Journal of clinical monitoring and computing
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J Clin Monit Comput · Aug 2019
Letter Case ReportsLimitations of near infrared spectroscopy (NIRS) in neurosurgical setting: our case experience.
One of the primary goals of anaesthesia in neurosurgical procedures is prevention of cerebral hypoxia leading to secondary neurological injury. Cerebral oximetry detects periods of cerebral hypoxemia and allows intervention for prevention of secondary brain injury and its sequelae. This can be achieved by the use of Near Infrared Spectroscopy (NIRS). ⋯ In a neurosurgical setting, the erroneous values on the operative side could be attributed to altered tissue boundary conditions resulting in a changed optical path, which is normally held as a constant in NIRS measurements. The altered tissue boundary conditions could be due to the presence of air or blood between the myocutaneous flapskull, skull-dura, dura-brain interphases. It could also be that the sensors' penetrating depth was inadequate to compensate for the increased distance between sensor and brain tissue, thereby resulting in inaccurately higher values (> 80%).
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J Clin Monit Comput · Aug 2019
Cerebrovascular assessment of patients undergoing shoulder surgery in beach chair position using a multiparameter transcranial Doppler approach.
Although the beach-chair position (BCP) is widely used during shoulder surgery, it has been reported to associate with a reduction in cerebral blood flow, oxygenation, and risk of brain ischaemia. We assessed cerebral haemodynamics using a multiparameter transcranial Doppler-derived approach in patients undergoing shoulder surgery. 23 anaesthetised patients (propofol (2 mg/kg)) without history of neurologic pathology undergoing elective shoulder surgery were included. Arterial blood pressure (ABP, monitored with a finger-cuff plethysmograph calibrated at the auditory meatus level) and cerebral blood flow velocity (FV, monitored in the middle cerebral artery) were recorded in supine and in BCP. ⋯ Changes between phases did not result in CrCP reaching diastolic ABP, therefore DCM did not reach critical values (≤ 0 mm Hg). BCP resulted in significant cerebral haemodynamic changes. If left untreated, reduction in cerebral blood flow may result in brain ischaemia and post-operative neurologic deficit.
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J Clin Monit Comput · Aug 2019
Observational StudyMuscular tissue oxygen saturation during robotic hysterectomy and postoperative nausea and vomiting: exploring the potential therapeutic thresholds.
The relationship between muscular tissue oxygen saturation (SmtO2) during surgery and postoperative nausea and vomiting (PONV) remains to be determined. Patients undergoing robotic hysterectomy participated in this prospective cohort study. SmtO2 of the brachioradialis muscle in the forearm was continuously monitored during surgery. ⋯ PONV occurred in 35 of 106 patients (33%). Based on the multivariable analysis, the SmtO2 threshold of 20% above baseline correlated with less PONV (OR 0.39; 95% CI 0.16-0.93; p = 0.034), and the following values correlated with more PONV: 5% below baseline (OR 2.37; 95% CI 1.26-4.45; p = 0.007), 20% below baseline (OR 16.08; 95% CI 3.05-84.73; p = 0.001), < 70% (OR 2.86; 95% CI 1.17-6.99; p = 0.021) and < 60% (OR 6.55; 95% CI 1.11-38.53; p = 0.038). Our study suggests that a potential therapeutic goal for PONV prophylaxis may be to maintain SmtO2 at > 70% and above baseline.
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J Clin Monit Comput · Aug 2019
Respiratory measurement using infrared thermography and respiratory volume monitor during sedation in patients undergoing endoscopic urologic procedures under spinal anesthesia.
We aimed to evaluate changes in respiratory pattern after sedation by simultaneously applying a respiratory volume monitor (ExSpiron1Xi, RVM) and infrared thermography (IRT) to patients undergoing spinal anesthesia during endoscopic urologic surgeries. After spinal anesthesia was performed, the patient was placed in a lithotomy position for surgery. Then, we established the baseline of the RVM, and started monitoring the mouth and nose with the infrared camera. ⋯ Hypopnea was detected in all subjects within the first 5 min by RVM: the median time required to detect hypopnea was 142.5 (IQR 115-185.2) s. The median time required for SpO2 to decrease > 4% from baseline was 160 (IQR 125-205) s. Our results suggest that IRT can be useful for rapid detection of respiratory changes in patients undergoing sedation following spinal anesthesia for endoscopic urologic procedures.