Matthew Luchette
Boston Children's Hospital
Boston, Massachusetts
Disclosure information not submitted.
Kerri LaRovere, MD
Assistant Professor of Neurology
Boston Children's Hospital, United States
Disclosure information not submitted.
Robert Tasker, MA, MD, MBBS, FRCP
Senior Associate Staff Physician
Boston Children's Hospital
Milton, Massachusetts
Disclosure information not submitted.
Alireza Akhondi-Asl, PhD
Instructor in Anaesthesia
Boston Children's Hospital, United States
Disclosure information not submitted.
Title: CPPopt Correlates with Mean Arterial Pressure in Patients With Acute Brain Injury
INTRODUCTION: Cerebral resuscitation following acute brain injury involves targeting a specific cerebral perfusion pressure (CPP) to prevent further injury. CPP outside of a patient’s theoretical zone of cerebrovascular autoregulation may increase the risk for ischemia or edema/hemorrhage from underperfusion or hyperperfusion, respectively. The CPP at which the Pearson’s correlation coefficient between mean arterial pressure (MAP) and mean intracranial pressure (ICP) is lowest is used to identify the theoretical CPP at which autoregulation is maintained (CPPopt). However, CPPopt is dependent on its input values, and may not truly represent an “optimal” CPP. We performed retrospective analyses of MAP and CPPopt reported in the literature describing patients with acute brain injury in order to determine an association between these values.
Methods: Using “CPPopt” and “Optimal CPP” as MeSH terms in Pubmed, we screened papers for inclusion. The inclusion criteria consisted of prospective or retrospective analyses that provided summary data for age, MAP, and CPPopt. The mean and standard deviation of these values were extracted. If not provided, the standard deviation was estimated using multiple imputation. Weighted linear regression was performed to calculate the slope and statistical significance of the association of CPPopt with MAP and age group (IsAdult, binary signifying adult or pediatric patient).
Results: Out of 83 papers screened (along with 1 identified in the reference lists), 11 papers fulfilled inclusion criteria. The summary data included 1464 participants ranging from 5 to 62 years old. The weighted linear regression between CPPopt, MAP, and age group (CPPopt = 0.99*MAP - 11*IsAdult - 9.8) showed statistical significance for the correlation coefficient between CPPopt and MAP (95% CI 0.05-1.92, p=0.04), but not between CPPopt and age group (CI -33.1-11.1, p=0.3).
Conclusions: These results suggest an association exists between CPPopt and MAP in patients with acute brain injury independent of the patient's age. This study is limited by the fact that standard deviation was not reported in all studies. Future studies should attempt to identify markers of cerebral autoregulation that are independent of its input values.