Criação do pneumoperitônio por punção no hipocôndrio esquerdo: sistema nebuloso (fuzzy) de suporte à decisão pela relação pressão/volume do posicionamento da ponta da agulha de Veress

• Ano de defesa: 2008
• Autor(a) principal: Becker Junior, Otavio Monteiro [UNIFESP]
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de São Paulo (UNIFESP)
• Palavras-chave em Português: Pneumoperitônio artificial; Insuflação/métodos; Laparoscopia/métodos; Procedimentos operatórios; Lógica Fuzzy
• Link de acesso: http://repositorio.unifesp.br/handle/11600/9278

Objectives: To evaluate the Veress needle left hypochondrium puncture efficiency, the accuracy of reported tests results and the prognosis value of intra peritoneal pressure measures as function of the injected gas volumes in a fuzzy logic modeling control system. Methods: 91 patients, without any restrictions, sequentially scheduled for video laparoscopic procedures were punctured in the left hypochondrium. They were all under general anesthesia and mechanical controlled ventilation as described in the protocol. Five tests regarding the intra abdominal positioning of the needle tip were carried out: aspiration test – AT, liquid infusion resistance test – ResT, infused liquid recovery test – RecT, dripping test – DT, and the initial intra peritoneal pressure test – IIPT. The test‟s results were compared with data from previous reports from demographic selected group. The levels of sensitivity (SE), specificity (SP), the predictive positive values (PPV) and the negative values (PNV) were calculated. The volume and pressure measures were recorded at every 20 seconds until 12 mmHg. Statistical and fuzzy inferential methods were applied for computational modeling. Results: 13 failures occurred. The AT showed SP=100% and PNV=100%. The ResT showed SE=100%, and SP=0, PPV=85,71%, PNV did not apply. The RecT showed SE= 100%, SP= 53,84%, PPV= 92,85%; PNV= 100%. DT: SE= 100%; SP= 61,53%; PPV= 93,97% PNV= 100%. The IIPP showed SE, SP, PPV e PNV=100%. The pressure values are function of the injected gas volume and suffers influence mainly from the BMI (R²= 73% for homogeneous group, R²=58,81% for heterogeneous). Conclusion: The left hypochondryum puncture is efficient, the tests carried out guide the surgeon despite BMI, sex distinction or previous surgery. The intra peritoneal pressure measure as function of the injected gas volume is a parameter of the needles‟ tip positioning, fluctuating according the body mass index, sex and previous surgery. Fuzzy logic demonstrated to be efficacious and efficient in modeling the volume/pressure relation. The heuristic knowledge was more efficient in building a fuzzy controller.