Superficial parasternal intercostal plane blocks in cardiac surgery: a systematic review and meta-analysis.

PURPOSE: Traditional multimodal analgesic strategies have several contraindications in cardiac surgery patients, forcing clinicians to use alternative options. Superficial parasternal intercostal plane blocks, anesthetizing the anterior cutaneous branches of the thoracic intercostal nerves, are being explored as a straightforward method to treat pain after sternotomy. We sought to evaluate the literature on the effects of superficial parasternal blocks on pain control after cardiac surgery. METHODS: We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs). We searched MEDLINE, Embase, CENTRAL, and Web of Science databases for RCTs evaluating superficial parasternal intercostal plane blocks in adult patients undergoing cardiac surgery via midline sternotomy published from inception to 11 March 2022. The prespecified primary outcome was opioid consumption at 12 hr. The risk of bias was assessed with the Cochrane Collaboration Risk of Bias Tool, and the quality of evidence was evaluated using the grading of recommendations, assessments, development, and evaluations. Outcomes were analyzed with a random-effects model. All subgroups were prespecified. RESULTS: We reviewed 1,275 citations. Eleven RCTs, comprising 756 patients, fulfilled the inclusion criteria. Only one study reported the prespecified primary outcome, precluding the possibility of meta-analysis. This study reported a reduction in opioid consumption (-11.2 mg iv morphine equivalents; 95% confidence interval [CI], -8.2 to -14.1) There was a reduction in opioid consumption at 24 hr (-7.2 mg iv morphine equivalents; 95% CI, -5.6 to -8.7; five trials; 436 participants; moderate certainty evidence). All five studies measuring complications reported that none were detected, which included a sample of 196 blocks. CONCLUSION: The literature suggests a potential benefit of using superficial parasternal blocks to improve acute postoperative pain control after cardiac surgery via midline sternotomy. Future studies specifying dosing regimens and adjuncts are required. STUDY REGISTRATION: PROSPERO (CRD42022306914); first submitted 22 March 2022.

RéSUMé: OBJECTIF: Il existe plusieurs contre-indications aux stratégies analgésiques multimodales traditionnelles chez la patientèle de chirurgie cardiaque, ce qui oblige les clinicien·nes à se tourner vers d'autres options. Les blocs des plans intercostaux parasternaux superficiels, anesthésiant les branches cutanées antérieures des nerfs intercostaux thoraciques, sont l'une des méthodes simples actuellement explorées pour traiter la douleur après une sternotomie. Nous avons cherché à évaluer la littérature sur les effets des blocs parasternaux superficiels sur le contrôle de la douleur après une chirurgie cardiaque. MéTHODE: Nous avons réalisé une revue systématique et une méta-analyse des études randomisées contrôlées (ERC). Nous avons fait des recherches dans les bases de données MEDLINE, Embase, CENTRAL et Web of Science pour en tirer les ERC évaluant les blocs des plans intercostaux parasternaux superficiels chez les patient·es adultes bénéficiant d'une chirurgie cardiaque par sternotomie médiane publiées depuis leur création jusqu'au 11 mars 2022. Le critère d'évaluation principal préspécifié était la consommation d'opioïdes à 12 heures. Le risque de biais a été évalué à l'aide de l'outil Cochrane Collaboration Risk of Bias, et la qualité des données probantes à l'aide de l'outil GRADE. Les résultats ont été analysés à l'aide d'un modèle à effets aléatoires. Tous les sous-groupes étaient préspécifiés. RéSULTATS: Nous avons examiné 1275 citations. Onze ERC, comprenant 756 patient·es, remplissaient les critères d'inclusion. Une seule étude a rapporté le critère d'évaluation principal préspécifié, ce qui a exclu la possibilité d'une méta-analyse. Cette étude a rapporté une réduction de la consommation d'opioïdes (−11,2 mg équivalents de morphine iv; intervalle de confiance [IC] à 95 %, −8,2 à −14,1). Il y a eu une réduction de la consommation d'opioïdes à 24 heures (−7,2 mg équivalents de morphine iv; IC 95 %, −5,6 à −8,7; cinq études; 436 participant·es; données probantes de certitude modérée). Les cinq études mesurant les complications ont rapporté qu'aucune complication n'avait été détectée, en incluant un échantillon de 196 blocs. CONCLUSION: La littérature suggère un avantage potentiel de l'utilisation de blocs parasternaux superficiels pour améliorer le contrôle de la douleur postopératoire aiguë après une chirurgie cardiaque par sternotomie médiane. Des études futures précisant les schémas posologiques et les adjuvants sont nécessaires. ENREGISTREMENT DE L'éTUDE: PROSPERO (CRD42022306914); soumis pour la première fois le 22 mars 2022.

Density-dependence and seasonal variation in reproductive output and sporophyte production in the kelp, Ecklonia radiata.

The kelp, Ecklonia radiata, is an abundant subtidal ecosystem engineer in southern Australia. Density-dependent changes in the abiotic environment engineered by Ecklonia may feedback to affect reproduction and subsequent recruitment. Here, we examined: 1) how the reproductive capacity of Ecklonia individuals in the field (zoospores released · mm-2 reproductive tissue) varied with adult density and time, and 2) how the recruitment of microscopic gametophytes and sporophytes was influenced by zoospore density at two times. Zoospore production did not vary with adult density, with only one month out of ten sampled over a 2-y period showing a significant effect of density. However, zoospore production varied hugely over time, being generally highest in mid-autumn and lowest in mid-late summer. There were strong effects of initial zoospore density on gametophyte and sporophyte recruitment with both a minimum and an optimum zoospore density for sporophyte recruitment, but these varied in time. Almost no sporophytes developed when initial zoospore density was <6.5 · mm-2 in spring or <0.5 · mm-2 in winter with optimum densities of 90-355 · mm-2 in spring and 21-261 · mm-2 in winter, which resulted in relatively high recruitment of 4-7 sporophytes · mm-2 . Sporophyte recruitment declined at initial zoospore densities >335 · mm-2 in spring and >261 · mm-2 in winter and was zero at very high zoospore densities. These findings suggest that although adult Ecklonia density does not affect per-capita zoospore production, because there is a minimum zoospore density for sporophyte production, a decline in population-level output could feedback to impact recruitment.

Iron supplementation for patients undergoing cardiac surgery: a systematic review and meta-analysis of randomized controlled trials.

PURPOSE: Iron supplementation has been evaluated in several randomized controlled trials (RCTs) for its potential to increase baseline hemoglobin and decrease red blood cell transfusion during cardiac surgery. This study's main objective was to evaluate the current evidence for iron administration in cardiac surgery patients. METHODS: We searched MEDLINE, EMBASE, CENTRAL, Web of Science databases, and Google Scholar from inception to 19 November 2020 for RCTs evaluating perioperative iron administration in adult patients undergoing cardiac surgery. The RCTs were assessed using a risk of bias assessment and the quality of evidence was assessed using the grading of recommendations, assessments, development, and evaluations. RESULTS: We reviewed 1,767 citations, and five studies (n = 554) met the inclusion criteria. The use of iron showed no statistical difference in incidence of transfusion (risk ratio, 0.86; 95% confidence interval, 0.65 to 1.13). Trial sequential analysis suggested an optimal information size of 1,132 participants, which the accrued information size did not reach. CONCLUSION: The current literature does not support or refute the routine use of iron therapy in cardiac surgery patients. TRIAL REGISTRATION: PROSPERO (CRD42020161927); registered 19 December 2019.

RéSUMé: OBJECTIF: La supplémentation en fer a été évaluée dans plusieurs études randomisées contrôlées (ERC) pour son potentiel à augmenter l'hémoglobine de base et à diminuer la transfusion d'érythrocytes pendant la chirurgie cardiaque. L'objectif principal de cette étude était d'évaluer les données probantes actuelles soutenant l'administration de fer chez les patients de chirurgie cardiaque. MéTHODE: Nous avons effectué des recherches dans les bases de données MEDLINE, EMBASE, CENTRAL, Web of Science et Google Scholar de leur création jusqu'au 19 novembre 2020 pour en extraire les ERC évaluant l'administration périopératoire de fer chez les patients adultes bénéficiant d'une chirurgie cardiaque. Les ERC ont été évaluées à l'aide d'une évaluation du risque de biais et la qualité des données probantes a été évaluée à l'aide du système de notation GRADE. RéSULTATS: Nous avons examiné 1767 citations et cinq études (n = 554) répondaient aux critères d'inclusion. L'administration de fer n'a montré aucune différence statistique dans l'incidence des transfusions (risque relatif, 0,86; intervalle de confiance à 95 %, 0,65 à 1,13). Selon l'analyse séquentielle des études, la taille d'information optimale serait de 1132 participants, une taille que l'information accumulée n'a pas atteint. CONCLUSION: La littérature actuelle ne soutient ni ne réfute l'utilisation systématique d'une thérapie à base de fer chez les patients de chirurgie cardiaque. ENREGISTREMENT DE L'éTUDE: PROSPERO (CRD42020161927); enregistrée le 19 décembre 2019.

Prospective External Validation of Three Preoperative Risk Scores for Prediction of New Onset Atrial Fibrillation After Cardiac Surgery.

BACKGROUND: Postoperative atrial fibrillation (POAF) is associated with early and late morbidity and mortality of cardiac surgical patients. Prophylactic treatment of atrial fibrillation (AF) has been recommended to improve outcome in cardiac surgical patients at high risk of developing POAF. Reliable models for prediction of POAF are needed to achieve that goal. This study attempted to externally validate 3 risk models proposed for preoperative prediction of POAF in cardiac surgical patients: the POAF score, the CHA2DS2-VASc score, and the Atrial Fibrillation Risk Index. METHODS: This was a prospective cohort study of 1416 adult patients who underwent nonemergent coronary artery bypass graft and/or valve surgery in a single cardiac surgical center between February 2014 and September 2015. A risk score for each of the 3 prediction models was calculated in each patient. All patients were followed for up to 2 weeks, or until hospital discharge, to observe the primary outcome of new onset AF requiring treatment. Discrimination was assessed using receiver operating characteristic curves. Calibration was assessed using the Pearson χ goodness-of-fit test and calibration plots. Utility of the score to implement AF prophylaxis based on the risk of POAF, in comparison to strategies of treating all patients, or not treating any patients, was assessed via a net benefit analysis. RESULTS: Of the 1416 patients included in this study, 478 had the primary outcome (33.8%). The areas under the receiver operating characteristic curve for prediction of POAF in the population subsets for which the scores were validated were as follows: 0.651 (95% confidence interval [CI], 0.621-0.681) for the POAF score, 0.593 (95% CI, 0.557-0.629) for the CHA2DS2-VASc score (P < .001 versus POAF score, P < .222 versus Atrial Fibrillation Risk Index), and 0.563 (95% CI, 0.522-0.604) for the Atrial Fibrillation Risk Index (P < .001 versus POAF score). The calibration analysis showed that the predictive models had a poor fit between the observed and expected rates of POAF. Net benefit analysis showed that AF preventive strategies based on these scores, and targeting patients with moderate or high risk of POAF, improve decision-making in comparison to preventive strategies of treating all patients. CONCLUSIONS: The 3 prediction scores evaluated in this study have limited ability to predict POAF in cardiac surgical patients. Despite this, they may be useful in preventive strategies targeting patients with moderate or high risk of PAOF in comparison with preventive strategies applied to all patients.

Interactive effects of canopy-driven changes in light, scour and water flow on microscopic recruits in kelp.

Ecosystem engineering kelp forms habitat and influences associated communities by altering abiotic conditions. These conditions can also affect the engineer's own demographic rates but the mechanisms underpinning these feedbacks are not well known. Here, we tested the interactive effects of three abiotic factors engineered by the Australasian kelp Ecklonia radiata (light, water flow and scour) on the early survivorship and growth of its outplanted microscopic recruits. After six weeks, recruit survivorship was high in the absence of scour and low light (2-3 times higher than when scour was present) and under low water flow-ambient light conditions. Growth of sporophytes was strongly related to light, with recruits under ambient light approximately four times larger after six weeks. Overall, reduced scour (for survivorship) and ambient light (for growth) appear crucial for maximising E. radiata recruitment suggesting a healthy forest can provide microenvironments to enhance survivorship while gaps in the canopy enhance growth.

Iron supplementation for patients undergoing cardiac surgery: a protocol for a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Iron administration has been evaluated in several randomized controlled trials for the potential of increasing baseline hemoglobin values and decreasing the incidence of red blood cell transfusion during cardiac surgery. We describe the protocol for a study aiming to evaluate the efficacy and safety of perioperative iron administration in patients undergoing cardiac surgery. METHODS: We will search MEDLINE, Embase, the Cochrane Central Register of Controlled Trials and the Web of Science, from inception to Nov. 19, 2020, for randomized controlled trials in any language evaluating the perioperative administration of iron in adult patients undergoing cardiac surgery; we will also include the first 50 results from Google Scholar. The primary outcome will be the incidence of red blood cell transfusion from the study intervention time until 8 weeks postoperatively. The secondary outcomes will be the number of red blood cell units transfused; change in ferritin level, reticulocyte count and hemoglobin concentration after iron administration; and adverse events. We will assess the risk of bias with the Cochrane Collaboration Risk of Bias Tool, and will analyze the primary and secondary outcomes using a random-effects model. INTERPRETATION: This study will summarize the current evidence about perioperative iron administration in patients undergoing cardiac surgery, help determine whether this intervention should be included in enhanced-recovery protocols, and shape future research if needed. The final manuscript will be submitted to a peer-reviewed journal. TRIAL REGISTRATION: PROSPERO no. CRD42020161927.

High kelp density attracts fishes except for recruiting cryptobenthic species.

As foundation species, kelp support productive and species rich communities; however, the effects of kelp structure on mobile species within these complex natural systems are often difficult to assess. We used artificial reefs with transplanted kelp to quantify the influence of kelp patch size and density on fish assemblages including the arrival of recruiting cryptobenthic species. Large patches with dense kelp supported the highest abundance, species richness, and diversity of fishes, with the addition of dense kelp tripling biomass and doubling richness. The abundance of recruits in artificial collectors declined with patch size and was halved on reefs with sparse kelp compared to reefs with dense kelp or no kelp. These results highlight the importance of dense kelp cover in facilitating biodiversity and indicate that kelp addition could support the recovery of degraded coastal ecosystems. Kelp also apparently drives complex interactions affecting the recruitment/behaviour of some cryptobenthic species.

Resilience and stability of kelp forests: The importance of patch dynamics and environment-engineer feedbacks.

Habitat forming 'ecosystem engineers' such as kelp species create complex habitats that support biodiverse and productive communities. Studies of the resilience and stability of ecosystem engineers have typically focussed on the role of external factors such as disturbance. However, their population dynamics are also likely to be influenced by internal processes, such that the environmental modifications caused by engineer species feedback to affect their own demography (e.g. recruitment, survivorship). In numerous regions globally, kelp forests are declining and experiencing reductions in patch size and kelp density. To explore how resilience and stability of kelp habitats is influenced by this habitat degradation, we created an array of patch reefs of various sizes and supporting adult Ecklonia radiata kelp transplanted at different densities. This enabled testing of how sub-canopy abiotic conditions change with reductions in patch size and adult kelp density, and how this influenced demographic processes of microscopic and macroscopic juvenile kelp. We found that ecosystem engineering by adult E. radiata modified the environment to reduce sub-canopy water flow, sedimentation, and irradiance. However, the capacity of adult kelp canopy to engineer abiotic change was dependent on patch size, and to a lesser extent, kelp density. Reductions in patch size and kelp density also impaired the recruitment, growth and survivorship of microscopic and macroscopic juvenile E. radiata, and even after the provisioning of established juveniles, demographic processes were impaired in the absence of sufficient adult kelp. These results are consistent with the hypothesis that ecosystem engineering by adult E. radiata facilitates development of juvenile conspecifics. Habitat degradation seems to impair the ability of E. radiata to engineer abiotic change, causing breakdown of positive intraspecific feedback and collapse of demographic functions, and overall, leading to reductions in ecosystem stability and resilience well before local extirpation.