Perfusion Index

This prospective, single-centre observational study evaluates changes in the peripheral Perfusion Index (PI) - a non-invasive parameter derived from the pulse-oximetry photoplethysmographic waveform - in women receiving epidural, or combined spinal-epidural (CSE) with intrathecal opioid only, analgesia during vaginal labor. Epidural-induced sympathetic block causes vasodilation and compensatory changes in peripheral vascular resistance, which alter peripheral perfusion and therefore PI. PI is recorded together with routinely monitored haemodynamic, obstetric and analgesia-related variables (including pain intensity on the Numeric Rating Scale, NRS) from before block placement until after delivery. The aims are: to describe the pattern and magnitude of PI changes during labor analgesia and the parameter's usefulness in this dynamic clinical setting; to assess the correlation between PI changes and reported pain; and to evaluate whether PI (its change or the absence of change) can help identify ineffective blocks early - for example those caused by catheter malposition or by sacral sparing in the second stage of labor. All measurements are non-invasive and consistent with the current standard of perinatal care.

The goal of this clinical trial is to determine if perfusion index (PI) can reliably predict changes in systolic blood pressure (SBP) in persons with spinal cord injury (SCI) during a cool temperature challenge. Participants with SCI can be 18-75 years of age, male or female, neurological level of injury C4-T12, ASIA Impairment Scale (AIS: A or B: motor complete) or gender and healthy age-matched able-bodied (AB) controls. The main question this study aims to answer is: can PI reliably predict change in SBP during a cool temperature challenge? The investigators hypothesize that PI can be used as a biomarker of SBP in persons with SCI. Researchers will compare the relationship of 1) changes in PI and SBP and 2) relationship of changes in other vital signs to SBP, during the cool temperature challenge. The researchers aim to determine if PI can be used as a biomarker of SBP in persons with SCI during a cool temperature challenge (experimental group/arm). Able-bodied controls (control group/arm) will receive the same intervention (cool challenge) as the experimental group. During the study, participants will be asked to wear only shorts and a T-shirt so that their skin can be exposed to the warm and cool temperatures of the 2 rooms. The investigators will put put on non-invasive sensors (taped or attached on the surface of your body) to measure PI, BP, and other vital signs. The investigators will record these measurements while the participant is seated in a wheelchair for 10 minutes in a warm room and up to 90 minutes in a cool room.

The costoclavicular approach of the infraclavicular brachial plexus block is widely used for upper extremity surgeries due to its reliable anatomy and high success rates. Patient positioning, particularly the degree of arm abduction, may influence the spread of local anesthetic and the characteristics of the block. However, the optimal arm abduction angle during this procedure remains unclear. This prospective randomized controlled trial aims to investigate the effect of two different arm abduction angles (90° and 120°) on block onset time and block success in patients undergoing hand, wrist, and forearm surgery under ultrasound-guided costoclavicular brachial plexus block. Patients will be randomly assigned to one of two groups according to the degree of arm abduction. The primary outcome is block onset time. Secondary outcomes include block success, sensory and motor block characteristics, perfusion index changes, hemodynamic parameters, readiness for surgery at 15 and 20 minutes, block performance time, need for additional anesthesia, postoperative neurological evaluation at 4 and 24 hours, complications, and patient satisfaction. The findings of this study are expected to provide evidence on optimal patient positioning to improve the effectiveness and reliability of ultrasound-guided costoclavicular brachial plexus block.

The aim of this observational study is to investigate how table position affects the development of block in patients undergoing spinal anesthesia. Perfusion index measurements will be used to answer this question. Patients who will undergo perfusion index measurement during surgery will be included in the study. These patients will be compared with patients whose anesthesiologists chose not to position them on the operating table. The study is planned to continue for approximately 40 days, and the data collected during this period will be used for evaluation.

This is a prospective observational study investigating the correlation between Perfusion Index (PI) ratio and End Diastolic Velocity (EDV) ratio as early predictors of successful supraclavicular brachial plexus block (SCBPB) in patients undergoing superficialization surgery of the upper limb.

The aim of this study is to evaluate the predictive role of the Peripheral Perfusion Index (PPI) in forecasting extubation success during the weaning process in intensive care unit (ICU) patients. The study will investigate the ability of PPI to predict extubation failure by comparing it with traditional weaning criteria, including the Rapid Shallow Breathing Index (RSBI), PaO₂/FiO₂ ratio, and respiratory rate.

This study aims to evaluate changes in perfusion index (PI) in pediatric patients undergoing elective surgery under low-flow anesthesia. PI will be monitored at multiple intraoperative and postoperative time points to assess its relationship with hemodynamic stability and depth of anesthesia. The study will also investigate whether low-flow anesthesia affects the incidence of emergence agitation (EA). Patients will be assigned to either low-flow or normal-flow anesthesia groups based on routine clinical practice. No intervention will be applied beyond standard care. The findings are expected to provide insight into the predictive value of PI in postoperative recovery and support safer anesthesia practices in pediatric populations.

In this thesis we will use the current state of knowledge that PI can provide a reliable information about the state of peripheral microcirculation during the state of sepsis and septic shock in ICU patients and that can interfere with the timing of starting vasopressor treatment in sepsis and septic shock

The aim of the study is to experimentally compare measured perfusion index values between smartwatch and a medical grade pulse oximeter in healthy subjects at rest and with and without motion artifacts and during exercise.