Hypertonic sodium lactate improves fluid balance and hemodynamics in porcine endotoxic shock.

INTRODUCTION: Based on the potential interest in sodium lactate as an energy substrate and resuscitative fluid, we investigated the effects of hypertonic sodium lactate in a porcine endotoxic shock. METHODS: Fifteen anesthetized, mechanically ventilated pigs were challenged with intravenous infusion of E. coli endotoxin. Three groups of five animals were randomly assigned to receive 5 mL/kg/h of different fluids: a treatment group received hypertonic sodium lactate 11.2% (HSL group); an isotonic control group receiving 0.9% NaCl (NC group); a hypertonic control group with the same amount of osmoles and sodium than HSL group receiving hypertonic sodium bicarbonate 8.4% (HSB group). Hemodynamic and oxygenation variables, urine output and fluid balance were measured at baseline and at 30, 60, 120, 210 and 300 min. Skin microvascular blood flow at rest and during reactive hyperemia was obtained using a laser Doppler flowmetry technique. Results were given as median with interquartile ranges. RESULTS: Endotoxin infusion resulted in hypodynamic shock. At 300 min, hemodynamics and oxygenation were significantly enhanced in HSL group: mean arterial pressure (103 [81-120] mmHg vs. 49 [41-62] in NC group vs. 71 [60-78] in HSB group), cardiac index (1.6 [1.2-1.8] L/min/m2 vs. 0.9 [0.5-1.1] in NC group vs. 1.3 [0.9-1.6] in HSB group) and partial pressure of oxygen (366 [308-392] mmHg vs. 166 [130-206] in NC group vs. 277 [189-303] in HSB group). At the same time, microvascular reactivity was significantly better in HSL group with a lower venoarterial CO2 tension difference (5.5 [4-10] mmHg vs. 17 [14-25] in NC group vs. 14 [12-15] in HSB group). The cumulative fluid balance was lower in HSL group (-325 [-655; -150] mL) compared to NC (+560 [+230; +900] mL, p = 0.008) and HSB (+185 [-110; +645] mL, p = 0.03) groups. CONCLUSIONS: In our hypodynamic model of endotoxic shock, infusion of hypertonic sodium lactate improves hemodynamic and microvascular reactivity with a negative fluid balance and a better oxygenation.

Impact of endotoxin challenge in obese pigs.

Studies exploring the influence of obesity on septic shock remain limited and controversial. Pigs were chosen as a clinically relevant species, resembling to humans in various functions. We hypothesize obesity may impair porcine acute endotoxic shock. Four groups of five "Yucatan" minipigs were studied: lean and obese control groups, lean lipopolysaccharide (LPS) group receiving Escherichia coli endotoxin (LPS) and obese LPS group receiving the same endotoxin dose. We measured hemodynamic and oxygenation parameters, skin microvascular blood flow at rest and during reactive hyperemia, von Willebrand factor, tumor necrosis factor α, and interleukin 6. All measurements were performed at baseline and at 30, 60, 90, 150, and 300 min. Results were given as median with 25th to 75th interquartile range. Control groups remained stable during the study period. In LPS groups, administration of endotoxin resulted in a typical hypokinetic shock. In obese LPS group at 300 min, we observed a significant impairment of cardiac index (1.2 [1.06-1.45] vs. 1.7 [1.57-1.97] L/min per m, P = 0.008) compared with the lean LPS group; moreover, pulmonary hypertension (mean arterial pressure: 42 [39-47] vs. 32 [28-34] mmHg, P = 0.008), hypoxemia (partial pressure of oxygen: 216 [178-262] vs. 325 [285-414] mmHg, P = 0.02), and lactate levels (5.8 [4.2-6.8] vs. 3.9 [2.2-5.5] mmol/L, P = 0.04) were significantly higher compared with the lean LPS group. Throughout the study, rest flow and peak flow during reactive hyperemia were more decreased in the obese LPS group. Compared with the lean LPS group, tumor necrosis factor α levels at 60 min (269 [178-428] vs. 126 [105-166] ng/mL, P = 0.03) and interleukin 6 levels at 300 min (101 [61-142] vs. 52 [36-64] ng/mL, P = 0.03) were significantly higher in the obese LPS group. In our model of endotoxic shock, obese pigs developed a more severe hemodynamic failure with pronounced microcirculatory dysfunction and proinflammatory response.

Laparoscopic surgery for rectal cancer: preoperative radiochemotherapy versus surgery alone.

BACKGROUND: A few studies have suggested advantages of laparoscopic surgery for rectal cancer. However, the role of laparoscopy has not been clearly defined specifically in cases after neoadjuvant radiochemotherapy. This study aimed to assess the impact of preoperative radiotherapy on the feasibility of laparoscopic rectal excision with sphincter preservation for rectal cancer. METHODS: From 1999 to 2010, the authors considered all patients treated by laparoscopic rectal excision with sphincter preservation for rectal cancer. Patients treated by long-course preoperative radiochemotherapy (45 Gy during 5 weeks) were compared with those treated by surgery alone. The end points of the study were mortality, conversion, and overall and surgical morbidity. RESULTS: Among 422 patients treated by laparoscopic conservative rectal excision, 292 received preoperative radiotherapy, and 130 had surgery alone. The two groups were similar in sex, age, body mass index, and American Society of Anesthesiologists (ASA) score. The mortality rate was 0.3% in the radiotherapy group and 0.8% in the surgical group (P = 0.52). The two groups did not differ in terms of conversion (19 vs. 15%; P = 0.39), overall morbidity (37 vs. 29%; P = 0.14), surgical morbidity (20 vs. 18%; P = 0.60), or anastomotic leakage (13 vs. 11%; P = 0.54). Multivariate analysis showed male gender and synchronous metastasis as independent factors of surgical morbidity. The independent factors of conversion were male gender, obesity, tumor stage, and type of anastomosis. Preoperative radiotherapy influenced neither conversion nor surgical morbidity. CONCLUSION: Long-course radiochemotherapy does not have an impact on the feasibility or short-term outcome of laparoscopic conservative rectal excision for rectal cancer.