RESUMO
Ruminal, post-ruminal and total tract crude protein disappearance of alfalfa hay and barley grain were measured using in vivo, in situ mobile bag and three-step in situ/in vitro enzyme procedures [3-step]. For in vivo, four Baluchi lambs [49.4 +/- 3.5 kg, body weight] were used in a 2 _ 2 Latin square design within 2 periods [24 days of each period]. Experimental diets were made of two alfalfa hay: barley grain ratios [DM basis] as 1.0:0.0 and 0.5:0.5. Diets were fed to animals for 24 days, with 7 days of feces collection. In situ mobile bag technique was followed by 12 h rumen incubation and then intestinal movement of the bags in rumen and post-rumen cannulated Holstein steers. The three-step procedure was followed by rumen incubation of samples for 12 h [using polyester bags] and enzymatic incubation of ruminal undegradable samples. In vivo total tract crude protein disappearance of alfalfa hay and barley grain [0.74 and 0.69, respectively] was significantly [P<0.01] lower than in situ mobile nylon bag [0.89 and 0.96, respectively] and the 3-step procedure [0.81 and 0.89, respectively]. Total tract crude protein disappearance from in situ mobile bag was significantly [P<0.01] higher than the 3-step technique. Post-ruminal disappearance of ruminal undegradable crude protein from alfalfa hay and barley grain using in situ mobile bag method [0.69 and 0.86, respectively] was significantly [P<0.01] higher than the 3-step enzymatic method [0.49 and 0.56, respectively]. Results of the present study showed that there was a significant difference between in vivo, in situ mobile bag and 3-step methods when total tract crude protein disappearance of barley grain and alfalfa hay was evaluated
RESUMO
Although it is assumed that appropriate care of endotracheal tubes and airway might prevent postintubation airway stenosis [PIAS], but this concept has not been investigated adequately. The purpose of the study was to investigate practical ways for prevention of PIAS in intubated patients. The study was implemented in 3 phases. First we collected information about methods of caring for airways and tubes in intensive care units in Tehran and other cities [control group] and data collection based on filling 10-20 questionnaires in each intensive care unit. Then we assessed patients who had PIAS and had been treated by us during a 6 year period [1994-2000] [study group]. In the final phase, collected data were analyzed and we looked for important pitfalls in caring for airways in intensive care units in our country and also looked for the practical measures to prevent PIAS. In phase I, 341 questionnaires were filled out in 18 intensive care units [12 in Tehran, 6 in other cities]. There were 133 females and 208 males aged 3 month to 98 years [mean 46.1]. Head injury was the commonest cause of intubations in 24%. of patients. Out of 356 tracheal tubes which had been used in these patients, 318 were high volume low pressure types [new tubes], and 32 were high pressure low volume types [old tubes]. In 179 patients [52.4%], there was not any type of care for tubes and airways by attending physicians, in 140 patients [41%] there was some kind of care although not organized or sufficient and in only 21 patients [6.1%] the care was organized and sufficient. Mean time of intubation was 8 days [1-45 days]. Tracheotomy had been undertaken without any established criteria and mostly by junior staff with low experience [usually junior residents]. In phase II, 120 patients were treated for PIAS [36 females, 84 males aging 1-83 years, mean 25.9 years]. Head injury was the cause of intubation in 78 [65%] patients, the site of stenosis was tracheal in 88 and laryngotracheal in 32 patients. More than half of the patients were intubated by inappropriate old tubes. Direct cause of stenosis was the cuff in 92, tip of the tubes in 15 and stoma in 10 patients. In 3 patients more than one factor were the causes. Mean time of intubation was 14.9 days [1-90] and mean length of stenosis was 3.2 cm [1-7]. Caring of tubes and airways was inappropriate and inorganized in all patients. Factors which were statistically different in study and control group were: time of intubation [14.9 day vs 8 days, P=0.000], suicide attempts [12 vs 5, P=0.000], head injuries [65% vs 24% P=0.000], Age [25.9y Vs 46y, P=0.05], using old tubes [50% vs 9% P=0.000], organized caring of tubes and airways [0.0%vs6.1%P=0.000]. The following measures are effective in decreasing the PIAS: decreasing time of intubation, using appropriate tubes, [including PVC tubes], continuous care of airway and tube, cuff monitoring and daily recording of information about tubes and cuff pressure, and special care for intubated young patients who had sustained head injury or had attempted suicide