Effects of the use of mechanical ventilation weaning protocol in the Coronary Care Unit: randomized study.

OBJECTIVE: To compare mechanical ventilation weaning based on a protocol using the spontaneous breathing trial against mechanical ventilation weaning without a standardized protocol in heart patients. METHODS: Prospective, open, randomized study. In 2006, 36 patients undergoing mechanical ventilation for over 24 hours were randomized into two groups: control group - eighteen patients whose mechanical ventilation weaning was performed according to the different procedures adopted by the multidisciplinary team; and experimental group - eighteen patients weaned according to previously established protocol. RESULTS: Control group patients started the weaning process sooner than experimental group patients (74.7 ± 14.7 hours vs. 185.7 ± 22.9 hours, P=0.0004). However, after the experimental group patients were ready for weaning, the extubation was carried out more rapidly than in the control group (149.1 ± 3.6 min vs. 4179.1 ± 927.8 min, P < 0.0001) with significantly lower reintubation rates (16.7% vs. 66.7%, P = 0.005). CONCLUSION: The use of a specific protocol based on the spontaneous breathing trial for mechanical ventilation weaning in heart patients had better outcomes than weaning carried out without a standardized protocol, with shorter weaning times and lower reintubation rates.

Efeitos da aplicação de protocolo de desmame de ventilação mecânica em Unidade Coronária: estudo randomizado / Effects of the use of mechanical ventilation weaning protocol in the Coronary Care Unit: randomized study

OBJETIVO: Comparar o desmame da ventilação mecânica realizado segundo a aplicação de protocolo baseado no teste de respiração espontânea e o mesmo procedimento realizado sem padronização, em pacientes cardiopatas. MÉTODOS: Estudo prospectivo, aberto e randomizado. Em 2006, 36 pacientes em ventilação mecânica há mais de 24 horas foram randomizados em dois grupos: grupo controle: 18 pacientes foram submetidos ao desmame da ventilação mecânica de acordo com os procedimentos adotados pela equipe multiprofissional e grupo experimental: 18 pacientes foram submetidos ao desmame de acordo com protocolo previamente estabelecido. RESULTADOS: Os pacientes do grupo controle iniciaram o desmame precocemente em relação ao grupo experimental (74,7 ± 14,7 horas vs. 185,7 ± 22,9 horas; P=0,0004), Porém, após os pacientes do grupo experimental estarem aptos ao desmame, este foi realizado em um tempo mais curto em relação ao grupo controle (149,1 ± 3,6 min vs. 4179,1 ± 927,8 min; P < 0,0001) com taxas de reintubação significativamente menores (16,7 por cento vs. 66,7 por cento; P = 0,005). CONCLUSÃO: O uso de um protocolo específico, baseado no Teste de Respiração Espontânea para desmame de ventilação mecânica, em pacientes cardiopatas, teve resultados melhores do que o desmame realizado sem um protocolo padronizado, com menor tempo de desmame e menores taxas de reintubação.

OBJECTIVE: To compare mechanical ventilation weaning based on a protocol using the spontaneous breathing trial against mechanical ventilation weaning without a standardized protocol in heart patients. METHODS: Prospective, open, randomized study. In 2006, 36 patients undergoing mechanical ventilation for over 24 hours were randomized into two groups: control group - eighteen patients whose mechanical ventilation weaning was performed according to the different procedures adopted by the multidisciplinary team; and experimental group - eighteen patients weaned according to previously established protocol. RESULTS: Control group patients started the weaning process sooner than experimental group patients (74.7 ± 14.7 hours vs. 185.7 ± 22.9 hours, P=0.0004). However, after the experimental group patients were ready for weaning, the extubation was carried out more rapidly than in the control group (149.1 ± 3.6 min vs. 4179.1 ± 927.8 min, P < 0.0001) with significantly lower reintubation rates (16.7 percent vs. 66.7 percent, P = 0.005). CONCLUSION: The use of a specific protocol based on the spontaneous breathing trial for mechanical ventilation weaning in heart patients had better outcomes than weaning carried out without a standardized protocol, with shorter weaning times and lower reintubation rates.

Tyrosine: a possible marker of severe intestinal injury during ischemia.

BACKGROUND: Long periods of ischemia can cause organ injury and dysfunction. The protein degradation occurring in the muscular layer and in the mucosa of the intestinal wall during ischemia may release amino acids into the intestinal lumen or into the circulation. The small intestine, like skeletal muscle, cannot synthesize or degrade tyrosine. Thus, the tyrosine concentration released from the gut mucosa reflects the balance between protein synthesis and degradation. We aimed to determine whether tyrosine can be used as a marker of intestinal injury during ischemia. METHODS: In 19 anesthetized rabbits, an ultrasonic flow probe was placed around the superior mesenteric artery to estimate blood flow. A segment from the ileum was isolated using two multilumen catheters with inflated balloons to create a closed segment for perfusion. Animals were allocated into three groups: a sham group without intervention (group I); a group submitted to superior mesenteric artery ligation only (group II); and a group submitted to 1 h of SMA clamping followed by 1 h of reperfusion (group III). Concentrations of lactate and tyrosine (fluorometry) were determined in the serum and the gut luminal perfusate. RESULTS: Gut luminal perfusate tyrosine concentrations increased significantly in group II (from 10 +/- 8 to 93 +/- 63 mm/mL at 2 h) and were significantly higher than in group I (26 +/- 24 mm/mL) and group III (11 +/- 13 mm/mL) (P < 0.05 for all). CONCLUSION: Tyrosine is released from cells into the lumen during severe intestinal ischemia. Regional measurements of tyrosine levels may be a useful indicator of severe intestinal villus compromise.