Time of dissociation between microcirculation, macrocirculation, and lactate levels in a rabbit model of early endotoxemic shock / 中华医学杂志(英文版)

BACKGROUND@#The relationship between macrocirculation and microcirculation remains controversial. The loss of coherence between microcirculation and macrocirculation has already been found in late-stage sepsis shock. The objective of this study was to determine the earliest possible time of detecting the loss of coherence between microcirculation and macrocirculation in early-stage endotoxemic shock.@*METHODS@#We randomized 24 female New Zealand white rabbits into two groups: endotoxemic shock group (n = 14) and control group (n = 10). Rabbits in the endotoxemic shock group were equipped with arterial and venous catheters and received an intravenous infusion of Escherichia coli lipopolysaccharide (LPS, 2 mg/kg over 10 min). Rabbits in the control group received the same dose of saline infusion. Microcirculatory perfusion parameters were assessed in the sublingual mucosa using sidestream dark-field video microscopy. Systemic hemodynamics and blood lactate levels were measured at baseline and over a 120-min period.@*RESULTS@#Ninety minutes after completing LPS infusion, all animals in the endotoxemic shock group developed a hypodynamic septic condition, characterized by low cardiac output and increased systemic vascular resistance; 120 min after completing LPS infusion, the mean arterial pressure decreased by 25% (P = 0.01), confirming ongoing endotoxemic shock. However, significant decreases in sublingual microcirculatory parameters of small vessels (microvascular flow index, perfused vessel density, and proportion of small perfused vessels) were observed 30 min after completing LPS infusion (P = 0.01, for all), and threshold decreases of 30% were found 60 min after completing LPS infusion (P = 0.001, for all) in the endotoxemic shock group. Lactate levels significantly increased to more than 2 mm/L at 90 min and more than 4 mm/L at 120 min in the endotoxemic shock group (P = 0.02 and P = 0.01, respectively).@*CONCLUSIONS@#Changes in microcirculatory perfusion precede changes in macrocirculation and lactate levels in a rabbit model of endotoxemia shock. Microcirculation, macrocirculation, and oxygen metabolism are distinct in early-stage endotoxic shock.

Sources of multidrug-resistant Acinetobacter baumannii and its role in respiratory tract colonization and nosocomial pneumonia in intensive care unit patients / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Multidrug-resistant Acinetobacter baumannii (MDRAB) is an important and emerging hospital-acquired pathogen worldwide. This study was conducted to identify the sources of MDRAB and its role in respiratory tract colonization and nosocomial pneumonia in intensive care unit (ICU) patients.</p><p><b>METHODS</b>We conducted a prospective active surveillance study of MDRAB in three ICUs at a Chinese Hospital from April to August 2011, to identify the sources of MDRAB and its role in respiratory tract colonization and nosocomial pneumonia.</p><p><b>RESULTS</b>One hundred and fourteen (13.0%) MDRAB isolates were detected from 876 specimens, with a sensitivity of 11.6% (55/474) in screening of the pharyngeal and tracheal swabs, and 14.7% (59/402) of the sputum/endotracheal aspirates. MDRAB colonization/infection was found in 34 (26.8%) of 127 patients, including 16 (12.6%) cases of pure colonization and 18 (14.2%) cases of pneumonia (two pre-ICU-acquired cases of pneumonia and 16 ICU-acquired cases of pneumonia). Previous respiratory tract MDRAB colonization was found in 22 (17.3%) patients: eight (6.3%) were pre-ICU-acquired colonization and 14 (11.0%) ICU-acquired colonization. Of eight pre-ICU-colonized patients, five were transferred from other wards or hospitals with hospitalization > 72 hours, and three came from the community with no previous hospitalization. Overall, 6/22 colonized patients presented with secondary pneumonia; only two (9.1%) colonized MDRAB strains were associated with secondary infections. Respiratory tract MDRAB colonization had no significant relationship with nosocomial pneumonia (P = 0.725). In addition, acute respiratory failure, mechanical ventilation, renal failure, and prior carbapenem use were risk factors for MDRAB colonization/infection.</p><p><b>CONCLUSIONS</b>A high proportion of cases of MDRAB colonization/infection in ICU patients were detected through screening cultures. About one-third were acquired from general wards and the community before ICU admission. The low incidence of MDRAB colonization-related pneumonia questions the appropriateness of targeted antibiotic therapy.</p>

The effects of earlier resuscitation on following therapeutic response in sepsis with hypoperfusion / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate the effects of early sufficient resuscitation on important organs function and their therapeutic response in sepsis with hypoperfusion.</p><p><b>METHODS</b>From January 2004 to December 2005, 34 sepsis patients with hypoperfusion in surgical and respiratory intensive care units were resuscitated sufficiently for the management of severe sepsis and septic shock. According to the time of resuscitation end points, these patients were divided to early resuscitation group (E group, 15 patients) and later group (L group, 19 patients). The important organs function and their therapeutic response followed resuscitation were investigated and compared in the tow groups.</p><p><b>RESULTS</b>After earlier sufficient resuscitation, the incidence of repeated resuscitation was 73.7% in L group and 20.0% in E group (P < 0.01); the incidence of steroids replacement, coagulation dysfunction and multiple organ dysfunction syndrome (MODS) were 63.2%, 73.7% and 68.4% respectively in L group and significantly higher than those in E group (P < 0.05). Seven days after resuscitation, the level of serum creatinine in E group was lower than that in L group (P < 0.05). In the day 1 and 7 after resuscitation, heart rate in E group was lower than that in L group (P < 0.05). Seven days post resuscitation, PaO(2) and PaO(2)/FiO(2) were higher in E group than in L group (P < 0.05). The mortality was 42.1% in L group and 13.3% in E group (P < 0.05).</p><p><b>CONCLUSIONS</b>Early sufficient resuscitation in sepsis patients with hypoperfusion could significantly enhance the effects of following treatment, relieve inflammation and coagulation reaction and thereby reduce the mortality.</p>