Kirkness CJ, Burr RL, Mitchell PH. Intracranial and blood pressure variability and long-term outcome after aneurysmal sub-arachnoid hemorrhage. Am J Crit Care Off Publ Am Assoc Crit Care Nurses. 2009;18(3):241–51. https://doi.org/10.4037/ajcc2009743.
Svedung Wettervik T, Howells T, Hånell A, Ronne-Engström E, Lewén A, Enblad P. Low intracranial pressure variability is associated with delayed cerebral ischemia and unfavorable outcome in aneurysmal subarachnoid hemorrhage. J Clin Monit Comput. 2021. https://doi.org/10.1007/s10877-021-00688-y.
Wettervik TS, Howells T, Hånell A, Ronne-Engström E, Lewén A, Enblad P. Intracranial pressure variability: a new potential metric of cerebral ischemia and energy metabolic dysfunction in aneurysmal subarachnoid hemorrhage? J Neurosurg Anesthesiol. 2022. https://doi.org/10.1097/ANA.0000000000000816 (ePub ahead of print).
Kirkness CJ, Burr RL, Mitchell PH. Intracranial pressure variability and long-term outcome following traumatic brain injury. Acta Neurochir Suppl. 2008;102:105–8. https://doi.org/10.1007/978-3-211-85578-2_21.
Svedung Wettervik T, Howells T, Enblad P, Lewén A. Intracranial pressure variability: relation to clinical outcome, intracranial pressure–volume index, cerebrovascular reactivity and blood pressure variability. J Clin Monit Comput. 2020;34(4):733–41. https://doi.org/10.1007/s10877-019-00387-9.
Balestreri M, Czosnyka M, Steiner LA, Schmidt E, Smielewski P, Matta B, Pickard JD. Intracranial hypertension: what additional information can be derived from ICP waveform after head injury? Acta neurochir. 2004;146(2):131–41. https://doi.org/10.1007/s00701-003-0187-y.
Zeiler FA, Ercole A, Placek MM, Hutchinson PJ, Stocchetti N, Czosnyka M, Smieleweski P. Association between physiologic signal complexity and outcomes in moderate and severe traumatic brain injury: a CENTER-TBI exploratory analysis of multiscale entropy. J Neurotrauma. 2020. https://doi.org/10.1089/neu.2020.7249.
Sykora M, Czosnyka M, Liu X, Donnelly J, Nasr N, Diedler J, Okoroafor F, Hutchinson P, Menon D, Smielewski P. Autonomic impairment in severe traumatic brain injury: a multimodal neuromonitoring study. Crit Care Med. 2016;44(6):1173–81. https://doi.org/10.1097/ccm.0000000000001624.
Soehle M, Gies B, Smielewski P, Czosnyka M. Reduced complexity of intracranial pressure observed in short time series of intracranial hypertension following traumatic brain injury in adults. J Clin Monit Comput. 2013;27(4):395–403. https://doi.org/10.1007/s10877-012-9427-0.
Svedung Wettervik T, Howells T, Lewén A, Enblad P. Blood pressure variability and optimal cerebral perfusion pressure—new therapeutic targets in traumatic brain injury. Neurosurgery. 2020;86(3):E300–9. https://doi.org/10.1093/neuros/nyz515.
Svedung Wettervik TM, Howells T, Enblad P, Lewén A. Temporal neurophysiological dynamics in traumatic brain injury: role of pressure reactivity and optimal cerebral perfusion pressure for predicting outcome. J Neurotrauma. 2019;36(11):1818–27. https://doi.org/10.1089/neu.2018.6157.
Ryttlefors M, Howells T, Nilsson P, Ronne-Engström E, Enblad P. Secondary insults in subarachnoid hemorrhage: occurrence and impact on outcome and clinical deterioration. Neurosurgery. 2007;61(4):704–14; discussion 705–14. https://doi.org/10.1227/01.Neu.0000298898.38979.E3.
Svedung Wettervik T, Howells T, Lewén A, Ronne-Engström E, Enblad P. Temporal dynamics of ICP, CPP, PRx, and CPPopt in high-grade aneurysmal subarachnoid hemorrhage and the relation to clinical outcome. Neurocrit Care. 2021. https://doi.org/10.1007/s12028-020-01162-4.
Howells T, Elf K, Jones PA, Ronne-Engstrom E, Piper I, Nilsson P, Andrews P, Enblad P. Pressure reactivity as a guide in the treatment of cerebral perfusion pressure in patients with brain trauma. J Neurosurg. 2005;102(2):311–7. https://doi.org/10.3171/jns.2005.102.2.0311.
Howells T, Johnson U, McKelvey T, Enblad P. An optimal frequency range for assessing the pressure reactivity index in patients with traumatic brain injury. J Clin Monit Comput. 2015;29(1):97–105. https://doi.org/10.1007/s10877-014-9573-7.
Gur D, Good WF, Wolfson SK Jr, Yonas H, Shabason L. In vivo mapping of local cerebral blood flow by xenon-enhanced computed tomography. Science (New York NY). 1982;215(4537):1267–8. https://doi.org/10.1126/science.7058347.
Yonas H, Darby JM, Marks EC, Durham SR, Maxwell C. CBF measured by Xe-CT: approach to analysis and normal values. J Cereb Blood Flow Metab Off J Int Soc Cereb Blood Flow Metab. 1991;11(5):716–25. https://doi.org/10.1038/jcbfm.1991.128.
Yonas H, Pindzola RP, Johnson DW. Xenon/computed tomography cerebral blood flow and its use in clinical management. Neurosurg Clin N Am. 1996;7(4):605–16.
Engquist H, Rostami E, Ronne-Engström E, Nilsson P, Lewén A, Enblad P. Effect of HHH-therapy on regional CBF after severe subarachnoid hemorrhage studied by bedside xenon-enhanced CT. Neurocrit Care. 2018;28(2):143–51. https://doi.org/10.1007/s12028-017-0439-y.
Engquist H, Rostami E, Enblad P. Temporal dynamics of cerebral blood flow during the acute course of severe subarachnoid hemorrhage studied by bedside xenon-enhanced CT. Neurocrit Care. 2019;30(2):280–90. https://doi.org/10.1007/s12028-019-00675-x.
Engquist H, Lewén A, Hillered L, Ronne-Engström E, Nilsson P, Enblad P, Rostami E. CBF changes and cerebral energy metabolism during hypervolemia, hemodilution, and hypertension therapy in patients with poor-grade subarachnoid hemorrhage. J Neurosurg. 2020. https://doi.org/10.3171/2019.11.Jns192759.
Svedung Wettervik T, Engquist H, Hånell A, Howells T, Rostami E, Ronne-Engström E, Lewén A, Enblad P. Cerebral blood flow and oxygen delivery in aneurysmal subarachnoid hemorrhage: relation to neurointensive care targets. Neurocrit Care. 2022. https://doi.org/10.1007/s12028-022-01496-1.
Svedung Wettervik T, Engquist H, Hånell A, Howells T, Rostami E, Ronne-Engström E, Lewén A, Enblad P. Cerebral microdialysis monitoring of energy metabolism: relation to cerebral blood flow and oxygen delivery in aneurysmal subarachnoid hemorrhage. J Neurosurg Anesthesiol. 2022. https://doi.org/10.1097/ana.0000000000000854.
Kety SS, Schmidt CFJAJoP-LC,. The determination of cerebral blood flow in man by the use of nitrous oxide in low concentrations. Am J Physiol. 1945;143(1):53–66.
Kety SS. The measurement of cerebral blood flow by means of inert diffusible tracers. Keio J Med. 1994;43(1):9–14. https://doi.org/10.2302/kjm.43.9.
Wilson JL, Pettigrew LE, Teasdale GM. Structured interviews for the Glasgow Outcome Scale and the extended Glasgow Outcome Scale: guidelines for their use. J Neurotrauma. 1998;15(8):573–85. https://doi.org/10.1089/neu.1998.15.573.
Teasdale GM, Pettigrew LE, Wilson JT, Murray G, Jennett B. Analyzing outcome of treatment of severe head injury: a review and update on advancing the use of the Glasgow Outcome Scale. J Neurotrauma. 1998;15(8):587–97. https://doi.org/10.1089/neu.1998.15.587.
Lipsitz LA, Goldberger AL. Loss of ‘complexity’ and aging. Potential applications of fractals and chaos theory to senescence. JAMA. 1992;267(13):1806–9. https://doi.org/10.1001/jama.1992.03480130122036.
Goldstein B, Fiser DH, Kelly MM, Mickelsen D, Ruttimann U, Pollack MM. Decomplexification in critical illness and injury: relationship between heart rate variability, severity of illness, and outcome. Crit Care Med. 1998;26(2):352–7. https://doi.org/10.1097/00003246-199802000-00040.
Hockel K, Schuhmann MU. ICP monitoring by open extraventricular drainage: common practice but not suitable for advanced neuromonitoring and prone to false negativity. Acta Neurochir Suppl. 2018;126:281–6. https://doi.org/10.1007/978-3-319-65798-1_55.
Aries MJ, de Jong SF, van Dijk JM, Regtien J, Depreitere B, Czosnyka M, Smielewski P, Elting JW. Observation of autoregulation indices during ventricular CSF drainage after aneurysmal subarachnoid hemorrhage: a pilot study. Neurocrit Care. 2015;23(3):347–54. https://doi.org/10.1007/s12028-015-0107-z.
Howells T, Johnson U, McKelvey T, Ronne-Engström E, Enblad P. The effects of ventricular drainage on the intracranial pressure signal and the pressure reactivity index. J Clin Monit Comput. 2017;31(2):469–78. https://doi.org/10.1007/s10877-016-9863-3.