Ultrasound mapping of soft tissue vascular anatomy proximal to the larynx: a prospective cohort study.

Background: Bleeding incidents during percutaneous dilatational tracheostomy are concerning, and most cases occur in patients with unrecognized and unanticipated anatomical variations in the vascular anatomy. However, the extent of this variation remains unclear. To address this knowledge gap, our study aimed to comprehensively map laryngeal vascular anatomy in a cohort of adult patients. Methods: Ultrasound assessments of the soft tissue in the neck were performed, spanning from the thyroid cartilage to the third tracheal ring and extending 2 cm laterally on both sidesperformed. We subdivided this area into 12 zones comprising four medial and eight lateral sections. A pre-planned form was used to document the presence of arteries or veins in each zone. The results are reported as odds ratios, 95% CIs, and corresponding P-values. Results: Five-hundred patients were enrolled from August 14, 2023, to November 13, 2023, at the University Hospital of Padua. Arteries and veins were identified in all investigated zones (varying from a minimum of 1.0%-46.4%). The presence of invessels progressively increased from the cricothyroid membrane to the third tracheal ring and from the midline to the paramedian laryngeal area. Conclusions: Given the prevalence of arteries and veins, particularly in areas where tracheostomies are commonly performed, we strongly advocate for routine ultrasound assessments before such procedures are performed.

Preoperative dexmedetomidine and intraoperative bradycardia in laparoscopic cholecystectomy: a meta-analysis with trial sequential analysis.

BACKGROUND: While laparoscopic surgical procedures have various advantages over traditional open techniques, artificial pneumoperitoneum is associated with severe bradycardia and cardiac arrest. Dexmedetomidine, an imidazole derivative that selectively binds to α2-receptors and has sedative and analgesic properties, can cause hypotension and bradycardia. Our primary aim was to assess the association between dexmedetomidine use and intraoperative bradycardia during laparoscopic cholecystectomy. METHODS: We performed a systematic review with a meta-analysis and trial sequential analysis using the following PICOS: adult patients undergoing endotracheal intubation for laparoscopic cholecystectomy (P); intravenous dexmedetomidine before tracheal intubation (I); no intervention or placebo administration (C); intraoperative bradycardia (primary outcome), intraoperative hypotension, hemodynamics at intubation (systolic blood pressure, mean arterial pressure, heart rate), dose needed for induction of anesthesia, total anesthesia requirements (both hypnotics and opioids) throughout the procedure, and percentage of patients requiring postoperative analgesics and experiencing postoperative nausea and vomiting and/or shivering (O); randomized controlled trials (S). RESULTS: Fifteen studies were included in the meta-analysis (980 patients). Compared to patients that did not receive dexmedetomidine, those who did had a higher risk of developing intraoperative bradycardia (RR: 2.81, 95% CI [1.34, 5.91]) and hypotension (1.66 [0.92,2.98]); however, they required a lower dose of intraoperative anesthetics and had a lower incidence of postoperative nausea and vomiting. In the trial sequential analysis for bradycardia, the cumulative z-score crossed the monitoring boundary for harm at the tenth trial. CONCLUSIONS: Patients undergoing laparoscopic cholecystectomy who receive dexmedetomidine during tracheal intubation are more likely to develop intraoperative bradycardia and hypotension.

Effect of dexmedetomidine on hemodynamic responses to tracheal intubation: A meta-analysis with meta-regression and trial sequential analysis.

STUDY OBJECTIVE: An uncontrolled adrenergic response during tracheal intubation may lead to life-threatening complications. Dexmedetomidine binds to α2-receptors and may attenuate this response. The primary aim of our meta-analysis is to investigate dexmedetomidine efficacy in attenuating sympathetic response to tracheal intubation, compared with placebo or no dexmedetomidine, in terms of heart rate and blood pressure at intubation. DESIGN: Meta-analysis with meta-regression and trial sequential analysis. SETTING: Systematic search from inception until December 1, 2020 in the following databases: Pubmed, Scopus, the Cochrane Central Register of Controlled Trials, EMBASE and Google Scholar. INTERVENTIONS: All randomized controlled trials investigating intravenous dexmedetomidine as premedication in adult patients undergoing tracheal intubation were included in our study. Studies were included without any language or publication date restriction. A trial sequential analysis and a post-hoc meta-regression were performed on the main outcomes. MEASUREMENTS: Hemodynamic parameters and heart rate at tracheal intubation, dose of anesthetic needed for induction of anesthesia, total anesthetic requirement throughout the operative procedure, postoperative pain and percentage of patients requiring analgesics at 24 postoperative hours, postoperative nausea and vomiting, intraoperative and postoperative bradycardia, hypotension, dizziness, shivering and/or respiratory depression. MAIN RESULTS: Ninety-nine included studies randomized 6833 patients. During laryngoscopy, all hemodynamic parameters were significantly greater in the no dexmedetomidine group. In particular, in the dexmedetomidine group, systolic blood pressure differed by -21.8 mm Hg (95% CI -26.6 to -17.1, p-value < 0.001, I2 97%), mean arterial pressure by -12.8 mm Hg (95% CI -15.6 to -10.0, p-value < 0.001, I2 98%), and heart rate by -16.9 bpm (95% CI -19.8 to -13.9, p-value < 0.001, I2 98%). CONCLUSIONS: Patients receiving premedication with dexmedetomidine for tracheal intubation, compared with no dexmedetomidine, have a lower blood pressure and heart rate, however, the risk of bradycardia and hypotension is relevant and its use during daily practice should be cautiously evaluated for each patient.