PICO Footnote 1 Question: In adult critically ill patients with hypotension and requiring vasopressor support, should we be prescribing a higher blood pressure target (MAP 75-85) when compared with a lower blood pressure target (MAP 60-70)?

Recommendation: We suggest against the use of a higher blood pressure (BP) target (MAP 75-85) when compared with a lower BP target (MAP 60-70) in adult critically ill patients with hypotension and requiring vasopressors. (Conditional recommendation)

This is a recommendation developed by the Canadian Critical Care Society and the Scandinavian Society of Anaesthesiology and Intensive Care Medicine (CCCS-SSAI) according to standards for trustworthy guidelines in collaboration with the MAGIC WikiRecs project. The WikiRecs project is an ongoing collaborative effort by a network of expert clinicians and methodologists whose aim is to produce trustworthy evidence summaries and clinical practice recommendations within 90 days of identifying potentially practice-changing evidence. See www.magicapp.org/public/guideline/OLwWKL for more details about methods and processes, full evidence summary (GRADE SoF-table), and practical information presented in multilayered formats—available on all digital devices. The electronic supplemental material also contains similar information expanding on the WikiRecs methods and processes.

Table Evidence profile outcomes studied, pooled relative and absolute estimates of effect, GRADE certainty rating, and summary statement
Full size table

Justification: We developed this recommendation according to the standards for trustworthy guidelines, including a systematic review that identified two randomized-controlled trials (894 patients) relevant to our clinical question.1,2 The larger trial included only patients with hypotension secondary to sepsis,1 whereas the other trial enrolled patients with distributive shock due to any etiology.2

Our weak recommendation against higher BP targets takes into consideration the absence of a demonstrated benefit and high resource demands associated with higher dose or longer duration vasopressor infusions (see Table). Additionally, it may be that the prescription of higher thresholds, and a subsequent need for higher doses of vasopressors to achieve these thresholds, leads to increased harm via increased myocardial ischemia and tachyarrhythmias. Nevertheless, this signal is limited by imprecision and risk of bias. This signal for harm may be more substantive in the elderly population based on subgroup analysis; however, the panel did not consider the evidence robust enough for a stronger recommendation in this population.

All outcome data were based on low or very low certainty evidence and, as such, the panel refrained from making a more definitive recommendation. The residual uncertainty was a result of lack of blinding of group allocation in the individual studies and imprecision of the pooled results. The guideline panel had significant internal debate as regards lowering the overall certainty for lack of blinding (risk of bias) in view of the objective nature of mortality as an outcome and the impracticalities of blinding an intervention such as BP targets. Other than lack of blinding, both trials had a low risk of bias for all other domains included in the Cochrane randomized-controlled trials tool.3 Ultimately, as intensive care unit mortality is often the result of end-of-life decision-making4 and in order to remain conservative in our overall certainty judgement, we decided to lower for risk of bias due to lack of blinding.

The guideline panel also acknowledged the difficulty in making recommendations without quality of life particulars, morbidity indices, or long-term outcome data. Prescribing higher BP targets may have had a different impact on these outcomes than on mortality, and therefore, may have affected our overall recommendation. Our patient representative identified this factor as a significant limitation, and this represents an important consideration for future research in this area.