Dora Catré

Anesthesia and surgical microvascular flaps

BACKGROUND AND OBJECTIVES Head and neck reconstructive surgery represents a major challenge facing the need to achieve a good cosmetic and functional outcome. Anesthesia may be an important and determining factor in the technique success due to its role in hemodynamic stability and regional blood flow. On the other hand, regional anesthesia, changes in blood volume, and vasoactive drugs may influence blood flow in the flap. Thus, due to the lack of recommendations based on evidence, the anesthetic technique of these procedures is most often inspired in pathophysiological considerations. The aim of this paper is to review relevant aspects regarding anesthetic practice in these cases. CONTENT Importance of the type of surgical flap, physiological considerations, and anesthetic approach. CONCLUSIONS In surgery with microvascular flaps, the anesthesiologist role includes optimizing the physiological conditions for the survival of the flap without increasing the non-surgical morbidity.

Early mortality after neonatal surgery: analysis of risk factors in an optimized health care system for the surgical newborn

OBJECTIVE Anesthetic and operative interventions in neonates remain hazardous procedures, given the vulnerability of the patients in this pediatric population. The aim was to determine the preoperative and intraoperative factors associated with 30-day post-operative mortality and describe mortality outcomes following neonatal surgery under general anesthesia in our center. METHODS Infants less than 28 days of age who underwent general anesthesia for surgery during an 11-year period (2000 - 2010) in our tertiary care pediatric center were retrospectively identified using the pediatric intensive care unit database. Multiple logistic regression was used to identify independent preoperative and intraoperative factors associated with 30-day post-operative mortality. RESULTS Of the 437 infants in the study (median gestational age at birth 37 weeks, median birth weight 2,760 grams), 28 (6.4%) patients died before hospital discharge. Of these, 22 patients died within the first post-operative month. Logistic regression analysis showed increased odds of 30-day post-operative mortality among patients who presented American Society of Anesthesiologists physical status (ASA) score 3 or above (odds ratio 19.268; 95%CI 2.523 - 147.132) and surgery for necrotizing enterocolitis/gastrointestinal perforation (OR 5.291; 95%CI 1.962 - 14.266), compared to those who did not. CONCLUSION The overall in-hospital mortality of 6.4% is within the prevalence reported for developed countries. Establishing ASA score 3 or above and necrotizing enterocolitis/gastrointestinal perforation as independent risk factors for early mortality in neonatal surgery may help clinicians to more adequately manage this high risk population.

Effect of traction sutures in the distal esophagus of the rat: a model for esophageal elongation by Foker's method.

SUMMARY This study aimed to evaluate a rat model of esophageal elongation using traction sutures by the Fokers method. After esophageal division and closure of the distal segment at approximately 4 mm from the cardia, traction sutures were placed for progressive stretching until the 7(th) postoperative day in the experimental group (n = 10), whilst no traction sutures were placed in the esophagus of the control group (n = 10). Clinical outcome as well as macroscopic and microscopic esophageal morphology were evaluated in both groups. All rats survived the surgical procedure and the anesthetic recovery period. Disruption of sutures during the traction period occurred in 20% of the rats, which required reoperation. Integrity of the stretched esophagus was confirmed at autopsy in all animals. In contrast to the control group, the experimental group showed a significantly more elongated (average length 6.10 +/- 1.10 mm versus 3.91 +/- 0.17 mm, (P = 0.0001)) and thicker esophagus (average mass 35.9 +/- 3.31 mg versus 15.6 +/- 1.71 mg in the control group, P = 0.0001). Histopathological examination showed a relatively well preserved morphology of the stretched esophagus. These observations suggest that esophageal stretching by traction sutures can be undertaken reliably in a rat model, resulting in elongation and mass increase of the stretched esophagus without important tissue damage. As this model mimics Fokers method, it may serve as a useful model in further research studies and may be used to train in surgical technique.

Fatores preditivos de complicações graves em cirurgia neonatal

OBJECTIVE To investigate the incidence and severity of early postoperative complications and to identify their risk factors in newborns undergoing surgery under general anesthesia. METHODS We conducted a retrospective analysis of data from 437 critically ill newborns undergoing surgery in a tertiary pediatric surgical center, between January 2000 and December 2010. Complications that occurred within the first 30 days after surgery were classified using the Clavien-Dindo system, for which grades III to V were considered severe. We used univariate and multivariate analysis to evaluate pre- and intraoperative variables potentially predictive of severe postoperative complications. RESULTS The incidence of at least one serious complication was 23%, with a median of one complication per patient 1:3. Altogether, there were 121 serious complications. Of these, 86 required surgical, endoscopic or radiological interventions (grade III), 25 endangered life, with uni or multi-organ failure (grade IV) and ten resulted in death (grade V). The most common complications were technical (25%), gastrointestinal (22%) and respiratory (21%). We identified four independent risk factors for severe postoperative complications: reoperation, operation for congenital diaphragmatic hernia, preterm birth less than 32 weeks of gestational age and abdominal surgery. CONCLUSION The incidence of severe postoperative complications after neonatal surgeries under general anesthesia remains high. The conditions considered independent risk factors for those can guide interventions to improve results.

Anestesia e retalhos microvascularizados

JUSTIFICATIVA E OBJETIVOS: A cirurgia reconstrutiva de cabeca e pescoco representa um grande desafio perante a necessidade de se conseguir um bom resultado estetico e funcional. A anestesia pode ser um fator importante e determinante no sucesso da tecnica dado o seu papel na estabilidade hemodinâmica e no fluxo de sangue regional. Por outro lado, a anestesia regional, as variacoes no volume sanguineo e o uso de farmacos vasoativos podem tambem influenciar o fluxo de sangue no retalho. Assim, devido a falta de recomendacoes baseadas em evidencia, a tecnica anestesica destes procedimentos e inspirada na maioria das vezes nas consideracoes patofisiologicas. O objetivo deste artigo e rever os aspectos relevantes no que diz respeito a pratica anestesica destes casos. CONTEUDO: Importância do tipo do retalho, consideracoes fisiologicas e abordagem anestesica. CONCLUSOES: O papel do anestesiologista inclui para cirurgia com retalhos microvasculares a otimizacao das condicoes fisiologicas para a sobrevida do retalho sem aumentar a morbidade nao cirurgica.

Lasting Developmental Effects of Neonatal Fentanyl Exposure in Preweanling Rats

The present study aimed to determine whether neonatal treatment with fentanyl has lasting effects on stressed developing brain. Six-day-old rats were assigned to one of three groups (10 males/group): (1) fentanyl (incision+fentanyl), (2) saline (incision+0.9% saline), and (3) unoperated (unoperated sham). Pups with a plantar paw incision received repetitive subcutaneous injections of fentanyl or vehicle through postnatal days (PNDs) 6 to 8. A nonoperated sham group served as nonstressed control. Studies included assessment of development from PND 6 to PND 21 (growth indices and behavioral testing). Fentanyl administered twice daily for three days after surgical incision had no impact on early growth and development, as measured on PND 9, but showed a lasting impact on later growth, enhanced behavioral development, and lower anxiety, as measured through PNDs 10–21. While this does not completely support a benefit from such treatment, our findings may contribute to support the neonatal use of fentanyl, when indicated, even in premature newborns.

Protective perioperative strategy using a third generation hydroxyethyl starch during surgery in a murine model of liver reperfusion injury

PURPOSE To investigate whether a third generation colloid, hydroxyethyl starch (HES 130/0.4), used for perioperative fluid therapy, protects the rat liver against the late-phase response of ischemia/reperfusion injury (IRI) and if inhibition of neutrophil hepatic infiltration plays a part in this mechanism. METHODS Wistar rats were used (8 in each group). Three groups had IRI induced by lobar vascular occlusion (60 minutes) and reperfusion (24 hours) and received HES (13 mL/kg iv), 7.5% saline (HS) (13 mL/kg iv) or no fluid. Three other groups were sham-operated and received the same fluid as the test groups. After 24 hours of reperfusion, blood was drawn for alanine aminotransferase (ALT) quantification and ischemic liver samples were taken for histological study (hematoxylin and eosin and chloroacetate staining of neutrophils). RESULTS HES treatment attenuated the elevation in serum ALT (P=0.001) and reduced the extent of hepatocellular necrosis (P<0.01) compared with the IRI controls. HES-mediated cytoprotection was associated with a decrease of infiltration of neutrophils in the necrotic areas (P<0.05) compared with the untreated IRI rats, but not with the volume control IRI rats (P>0.05). CONCLUSION Hydroxyethyl starch suppresses inflammatory response and ameliorates the late-phase response of hepatic ischemia/reperfusion injury.

Anestesia em pacientes com teste de coombs direto positivo: relato de três casos

JUSTIFICATIVA E OBJETIVOS: Existe associacao entre anemias hemoliticas autoimunes (AHA) e doenca neoplasica, com consequente incompatibilidade sanguinea que dificulta a transfusao destes pacientes. Os autores descrevem e discutem a conduta em tres casos com Teste de Coombs Direto (TCD) positivo e impossibilidade de determinacao de grupo sanguineo propostos para intervencao cirurgica por doenca neoplasica. RELATO DOS CASOS: 1o caso: paciente do sexo masculino, 87 anos, ASA III, para intervencao cirurgica por neoplasia do colon. Apresentou TCD positivo, foi tratado com corticoide, imunoglobulina (Ig) e eritropoietina, tendo-se conseguido tipar. No intraoperatorio, administrou-se uma unidade de concentrado eritrocitario (UCE) sem incidentes. Faleceu 24 horas depois por acidente vascular encefalico isquemico. 2o caso: paciente do sexo masculino, 77 anos, ASA III, para intervencao cirurgica de carcinoma gastrico. Apresentou TCD positivo, realizou tratamento com corticoide e Ig, nao se conseguindo tipar. A intervencao cirurgica decorreu sem incidentes. Faleceu ao 18o dia pos-operatorio apos parada cardiorrespiratoria. 3o caso: paciente do sexo feminino, 80 anos, ASA IV, para laparotomia exploradora de urgencia. Apresentou tambem TCD positivo. A intervencao cirurgica (hemicolectomia) decorreu sem incidentes. Faleceu as 48 horas do pos-operatorio com acidente vascular encefalico isquemico. CONCLUSOES: Os autoanticorpos (Ac) circulantes nas AHA podem impossibilitar tipagem sanguinea e disponibilidade de sangue compativel para transfusao. O tratamento correto da AHA visa a remissao dos Ac e ao tratamento da anemia. Na urgencia em transfundir sem possibilidade de tipagem, a transfusao sanguinea surge como medida life-saving.

Anesthesia in patients with positive direct coombs test: report of three cases

BACKGROUND AND OBJECTIVES Neoplasias can be associated with autoimmune hemolytic anemia (AHA) with the consequent blood incompatibility that hinders blood transfusion. The authors describe and discuss the conduct in three patients undergoing surgical intervention for neoplastic disease with positive Coombs Test (CT), and the impossibility to determine the blood type. CASE REPORT 1st case: 87-year old male patient, ASA III, scheduled for surgery for colon neoplasia. The patient had positive CT, being treated with corticosteroids, immunoglobulin (Ig), and erythropoietin, after which it was possible to determine his blood type. One unit of packed-red blood cells (PRBC) was transfused intraoperatively without intercurrences. Twenty four hours after the transfusion, the patient died due to an ischemic stroke. 2nd case: 77-year old male patient, ASA III, scheduled for surgery for a gastric carcinoma. The patient had a positive CT, being treated with corticosteroids and Ig, but we were unable to determine his blood type. The surgery was performed without intercurrences. The patient died on the 18th postoperative day after a cardiorespiratory arrest. 3rd case: 80-year old female patient, ASA IV, undergoing emergency exploratory laparotomy. She also had a positive CT. The surgery (hemicolectomy) was performed without intercurrences. The patient died 48 hours after the surgery from an ischemic stroke. CONCLUSIONS Circulating autoantibodies in AHA can make it impossible to determine the blood type to transfuse compatible blood. Proper treatment of AHA is aimed at remission of autoantibodies and anemia. When it is not possible to determine the blood type, the procedure should be a life-saving blood transfusion.