Rationale: Delirium is a common and severe complication after neurosurgical procedures. Music before, during and after surgical procedures has proven its effectiveness in reducing pain, anxiety, stress and opioid medication in surgical patients. These symptoms belong to the main eliciting factors for developing delirium. Effective preventive therapy for delirium is not available. The investigators hypothesize that music listening, being a sustainable intervention with negligible risk of side effects, can lower delirium incidence among neurosurgical patients, resulting in reduction of in-hospital stays, healthcare costs and post-operative morbidity and mortality.

Objective: To assess the effect of peri-operative music on post-operative delirium in patients undergoing a craniotomy.

Study design: Single-centre prospective randomized controlled trial.

Study population: Adult patients undergoing a craniotomy at the Erasmus MC in Rotterdam.

Intervention: Recorded music, with headphones or earphones, before, during and after surgery.

Main study parameters/endpoints: Diagnosis of post-operative delirium screened by the DOS score confirmed by the consultant psychiatrist following the DSM-V criteria.

Rationale:

Delirium is a common and severe complication after neurosurgical procedures. Music before, during and after surgical procedures has proven its effectiveness in reducing pain, anxiety, stress and opioid medication in surgical patients. These symptoms belong to the main eliciting factors for developing delirium. Effective preventive therapy for delirium is not available. The investigators hypothesize that music listening, being a sustainable intervention with negligible risk of side effects, can lower delirium incidence among neurosurgical patients, resulting in reduction of in-hospital stays, healthcare costs and post-operative morbidity and mortality.

Objective:

To assess the effect of peri-operative music on post-operative delirium in patients undergoing a craniotomy.

Hypothesis effect and sample size:

The investigators expect an incidence of delirium in our control group of 30%. This is based on literature documenting incidence of delirium in neurosurgical patients in a northern European population of 29-33%.The expected effect cannot be based on previous literature since no adequate trials exist on the effect of music on delirium. Other non-pharmacological interventions in delirium prevention mention a relative reduction of 36-77%. The investigators will consider the intervention clinical relevant if a relative reduction of 60% with an absolute reduction of 18% is achieved. Taking into account the incidence of delirium of 30%, a power of 80%, a two-sided significant p-value of <0,05 in a 1:1 randomization leads to a sample size of 90 patients per arm. The investigators expect a loss to follow-up of 5% and will therefore include 189 patients.

Interventions:

Patients will be randomly allocated to either the intervention (music) or control (standard care) group. Participants in the music group will receive headphones with music 30 minutes before surgery. Patients will be able to choose music from a preselected list composed by a team consisting of researchers and dedicated music therapists. The headphones will be removed just before entering the operating room. Once in the operating room they will receive earphones after intubation, compatible with the Mayfield and site of operation. The intraoperative music intervention will be continued during the surgical procedure and discontinued just before detubation. The duration of the intraoperative music intervention depends on the duration of surgery and will be documented. After surgery, during recovery at the post-operative care unit (PACU) another 30 minutes of music through headphones will be given. The following 3 days at the neurosurgical ward they will receive music twice per day for 30 minutes.

Primary outcome: The primary outcome measure is presence or absence of postoperative delirium within the first 5 days after surgery. All participating patients on the ward will be screened using the Delirium Observation Screening (DOS) scale. Additional to the DOS, in case of raised suspicion of delirium, a psychiatrist is consulted to confirm or reject clinical diagnosis of delirium based on the DSM-V criteria.

Secondary outcome:

• Severity and duration of delirium (DRS-R-98)
• Pre-operative anxiety (VAS-A)
• Activation of the parasympathetic nervous system measured with HRV.
• Depth of anaesthesia registered with Bispectral Index (BIS).
• Peri-operative medication use.
• Postoperative pain (NRS).
• Patients with postoperative complications (AE/SAE's).
• Hospital length of stay (days).
• Cognitive function (MoCA).
• Patient functional outcome (KPS).
• Patient functional outcome (mRS).
• Mortality and readmission rate.
• Patient-reported outcome (EORTC-QLQ-C30)
• Patient-reported outcome (EORTC-QLQ-BN20)
• Patient-reported outcome (EQ-5D).
• Patient satisfaction (VAS).
• Economic evaluation / cost-effectiveness (iPCQ).

Inclusion Criteria:

1. Patients undergoing a craniotomy.
2. Adult patients (cq age ≥18 years)
3. Sufficient knowledge of the Dutch language to understand the study documents in the judgement of the attending physician or researcher.
4. Provision of written informed consent by patient or legal representative.

Exclusion Criteria:

1. Impaired awareness before surgery (i.e. GCS < M6).
2. Planned post-operative ICU admission.
3. Suspected delirium (defined as fluctuating awareness).
4. Current antipsychotic treatment
5. Patients undergoing interventions impeding supply of music (e.g. surgical translabyrinthine approach, awake surgery).
6. Severe bilateral hearing impairment, defined as no verbal communication possible.
7. Current participation in other clinical trials interfering with results.

Music vs. standard clinical care. No blinding of treatment was conducted.