Machine Learning Prediction of Spinal Anaesthesia Block Duration
Artificial Intelligence-Based Prediction of Sensory and Motor Block Duration Following Spinal Anaesthesia: A Prospective Observational Prediction Model Development Study
The duration of sensory and motor block after spinal anaesthesia varies widely between patients given the same dose of local anaesthetic. Much of this variability is explained by differences in lumbosacral cerebrospinal fluid volume, which cannot be measured routinely in clinical practice but is related to simple body measurements such as abdominal circumference and vertebral column length. This prospective observational study will develop and internally validate prediction models for the duration of sensory and motor block following spinal anaesthesia in adults undergoing elective surgery. Preoperative clinical and anthropometric variables will be recorded, and block regression will be assessed serially after intrathecal injection. Machine learning methods (lasso regression, ridge regression, random forest, extreme gradient boosting, and support vector regression) will be developed and compared against multivariable linear regression as the reference model. The aim is a practical tool that helps anaesthetists anticipate how long a spinal block will last in an individual patient, supporting decisions about case scheduling, supplementation, and discharge planning.
Studienübersicht
Status
Detaillierte Beschreibung
Background. Spinal anaesthesia produces block of unpredictable duration. Cerebrospinal fluid volume in the lumbosacral region is the dominant determinant of block spread and regression, and correlates inversely with abdominal circumference and directly with vertebral column length. Existing single-variable rules perform poorly, and no validated multivariable model is in routine clinical use. Objectives. The primary objective is to develop and internally validate models predicting the duration of sensory block and the duration of motor block after single-shot spinal anaesthesia. The secondary objective is to compare the predictive performance of machine learning approaches with conventional multivariable linear regression. Design. Single-centre prospective observational cohort study. No study-directed intervention is applied; anaesthetic technique, drug, and dose are determined by the attending anaesthetist according to routine practice and are recorded as candidate predictors. Assessments. Sensory block level is assessed bilaterally by pinprick with a 25-gauge needle along the mid-clavicular line, over dermatomes T4 to S1. Motor block is assessed using the modified Bromage scale (0-3). Assessments are performed at fixed intervals from intrathecal injection until complete regression of sensory and motor block. Candidate predictors. Age, sex, height, weight, body mass index, abdominal circumference, vertebral column length, ASA physical status, local anaesthetic dose and baricity, and adjuvant use. Sample size. A target of 255 participants was derived using the Riley criteria for continuous-outcome prediction models (pmsampsize), assuming 9 candidate predictors, an outcome standard deviation of 40 minutes, anticipated R-squared of 0.35, shrinkage of at least 0.90, and a multiplicative margin of error of 1.10. The four criteria yielded 183, 183, 234, and 246; the largest requirement of 246 was inflated by approximately 4 per cent for attrition. Analysis. Model development will use nested repeated 10-fold cross-validation with bootstrap optimism correction. Performance will be reported as R-squared, root mean squared error, and mean absolute error, with calibration plots. SHAP values will be used to describe predictor contributions. Reporting will follow TRIPOD+AI.
Studientyp
Einschreibung (Geschätzt)
Kontakte und Standorte
Studienkontakt
- Name: Salaheldin A Abdelaziz Ahmed
- Telefonnummer: +966508818713
- E-Mail: saladin28.sa@gmail.com
Teilnahmekriterien
Zulassungskriterien
Studienberechtigtes Alter
Akzeptiert gesunde Freiwillige
Studienberechtigte Geschlechter
Probenahmeverfahren
Studienpopulation
Consecutive adults scheduled for elective surgery under single-shot spinal anaesthesia at Specialized Medical Center, King Fahad campus, Riyadh.
Beschreibung
Inclusion Criteria:
- Adults scheduled for elective surgery under single-shot spinal anaesthesia
- ASA physical status I to III
- Written informed consent obtained
Exclusion Criteria:
- Contraindication to neuraxial anaesthesia (coagulopathy, local or systemic infection, raised intracranial pressure, patient refusal)
- Failed or incomplete block requiring conversion to general anaesthesia
- Repeated or top-up intrathecal injection
- Pregnancy
- Known spinal deformity or previous spine surgery
- Pre-existing neurological or neuromuscular disease affecting sensory or motor assessment
- Inability to cooperate with sensory and motor assessment
Studienplan
Wie ist die Studie aufgebaut?
Designdetails
- Beobachtungsmodelle: COHORT
- Zeitperspektiven: PROSPECTIVE
Was misst die Studie?
Primäre Ergebnismessungen
Ergebnis Maßnahme |
Maßnahmenbeschreibung |
Zeitfenster |
|---|---|---|
|
Duration of sensory block
Zeitfenster: Up to 8 hours after intrathecal injection
|
Time from completion of intrathecal injection to regression of sensory block to the S1 dermatome, assessed bilaterally by pinprick with a 25-gauge needle along the mid-clavicular line |
Up to 8 hours after intrathecal injection
|
|
Duration of motor block
Zeitfenster: Up to 8 hours after intrathecal injection
|
Time from completion of intrathecal injection to return to modified Bromage score 0 (full ability to flex knee and ankle) |
Up to 8 hours after intrathecal injection
|
Sekundäre Ergebnismessungen
Ergebnis Maßnahme |
Maßnahmenbeschreibung |
Zeitfenster |
|---|---|---|
|
Predictive performance of machine learning models
Zeitfenster: Through study completion, an average of 20 months
|
R-squared, root mean squared error, mean absolute error, and calibration slope for lasso regression, ridge regression, random forest, extreme gradient boosting, and support vector regression, each compared with multivariable linear regression as the reference model |
Through study completion, an average of 20 months
|
|
Time to peak sensory block level
Zeitfenster: Up to 30 minutes after intrathecal injection
|
Time from intrathecal injection to the highest dermatomal level of sensory block, assessed by pinprick |
Up to 30 minutes after intrathecal injection
|
Mitarbeiter und Ermittler
Sponsor
Ermittler
- Hauptermittler: Salaheldin A abdelaziz Ahmed, Specialized Medical Center
Studienaufzeichnungsdaten
Haupttermine studieren
Studienbeginn (Geschätzt)
Primärer Abschluss (Geschätzt)
Studienabschluss (Geschätzt)
Studienanmeldedaten
Zuerst eingereicht
Zuerst eingereicht, das die QC-Kriterien erfüllt hat
Zuerst gepostet (Tatsächlich)
Studienaufzeichnungsaktualisierungen
Letztes Update gepostet (Tatsächlich)
Letztes eingereichtes Update, das die QC-Kriterien erfüllt
Zuletzt verifiziert
Mehr Informationen
Begriffe im Zusammenhang mit dieser Studie
Schlüsselwörter
Andere Studien-ID-Nummern
- IRBSMC1-2026-0001
Plan für individuelle Teilnehmerdaten (IPD)
Planen Sie, individuelle Teilnehmerdaten (IPD) zu teilen?
Beschreibung des IPD-Plans
De-identified individual participant data underlying published results, together with the data dictionary and model code, will be made available to researchers whose proposed use has been approved by an independent review committee. Requests should be directed to the principal investigator. Data will be available from 6 months to 36 months after publication of the primary results.
IPD-Sharing-Zeitrahmen
Data will become available 6 months after publication of the primary results and will remain available for 36 months
IPD-Sharing-Zugriffskriterien
Requests should be directed to the principal investigator. Proposals will be reviewed by the principal investigator and the Specialized Medical Center Institutional Review Board. Requesters must provide a methodologically sound proposal and sign a data access agreement.
Art der unterstützenden IPD-Freigabeinformationen
- STUDIENPROTOKOLL
- SAFT
- ICF
- ANALYTIC_CODE
Arzneimittel- und Geräteinformationen, Studienunterlagen
Studiert ein von der US-amerikanischen FDA reguliertes Arzneimittelprodukt
Studiert ein von der US-amerikanischen FDA reguliertes Geräteprodukt
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