ABSTRACT
BACKGROUND: Protamine administration post-cardiopulmonary bypass (CPB) can potentially cause hemodynamic instability. Histamine released from mast cells is believed to be responsible for hypotension after protamine administration. The aim of this study was to examine the effects of pretreatment with H1 and H2 antihistamines on changes in systemic arterial pressure following protamine administration. METHODS: This study was a randomized, triple-blinded, placebo-controlled study, conducted at a university hospital. Forty adult patients undergoing elective coronary artery bypass grafting (CABG) or single valve surgery were included. The patients were randomly allocated (20 patients in each group) to receive a single dose of combined chlorpheniramine 10 mg and ranitidine 50 mg or normal saline intravenously immediately after separation from CPB prior to protamine administration. Trajectory changes in systolic blood pressure (SBP), mean arterial pressure (MAP), and vasoactive-inotropic score (VIS) from baseline until 35 minutes following protamine administration (24-time points) were compared between the two groups. Serial serum tryptase levels were also obtained at baseline, 30 and 60 minutes after protamine was given. RESULTS: Forty patients were included in the analysis. Demographic and baseline blood pressure were similar between the two groups. At 30 minutes after protamine administration, there were no significant differences in both crude SBP [mean difference: -7.1 mmHg, 95% confidence interval (CI), -1.1 to 15.3 mmHg, P=0.09] and SBP after adjustment for the European System for Cardiac Operative Risk Evaluation (EuroSCORE II), CPB time, and VIS (mean difference: -3.9 mmHg, 95% CI, -11.9 to 4.0 mmHg, P=0.33). There were also no significant differences in crude MAP (mean difference: -2.1 mmHg, 95% CI, -6.9 to 2.7 mmHg, P=0.39) and adjusted MAP (mean difference: -0.7 mmHg, -5.9 to 4.4 mmHg, P=0.78) between the two groups. None of the patients in both groups had a significant increase in serum tryptase from baseline. No differences in median serum tryptase levels at baseline, 30 and 60 minutes were demonstrated between the two groups. CONCLUSIONS: Pretreatment with H1 and H2 antihistamines does not attenuate blood pressure responses to protamine administration in patients after CPB. Mechanisms other than histamine release from mast cells might be responsible for protamine-induced cardiovascular changes. TRIAL REGISTRATION: ClinicalTrials.gov NCT03583567.
ABSTRACT
BACKGROUND: The use of medical radiation in diagnosis and procedural and surgical treatment is increasing. Therefore, healthcare personnel should be adequately aware and knowledgeable about radiation hazards to protect themselves and their patients from its adverse effects. The objective of this study was to examine awareness about radiation hazards and knowledge about protection methods among the anesthesia personnel and surgical subspecialists of a quaternary care academic center. METHODS: A validated questionnaire was completed by anesthetic personnel and surgical subspecialists. It consisted of questions that required demographic information and assessed awareness about radiation hazards. In addition, 15 multiple-choice questions assessed knowledge about radiation across the following domains: the main principle of radiation protection, personal annual radiation dose, personal protection equipment, safe distance from an X-ray machine, and susceptible organs. RESULTS: A total of 270 potential participants were emailed and invited to respond to an online questionnaire, and the response rate was 79.3%. Of the 214 participants, 69.2% were women; the mean age of the sample was 34.8 years. Most of the participants (63.1%) considered radiation exposure that occurs as a part of daily work to be very harmful; 86.4% and 78.5% reported that they always wore a lead apron and a thyroid shield when working in an environment that entails radiation exposure, respectively. The mean score for knowledge about radiation hazards and protection was 6.4 ± 2.0 (maximum possible score = 15) Therefore, there is a need to improve anesthetic personnel and surgical subspecialists' knowledge about radiation protection, especially with regard to the use of lead goggles and harmful doses of radiation. CONCLUSION: The present findings suggest that there is a reasonable level of awareness but a relative lack of knowledge about radiation hazards and protection among anesthesia personnel and surgical subspecialists. Therefore, continuing medical education on radiation hazards and protection must be mandated.
