The challenge of postoperative delirium in maxillofacial surgery

Postoperative delirium (POD), an acute and reversible disturbance of consciousness, represents a major obstacle to clinical recovery in oral and maxillofacial surgery (OMFS). Although it is often perceived as a complication specific to elderly patients, its incidence following tumour resection or mandibular reconstruction heavily impacts the length of hospital stay and mortality rates. Despite the severity of these episodes of confusion and inattention, data specific to the maxillofacial field remain fragmentary, with studies having so far largely focused on general or orthopaedic surgery.

This systematic review with meta-analysis aims to perform a rigorous quantitative synthesis of the risk factors for POD exclusively in adult patients in OMFS. The authors seek to identify the critical variables — preoperative, surgical and pharmacological — that precipitate this behavioural instability. The study is based on the hypothesis that the specific features of OMFS, notably the extent of local tissue trauma, the complexity of airway management and the specific reactions to anaesthetic protocols of the facial region, constitute determining triggers, distinct from conventional surgical risk factors.

Methodology: A rigorous selection protocol

This systematic review and meta-analysis was conducted according to the PRISMA 2020 guidelines and registered in the PROSPERO database (CRD420251267779). The objective was to identify the risk factors for postoperative delirium (POD) specifically in the context of oral and maxillofacial surgeries (OMFS).

• Search strategy: A systematic search was conducted up to 10 December 2025 on PubMed, Web of Science, Embase and the Cochrane Library. Two researchers performed the searches independently.
• Population and inclusion criteria: The study targets adult patients undergoing OMFS procedures (tumour resections, mandibular reconstructions, traumatology or oral rehabilitation). Only studies using validated diagnostic tools such as the DSM-IV, DSM-5 or ICD-10 were included.
• Selection and sample: Of 828 initially identified articles, 616 were reviewed after removing duplicates. Ultimately, 7 clinical studies (cohort and case-control) were selected, comprising a total of 2,398 patients.
• Quality assessment: The risk of bias was analysed using the Newcastle-Ottawa Scale (NOS), evaluating the selection of populations, comparability and exposure.
• Statistical analyses: Data processing was performed using Stata 15.0 software. Statistical heterogeneity between the studies was measured using Cochran's Q test and the I² statistic.

Selection process and document flow

The systematic search, conducted up to 10 December 2025, initially identified 828 articles across four major databases. After the removal of 202 duplicates, 616 articles underwent an initial screening based on titles and abstracts. A thorough full-text review led to the exclusion of three specific studies: one for a lack of relevant outcomes (n=1), another for the use of combined interventions (n=1) and the last due to data unavailability (n=1).

Characteristics of the population and included studies

The final analysis is based on the synthesis of 7 clinical articles meeting the PRISMA inclusion criteria. This meta-analysis compiles data from a total cohort of 2,398 patients who underwent oral and maxillofacial surgery (OMFS) procedures.

Qualitative observations on the surgical profile

Although the review initially targeted the entire spectrum of maxillofacial surgery, the authors note a concentration of data on high-complexity surgical populations. The included studies predominantly focus on:

• Major oncological surgery (oral cancers, head and neck tumours).
• Complex reconstruction procedures, particularly using free flaps.
• Procedures involving specific challenges in airway management and prolonged recovery periods.

The methodological quality of the studies was assessed using the Newcastle-Ottawa Scale (NOS), covering the dimensions of selection, comparability and exposure. Statistical analysis used Odds Ratios (OR) with a 95% confidence interval, processed using a random-effects model to account for potential heterogeneity between the studies.

OMFS, a specific setting for delirium

The analysis of this systematic review, including seven studies and a total cohort of 2,398 patients, highlights an often underestimated clinical reality: postoperative delirium (POD) in maxillofacial surgery is not a universal geriatric inevitability, but a risk closely linked to the complexity of the procedure. The results suggest that classic factors (age, pre-existing cognitive impairment, malnutrition) combine here with triggers specific to our specialty, such as the severe tissue trauma of free flap reconstructions and the challenges of airway management.

The strength of this synthesis lies in isolating determining variables such as anaemia, infections and the use of sedatives. For the practitioner, this means that the patient's cognitive trajectory depends not only on their medical history, but also on immediate perioperative management. Severe local pain, characteristic of invasive procedures in the oral cavity, emerges as a critical lever upon which we can act to limit the incidence of POD.

However, the authors highlight a major methodological limitation: current literature focuses almost exclusively on major oncological and reconstructive surgery. There is a glaring lack of data regarding traumatology procedures or major oral rehabilitation in private practice. This hyper-specialisation of data limits the generalisability of the results to the entire spectrum of oral and maxillofacial surgery. Nevertheless, the impact of POD on in-hospital mortality and the cost of care justifies a systematic screening strategy for frail patients as early as the preoperative consultation.

Summary of the risks of postoperative delirium in maxillofacial surgery

This systematic review, including 7 studies for a total of 2,398 patients, highlights that postoperative delirium (POD) is not exclusive to elderly patients in general surgery. In oral and maxillofacial surgery (OMFS), particularly during tumour resections and complex free flap reconstructions, the incidence is correlated with critical factors such as advanced age, pre-existing cognitive impairment, malnutrition and postoperative pain intensity.

In practical terms, for the practitioner:

• Target preoperative screening: Systematically identify frail patients (over 65 years of age, cognitive history or poor nutritional status) before major oncological or reconstructive procedures.
• Optimising analgesia: As severe local pain is a major trigger in OMFS, a rigorous and multimodal analgesic protocol is essential to limit post-surgical agitation and confusion.
• Enhanced monitoring in reconstruction: Exercise heightened vigilance during the first 48 hours in patients undergoing prolonged or complex surgeries, to reduce the length of hospital stay and mortality risks associated with POD.

Technical glossary of the study

POD (Postoperative Delirium): Acute and reversible disturbance of consciousness occurring after surgery. It is characterised by inattention, confusion and disorientation, significantly increasing morbidity and length of hospital stay.

OMFS (Oral and Maxillofacial Surgery): Surgical specialty treating pathologies of the oral cavity, the maxillofacial region and associated tissues. This study focuses on the delirium risks specific to these procedures (mandibular reconstructions, oncology, oral rehabilitation).

Free flap reconstruction: Complex free flap reconstruction technique, cited in the study as a highly complex procedure often associated with the development of postoperative cognitive disorders in head and neck oncological surgery.

PROSPERO: International prospective register of systematic reviews. This study is registered there (CRD420251267779), ensuring protocol transparency and limiting the risk of publication bias.

DSM-IV / ICD-10: Standardised diagnostic frameworks (Diagnostic and Statistical Manual of Mental Disorders and International Classification of Diseases) used in the methodology to formally validate cases of postoperative delirium.

PRISMA 2020: International reporting standard (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) followed by the authors to structure this meta-analysis and ensure the rigour of the data selection process.

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