Pedro Poso Ruiz Neto

Preoxygenation in children: for how long?

Although preoxygenation has been extensively studied, to our knowledge this is the first study addressing its optimal length in children, who form a high risk group for developing hypoxaemia during induction of anaesthesia. Recommended preoxygenation times in children range between 1 and 4 min, but whether one of these times maintains arterial oxygen saturation (Sao2) at an adequate level for a longer time period is unknown. This study was performed on 11 healthy children, randomly distributed into either Group 1 (1 min of preoxygenation, n = 6) or Group 2 (3 min of preoxygenation, n = 5). Sao2 was measured by pulse oximetry. While the patients were breathing room air, Sao2 was similar in both groups (97%) and rose to 100% after preoxygenation in all patients. After intravenous induction of anaesthesia and muscle relaxation, all patients became apnoeic. The time taken for the Sao2 to decrease to 90% was measured. In Group 1 this occurred in 91 s, whereas Group 2 required 144 s. Thus, a 3‐min rather than a 1‐min period of preoxygenation would appear to maintain Sao2 at a safe level for a longer time in children.

O sistema respiratório e o idoso: implicações anestésicas

BACKGROUND AND OBJECTIVES Respiratory complications are responsible for a major number of elderly deaths after surgical procedures. Aging entails an important decrease in respiratory system functional reserves, while an increasing number of elderly people are being submitted to increasingly complex procedures. This study is a review of the respiratory system during aging and of anesthesia-induced changes in the elderly, emphasizing preoperative evaluation of respiratory function, postoperative pulmonary complications and details of anesthetic management. CONTENTS Physiologic respiratory changes due to aging are presented, with emphasis in pulmonary volume and capacity abnormalities, respiratory mechanics and gas exchange provided by anesthesia. Perioperative pulmonary mortality and morbidity in elderly patients are addressed, emphasizing the importance of appropriate preoperative evaluation, from stress tests to specific tests, to quantify pulmonary functional reserves. Appropriate anesthetic techniques for the elderly are discussed. CONCLUSIONS Aging brings about several respiratory system changes. Evidences have shown that, even in the absence of pulmonary disease, advanced age is a risk factor for postoperative pulmonary complications. It is necessary a thorough evaluation of preoperative respiratory function, adequate anesthetic management and specific postoperative care.JUSTIFICATIVA E OBJETIVOS: As complicacoes respiratorias sao responsaveis por grande parte dos obitos apos procedimentos cirurgicos que ocorrem na populacao geriatrica. O envelhecimento causa importante diminuicao da reserva funcional do sistema respiratorio, e um numero crescente de pacientes idosos esta sendo submetido a procedimentos cada vez mais complexos. O objetivo deste trabalho e revisar o sistema respiratorio durante o processo de envelhecimento, as alteracoes causadas pela anestesia no idoso, enfatizando a avaliacao pre-operatoria da funcao respiratoria, complicacoes pulmonares pos-operatorias e detalhes do manuseio anestesico. CONTEUDO: Sao apresentadas as alteracoes respiratorias fisiologicas do envelhecimento. Sao enfatizadas as alteracoes de volume e capacidades pulmonares, da mecânica respiratoria e de trocas gasosas proporcionadas pela anestesia. Sao abordados aspectos relativos a morbimortalidade pulmonar pos-operatoria em geriatria, destacando-se a importância da adequada avaliacao pre-operatoria, considerando-se desde testes de esforco ate testes especificos que quantificam a reserva funcional pulmonar. Sao discutidas tecnicas anestesicas apropriadas em idosos. CONCLUSOES: O envelhecimento e acompanhado de alteracoes no sistema respiratorio. Evidencias demonstram que mesmo na ausencia de pneumopatia, a idade avancada constitui fator de risco para complicacoes pulmonares no pos-operatorio. Deve haver preocupacao com adequada avaliacao pre-operatoria da funcao respiratoria, apropriado manuseio anestesico e cuidados pos-operatorios especificos.

[The respiratory system and the elderly: anesthetic implications.].

BACKGROUND AND OBJECTIVES Respiratory complications are responsible for a major number of elderly deaths after surgical procedures. Aging entails an important decrease in respiratory system functional reserves, while an increasing number of elderly people are being submitted to increasingly complex procedures. This study is a review of the respiratory system during aging and of anesthesia-induced changes in the elderly, emphasizing preoperative evaluation of respiratory function, postoperative pulmonary complications and details of anesthetic management. CONTENTS Physiologic respiratory changes due to aging are presented, with emphasis in pulmonary volume and capacity abnormalities, respiratory mechanics and gas exchange provided by anesthesia. Perioperative pulmonary mortality and morbidity in elderly patients are addressed, emphasizing the importance of appropriate preoperative evaluation, from stress tests to specific tests, to quantify pulmonary functional reserves. Appropriate anesthetic techniques for the elderly are discussed. CONCLUSIONS Aging brings about several respiratory system changes. Evidences have shown that, even in the absence of pulmonary disease, advanced age is a risk factor for postoperative pulmonary complications. It is necessary a thorough evaluation of preoperative respiratory function, adequate anesthetic management and specific postoperative care.JUSTIFICATIVA E OBJETIVOS: As complicacoes respiratorias sao responsaveis por grande parte dos obitos apos procedimentos cirurgicos que ocorrem na populacao geriatrica. O envelhecimento causa importante diminuicao da reserva funcional do sistema respiratorio, e um numero crescente de pacientes idosos esta sendo submetido a procedimentos cada vez mais complexos. O objetivo deste trabalho e revisar o sistema respiratorio durante o processo de envelhecimento, as alteracoes causadas pela anestesia no idoso, enfatizando a avaliacao pre-operatoria da funcao respiratoria, complicacoes pulmonares pos-operatorias e detalhes do manuseio anestesico. CONTEUDO: Sao apresentadas as alteracoes respiratorias fisiologicas do envelhecimento. Sao enfatizadas as alteracoes de volume e capacidades pulmonares, da mecânica respiratoria e de trocas gasosas proporcionadas pela anestesia. Sao abordados aspectos relativos a morbimortalidade pulmonar pos-operatoria em geriatria, destacando-se a importância da adequada avaliacao pre-operatoria, considerando-se desde testes de esforco ate testes especificos que quantificam a reserva funcional pulmonar. Sao discutidas tecnicas anestesicas apropriadas em idosos. CONCLUSOES: O envelhecimento e acompanhado de alteracoes no sistema respiratorio. Evidencias demonstram que mesmo na ausencia de pneumopatia, a idade avancada constitui fator de risco para complicacoes pulmonares no pos-operatorio. Deve haver preocupacao com adequada avaliacao pre-operatoria da funcao respiratoria, apropriado manuseio anestesico e cuidados pos-operatorios especificos.

El sistema respiratorio y el anciano: implicaciones anestésicas

BACKGROUND AND OBJECTIVES Respiratory complications are responsible for a major number of elderly deaths after surgical procedures. Aging entails an important decrease in respiratory system functional reserves, while an increasing number of elderly people are being submitted to increasingly complex procedures. This study is a review of the respiratory system during aging and of anesthesia-induced changes in the elderly, emphasizing preoperative evaluation of respiratory function, postoperative pulmonary complications and details of anesthetic management. CONTENTS Physiologic respiratory changes due to aging are presented, with emphasis in pulmonary volume and capacity abnormalities, respiratory mechanics and gas exchange provided by anesthesia. Perioperative pulmonary mortality and morbidity in elderly patients are addressed, emphasizing the importance of appropriate preoperative evaluation, from stress tests to specific tests, to quantify pulmonary functional reserves. Appropriate anesthetic techniques for the elderly are discussed. CONCLUSIONS Aging brings about several respiratory system changes. Evidences have shown that, even in the absence of pulmonary disease, advanced age is a risk factor for postoperative pulmonary complications. It is necessary a thorough evaluation of preoperative respiratory function, adequate anesthetic management and specific postoperative care.JUSTIFICATIVA E OBJETIVOS: As complicacoes respiratorias sao responsaveis por grande parte dos obitos apos procedimentos cirurgicos que ocorrem na populacao geriatrica. O envelhecimento causa importante diminuicao da reserva funcional do sistema respiratorio, e um numero crescente de pacientes idosos esta sendo submetido a procedimentos cada vez mais complexos. O objetivo deste trabalho e revisar o sistema respiratorio durante o processo de envelhecimento, as alteracoes causadas pela anestesia no idoso, enfatizando a avaliacao pre-operatoria da funcao respiratoria, complicacoes pulmonares pos-operatorias e detalhes do manuseio anestesico. CONTEUDO: Sao apresentadas as alteracoes respiratorias fisiologicas do envelhecimento. Sao enfatizadas as alteracoes de volume e capacidades pulmonares, da mecânica respiratoria e de trocas gasosas proporcionadas pela anestesia. Sao abordados aspectos relativos a morbimortalidade pulmonar pos-operatoria em geriatria, destacando-se a importância da adequada avaliacao pre-operatoria, considerando-se desde testes de esforco ate testes especificos que quantificam a reserva funcional pulmonar. Sao discutidas tecnicas anestesicas apropriadas em idosos. CONCLUSOES: O envelhecimento e acompanhado de alteracoes no sistema respiratorio. Evidencias demonstram que mesmo na ausencia de pneumopatia, a idade avancada constitui fator de risco para complicacoes pulmonares no pos-operatorio. Deve haver preocupacao com adequada avaliacao pre-operatoria da funcao respiratoria, apropriado manuseio anestesico e cuidados pos-operatorios especificos.