Blood Pressure (BP) is one of the vital hemodynamic parameters that we often aim to optimize for critically ill patients. Our decisions regarding BP targets, and ensuing use (or avoidance) of vasopressor agents, may directly impact on outcomes for these patients. Despite being a fundamental tenet of critical care, there is a lack of quality evidence to suggest optimal BP targets or to guide the use of vasopressors for individual patients with shock. A mean arterial BP (MAP) of 65-70 mmHg is an often-cited initial BP target for patients during vasopressor therapy. Use of vasopressors to maintain MAP of 65 mmHg or greater remains one of the core clinical criteria in the new definition of septic shock. However, such standard targets are unlikely to be applicable to all patients, many of whom would have a basal MAP higher than 65-70 mmHg, often to a varying degree, during their usual pre-illness state. Therefore, a vasopressor therapy guided by standard BP thresholds may result in a variable degree of untreated relative hypotension, which is associated with new-onset acute kidney injury (AKI). From a physiological standpoint, any relative reduction in net perfusion pressure across an organ’s vasculature can overwhelm its autoregulatory mechanisms, which are already under stress during a shock state. In a recent major RCT, among patients with chronic hypertension, targeting a higher MAP of 80-85 mmHg, versus 65-70 mmHg, showed a lower incidence of subsequent AKI, but with no difference in mortality. However, this RCT did not take patients’ pre-illness basal BP into account, making it difficult to extrapolate these results to those patients with chronic hypertension, who usually have a well-controlled basal BP, or to those patients, who although have a higher-than-normal basal BP but are not formally diagnosed with hypertension. Accounting for a patient’s pre-illness basal BP can minimize variation in the degree of untreated relative hypotension that is often inadvertently accepted in conventional care. It is a simple, but untested, strategy. Further, new tools that can monitor cerebral autoregulation in real-time are on the horizon and have shown some promise in suggesting an optimal BP for individual patients with shock. This technology can further help adjust the initial BP target as a patient deteriorates or recovers from the shock state. 

1. BLOOD PRESSURE
TARGETS
RAKSHIT PANWAR
STAFF SPECIALIST
ICU, JOHN HUNTER HOSPITAL

2. NO CONFLICT OF INTEREST

3. BLOOD PRESSURE TARGETS

6. INDIVIDUALIZING

7. •Acute aortic
syndrome
•Post-op aortic surgery
•Actively bleeding
LowerBP
target

8. •Acute aortic
syndrome
•Post-op aortic surgery
•Actively bleeding
Subarachnoid
hemorrhage with
vasospasm
Traumatic Brain
Injury
LowerBP
target
HigherBP
target
No unanimous agreement about optimum blood pressure

10. Recent major RCTs Target MAP (mmHg)
VASST trial, NEJM 2008 65-75
SEPSISPAM trial, NEJM 2014 65-70 vs 80-85
ARISE trial, NEJM 2014 ≥65
ProMISe trial, NEJM 2015 ≥65
LeoPARDS trial, NEJM 2016 65-70
ATHOS-3 trial; NEJM 2017 65-75
APROCCHSS trial, NEJM 2018 ≥65

19. Cardiac Index

20. SEPSISPAM RCT,
NEJM 2014

22. SEPSISPAM RCT, NEJM
2014
OVATION pilot-RCT, ICM 2016

23. HTN +

25. REALLY

31. Subject Usual SBP/DBP, mmHg
A 88/ 55
B 100/ 62
C 112/ 71
D 120/ 82
E 138/ 88
50
65
80
95
110
A B C D E
Usual MAP

32. Patient Usual MAP, mmHg Drop in MAP by10 mmHg
A 65 55
B 75 65
C 85 75
D 95 85
E 105 95
50
65
80
95
110
A B C D E
Usual MAP

33. 50
65
80
95
110
A B C D E
Usual MAP
Patient Usual MAP, mmHg Drop in MAP by10 mmHg
A 65 55
B 75 65
C 85 75
D 95 85
E 105 95
Standard
MAP
target
range

34. 50
65
80
95
110
A B C D E
Usual MAP
Patient Usual MAP, mmHg Relative drop in MAP for
being flagged, mmHg
A 65 0
B 75 10
C 85 20
D 95 30
E 105 40
Standard
MAP
target
range

35. 50
65
80
95
110
A B C D E
Usual MAP
BP-
deficit
Standard
MAP
target
range

37. Image adapted from Encyclopædia Britannica Online.80
Pressure gradient
When autoregulation is impaired, MPP (= MAP–CVP) becomes the key
driver for renal (or cerebral) perfusion, unless IAP (or ICP) exceeds CVP.
↓MAP ↑CVP
↓MPP
Fig. 1

38. Basaltissuebloodflow
Mean Perfusion Pressure
(MPP)
Basal MPP
Lower limit of
autoregulation
Upper limit of
autoregulation
Intact
autoregulation

39.  Advanced age [J Neurosurg. 2005]
 Sepsis [Crit Care. 2015]
 Severe sepsis & septic shock [Neurocrit Care. 2010; Crit Care. 2012 ]
 Post cardiac arrest [Stroke. 2001]
 Meningitis [J Appl Physiol. 2007]
 Diabetes [Diabet Med. 2003]
 Liver failure [J Hepatol. 1995]
 Ischemic stroke [Cerebrovasc Dis. 2010]
 Obstructive sleep apnea [Eur J Neurol. 2009]
 Immediate post-operative state [J Thorac Cardiovasc Surg. 2008]

40. Basaltissuebloodflow
Mean Perfusion Pressure
(MPP)
Co-morbidities
Critical illness
Impaired autoregulation
Theoretical pressure-flow
relationship when autoregulation
is lost.
Basal MPP

41. Medline, Pubmed, Embase, Google Scholar
Limited to 1996-April 2017, human adults
Studies excluded
431- Not focused on BP targets
16- No consideration of pre-morbid BP
3- Review articles on a separate question
Studies included after a full paper
review
6- observational studies
1- cross-over trial
436 records identified
through database searching
21 additional records identified
through hand searching
references

45. • Renal dysfunction: 33% vs. 49%; RR 0.70 (CI: 0.53-0.90), P=0.01
• Altered conscious state: 5% vs. 16%; RR 0.34 (CI: 0.16-0.75), P=0.007

47. 1. JHH
2. RPA
3. Canberra
4. St George
5. Austin
6. RBWH
7. Geelong

48. 1. JHH
2. Canberra

50. E-mail: Rakshit.Panwar@hnehealth.nsw.gov.au

54. NIRS