The smaller volemic state from hypertonic (7.5%) saline (HS) solution administration in hemorrhagic shock can determine lesser systemic oxygen delivery and tissue oxygenation than conventional plasma expanders. In a model of hemorrhagic shock in dogs, we studied the systemic and gastrointestinal oxygenation effects of HS and hyperoncotic (6%) dextran-70 in combination with HS (HSD) solutions in comparison with lactated Ringer's (LR) and (6%) hydroxyethyl starch (HES) solutions. Forty-eight mongrel dogs were anesthetized, mechanically ventilated, and subjected to splenectomy. A gastric air tonometer was placed in the stomach for intramucosal gastric CO(2) (Pgco(2)) determination and for the calculation of intramucosal pH (pHi): The dogs were hemorrhaged (42% of blood volume) to hold mean arterial blood pressure at 40-50 mm Hg over 30 min and were then resuscitated with LR (n = 12) in a 3:1 relation to removed blood volume; HS (n = 12), 6 mL/kg; HSD (n = 12), 6 mL/kg; and HES (mean molecular weight, 200 kDa; degree of substitution, 0.5) (n = 12) in a 1:1 relation to the removed blood volume. Hemodynamic, systemic, and gastric oxygenation variables were measured at baseline, after 30 min of hemorrhage, and 5, 60, and 120 min after intravascular fluid resuscitation. After fluid resuscitation, HS showed significantly lower arterial pH and mixed venous Po(2) and higher systemic oxygen uptake index and systemic oxygenation extraction than LR and HES (P < 0.05), whereas HSD showed significantly lower arterial pH than LR and HES (P < 0.05). Only HS and HSD did not return arterial pH and pHi to control levels (P < 0.05). In conclusion, all solutions improved systemic and gastrointestinal oxygenation after hemorrhagic shock in dogs. However, the HS solution showed the worst response in comparison to LR and HES solutions in relation to systemic oxygenation, whereas HSD showed intermediate values. HS and HSD solutions did not return regional oxygenation to control values.

When operated by trained professionals, and provided safety rules are followed, laser is useful and safe both for patients and the medical staff.

A pressão expiratória final de dióxido de carbono (PETCO2) está disponível nas salas de operações, como tecnologia anestésica, relacionando-se com metabolismo, ventilação e circulação. Quando os dois primeiros parâmetros estão controlados, a PETCO2 reflete o fluxo pulmonar, portanto o débito cardíaco (DC). A PETCO2 menor que 20 mmHg está associada com baixo DC (< 2L/min), mesmo que outros parâmetros hemodinâmicos estejam adequados. A propósito, aumentos posteriores da pré-carga, redução da pós-carga, estabelecimento de adequado sincronismo atrioventricular ou aumento no inotropismo são necessários para elevar a PETCO2 acima de 25 mmHg. A literatura descreve o uso de PETCO2 como avaliação adequada da ressuscitação cardiopulmonar depois de parada cardíaca, sendo método alternativo à termodiluição na avaliação do DC. Pouco tem sido relatado sobre o seu uso na cirurgia cardíaca. O objetivo do presente trabalhado foi avaliar o momento adequado para o "desmame" da circulação extracorpórea (CEC), considerando a PETCO2 como parâmetro de avaliação do DC. No período de junho de 1996 a junho de 1997, 200 pacientes foram submetidos a cirurgia cardíaca com CEC, com avaliação da medida da PETCO2 na saída da CEC. A PETCO2 em torno de 27 mmHg foi indicativa de um bom DC, o suficiente para o desmame da CEC, desde que outros parâmetros hemodinâmicos e metabólicos estivessem adequados. Nenhum paciente retornou à CEC por falha cardiopulmonar, podendo ser utilizado como método confiável para o "desmame" da CEC.
Capnography has been recommended as an anesthetic technique and the end-tidal carbon dioxide tension (PETCO2) is available in the operating room. PETCO2 is governed by metabolism, ventilation and circulation. When the first two parameters are controlled, PETCO2 reflects the lung flow, therefore the cardiac output. Studies have shown that PETCO2 lower than 20 mmHg is invariably associated with a cardiac output less than 2 L/min, even if other hemodynamic parameters are appropriate. Further increases in the preload, reduction of the afterload, establishment of an appropriate atrioventricular synchrony or increasing inotropy is necessary to increase PETCO2 above 25 mmHg. A considerable body of literature describes the use of PETCO2 to assess the adequacy of cardiopulmonary resuscitation after cardiac arrest. Besides, attempts have been made to use PETCO2 as an alternative to the thermodilution technique for determining cardiac output. Little has been reported of its use in cardiac surgery. From June 1996 to June 1997 we have studied 200 patients, submitted to CPB suggesting that PETCO2 around 27 mmHg would indicate a cardiac output good enough to wean the patients on the cardiopulmonary circulation so long as other hemodynamic and metabolic parameters were adequate. None of the patients required CPB giving us the impression that end-tidal carbon dioxide tension generally indicates an appropriate cardiac output