An interventional study of Perfusion index measurement in Forearm Surgeries and Brachial Plexus Blockade, sponsored by Adiyaman University Research Hospital. Not yet recruiting at 1 site in Turkey (Türkiye). Open to participants aged 18 Years to 65 Years. Per ClinicalTrials.gov, last updated 2026-11-02.
Sponsored by Adiyaman University Research Hospital · Not applicable, Interventional, and Diagnostic
Postoperative differentiation between residual regional anesthetic effect and other causes of persistent sensory or motor deficit is a common clinical problem after peripheral nerve blocks. Perfusion index (PI), a noninvasive pulse oximetry-derived measure of peripheral perfusion, rises after sympathetic blockade and has been studied for predicting block success and duration. However, its ability to detect the resolution of a block has not been established. This prospective observational study will evaluate the diagnostic accuracy of the PI ratio between the blocked and contralateral hand for detecting sensory and motor block resolution in adult patients undergoing elective forearm surgery under ultrasound-guided infraclavicular brachial plexus block. PI, sensory block (pinprick), and motor block will be assessed repeatedly from before the block until 24 hours postoperatively. Cut-off values of the PI ratio for the first regression and the complete resolution of sensory and motor block will be determined using ROC analysis.
Peripheral nerve blocks provide effective postoperative analgesia, but persistent numbness or weakness after surgery raises the question of whether the deficit reflects the expected duration of the local anesthetic or another cause, such as surgical or positioning-related nerve injury. Current assessment relies on repeated clinical examination and the passage of time. PI reflects peripheral vascular tone and increases in a blocked limb because of sympathetic blockade. Previous studies have examined PI mainly for predicting block success and duration; data on whether PI can objectively indicate the offset of block are lacking.
To determine the diagnostic accuracy of the PI ratio (blocked hand / contralateral hand) for detecting resolution of sensory and motor blockade after infraclavicular brachial plexus block, and to establish cut-off values for the first regression and complete resolution of each.
Prospective, single-center, observational diagnostic accuracy study. Fifty adult patients (18-65 years) scheduled for elective forearm surgery under infraclavicular brachial plexus block will be included after written informed consent. Patients with preoperative neurological deficit, peripheral vascular disease or Raynaud phenomenon, diabetic neuropathy, pathology of the contralateral arm, or failed block will be excluded or . The block technique, local anesthetic type, concentration, and volume will be standardized.
PI will be measured with a pulse oximeter probe placed on the same finger of both hands at the following time points: before the surgery; 5, 10, 15, and 30 minutes after the block; and 30, 60, 90, and 120 minutes, and 4, 6, 8, 12, 16, and 24 hours postoperatively. The PI ratio will be calculated as operated-side PI divided by contralateral-side PI. At each time point, sensory block will be assessed by pinprick and motor block will be assessed using a 4-point upper extremity motor scale by an investigator blinded to PI values: Grade 0, able to raise the extended arm to 90° for 2 s; Grade 1, able to flex the elbow and move the fingers but unable to raise the extended arm; Grade 2, unable to flex the elbow but able to move the fingers; Grade 3, inability to move the arm, elbow, or fingers. The time to first regression and the time to complete resolution of sensory and motor block will be recorded. Room temperature, tourniquet duration and pressure, surgery type, age, and analgesic consumption will be recorded as potential confounders.
The primary outcome is the diagnostic accuracy (ROC AUC, sensitivity, specificity) of the PI ratio for complete resolution of sensory and motor block. Secondary outcomes include the PI ratio cut-off for first regression, the time course of the PI ratio after block, and the relationship of the PI ratio with clinical block status. Because repeated measurements are obtained from each patient, analyses will account for within-patient correlation (e.g., cluster bootstrap or mixed-effects models). Optimal cut-offs will be determined using the Youden index with 95% confidence intervals.
If validated, the PI ratio may help clinicians judge whether a persistent postoperative deficit is plausibly attributable to residual block. The study is not designed to diagnose nerve injury; any patient with a persistent deficit will be followed according to clinical practice.
Adiyaman University Research Hospital is the lead sponsor of 51 studies on the registry; 11 are open to participants now.
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
ASA physical status
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Adult patients (18-65 years) undergoing elective forearm surgery under ultrasound-guided infraclavicular brachial plexus block. Perfusion index of both hands is measured noninvasively before the surgery, at 5, 10, 15 and 30 minutes after the block, and at 30, 60, 90 and 120 minutes, and 4, 6, 8, 12, 16 and 24 hours postoperatively. At each time point, sensory block (pinprick) and motor block (4-point upper extremity motor scale) are assessed. No treatment beyond routine anesthetic and surgical care is applied.
Diagnostic Test: Perfusion index measurement
Noninvasive measurement of perfusion index (PI) using a pulse oximeter probe placed on the same finger of both hands at predefined time points: before the block; 5, 10, 15 and 30 minutes after the block; and 30, 60, 90 and 120 minutes, and 4, 6, 8, 12, 16 and 24 hours postoperatively. The PI ratio (operated hand / contralateral hand) is calculated. The measurement does not alter anesthetic or surgical management.
Diagnostic accuracy of perfusion index ratio for resolution of motor block
Area under the ROC curve, optimal cut-off value, sensitivity and specificity of the perfusion index ratio (operated hand / contralateral hand) for detecting complete resolution of motor block after infraclavicular brachial plexus block. Complete resolution is defined as Grade 0 on the 4-point upper extremity motor scale (able to raise the extended arm to 90 degrees for 2 seconds). Motor status is assessed by a blinded investigator at each time point.
Time frame: before the surgery, at 5, 10, 15 and 30 minutes after the block, and at 30, 60, 90 and 120 minutes, and 4, 6, 8, 12, 16 and 24 hours postoperatively
Diagnostic accuracy of perfusion index ratio for resolution of sensory block
Area under the ROC curve, optimal cut-off value, sensitivity and specificity of the perfusion index ratio (operated hand / contralateral hand) for detecting complete resolution of sensory block after infraclavicular brachial plexus block. Complete resolution is defined as pinprick sensation equal to that of the contralateral hand. Sensory status is assessed by a blinded investigator at each time point.
Time frame: before the surgery, at 5, 10, 15 and 30 minutes after the block, and at 30, 60, 90 and 120 minutes, and 4, 6, 8, 12, 16 and 24 hours postoperatively
Perfusion index ratio cut-off for first regression of motor block
Area under the ROC curve, optimal cut-off value, sensitivity and specificity of the perfusion index ratio (operated hand / contralateral hand) for detecting the first regression of motor block after infraclavicular brachial plexus block. First regression is defined as the first decrease in motor grade on the 4-point upper extremity motor scale from the maximal block level, assessed by a blinded investigator.
Time frame: Before the surgery, at 5, 10, 15 and 30 minutes after the block, and at 30, 60, 90 and 120 minutes, and 4, 6, 8, 12, 16 and 24 hours postoperatively
Perfusion index ratio cut-off for first regression of sensory block
Area under the ROC curve, optimal cut-off value , sensitivity and specificity of the perfusion index ratio (operated hand / contralateral hand) for detecting the first regression of sensory block after infraclavicular brachial plexus block. First regression is defined as the first return of pinprick sensation in the operated hand, assessed by a blinded investigator.
Time frame: Before the surgery, at 5, 10, 15 and 30 minutes after the block, and at 30, 60, 90 and 120 minutes, and 4, 6, 8, 12, 16 and 24 hours postoperatively
Relationship between perfusion index ratio and clinical block status
Correlation between the perfusion index ratio and motor grade (4-point upper extremity motor scale) and sensory block status (pinprick) at each time point, using methods that account for repeated measurements within patients.
Time frame: Before the surgery, at 5, 10, 15 and 30 minutes after the block, and at 30, 60, 90 and 120 minutes, and 4, 6, 8, 12, 16 and 24 hours postoperatively
Duration of sensory and motor block
Time from completion of the block to first regression and to complete resolution of sensory block (pinprick) and motor block (4-point upper extremity motor scale), assessed by a blinded investigator.
Time frame: Before the surgery, at 5, 10, 15 and 30 minutes after the block, and at 30, 60, 90 and 120 minutes, and 4, 6, 8, 12, 16 and 24 hours postoperatively
Plan to share: Undecided
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Adiyaman University Research Hospital