Heart Rate Variability and Processed EEG Features as Predictors of Postoperative Outcomes After Cranial Neurosurgery
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- This is an observational study: the protocol does not assign a study treatment.
- Who it may be relevant to
- Registry conditions: Cranial Neurosurgery. Basic parameters: from 18 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Italy
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
Unsure about the terms? Read our patient guide →
Official title
Heart Rate Variability and Processed EEG Features as Predictors of Postoperative Outcomes After Cranial Neurosurgery - A Prospective Observational Study in the Post-Anesthesia Care Unit
Overview
Patients undergoing cranial neurosurgery face a high-risk postoperative period, particularly during emergence from anesthesia and early recovery in the post-anesthesia care unit (PACU). Standard monitoring provides limited insight into brain and autonomic recovery processes. Heart rate variability (HRV) and processed electroencephalography (pEEG) may offer complementary markers of autonomic and cortical function, with potential to improve early detection of complications and guide individualized care.
Detailed description
Patients undergoing cranial neurosurgery face a particularly vulnerable postoperative course. The immediate hours after surgery represent a high-risk window, as the transition from anesthesia to recovery is marked by abrupt physiological shifts and the potential for neurological or systemic instability. As patients transition from deep anesthesia to consciousness, dynamic fluctuations in autonomic tone and cortical activity reflect the brain's ability to recover from surgical and anesthetic stress. Smooth emergence and extubation are therefore essential: coughing, hypertension, or surges in intracranial pressure (ICP) can endanger hemostasis and compromise brain protection. Most serious complications-such as intracranial bleeding, cerebral edema, ischemia, hydrocephalus, or herniation-tend to arise within the first hours after surgery.
The Post Anesthesia Care Unit (PACU) constitutes a important window of observation. At this critical phase many strategies have been developed to protect the brain from complication triggering events. For example, remifentanil infusion-whether manual or target-controlled at effect-site concentrations, like adopted at our institution, titrated to suppress airway reflexes and blunt cardiovascular responses-have been shown to promote safe and controlled awakening while preserving prompt neurological evaluation(1-6), facilitating the identification of surgical from anesthetic causes of delayed recovery. Any unrecognized or delayed deterioration early after surgery may herald potentially warning signs, highlighting the need for accurate, physiology-based monitoring to support timely detection and intervention.
Standard monitoring-focused largely on vital signs-offers limited insight into the underlying brain and autonomic processes that govern recovery. Heat rate variability (HRV) and processed electroencephalography (pEEG) features, may provide novel means to characterize patient vulnerability in the PACU, improving risk stratification and guiding individualized perioperative care.
Primary outcome measures
- Temporal trajectories of HRV and pEEG after Neurosurgery in the PACU [Time frame: 1 year]
Secondary outcome measures (4)
- Correlation Between HRV/pEEG Parameters in PACU and Incidence of Early Postoperative Complications Within 48 Hours [Time frame: 48 hours after surgery]
- Correlation Between HRV/pEEG Parameters and Perioperative Drug Exposure [Time frame: Intraoperative period]
- Correlation Between HRV/pEEG Parameters and Perioperative Clinical Variables [Time frame: Intraoperative period]
- Feasibility and Data Quality of HRV and pEEG Monitoring in PACU [Time frame: First 60 minutes of PACU stay]
Eligibility criteria
Inclusion criteria
- Adult patients (≥18 years) scheduled for elective cranial neurosurgery.
- Planned extubation in the PACU after surgery.
- Ability to obtain high-quality ECG and EEG recordings intra- and postoperatively (≥60 min expected PACU monitoring).
- Written informed consent signed preoperatively.
Exclusion criteria
- Pre-existing severe cardiac arrhythmias (e.g., atrial fibrillation, frequent ectopy) or pacemaker dependence.
- Known severe autonomic neuropathy (e.g., advanced diabetes, Parkinson's disease with autonomic failure).
- Preoperative conditions associated with abnormal EEG (status epilepticus, uncontrolled seizures, sedative/hypnotic overdose).
- Intraoperative or immediate postoperative events necessitating continued mechanical ventilation or ICU admission (e.g., massive bleeding, intraoperative arrest).
- Inability to provide informed consent (e.g., cognitive impairment, language barrier without interpreter).
- Refusal of informed consent
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Observational model
- Cohort
Study locations
Italy · 1 center
- Fondazione IRCCS Istituto Neurologico Carlo Besta — Milan
Publications
- Marino L, Badenes R, Bilotta F. Heart Rate Variability for Outcome Prediction in Intracerebral and Subarachnoid Hemorrhage: A Systematic Review. J Clin Med. 2023 Jun 28;12(13):4355. doi: 10.3390/jcm12134355. PMID 37445389
- Frandsen MN, Mehlsen J, Foss NB, Kehlet H. Preoperative heart rate variability as a predictor of perioperative outcomes: a systematic review without meta-analysis. J Clin Monit Comput. 2022 Aug;36(4):947-960. doi: 10.1007/s10877-022-00819-z. Epub 2022 Jan 29. PMID 35092527
- Winchell RJ, Hoyt DB. Analysis of heart-rate variability: a noninvasive predictor of death and poor outcome in patients with severe head injury. J Trauma. 1997 Dec;43(6):927-33. doi: 10.1097/00005373-199712000-00010. PMID 9420107
- Liu X, Wan H, Wang H, Zhang G, Zhong Q, Duan X. Correlation between heart rate variability and perioperative neurocognitive disorders in patients undergoing non-cardiac surgery: A retrospective cohort study. PLoS One. 2024 Apr 2;19(4):e0297337. doi: 10.1371/journal.pone.0297337. eCollection 2024. PMID 38564647
- Satomoto M. Predicting Postoperative Emergence Delirium From the Heart Rate Variability of Patients Undergoing Elective Cardiac Surgery. Cureus. 2023 Feb 3;15(2):e34613. doi: 10.7759/cureus.34613. eCollection 2023 Feb. PMID 36891021
- Li X, Deng X, Huang Z, Kowark A, Coburn M, Zhang G, Duan X. Relationship between Heart Rate Variability and Postoperative Cognitive Dysfunction in Elderly Patients. Am J Health Behav. 2023 Feb 28;47(1):65-74. doi: 10.5993/AJHB.47.1.8. PMID 36945090
- Perez-Otal B, Aragon-Benedi C, Pascual-Bellosta A, Ortega-Lucea S, Martinez-Ubieto J, Ramirez-Rodriguez JM; Research Group in Anaesthesia, Resuscitation, and Perioperative Medicine of Institute for Health Research Aragon (ISS Aragon). Neuromonitoring depth of anesthesia and its association with postoperative delirium. Sci Rep. 2022 Jul 26;12(1):12703. doi: 10.1038/s41598-022-16466-y. PMID 35882875
- Shahiri TS, Richard-Lalonde M, Richebe P, Gelinas C. Exploration of the Nociception Level (NOL) Index for Pain Assessment during Endotracheal Suctioning in Mechanically Ventilated Patients in the Intensive Care Unit: An Observational and Feasibility Study. Pain Manag Nurs. 2020 Oct;21(5):428-434. doi: 10.1016/j.pmn.2020.02.067. Epub 2020 Apr 27. PMID 32354616
Identifiers
NCT: NCT07443072 · HERO-PACU