Del Nido versus warm blood cardioplegia in adult patients with a low ejection fraction

Background Del Nido cardioplegia was recently introduced to adult cardiac surgery with encouraging results. The effect of Del Nido cardioplegia in patients with low ejection fraction (EF) has not been thoroughly evaluated. The objective of this study was to assess the safety of Del Nido cardioplegia in adult patients with low EF compared to intermittent warm blood cardioplegia. Results During 2018 and 2019, 73 adult patients with an EF of ≤ 40% underwent cardiac surgery using Del Nido cardioplegia. The patients were compared to a historical cohort of consecutive patients with low EF who had intermitted warm blood cardioplegia (n = 81). Patients who had Del Nido cardioplegia had significantly lower EuroSCORE II (2.73 (1.7–4.1) vs. 4.5 (2.4–7.4), P = 0.004). There were no differences in creatinine clearance and preoperative echocardiographic data between the groups. Cardiopulmonary bypass and cross-clamp times were non-significantly lower with Del Nido cardioplegia. There were no differences in stroke and postoperative echocardiographic data between the groups. No hospital mortality was reported in both groups. Peak troponin levels were significantly higher in patients who had Del Nido cardioplegia (0.88 (0.58–1.47) vs. 0.7 (0.44–1.01) ng/dL; P = 0.01); however, after multivariable regression analysis, cardiopulmonary bypass time was the only predictor of postoperative troponin level (coefficient 0.005 (95% CI: 0.003–0.008); P < 0.001). ICU stay was significantly longer in patients who had Del Nido cardioplegia (4 (3–6) vs. 2(1–4) days, P < 0.001), while postoperative hospital stay did not differ between the groups. After multivariable regression, the use of intermittent warm blood cardioplegia was significantly associated with shorter ICU stay (coefficient − 1.80 (95% CI − 3.06 – -0.55); P = 0.01). Conclusions Prolonged ICU was reported with Del Nido cardioplegia; however, there were no differences in the duration of hospital stay and the clinical outcomes between the groups. Despite the proven efficacy of intermittent warm blood cardioplegia, the use of Del Nido cardioplegia might be safe in patients with low EF.

Effects of Del Nido and Terminal Warm Blood Cardioplegia on Myocardial Protection and Rhythm in Isolated CABG Patients

Objective: To investigate the effect of using del Nido cardioplegia+terminal hot-shot blood cardioplegia on myocardial protection and rhythm in isolated coronary bypass patients. Material and methods: A total of 122 patients were given cold (+4-8C') del Nido cardioplegia antegrade and evaluated. Del Nido+terminal warm blood cardioplegia (TWBCP) was applied to 63 patients out of 122 patients, while del Nido cardioplegia alone was applied to the other 59 patients. The preoperative and postoperative data of the patients were recorded and compared. Results: There was a significant statistical difference between the groups, in terms of volume with more cardioplegia in the del Nido+terminal warm blood cardioplegia group. Although there was no significant difference between cardiac arrest times in both groups, a statistically significant difference was found in the del Nido+terminal warm blood cardioplegia group in the starting to work time of the heart. No difference found between the groups regarding myocardial preservation. Conclusions: We can add a return to spontaneous sinus rhythm to the advantages of terminal warm blood cardioplegia and del Nido cardioplegia in literature. We think it would be a good strategy to extend the safe ischemic time limit of del Nido to 120 minutes with a terminal warm blood cardioplegia. It seems that cardioplegia techniques that will be developed by adding the successful and superior results of crystalloid cardioplegia applications, such as single dose del Nido in various open heart surgery operations and the superior myocardial return effects of terminal warm blood cardioplegia, will be used routinely in the future.

Long-Term Protective Effects of Single-Dose infusion of Warm Blood Cardioplegic Solution in a mini-pig model on the background of intraoperative anemia

Objectives: The tolerable ischemic time for many cardioplegia solutions has not been established yet. The aim of this study was to estimate the effect of a single-dose of cardioplegia solution Normacor (solution No. 1) and to establish the tolerable ischemic time in a normothermic cardiopulmonary bypass mini-pig model on the background of intraoperative anemia. Methods: Five female mini-pigs (34plus-or-minus sign3 kg, 6-month-old) were subjected to 180 min or 210 min of cardiac arrest by single-dose 400 ml Normacor cardioplegia (solution No. 1). A needle biopsy was taken from the left ventricle before the aortic cross-clamping and every 30 minutes after it. The restoration of left ventricle contractility was assessed by the clinical indicators, catecholamine support, morphological and immunohistochemical examination. Results: The morphological signs of cardiomyocytes ischemia were found after 120 minutes of aortic cross-clamping. According to the content of succinate dehydrogenase and hypoxia-inducible factor, the signs of the cardiomyocytes ischemic injury onset were detected at the same time point. During the entire period of aortic cross-clamping atrial activity was observed in all cases. The proposed single-dose ischemic time for re-dosing of cardioplegia is 120 minutes or ventricular activity onset. Conclusions: Safe and effective cardioprotection can be achieved with warm blood cardioplegia Normacor (solution No. 1) within 120 minutes for a single-dose infusion.

Synthesis of a synthetic analogue for the Sitophilus weevil aggregation pheromone and study on its hygienic and toxicological indexes

The work was initiated to study hygienic and toxicological indices of a synthetic analogue for the Sitophilus weevil aggregation pheromone. The toxicity testing of 5-hydroxy-4-methyl-3-heptanone demonstrated its extremely low toxicity for the warm-blood animals, as compared to the one of the typical pesticides. The average lethal dose of the product per orally administered to the white mice was established to be 4375.0 mg kg-1 LD16 and LD84 being 2225.0 mg kg-1 and 6550.0 mg kg-1, respectively. The average lethal dose for rabbits was 5900.0 mg kg-1 5-hydroxy-4-methyl-3-heptanone proved to have a mild skin and conjunctival irritant action, and equally mild functional cumulation. As to chronic toxicity, the acceptable daily dose of 4.3 mg/person/d was calculated and scientifically substantiated. The odor threshold was determined at the dose ranging from 0.35 to 0.7 mg l-1 with the practical limit ranging from 0.35 to 1.5 mg l-1, taste sensation threshold was found at the dose ranging from 1.0 to 3.0 mg l-1 with the practical limit ranging from 3.0 to 7.0 mg l-1

COMPARISON STUDY: INTERMITTENT ANTIGRADE WARM CARDIOPLEGIA VERSUS ANTIGRADE COLD INTERMITTENT BLOOD CARDIOPLEGIA FOR MYOCARDIAL PROTECTION DURING ELECTIVE ON PUMP CORONARY ARTERY BYPASS GRAFTING IN EARLY POST-OPERATIVE PERIOD

Background: Defending the heart against potential damage during cross-clamping is the most important and vital step to ensuring a successful surgical outcome(1). The creation of cardioplegia solutions was one of the major advances in cardiac surgery that allowed surgeons to conduct complicated surgical procedures to avoid myocardial injury (14). Treating cardioplegia at a cool temperature would be a significant factor in lowering myocardial metabolism. However, the reduction in myocardial metabolism due to hypothermia, compared with that achieved by diastolic arrest, is usually very negligible. Since Normothermias enzymatic and cellular processes work better (7). Owing to the propensity of the heart to resume electrical operation during normothermia, however, this must be administered consistently or only with short interruptions (4). Terminal warm blood cardioplegia (hot shot) is normally done just before the elimination of the aortic cross-clamp since it has been demonstrated that myocardial metabolism is increasing (23). Methods: A prospective controlled randomised study (200 hundred patients aged 40 to 65 years of both sexes underwent elective CABG pump surgery) will be included. They will be divided into three groups of patients: Group I:includes 100 Patients who received intermittent cold blood cardioplegia. Group II:includes 100 Patients who received intermittent warm blood cardioplegia with controlled reperfusion for 3 minutes before aortic unclamping. Study made from January, 2019 to August, 2020, at National Heart Institute.All patients were thoroughly evaluated preoperatively, intraoperatively, and postoperatively. Results: We hypothesized that in our patient cohort, warm blood cardioplegia could be as successful as or even better than the conventional antegrade cold blood cardioplegia. Patients were randomised into two similar blocks, each of which consisted of 100 patients, each of whom obtained one of the two cardioplegic solutions. Our analysis did not indicate a statistically important difference in the post-operative release of myocardial biomarkers (Troponin I) & CK in both classes. This finding did not significantly reflect the clinical outcome of our patient, which may indicate similar myocardial protection in primary low-risk CABG patients for both cold and warm blood cardioplegia. Conclusion: During the time of cardiac arrest, both methods tend to enable an equal and adequate approach for myocardial defence. To attain improved myocardial defence, warm blood cardioplegia needs a shorter administration interval. Therefore, the choice between one type of cardioplegia and the other remains at the discretion of the surgeon. The statistically minor variation found in the release of myocardial enzymes did not translate into distinct clinical results.

Intermittent antegrade warm-blood versus cold-blood cardioplegia in children undergoing open heart surgery: a protocol for a randomised controlled study (Thermic-3)

IntroductionSurgical repair of congenital heart defects often requires the use of cardiopulmonary bypass (CPB) and cardioplegic arrest. Cardioplegia is used during cardiac surgery requiring CPB to keep the heart still and to reduce myocardial damage as a result of ischaemia–reperfusion injury. Cold cardioplegia is the prevalent method of myocardial protection in paediatric patients; however, warm cardioplegia is used as part of usual care throughout the UK in adults. We aim to provide evidence to support the use of warm versus cold blood cardioplegia on clinical and biochemical outcomes during and after paediatric congenital heart surgery.Methods and analysisWe are conducting a single-centre randomised controlled trial in paediatric patients undergoing operations requiring CPB and cardioplegic arrest at the Bristol Royal Hospital for Children. We will randomise participants in a 1:1 ratio to receive either ‘cold-blood cardioplegia’ or ‘warm-blood cardioplegia’. The primary outcome will be the difference between groups with respect to Troponin T levels over the first 48 postoperative hours. Secondary outcomes will include measures of cardiac function; renal function; cerebral function; arrythmias during and postoperative hours; postoperative blood loss in the first 12 hours; vasoactive-inotrope score in the first 48 hours; intubation time; chest and wound infections; time from return from theatre until fit for discharge; length of postoperative hospital stay; all-cause mortality to 3 months postoperative; myocardial injury at the molecular and cellular level.Ethics and disseminationThis trial has been approved by the London – Central Research Ethics Committee. Findings will be disseminated to the academic community through peer-reviewed publications and presentation at national and international meetings. Patients will be informed of the results through patient organisations and newsletters to participants.Trial registration numberISRCTN13467772; Pre-results.

Beat the heat: Culex quinquefasciatus regulates its body temperature during blood-feeding

Mosquitoes are regarded as one of the most dangerous animals on earth. As they are responsible for the spread of a wide range of both human and animal diseases, research of the underlying mechanisms of their feeding behavior and physiology is critical. Among disease vector mosquitoes, Culex quinquefasciatus, which is a known carrier of West Nile virus and Western Equine Encephalitis, remains relatively understudied. As blood sucking insects, adaptations (either at the molecular or physiological level) while feeding on warm blood is crucial to their survival, as overheating can result in death due to heat stress. Our research aims to study how Cx. quinquefasciatus copes with heat associated with the ingestion of a warm blood-meal and to possibly uncover the adaptations this species uses to avoid thermal stress. Through the use of thermographic imaging, we analyzed the body temperature of Cx. quinquefasciatus while blood feeding. Infrared thermography has allowed us to identify a cooling strategy, evaporative cooling via the production of fluid droplets, and an overall low body temperature in comparison to the blood temperature during feeding. Understanding Cx. quinquefasciatus’ adaptations and various strategies that they employ to reduce their body temperature while blood-feeding constitutes the first step towards the discovery of potential targets of opportunity for their control.HighlightsMosquitoes have evolved to cope with heat stress associated with warm blood ingestionCulex quinquefasciatus displays heterothermy while blood-feedingThe abdominal temperature decreases due to evaporative cooling using urine dropletsOverall, the mosquito body temperature is much cooler than the ingested blood

Size Matters: Zoo Data Analysis Shows that the White Blood Cell Ratio Differs between Large and Small Felids

The total number of white blood cells (WBCs) is related the immune system. In mammals, it is affected by the body mass, but it is unclear how the numbers of different WBC types correlate with this parameter. We analyzed the effect of body mass on WBC number and ratio in felids, where species are similar in diet (warm-blood vertebrates) and reproductive strategy (promiscuity). Based on zoo veterinary data (ZIMS database) we analyzed the effect of body mass on WBC number and neutrophils/lymphocytes ratio in 26 species of felids. The number of WBCs correlated with the body masses of animals: large cats had more WBC, which may be due to greater risks of infection associated with larger body surface, lifespan and home range size. For the first time we found obvious differences in the number of WBC types. Large cats also had more neutrophils and monocytes but fewer lymphocytes than smaller cats. The ratio of neutrophils to lymphocytes is greater in large felids. This phenomenon may be related to diet (relative prey size and kill utilization time), which suggests regular contact of large cats with bacterial and protozoal pathogens in contrast to the small cats.