Perioperative mortality related to anesthesia within 48 h and up to 30 days following surgery: A retrospective cohort study of 11,562 anesthetic procedures.

STUDY OBJECTIVE: Studying postoperative in-hospital mortality is crucial to the understanding of the perioperative process failures and to the implementation of strategies to improve patient outcomes. We intend to classify the causes of perioperative deaths up to 30 days after procedures requiring anesthesia and to evaluate the risk factors for early (48 h) or late (30 day) mortality. DESIGN: Retrospective cohort study. SETTING: A quaternary University Hospital from South Brazil. PATIENTS: The information related to the perioperative care was collected from surgeries performed between January 2012 and December 2011. INTERVENTIONS: None (observational study). MEASUREMENTS: Three anesthesiologists classified the causes of deaths according to the ANZCA (Australian and New Zealand College of Anesthetists) classification, used in the report of Anesthesia-Related Mortality in Australia since 1985, which defines eight death categories. The risk factors for early or late death were analyzed in a regression model. MAIN RESULTS: 11.562 surgeries were performed, with a mortality incidence of 2.75% within 30 days (319 deaths). Most deaths were inevitable (50.7%), as they were related to advanced illnesses and would occur regardless of anesthetic or surgical procedures. The second most common cause was related to surgical complications (25%). The death rate having anesthesia as a likely contributor was 1.72:10.000 procedures, and as a potential contributor 7.78:10.000. These deaths occurred significantly earlier (<48 h) when compared to deaths from other causes. Transoperative vasopressor, extremes of age and out-of-hour surgery were independent variables associated to early deaths. CONCLUSIONS: The study confirms that postoperative mortality in which anesthesia was involved occurred earlier in the perioperative period. In addition, it was revealed that this involvement of anesthesia as a morbidity contributor shows higher frequency when considering the anesthesiologist perioperative role, and when assessing the mortality in the long term (30 days).

[Predictors of in-hospital mortality in patients undergoing elective surgery in a university hospital: a prospective cohort]. / Preditores de mortalidade intra­hospitalar em pacientes submetidos a cirurgias não eletivas em um hospital universitário: uma coorte prospectiva.

INTRODUCTION: Morbidity and mortality associated with urgent or emergency surgeries are high compared to elective procedures. Perioperative risk scores identify the non-elective character as an independent factor of complications and death. The present study aims to characterize the population undergoing non-elective surgeries at the Hospital de Clínicas de Porto Alegre and identify the clinical and surgical factors associated with death within 30 days postoperatively. METHODOLOGY: A prospective cohort study of 187 patients undergoing elective surgeries between April and May 2014 at the Hospital de Clínicas, Porto Alegre. Patient-related data, pre-operative risk situations, and surgical information were evaluated. Death in 30 days was the primary outcome measured. RESULTS: The mean age of the sample was 48.5 years, and 84.4% of the subjects had comorbidities. The primary endpoint was observed in 14.4% of the cases, with exploratory laparotomy being the procedure with the highest mortality (47.7%). After multivariate logistic regression, age (odds ratio [OR] 1.0360, p <0.05), anemia (OR 3.961, p <0.05), acute or chronic renal insufficiency (OR 6.075, p <0.05), sepsis (OR 7.027, p <0.05), and patient-related risk factors for mortality, in addition to the large surgery category (OR 7.502, p <0.05) were identified. CONCLUSION: The high mortality rate found may reflect the high complexity of the institution's patients. Knowing the profile of the patients assisted helps in the definition of management priorities, suggesting the need to create specific care lines for groups identified as high risk in order to reduce perioperative complications and deaths.

In vivo glioblastoma growth is reduced by apyrase activity in a rat glioma model.

BACKGROUND: ATP is an important signalling molecule in the peripheral and central nervous system. Both glioma growth and tumor resection induces cell death, thus liberating nucleotides to the extracellular medium. Nucleotides are hydrolyzed very slowly by gliomas when compared with astrocytes and induce neuronal cell death and glioma proliferation. The objective of the present study was to test the involvement of extracellular ATP in glioblastoma growth in a rat glioma model. METHODS: To deplete the extracellular ATP, the enzyme apyrase was tested on the treatment of gliomas implanted in the rats CNS. One million glioma C6 cells in 3 microliters of DMEM/FCS were injected in the right striata of male Wistar rats, 250-270 g. After 20 days, the rats were decapitated and the brain sectioning and stained with hematoxylin and eosine. We performed immunohistochemical experiments with Ki67, CD31 and VEGF. Total RNA was isolated from cultured glioma C6 cells and the cDNA was analyzed by Real Time-PCR with primers for the NTPDase family. RESULTS: C6 glioma cells effectively have a low expression of all NTPDases investigated, in comparison with normal astrocytes. The implanted glioma co-injected with apyrase had a significant reduction in the tumor size (p < 0.05) when compared with the rats injected only with gliomas or with gliomas plus inactivated apyrase. According to the pathological analysis, the malignant gliomas induced by C6 injection and co-injected with apyrase presented a significant reduction in the mitotic index and other histological characteristics that indicate a less invasive/proliferative tumor. Reduction of proliferation induced by apyrase co-injection was confirmed by counting the percentage of Ki67 positive glioma cell nuclei. According to counts with CD31, vessel density and neoformation was higher in the C6 group 20 days after implantation. Confirming this observation, rats treated with apyrase presented less VEGF staining in comparison to the control group. CONCLUSION: These results indicate that the participation of extracellular ATP and the ecto-nucleotidases may be associated with the development of this type of brain tumor in an in vivo glioma model.

Intravenous apyrase administration reduces arterial thrombosis in a rabbit model of endothelial denudation in vivo.

The role of adenine nucleotides on vascular and platelet functions has long been established. Apyrase (CD39) takes part of a family of ecto-enzymes that hydrolyze adenosine diphosphate and adenosine triphosphate. The participation of apyrase in the thromboregulatory system is under study. An in vivo experimental model of acute arterial thrombosis was used to test the hypothesis that administering a soluble form of potato apyrase could prevent thrombus formation. Twenty-five white New Zealand male rabbits suffered balloon aortic endothelium denudation and, after 15 days, they were submitted to a thrombosis-triggering protocol with a procoagulant (Russel's viper venom) and epinephrine. After the thrombosis-triggering protocol, 12 animals received two soluble apyrase administrations intravenously (with 90 min intervals), while 13 control animals received no apyrase. Three hours after the triggering protocol, the animals were killed and the rate and area of arterial thrombosis were analyzed. The rate of thrombosis in the apyrase group was significantly lower than that of the control group (16.7 versus 69%, respectively; P = 0.015), as was the area of thrombosis (1.7 +/- 4.3 versus 21.7 +/- 37.4 mm2, respectively; P = 0.008). Our results confirm that apyrase participates in homeostasis through a potent anti-thrombotic effect.

Predictors of in-hospital mortality in patients undergoing elective surgery in a university hospital: a prospective cohort / Preditores de mortalidade intra-hospitalar em pacientes submetidos a cirurgias não eletivas em um hospital universitário: uma coorte prospectiva

Abstract Introduction Morbidity and mortality associated with urgent or emergency surgeries are high compared to elective procedures. Perioperative risk scores identify the non-elective character as an independent factor of complications and death. The present study aims to characterize the population undergoing non-elective surgeries at the Hospital de Clínicas de Porto Alegre and identify the clinical and surgical factors associated with death within 30 days postoperatively. Methodology A prospective cohort study of 187 patients undergoing elective surgeries between April and May 2014 at the Hospital de Clínicas, Porto Alegre. Patient-related data, pre-operative risk situations, and surgical information were evaluated. Death in 30 days was the primary outcome measured. Results The mean age of the sample was 48.5 years, and 84.4% of the subjects had comorbidities. The primary endpoint was observed in 14.4% of the cases, with exploratory laparotomy being the procedure with the highest mortality (47.7%). After multivariate logistic regression, age (odds ratio [OR] 1.0360, p < 0.05), anemia (OR 3.961, p < 0.05), acute or chronic renal insufficiency (OR 6.075, p < 0.05), sepsis (OR 7.027, p < 0.05), and patient-related risk factors for mortality, in addition to the large surgery category (OR 7.502, p < 0.05) were identified. Conclusion The high mortality rate found may reflect the high complexity of the institution's patients. Knowing the profile of the patients assisted helps in the definition of management priorities, suggesting the need to create specific care lines for groups identified as high risk in order to reduce perioperative complications and deaths.

Resumo Introdução Quando comparada a procedimentos eletivos, a morbimortalidade associada às cirurgias de urgência ou emergência é alta. Escores de risco perioperatório identificam o caráter não eletivo como fator independente de complicações e morte. O presente estudo objetiva caracterizar a população submetida a cirurgias não eletivas no Hospital de Clínicas de Porto Alegre e identificar fatores clínicos e cirúrgicos associados à morte em 30 dias no pós-operatório. Metodologia Coorte prospectiva de 187 pacientes submetidos a cirurgias não eletivas entre abril e maio de 2014 no Hospital de Clínicas de Porto Alegre. Avaliaram-se dados relacionados ao paciente, situações de risco pré-operatórias e informações do âmbito cirúrgico. Mensurou-se óbito em 30 dias como desfecho primário. Resultados A média de idade da amostra foi 48,5 anos; 84,4% dos indivíduos apresentavam comorbidades. O desfecho primário foi observado em 14,4% dos casos, laparotomia exploradora foi o procedimento com maior mortalidade (47,7%). Após regressão logística multivariada, identificaram-se idade (odds ratio [OR] 1.0360, p < 0,05), anemia (OR 3.961, p < 0,05), insuficiência renal aguda ou crônica agudizada (OR 6.075, p < 0,05) e sepse (OR 7.027, p < 0,05) como os fatores de risco relacionados ao paciente significativos para mortalidade, além da categoria cirurgia de grande porte (OR 7.502, p < 0,05). Conclusão A elevada taxa de mortalidade encontrada pode refletir a alta complexidade dos pacientes da instituição. O conhecimento do perfil dos pacientes atendidos auxilia na definição de prioridades de gerenciamento, sugere a necessidade de criação de linhas de cuidado específicas para grupos identificados como de alto risco, a fim de reduzir complicações e óbitos no perioperatório.