Beliefs of physician directors on the management of devastating brain injuries at the Canadian emergency department and intensive care unit interface: a national site-level survey.

PURPOSE: Insufficient evidence-based recommendations to guide care for patients with devastating brain injuries (DBIs) leave patients vulnerable to inconsistent practice at the emergency department (ED) and intensive care unit (ICU) interface. We sought to characterize the beliefs of Canadian emergency medicine (EM) and critical care medicine (CCM) physician site directors regarding current management practices for patients with DBI. METHODS: We conducted a cross-sectional survey of EM and CCM physician directors of adult EDs and ICUs across Canada (December 2022 to March 2023). Our primary outcome was the proportion of respondents who manage (or consult on) patients with DBI in the ED. We conducted subgroup analyses to compare beliefs of EM and CCM physicians. RESULTS: Of 303 eligible respondents, we received 98 (32%) completed surveys (EM physician directors, 46; CCM physician directors, 52). Most physician directors reported participating in the decision to withdraw life-sustaining measures (WLSM) for patients with DBI in the ED (80%, n = 78), but 63% of these (n = 62) said this was infrequent. Physician directors reported that existing neuroprognostication methods are rarely sufficient to support WLSM in the ED (49%, n = 48) and believed that an ICU stay is required to improve confidence (99%, n = 97). Most (96%, n = 94) felt that providing caregiver visitation time prior to WLSM was a valid reason for ICU admission. CONCLUSION: In our survey of Canadian EM and CCM physician directors, 80% participated in WLSM in the ED for patients with DBI. Despite this, most supported ICU admission to optimize neuroprognostication and patient-centred end-of-life care, including organ donation.

RéSUMé: OBJECTIF: L'insuffisance des recommandations fondées sur des données probantes pour guider les soins aux individus atteints de lésions cérébrales dévastatrices rend ces personnes vulnérables à des pratiques incohérentes à la jonction entre le service des urgences et de l'unité de soins intensifs (USI). Nous avons cherché à caractériser les croyances des directeurs médicaux canadiens en médecine d'urgence et médecine de soins intensifs concernant les pratiques de prise en charge actuelles des personnes ayant subi une lésion cérébrale dévastatrice. MéTHODE: Nous avons réalisé un sondage transversal auprès des directeurs médicaux des urgences et des unités de soins intensifs pour adultes du Canada (décembre 2022 à mars 2023). Notre critère d'évaluation principal était la proportion de répondant·es qui prennent en charge (ou jouent un rôle de consultation auprès) des personnes atteintes de lésions cérébrales dévastatrices à l'urgence. Nous avons effectué des analyses en sous-groupes pour comparer les croyances des médecins des urgences et des soins intensifs. RéSULTATS: Sur les 303 personnes répondantes admissibles, 98 (32 %) ont répondu aux sondages (directions médicales des urgences, 46; directions médicales d'USI, 52). La plupart des directeurs médicaux ont déclaré avoir participé à la décision de retirer des traitements de maintien des fonctions vitales (TFMV) pour des patient·es atteint·es de lésions cérébrales dévastatrices à l'urgence (80 %, n = 78), mais 63 % (n = 62) ont déclaré que c'était peu fréquent. Les directions médicales ont indiqué que les méthodes de neuropronostic existantes sont rarement suffisantes pour appuyer le retrait des TMFV à l'urgence (49 %, n = 48) et croyaient qu'un séjour aux soins intensifs était nécessaire pour améliorer leur confiance en ces méthodes (99 %, n = 97). La plupart (96 %, n = 94) estimaient que le fait d'offrir du temps de visite aux personnes soignantes avant le retrait des TMFV était un motif valable d'admission aux soins intensifs. CONCLUSION: Dans le cadre de notre sondage mené auprès des directions médicales des services d'urgence et des USI au Canada, 80 % d'entre elles ont participé au retrait de TMFV à l'urgence pour des patient·es souffrant de lésions cérébrales dévastatrices. Malgré cela, la plupart d'entre elles étaient en faveur d'une admission aux soins intensifs afin d'optimiser le neuropronostic et les soins de fin de vie axés sur les patient·es, y compris le don d'organes.

Cardiovascular magnetic resonance in pregnancy: insights from the cardiac hemodynamic imaging and remodeling in pregnancy (CHIRP) study.

BACKGROUND: Cardiovascular disease in pregnancy is the leading cause of maternal mortality in North America. Although transthoracic echocardiography (TTE) is the most widely used imaging modality for the assessment of cardiovascular function during pregnancy, little is known on the role of cardiovascular magnetic resonance (CMR). The objective of the Cardiac Hemodynamic Imaging and Remodeling in Pregnancy (CHIRP) study was to compare TTE and CMR in the non-invasive assessment of maternal cardiac remodeling during the peripartum period. METHODS: Between 2010-2012, healthy pregnant women aged 18 to 35 years were prospectively enrolled. All women underwent TTE and CMR during the third trimester and at least 3 months postpartum (surrogate for non-pregnant state). RESULTS: The study population included a total of 34 women (mean age 29 ± 3 years). During the third trimester, TTE and CMR demonstrated an increase in left ventricular end-diastolic volume from 95 ± 11 mL to 115 ± 14 mL and 98 ± 6 mL to 125 ± 5 mL, respectively (p<0.05). By TTE and CMR, there was also an increase in left ventricular (LV) mass during pregnancy from 111 ± 10 g to 163 ± 11 g and 121 ± 5 g to 179 ± 5 g, respectively (p<0.05). Although there was good correlation between both imaging modalities for LV mass, stroke volume, and cardiac output, the values were consistently underestimated by TTE. CONCLUSION: This CMR study provides reference values for cardiac indices during normal pregnancy and the postpartum state.

Congenital absence of nitric oxide synthase 3 potentiates cardiac dysfunction and reduces survival in doxorubicin- and trastuzumab-mediated cardiomyopathy.

BACKGROUND: Doxorubicin (DOX) and trastuzumab (TRZ) are highly effective chemotherapeutic agents in the breast cancer setting, limited by their cardiotoxic side effects. Among the potential mechanisms for this drug-induced cardiomyopathy, increased production of oxidative stress (OS) through a nitric oxide synthase 3 (NOS3)-dependent pathway has gained recent attention. The objective of the study was to determine the role of NOS3 and OS in a clinically relevant female murine model of DOX- and TRZ-induced heart failure. METHODS: A total of 120 female mice (60 wild-type [WT] and 60 NOS3 knockout [NOS3(-/-)]) were treated with either 0.9% saline, DOX, TRZ, or DOX with TRZ (DOX+TRZ). Serial echocardiography was performed for a total of 10 days, after which the mice were euthanized for histological and biochemical analyses. RESULTS: In WT female mice receiving DOX+TRZ, left ventricular ejection fraction (LVEF) decreased from 75 ± 3% at baseline to 46 ± 2% at day 10 (P < 0.05). In the NOS3(-/-) group, LVEF decreased from 72 ± 3% at baseline to 35 ± 2% at day 10 (P < 0.05). LVEF was significantly lower in NOS3(-/-) female mice receiving DOX+TRZ than WT mice at day 10 (P < 0.05). Compared with WT, NOS3(-/-) female mice also demonstrated increased mortality after treatment with DOX+TRZ, corroborating the echocardiographic findings. Histological analysis demonstrated increased myofibrillar degradation and loss of cell integrity in NOS3(-/-) female mice treated with DOX+TRZ. There was increased generation of oxidized phosphatidylcholine, a marker of OS, in NOS3(-/-) female mice receiving DOX+TRZ compared with control mice. CONCLUSIONS: Congenital absence of NOS3 potentiates the cardiotoxic side effects of DOX+TRZ in an acute female murine model of chemotherapy-induced cardiomyopathy.