is more frequent in children and female. The cause for this phenomenon is not well understood but in clinical practice it is associated with an easy airway. Interestingly, in the pediatric population with Mallampati class zero airway, the difficult airway has not been reported to date. CONCLUSIONS: Mallampati Class Zero is associated with an easy airway and it should be included as a different class in the modified Mallamapti classification, which would also contribute to its spread between professionals involved in the airway management and will favour increasing investigation and knowledge about it.

Renal and Neurologic Benefit of Levosimendan vs Dobutamine in Patients With Low Cardiac Output Syndrome After Cardiac Surgery: Clinical Trial FIM-BGC-2014-01.

BACKGROUND: Low-cardiac output syndrome (LCOS) after cardiac surgery secondary to systemic hypoperfusion is associated with a higher incidence of renal and neurological damage. A range of effective therapies are available for LCOS. The beneficial systemic effects of levosimendan persist even after cardiac output is restored, which suggests an independent cardioprotective effect. METHODS: A double-blind clinical trial was conducted in patients with a confirmed diagnosis of LCOS randomized into two treatment groups (levosimendan vs. dobutamine). Monitoring of hemodynamic (cardiac index, systolic volume index, heart rate, mean arterial pressure, central venous pressure, central venous saturation); biochemical (e.g. creatinine, S100B protein, NT-proBNP, troponin I); and renal parameters was performed using acute kidney injury scale (AKI scale) and renal and brain ultrasound measurements [vascular resistance index (VRI)] at diagnosis and during the first 48 h. RESULTS: Significant differences were observed between groups in terms of cardiac index, systolic volume index, NT-proBNP, and kidney injury stage at diagnosis. In the levosimendan group, there were significant variations in AKI stage after 24 and 48 h. No significant differences were observed in the other parameters studied. CONCLUSION: Levosimendan showed a beneficial effect on renal function in LCOS patients after cardiac surgery that was independent from cardiac output and vascular tone. This effect is probably achieved by pharmacological postconditioning. CLINICAL TRIAL REGISTRATION: EUDRA CT, identifier 2014-001461-27. https://www.clinicaltrialsregister.eu/ctr-search/search?query=2014-001461-27.

Anesthesia in Combination with Propofol Increases Disease-Free Survival in Bladder Cancer Patients Who Undergo Radical Tumor Cystectomy as Compared to Inhalational Anesthetics and Opiate-Based Analgesia.

BACKGROUND: The effect of anesthetic techniques on cancer recurrence has been the subject of intensive research in the past years, as it affects a large proportion of the population. The use of opioids and halogenated agents in cancer patients during the perioperative period may be related to higher rates of cancer recurrence and reduced disease-free survival. METHODS: This was a prospective study. The sample was composed of 100 patients who underwent a radical cystectomy for infiltrating bladder cancer in a reference center. We compared disease-free survival associated with combined anesthesia versus opiate-based analgesia. The relationship between the administered hypnotic and disease-free survival was also investigated. RESULTS: The median disease-free survival of the patients who received combined anesthesia was 585 (240-1,005) days versus 210 (90-645) days in the other group. A significant difference was observed between the two groups (p = 0.01). Combined analysis of all groups revealed significant differences in disease-free survival between patients who received combined anesthesia with propofol (510 [315-1,545] disease-free days) and those who received sevoflurane and opioids (150 [90-450] disease-free days) (p = 0.02). CONCLUSIONS: Anesthesia may play a crucial role in tumor relapse, as it is administered at the moment of the greatest risk of dissemination: surgical handling of the tumor. Opioids and volatile agents have been related to an increased risk for cancer recurrence. We compared the use of propofol + local anesthesia versus sevoflurane + opioids and also found that disease-free survival was longer among patients who received propofol + local anesthesia. Disease-free survival increases with the use of propofol in combination with epidural anesthesia in patients who undergo surgery for infiltrating bladder cancer.

Anesthetic-induced Myocardial Conditioning: Molecular Fundamentals and Scope.

BACKGROUND: The pre- and post-conditioning effects of halogenated anesthetics make them most suitable for cardiac surgery. Several studies have demonstrated that the mechanism of drug-induced myocardial conditioning is enzyme-mediated via messenger RNA and miRNA regulation. The objective of this study was to investigate the role that miRNAs play in the cardioprotective effect of halogenated anesthetics. For such purpose, we reviewed the literature to determine the expression profile of miRNAs in ischemic conditioning and in the complications prevented by these phenomena. METHODS: A review was conducted of more than 100 studies to identify miRNAs involved in anesthetic-induced myocardial conditioning. Our objective was to determine the miRNAs that play a relevant role in ischemic disease, heart failure and arrhythmogenesis, which expression is modulated by the perioperative administration of halogenated anesthetics. So far, no studies have been performed to assess the role of miRNAs in anesthetic-induced myocardial conditioning. The potential of miRNAs as biomarkers and miRNAs-based therapies involving the synthesis, inhibition or stimulation of miRNAs are a promising avenue for future research in the field of cardiology. RESULTS: Each of the cardioprotective effects of myocardial conditioning is related to the expression of several (not a single) miRNAs. The cumulative evidence on the role of miRNAs in heart disease and myocardial conditioning opens new therapeutic and diagnostic opportunities. CONCLUSION: Halogenated anesthetics regulate the expression of miRNAs involved in heart conditions. Further research is needed to determine the expression profile of miRNAs after the administration of halogenated drugs. The results of these studies would contribute to the development of new hypnotics for cardiac surgery patients.

Cardioprotection with halogenated gases: how does it occur?

Numerous studies have studied the effect of halogenated agents on the myocardium, highlighting the beneficial cardiac effect of the pharmacological mechanism (preconditioning and postconditioning) when employed before and after ischemia in patients with ischemic heart disease. Anesthetic preconditioning is related to the dose-dependent signal, while the degree of protection is related to the concentration of the administered drug and the duration of the administration itself. Triggers for postconditioning and preconditioning might have numerous pathways in common; mitochondrial protection and a decrease in inflammatory mediators could be the major biochemical elements. Several pathways have been identified, including attenuation of NFκB activation and reduced expression of TNFα, IL-1, intracellular adhesion molecules, eNOS, the hypercontraction reduction that follows reperfusion, and antiapoptotic activating kinases (Akt, ERK1/2). It appears that the preconditioning and postconditioning triggers have numerous similar paths. The key biochemical elements are protection of the mitochondria and reduction in inflammatory mediators, both of which are developed in various ways. We have studied this issue, and have published several articles on cardioprotection with halogenated gases. Our results confirm greater cardioprotection through myocardial preconditioning in patients anesthetized with sevoflurane compared with propofol, with decreasing levels of troponin and N-terminal brain natriuretic peptide prohormone. The difference between our studies and previous studies lies in the use of sedation with sevoflurane in the postoperative period. The results could be related to a prolonged effect, in addition to preconditioning and postconditioning, which could enhance the cardioprotective effect of sevoflurane in the postoperative period. With this review, we aim to clarify the importance of various mechanisms involved in preconditioning and postconditioning with halogenated gases, as supported by our studies.