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Noonan syndrome (NS) is characterized by various abnormalities and is complicated with cardiac diseases, such as hypertrophic cardiomyopathy, in > 80% of cases. Minimum hemodynamic changes are a crucial factor during general anesthesia in such patients. We report the case of a patient with NS and hypertrophic obstructive cardiomyopathy (HOCM) who underwent general anesthesia using remimazolam, a new ultrashort-acting benzodiazepine anesthetic, which is expected to cause less circulatory depression. A 19-year-old woman with NS complicated with HOCM was scheduled to undergo extraction of the wisdom teeth and second molar under general anesthesia. Preoperative evaluation revealed HOCM with left ventricular outflow tract obstruction and the patient had chronic heart failure. After the placement of an arterial line under moderate sedation with remimazolam, general anesthesia was induced with remimazolam, fentanyl, and rocuronium, followed by anesthesia maintenance with remimazolam and remifentanil. Tracheal intubation was performed using videolaryngoscopy. Local anesthesia and inferior alveolar nerve block were performed using adrenaline-free local anesthetics. Intraoperatively, low-dose phenylephrine was administered continuously to maintain peripheral vascular resistance. At the end of surgery, the endotracheal tube was replaced with an i-gel® supraglottic airway device before emergence from general anesthesia. After full recovery from anesthesia, the i-gel® was removed, and the patient was transferred to the hospital ward. The perioperative blood pressure and heart rate were maintained within normal ranges, and no cardiovascular events occurred during anesthesia. Anesthesia management using remimazolam and low-dose phenylephrine with reduction in perioperative stress may provide an appropriate circulatory condition for noncardiac surgery in patients with HOCM. [ABSTRACT FROM AUTHOR]

Abstract Background The various autonomic control systems lead to characteristic changes in heart rate (HR) and blood pressure (BP) during acute hemorrhage. However, cardiovascular autonomic neuropathy due to diabetes mellitus may interfere with the normal compensation for hemorrhage. Materials and methods A controlled graded bleeding (6 - 36% loss of estimated total blood volume: ETBV) was performed in streptozotocin-induced diabetic rats (STZ rats) under a conscious state. Hemodynamic and autonomic responses to acute hemorrhage were examined using analysis of BP-HR variability. The effects of dextran treatment after hemorrhage were also examined. Results A significant reduction in mean arterial pressure began at 12% ETBV loss in STZ rats and 18% in the control rats, respectively. When blood loss reached 18% of TEBV, the decrease in HR was prominent in STD rats due to the activation of a parasympathetic drive, as indicated by the increase in high frequency (HF; 0.75~3.0 Hz) power in HR variability, while in the control rats this response was not observed. The administration of dextran prevented the activation of the parasympathetic drive in STZ rats during hemorrhaging. In the control rats, the dextran treatment sustained the initial increase in HR with reduced HF power in HR variability. Conclusion STZ rats showed different hemodynamic and autonomic responses to acute hemorrhage from the control rats. STZ rats were prone to develop bradycardiac hypotension characterized by marked parasympathetic activation during hemorrhaging. This finding suggests enhancement of the Bezold-Jarisch reflex in STZ rats. Dextran treatment to maintain a normovolemic hemorrhage state inhibits this reflex.

This study aimed to investigate the occurrence of subpontic tissue enlargement (STE) beneath a mandibular fixed partial denture. A 55-year-old Japanese woman received periodontal therapy and cross-arch fixed partial dentures were placed in the maxilla and mandible. After 18 years, STE developed in the left posterior region of the mandible. It was presumed that biomechanical loading in the mandible, along with other factors, might have caused the STE in this particular patient. [ABSTRACT FROM AUTHOR]