Development of a Puncture Technique for Implanting Temporary Vascular Shunts in a Porcine Model.

BACKGROUND: Temporary vascular shunts (TVSs) are an effective tool for rapidly restoring blood flow to a limb or organ that has experienced vascular injury and ischemia and for which revascularization is not an immediate option. Usually, through an opening in the skin, the TVS is positioned within the proximal and distal stumps of the injured vessel, restoring perfusion and stopping the ischemia. The aim of this study is to compare standard TVS technique and a developed puncture technique for implanting TVS and to evaluate the utility and feasibility of this protocol after arterial lesions, in pigs. METHODS: Vascular injuries were inflicted in both hind limbs of 30 pigs, and vascular interventions were performed, using standard and puncture TVS. Because each pig was implanted with both types of TVSs, it was possible to simultaneously monitor, analyze, and compare parameters such as, the mean arterial pressure (MAP, in mm Hg), blood flow (mL/min), and insertion times, in the same animal. RESULTS: It was observed that the MAP in the limbs recovered and approached systemic MAP, in 100% of the experiments, in both groups. Analysis of the blood flow data showed that this parameter was significantly reduced in the puncture TVS group (110.36 ± 9.99 mL/min vs. 153.20 ± 18.57 mL/min, P = 0.001). On the other hand, the insertion time for the standard TVS was significantly greater than that of the puncture shunt (15.32 ± 3.08 min vs. 10.37 ± 1.7 min, P = 0.001). Furthermore, it was found that the primary and secondary patency and complication rates were similar for both TVS types. CONCLUSION: Thus, given the adequate MAP recovery and reduction in implantation time observed in this experimental and in an animal model study, the use of the puncture TVS technique is effective and feasible.

Adapting the Bird Mark 7 to deliver noninvasive continuous positive airway pressure: a bench study.

OBJECTIVE: To test the efficiency of the Bird Mark 7 ventilator adapted to deliver continuous positive airway pressure (CPAP) in noninvasive positive pressure ventilation. METHODS: This was an experimental study using a mechanical model of the respiratory system. A Bird Mark 7 ventilator was supplied with 400 and 500 kPa and tested at CPAP of 5, 10 and 15 cmH2O. The following variables were analyzed: difference between the preset CPAP and the CPAP actually attained CPAP (trueCPAP); area of airway pressure at the CPAP level employed (AREA CPAP); and tidal volume generated. RESULTS: Adapting the Bird Mark 7 to offer CPAP achieved the expected tidal volume in all situations of inspiratory effort (normal or high), ventilator pressure supply (400 or 500 kPa) and CPAP value (5, 10 or 15 cmH2O). At a CPAP of 5 or 10 cmH2O, the trueCPAP was near the preset level, and the AREA CPAP was near zero. However, at a CPAP of 15 cmH2O, the value remained below the preset, and the AREA CPAP was high. CONCLUSION: The efficiency of Bird Mark 7 adaptation in offering CPAP was satisfactory at 5 and 10 cmH2O but insufficient at 15 cmH2O. If adapted as described in our study, the Bird Mark 7 might be an option for offering CPAP up to 10 cmH2O in areas where little or no equipment is available.

Adaptação do Bird Mark 7 para oferta de pressão positiva contínua nas vias aéreas em ventilação não-invasiva: estudo em modelo mecânico / Adapting the Bird Mark 7 to deliver noninvasive continuous positive airway pressure: a bench study

OBJETIVO: Testar a eficiência da adaptação do ventilador Bird Mark 7 para oferecer pressão positiva contínua nas vias aéreas, conhecida como continuous positive airway pressure (CPAP) em inglês, em ventilação não-invasiva. MÉTODOS: Estudo experimental utilizando um modelo mecânico do sistema respiratório. O Bird Mark 7 foi alimentado com 400 e 500 kPa e foi testado em CPAP de 5, 10 e 15 cmH2O. Para avaliar a eficiência da adaptação foram analisados os seguintes variáveis: diferença entre a CPAP pré-determinada e a CPAP realmente atingida (CPAPreal); área da pressão da via aérea sob o nível de CPAP ajustado (ÁREA CPAP); e volume corrente gerado. RESULTADOS: A adaptação do Bird Mark 7 para oferecer CPAP em ventilação não-invasiva conseguiu atingir o volume corrente esperado em todas as situações de esforço inspiratório (normal ou elevado), pressão de alimentação (400 ou 500 kPa) e valor de CPAP (5, 10 ou 15 cmH2O). Para os CPAPs de 5 e 10 cmH2O, o CPAPreal foi muito próximo do pré-determinado, e a ÁREA CPAP teve valor próximo de zero. Para o CPAP de 15 cmH2O, o CPAPreal ficou abaixo do pré-determinado, e a ÁREA CPAP teve valor elevado. CONCLUSÃO: A eficiência da adaptação do Bird Mark 7 para oferecer CPAP em ventilação não-invasiva foi boa para os valores de CPAP de 5 e 10 cmH2O e insuficiente para CPAP de 15 cmH2O. Se adaptado como em nosso estudo, o Bird Mark 7 pode ser uma opção para oferta de CPAP até 10 cmH2O em locais onde equipamentos de ventilação não-invasiva são escassos ou inexistentes.

OBJECTIVE: To test the efficiency of the Bird Mark 7 ventilator adapted to deliver continuous positive airway pressure (CPAP) in noninvasive positive pressure ventilation. METHODS: This was an experimental study using a mechanical model of the respiratory system. A Bird Mark 7 ventilator was supplied with 400 and 500 kPa and tested at CPAP of 5, 10 and 15 cmH2O. The following variables were analyzed: difference between the preset CPAP and the CPAP actually attained CPAP (trueCPAP); area of airway pressure at the CPAP level employed (AREA CPAP); and tidal volume generated. RESULTS: Adapting the Bird Mark 7 to offer CPAP achieved the expected tidal volume in all situations of inspiratory effort (normal or high), ventilator pressure supply (400 or 500 kPa) and CPAP value (5, 10 or 15 cmH2O). At a CPAP of 5 or 10 cmH2O, the trueCPAP was near the preset level, and the AREA CPAP was near zero. However, at a CPAP of 15 cmH2O, the value remained below the preset, and the AREA CPAP was high. CONCLUSION: The efficiency of Bird Mark 7 adaptation in offering CPAP was satisfactory at 5 and 10 cmH2O but insufficient at 15 cmH2O. If adapted as described in our study, the Bird Mark 7 might be an option for offering CPAP up to 10 cmH2O in areas where little or no equipment is available.

Acurácia da rinometria na avaliação da válvula nasal: estudo em 385 pacientes / The accuracy of rhinometry in the evaluation of the nasal valve: study in 385 patients

Introdução: A rinometria acústica (RA) avalia área e volume de regiões anteriores do nariz. O início do rinograma apresenta dois entalhes: o segundo corresponde à área de secção transversa da válvula nasal (ASM2). O objetivo deste estudo é avaliar a válvula nasal. Método: Foram incluídos neste estudo 385 pacientes, 93 com queixa funcional. Utilizamos o aparelho de rinometria acústica da Rhinometrics, o Rhino Scan 2.5. Os gráficos foram armazenados e a ASM2 (exame com vasoconstrictor) foi analisada para determinar os parâmetros da rinometria nos pacientes com e sem queixa funcional. Resultados: Dentre os pacientes avaliados, observamos: 224 pacientes com ASM2 > 0,40cm² sem queixa funcional, 68 pacientes com ASM2 entre 0,25 e 0,40 cm² sem queixa funcional e 93 pacientes com queixa funcional, sendo 28 entre 0,25 e 0,40 cm² e 65 < 0,25 cm². Discussão: Os resultados observados demonstram que nenhum paciente com ASM2 maior do que 0,40 cm2 tem queixa funcional, o que permite classificar a válvula nasal interna como funcionante, assim como nenhum paciente com ASM2 menor do que 0,25 cm² consegue respirar adequadamente, o que leva a uma condição de válvula denominada insuficiente. Alguns pacientes com ASM2 entre 0,25 e 0,40cm² apresentaram queixa funcional, enquanto outros não, portanto, as válvulas nasais com este valor de área de secção transversa são classificadas como limítrofes. Conclusão: Rinometria é o único método que avalia a insuficiência da válvula nasal interna de maneira objetiva.

Introduction: Acoustic rhinometry (RA) is evaluates area and volume of regions above the nose. The beginning of rhinogram presents two notches: the second is the cross-sectional area of the nasal valve (ASM2). The purpose of this study is to evaluate the nasal valve, which limits the area for greater resistance to nasal airflow, about half the total resistance in patients with and without nasal respiratory complaint. Methods: The study included 385 patients in this study, 93 with functional complaint. We use the apparatus of the acoustic rhinometry Rhinometrics, the Rhino Scan 2.5. The graphics were stored and ASM2 (examination with vasoconstrictor) were analyzed to determine the parameters of rhinometry in patients with and without functional complaint. Results: 224 patients with ASM2> 0.40 cm² without complaint functional, 68 patients with ASM2 between 0.25 and 0.40 cm² without complaint functional and 93 patients with functional complaint, being 28 between 0.25 and 0.40 cm² and 65 <0.25 cm². Discussion: The findings show that no patient with ASM2 greater than 0.40 cm² have functional complaint, which qualify as the internal nasal valve functioning, and no patient with ASM2 less than 0.25 cm² can breathe properly, which leads to a condition called insufficient valve. Some patients with ASM2 between 0.25 and 0.40 cm² have complained functional, while others do not, therefore, the nasal valve with a figure of cross-sectional area are classified as borderline. Conclusion: The Rhinometry is the only method that assesses the failure of internal nasal valve so objective.