[Effects of two dimensional gray-scale blood flow imaging combined with color Doppler flow imaging in guiding arterial puncture and catheterization through wounds in patients with large burns].

Objective: To explore the effects of two dimensional gray-scale blood flow imaging (hereinafter referred to as " B-flow" ) combined with color Doppler flow imaging (CDFI) in guiding arterial puncture and catheterization through wounds in patients with large burns. Methods: Sixty-seven patients with large burns who met the inclusion criteria and hospitalized in the First Hospital of Jilin University from January 2017 to January 2019 were enrolled in the prospectively randomized control study. According to the random number table, CDFI alone group was allocated with 35 patients (23 males and 12 females) and B-flow+ CDFI group with 32 patients (22 males and 10 females), aged 19-60 and 18-58 years, respectively. According to the progress of the disease, arterial puncture and catheterization were performed in the right time. During the operation, CDFI was used alone for guidance in patients of CDFI alone group, while B-flow and CDFI were used together for guidance in patients of B-flow+ CDIF group. Based on the first time of catheterization, the catheterization location, one-time catheterization success rate, post-back stitching re-catheterization success rate, catheterization failure rate, catheterization duration, and incidences of wound sepsis, catheter-related bloodstream infection, and arterial thrombosis within post catheterization day (PCD) 3 of patients in the two groups were recorded. Data were statistically analyzed with the independent-sample t test, chi-square test or Fisher's exact probability test. Results: (1) All the patients underwent catheterization through wounds, and there was no statistically significant difference in catheterization location of patients between the two groups (χ(2)=0.574, P>0.05). The one-time catheterization success rate of patients in B-flow+ CDFI group was 81.25% (26/32), which was obviously higher than 51.43% (18/35) in CDFI alone group (χ(2)=6.594, P<0.05). The catheterization failure rate of patients in B-flow+ CDFI group was 3.12% (1/32), which was obviously lower than 20.00% (7/35) in CDFI alone group (P<0.05). The post-back stitching re-catheterization success rate of patients was similar between the two groups (χ(2)=1.029, P>0.05). (3) The catheterization duration of patients was (15.7±1.1) min in B-flow+ CDFI group, which was obviously shorter than (17.1±2.2) min in CDFI alone group (t=11.316, P<0.01). (4) Within PCD 3, the incidences of wound sepsis and catheter-related bloodstream infection of patients in CDFI alone group were 2.86% (1/35) and 0, close to 0 and 3.12% (1/32) in B-flow+ CDFI group (P>0.05); the incidence of arterial thrombosis of patients in B-flow+ CDFI group was 0, which was obviously lower than 20.00% (7/35) in CDFI alone group (P<0.05). Conclusions: Compared with CDFI alone, B-flow combined with CDFI can improve the success rate of arterial puncture and catheterization through wounds in large area burn patients, shorten the catheterization duration, and effectively reduce the incidence of arterial thrombosis after catheterization, with a good clinical application value.

Chronic stimulation of mammalian muscle: changes in metabolite concentrations in individual fibers.

Single fibers were analyzed from rabbit fast-twitch tibialis anterior muscles freeze-clamped during continuous stimulation at 10 Hz for up to 8 wk. ATP declined after 1 wk to a stable level approximately 30% below controls. Phosphocreatine decreased earlier and to a greater extent (approximately 50%). Glycogen varied considerably among stimulated fibers and decreased on average approximately 75% by 8 wk. Glucose, lactate, citrate, and malate had changed little in the first 30 h and then increased four-, two-, four-, and sevenfold, respectively, over the next 5 wk. Glucose 6-phosphate showed the most unexpected behavior: with an overall upward trend, it descended to extremely low values (10% of control) after approximately 1 wk of stimulation. As long as high- and low-oxidative fibers were present, the former showed slightly higher levels of ATP, lactate, and malate; other metabolites did not differ in a consistent way. These unexpected observations, which differ strikingly from data for acute stimulation, shed light on adaptations that enable a chronically stimulated muscle to sustain a continuous high level of ATP utilization.