Relationship between peripheral ischemic microvascular reserve, persistent hyperlactatemia, and its temporal dynamics in sepsis: a post hoc study

Abstract

Objective To measure the prognostic value of peripheral ischemic microvascular reserve in the context of persistent sepsis-induced hyperlactatemia and measure its influence on the temporal dynamics of lactate and the strength of association between these variables. Methods This post hoc analysis of the peripheral perfusion index/postocclusive reactive hyperemia trial, an observational cohort study that enrolled patients with sepsis who persisted with lactate levels ≥ 2mmol/L after fluid resuscitation (with or without shock). Peripheral ischemic microvascular reserve was evaluated using the association of the peripheral perfusion index and postocclusive reactive hyperemia techniques. The cutoff point of ∆ peripheral perfusion index peak values (%) defined the groups with low (≤ 62%) and high peripheral ischemic microvascular reserve (> 62%). Results A total of 108 consecutive patients with persistent sepsis-induced hyperlactatemia were studied. The high peripheral ischemic microvascular reserve group showed higher 28-day mortality than the low peripheral ischemic microvascular reserve group (p < 0.01). The temporal dynamics of lactate within the first 48 hours showed a rapid decrease in lactate levels in the low peripheral ischemic microvascular reserve group (p < 0.01). However, this result was not reproduced in the linear mixed effects model. A weak correlation between peripheral ischemic microvascular reserve (%) and lactate level (mmol/L) was observed within the first 24 hours (r = 0.23; p < 0.05). Conclusion The prognostic value of high peripheral ischemic microvascular reserve was confirmed in the context of persistent sepsis-induced hyperlactatemia. Although there was a weak positive correlation between peripheral ischemic microvascular reserve value and lactate level within the first 24 hours of sepsis diagnosis, the low peripheral ischemic microvascular reserve group appeared to have a faster decrease in lactate over the 48 hours of follow-up.

The relationship of postocclusive reactive hyperemia assessed by the plethysmographic perfusion index to lactate clearance: a new piece in the unsolved puzzle of tissue perfusion and oxygenation in septic shock

“…The findings of Miranda et al ( 9 ) and Menezes et al ( 10 , 12 ) are not necessarily paradoxical and could reflect the intricate abnormalities of reactive hyperemia and tissue oxygenation in septic shock. The delayed response to reach the peak PI, in comparison to nonseptic patients, could be an expression of altered reactive hyperemia.…”

“…Its combination with a VOT not only provides new insights into the complexity of microvascular recruitment but also improves the prognostic ability. Even though the study from Miranda et al ( 9 ) adds new information to the previous findings of Menezes et al, ( 10 , 12 ) the interpretation and the clinical usefulness of the test are not straightforward. Further research is needed to completely understand the meaning and mechanisms of these interesting findings.…”

“…In this issue of Critical Care Science, Miranda et al publish a new contribution to our understanding of this issue. ( 9 ) Previously, Menezes et al showed that patients with septic shock, compared to nonseptic controls, took longer to reach the peak PI after a VOT (70 [53 - 92] versus 48 [36 - 60] sec). ( 10 ) Although the maximal variation in the PI (∆PI) was similar in the two groups (71 [32 - 125] versus 79 [30 - 137] %), the change in the first 60 sec after the VOT (∆PI 0-60 ) was lower in the septic group (1 [-19 - 40] versus 39 [6 - 75] %).…”

“…Now, Miranda et al ( 9 ) studied a series of patients with septic shock who maintained hyperlactatemia after resuscitation within the first day of diagnosis. Their goals were to confirm the prognostic value of the test and to assess its relationship with lactate level.…”