RESUMO
Objective@#To explore the guiding significance of pulse contour cardiac output (PiCCO) monitoring technology in the treatment of fluid replacement during shock stage of extensive burn in clinic.@*Methods@#Sixty-five patients with extensive burn hospitalized in our unit from January 2014 to December 2018, conforming to the inclusion criteria, were recruited to conduct a prospective controlled research. According to the order of admission, 35 odd-numbered patients and 30 even-numbered patients were enrolled in routine rehydration group (25 males and 10 females) and PiCCO monitoring rehydration group (21 males and 9 females) respectively, with the age of (48±9) and (44±8) years respectively. All patients of the two groups were rehydrated according to the rehydration formula of the Third Military Medical University during shock stage. The rehydration speed was adjusted in routine rehydration group according to the general indexes of shock such as central venous pressure, mean arterial pressure, heart rate, respiratory rate, urine volume, and clinical symptoms of patients. PiCCO monitoring was performed in patients of PiCCO monitoring rehydration group, and the global end-diastolic volume index combined with the other relevant indicators of PiCCO were used to guide rehydration on the basis of the monitoring indicators of routine rehydration group. The heart rates and positive fluid balance volumes at post injury hour (PIH) 8, 16, 24, 32, 40, 48, 56, 64, and 72, the diuretic dosage at PIH 48 and 72, the total fluid replacement volumes, urine volumes, blood lactic acid, platelet count, and hematocrit at PIH 24, 48, and 72, the length of intensive care unit (ICU) stay, and the incidence of complications and death within 28 days after injury were compared between patients in the two groups. Data were processed with analysis of variance for repeated measurement, t test, Bonferroni correction, Mann-Whitney U test, chi-square test, and Fisher′s exact probability test.@*Results@#The heart rates of patients in the two groups were similar at PIH 8, 16, 24, 32, 40, 48, and 56 (t=0.775, 1.388, 2.511, 2.203, 1.654, 2.303, 1.808, P>0.05), and the heart rates of patients in PiCCO monitoring rehydration group at PIH 64 and 72 were obviously lower than those of routine rehydration group (t=3.229, 3.357, P<0.05 or P<0.01). The positive fluid balance volumes of patients in the two groups were similar at PIH 8, 16, 40, and 56 (t=0.768, 1.670, 2.134, 2.791, P>0.05), and the positive fluid balance volumes of patients in PiCCO monitoring rehydration group at PIH 24, 32, 48, 64, and 72 were obviously less than those of routine rehydration group (t=3.364, 4.047, 2.930, 2.950, 2.976, P<0.05 or P<0.01). The amount of diuretics used by patients in the two groups was similar at PIH 48 and 72 (Z=-0.697, -1.239, P>0.05). The total fluid replacement volumes of patients in PiCCO monitoring rehydration group at PIH 24, 48, and 72 were (13 864±4 241), (9 532±2 272), and (8 480±2 180) mL, respectively, obviously more than those in routine rehydration group [(10 388±2 445), (8 095±1 720), and (7 059±1 297) mL, respectively, t=-3.970, -2.848, -3.137, P<0.05 or P<0.01]. The urine volumes of patients in the two groups at PIH 24 were close (t=-1.027, P>0.05). The urine volumes of patients in PiCCO monitoring rehydration group at PIH 48 and 72 were (3 051±702) and (3 202±624) mL respectively, obviously more than those in routine rehydration group [(2 401±588) and (2 582±624) mL respectively, t=-4.062, -4.001, P<0.01]. The levels of blood lactate acid of patients in PiCCO monitoring rehydration group at PIH 24, 48, and 72 were obviously lower than those in routine rehydration group (t=4.758, 6.101, 3.938, P<0.01). At PIH 24 and 48, the values of the platelet count of patients in PiCCO monitoring rehydration group were obviously higher than those in routine rehydration group (t=-2.853, -2.499, P<0.05), and the values of hematocrit of patients in PiCCO monitoring rehydration group were obviously lower than those in routine rehydration group (t=2.698, 4.167, P<0.05 or P<0.01). Both the platelet count and hematocrit of patients in the two groups were similar at PIH 72 (t=-1.363, 0.476, P>0.05). The length of ICU stay of patients in PiCCO monitoring rehydration group was obviously shorter than that of routine rehydration group (t=2.184, P<0.05). Within 28 days after injury, the incidence of complications of patients in routine rehydration group was obviously higher than that in PiCCO monitoring rehydration group (P<0.05), while the mortality rate of patients in routine rehydration group was similar to that in PiCCO monitoring rehydration group (P>0.05).@*Conclusions@#The application of PiCCO monitoring technology in monitoring fluid replacement in patients with extensive burn can quickly correct shock, reduce the occurrence of organ complications caused by improper fluid replacement, and shorten the length of ICU stay, which is of great significance in guiding the treatment of burn shock.
RESUMO
<p><b>OBJECTIVE</b>To observe the effects of low molecular weight heparin (LMWH) on the inflammatory response and vascular injury in rat after electric burn.</p><p><b>METHODS</b>A homemade regulator and transformer apparatus was used to reproduce the model of electric burn (0.5 cm×0.5 cm in size) with depth from full-thickness to full-thickness skin plus muscle and bone on the middle of the inside of right hind limb in 60 Wistar rats. The open wounds were covered with 20 g/L sulfadiazine silver paste immediately after injury. The wound condition was observed every day. The injured rats were divided into group LMWH and control group (C) according to the random number table, with 30 rats in each group. Rats in group LMWH were given subcutaneous injection of LMWH (1 U/g) in abdominal wall, 2 times a day. No other treatment was given in rats in group C. On post burn day (PBD) 3, 5, and 10, 10 rats respectively of two groups were sacrificed. The damaged tissue of wound and that around the wound (1.0 cm×0.5 cm in size) were excised, and heart blood was obtained. The pathological changes and thrombosis in damaged tissue were observed with HE, Masson, and aldehyde fuchsin staining, and the thrombosis rate was calculated. Serum contents of TNF-α and endothelin-1 were determined with ELISA. The mRNA expression of TNF-α in damaged tissue was detected with RT-PCR. Data were processed with Levene homogeneity test, analysis of variance of factorial design, LSD- t test, SNK- q test, and Friedman M nonparametric test.</p><p><b>RESULTS</b>(1) The injured limb of rats was obviously swollen after electric burn, which reached deeply to the muscle and bone. Compared with those of group C, the swelling of rats subsided slightly faster and the inflammatory response was lighter in group LMWH at each time point. (2) The necrosis of damaged tissue and profuse infiltration of inflammatory cells were observed. Dilatation of blood vessels, congestion and thrombosis, and swelling, necrosis, and desquamation of vascular endothelial cells were observed in the damaged tissue. Damaged blood vessel wall, ruptured elastic fiber, loss of internal elastic membrane, and other pathological changes were observed in the damaged tissue of rats in the two groups. Above lesions were improved gradually along with the passage of time, and the improvement was more obvious in rats of group LMWH compared with that of group C on PBD 5 and 10. (3) The thrombosis rates of rats in group LMWH were obviously lower than those of rats in group C (F = 4.921, P < 0.05). The thrombosis rates of rats in group LMWH on PBD 3 and 10 were respectively (0.07 ± 0.11)% and (0.03 ± 0.05)%, which were significantly lower than those of rats in group C [(0.16 ± 0.15)% and (0.13 ± 0.18)%, with t values respectively 2.17 and 2.07, P values below 0.05]. In group LMWH, the thrombosis rate of rats on PBD 10 was obviously lower than that on PBD 3 (t = 3.61, P < 0.05). (4) The serum contents of TNF-α and endothelin-1 of rats in group LMWH were significantly lower than those of rats in group C (F = 47.161, χ(2) = 81.46, P values below 0.01). In group LMWH, TNF-α contents were respectively (71 ± 24), (74 ± 14), (72 ± 20) pg/mL, and endothelin-1 contents were respectively (20.9 ± 3.2), (19.8 ± 5.2), (18.6 ± 1.1) ng/mL on PBD 3, 5, and 10, and they were significantly lower than those of rats in group C [(195 ± 148), (96 ± 20), (159 ± 46) pg/mL and (38.8 ± 15.4), (27.9 ± 3.6), (25.6 ± 7.6) ng/mL, with t values from 3.81 to 8.05, q values from 4.41 to 7.85, P < 0.05 or P < 0.01]. (5) The mRNA expression levels of TNF-α in damaged tissue of rats in group LMWH were significantly lower than those of rats in group C (F = 199.113, P < 0.01). The mRNA expression levels of TNF-α of rats in group LMWH were respectively 0.93 ± 0.10, 1.15 ± 0.12, 1.21 ± 0.11 on PBD 3, 5, and 10, and they were significantly lower than those of group C (1.68 ± 0.15, 1.43 ± 0.12, 1.50 ± 0.13, with t values from 3.75 to 6.12, P < 0.05 or P < 0.01). In group LMWH, the mRNA expression level of TNF-α of rats on PBD 10 was obviously higher than that on PBD 3 (t = 3.61, P < 0.05).</p><p><b>CONCLUSIONS</b>LMWH intervention can ameliorate vascular injury and inflammatory response of electrically burned wounds in rats, and it decreases thrombosis rate in the vessels of injured limb.</p>