Restrictive fluid resuscitation in combination with damage control resuscitation: time for adaptation.

BACKGROUND: Damage control resuscitation (DCR) conveys a survival advantage in patients with severe hemorrhage. The role of restrictive fluid resuscitation (RFR) when used in combination with DCR has not been elucidated. We hypothesize that RFR, when used with DCR, conveys an overall survival benefit for patients with severe hemorrhage. METHODS: This is a retrospective analysis from January 2007 to May 2011 at a Level I trauma center. Inclusion criteria included penetrating torso injuries, systolic blood pressure less than or equal to 90 mm Hg, and managed with DCR and damage control surgery (DCS). There were two groups according to the quantity of fluid before DCS: (1) standard fluid resuscitation (SFR) greater than or equal to 150 mL of crystalloid; (2) RFR less than 150 mL of crystalloid. Demographics and outcomes were analyzed. RESULTS: Three hundred seven patients were included. Before DCS, 132 (43%) received less than 150 mL of crystalloids, grouped under RFR; and 175 (57%) received greater than or equal to 150 mL of crystalloids, grouped under SFR. Demographics and initial clinical characteristics were similar between the study groups. Compared with the SFR group, RFR patients received less fluid preoperatively (129 mL vs. 2,757 mL; p < 0.001), exhibited a lower intraoperative mortality (9% vs. 32%; p < 0.001), and had a shorter hospital length of stay (13 vs. 18 days; p = 0.02). Patients in the SFR group had a lower trauma intensive care unit mortality (5 vs. 12%; p = 0.03) but exhibited a higher overall mortality. Patients receiving RFR demonstrated a survival benefit, with an odds ratio for mortality of 0.69 (95% confidence interval, 0.37-0.91). CONCLUSION: To the best of our knowledge, this is the first civilian study that analyzes the impact of RFR in patients managed with DCR. Its use in conjunction with DCR for hypotensive trauma patients with penetrating injuries to the torso conveys an overall and early intraoperative survival benefit. LEVEL OF EVIDENCE: Therapeutic study, level IV.

Positive and negative generation effects, hypermnesia, and total recall time.

Self-generated information is typically remembered better than perceived information (the generation effect). Experimental design produces an important limiting condition for this effect: Generation enhances recall in within-subjects designs, but typically not in between-subjects designs. However, Mulligan (2001) found that the generation effect emerged over repeated recall tests in a between-subjects design, calling into question the generality of this limiting condition. Two experiments further delineated the emergent generation effect Experiment 1 demonstrated that this effect does not require multiple discrete recall tests but may emerge on a single recall test of long duration. Experiment 2 demonstrated that the negative generation effect (a reversal of the typical generation effect produced under certain conditions) is abolished by multiple recall tests. In both experiments, the generate condition produced greater hypemnesia (increased recall over tests) than did the read condition.