Respiratory induced dynamic variations of stroke volume and its surrogates as predictors of fluid responsiveness: applicability in the early stages of specific critical states

Abstract

Respiratory induced dynamic variations of stroke volume and its surrogates are very sensitive and specific predictors of fluid responsiveness, but their use as targets for volume management can be limited. In a recent study, limiting factors were present in 53 % of surgical patients with inserted arterial line. In the intensive care unit (ICU) population the frequency is presumably higher, but the real prevalence is unknown. Our goal was to study the feasibility of dynamic variations guided initial volume resuscitation in specific critical states. We have performed a 5 year retrospective evaluation of patients admitted with diagnosis sepsis, polytrauma, after high risk surgery or cardiac arrest. Occurrence of major (sedation, mandatory ventilation and tidal volume, open chest and arrhythmias) and minor limiting factors (PEEP level, use of vasopressors and presence of arterial catheter) was screened within the first 24 h after admission. In the study period 1296 patients were hospitalized in our ICU with severe sepsis (n = 242), polytrauma (n = 561), after high risk surgery (n = 351) or cardiac arrest (n = 141). From these patients 549 (42.4 %) fulfilled all major criteria for applicability of dynamic variations. In our evaluation only limited number of patients admitted for polytrauma (51 %), sepsis (37 %), after cardiac arrest (39 %) or surgical procedure (33 %) fulfil all the major criteria for use of dynamic variations at the ICU admission. The prevalence was similar in patients with shock. Occurrence of minor factors can pose further bias in evaluation of these patients. General use of dynamic variations guided protocols for initial resuscitations seems not universally applicable.

Applicability of respiratory variations in stroke volume and its surrogates for dynamic fluid responsiveness prediction in critically ill patients: a systematic review of the prevalence of required conditions

“…Their use varied from only 192 of 4,792 patients (4%), which had the required conditions for assessing fluid responsiveness in the study by Maguire et al. (16) to 59% of critically ill patients in the study by Benes et al (17) All other studies of critical care patients had a lower use of vasopressors (13.5 to 28.5%).…”

“…(10,11,16-18) There were one prospective, (11) two retrospective (16,17) and two one one-day point prevalence studies. (10,18) One study was performed in a surgical room (16) and the remaining were all performed in intensive care units (ICU).…”

“…The study by Benes et al selected a population in which required conditions for preload responsiveness were only assessed in patients with the following conditions: sepsis, trauma, postoperative and post-cardiac arrest. (17) Three studies included patients from more than one center (Table 1). …”

“…Maguire et al (16) defined it as 5cmH 2 O, and 56.4% of all mechanically ventilated patients had a PEEP equal to or lower than that. Benes et al (17) defined the PEEP cutoff as 10cmH 2 O, and 52.9% of mechanically ventilated patients had a PEEP level equal to or lower than that. All identified studies used a threshold of 8mL/kg as the cutoff of validity for the SVV or surrogate.…”

Use of ‘tidal volume challenge’ to improve the reliability of pulse pressure variation

“…Recent studies [18–20] have questioned the applicability of PPV and SVV in the ICU. Tests like passive leg raising (PLR) [21–23] and end‐expiratory occlusion [24–26] can reliably predict fluid responsiveness and have been proposed as alternatives to be performed in these situations.…”