Prediction of preload dependency using phenylephrine-induced peripheral perfusion index during general anaesthesia: a prospective observational study.

BACKGROUND: Tracking preload dependency non-invasively to maintain adequate tissue perfusion in the perioperative period can be challenging.The effect of phenylephrine on stroke volume is dependent upon preload. Changes in stroke volume induced by phenylephrine administration can be used to predict preload dependency. The change in the peripheral perfusion index derived from photoplethysmography signals reportedly corresponds with changes in stroke volume in situations such as body position changes in the operating room. Thus, the peripheral perfusion index can be used as a non-invasive potential alternative to stroke volume to predict preload dependency. Herein, we aimed to determine whether changes in perfusion index induced by the administration of phenylephrine could be used to predict preload dependency. METHODS: We conducted a prospective single-centre observational study. The haemodynamic parameters and perfusion index were recorded before and 1 and 2 min after administering 0.1 mg of phenylephrine during post-induction hypotension in patients scheduled to undergo surgery. Preload dependency was defined as a stroke volume variation of ≥ 12% before phenylephrine administration at a mean arterial pressure of < 65 mmHg. Patients were divided into four groups according to total peripheral resistance and preload dependency. RESULTS: Forty-two patients were included in this study. The stroke volume in patients with preload dependency (n = 23) increased after phenylephrine administration. However, phenylephrine administration did not impact the stroke volume in patients without preload dependency (n = 19). The perfusion index decreased regardless of preload dependency. The changes in the perfusion index after phenylephrine administration exhibited low accuracy for predicting preload dependency. Based on subgroup analysis, patients with high total peripheral resistance tended to exhibit increased stroke volume following phenylephrine administration, which was particularly prominent in patients with high total peripheral resistance and preload dependency. CONCLUSION: The findings of the current study revealed that changes in the perfusion index induced by administering 0.1 mg of phenylephrine could not predict preload dependency. This may be attributed to the different phenylephrine-induced stroke volume patterns observed in patients according to the degree of total peripheral resistance and preload dependency. TRIAL REGISTRATION: University Hospital Medical Information Network (UMIN000049994 on 9/01/2023).

Cardiac Arrest due to Failed Pacemaker Capture After Peripheral Nerve Blockade With Levobupivacaine: A Case Report.

We describe a patient with a pacemaker who developed cardiac arrest shortly after ultrasound-guided rectus sheath block for postoperative analgesia. The cause of cardiac arrest was capture failure due to an increased pacing threshold, and the patient was promptly treated by increasing the pacing amplitude. Local anesthetics used for rectus sheath block might have affected the pacing threshold and caused pacing capture failure, since local anesthetics can block cardiac sodium channels. Anesthesiologists should recognize the risk of pacemaker capture failure when a large amount of local anesthetic is given to patients with a cardiac pacemaker.

Large volume infusions of hydroxyethyl starch during cardiothoracic surgery may be associated with postoperative kidney injury: propensity-matched analysis.

BACKGROUND: The safety of intraoperative administration of hydroxyethyl starch (HES) has been debated. We hypothesized that intraoperative use of HES is associated with postoperative acute kidney injury (AKI) following cardiopulmonary bypass (CPB). MATERIALS AND METHODS: Patients who underwent cardiothoracic surgery using CPB between 2007 and 2014 were retrospectively reviewed. The incidence of AKI within 7 days after surgery, defined by the Kidney Disease Improving Global Outcome criteria, was compared for patients who did or did not receive 6% (70/0.5) or 6% (130/0.4) HES for anesthesia management before or after CPB. Multivariable logistic regression and propensity matching analysis were performed to examine whether use of HES is associated with postoperative AKI. Outcomes comparing patients receiving HES ≥ 1000 mL and < 1000 mL were also compared. RESULTS: Data from 1976 patients were reviewed. All patients received 70/0.5 HES as a part of the priming solution for CPB. The incidence of postoperative AKI was 28.2% in patients who received HES and 26.0% in patients who did not (p = 0.33). In multivariable analysis, there was no correlation between the use of HES and the incidence of AKI (odds ratio 0.87, 95% CI 0.30-2.58, p = 0.81). Propensity matching showed that the incidence of AKI was not significantly different between 481 patients administered with HES and 962 patients (26.6% vs. 26.9%, p = 0.95) who did not receive HES for anesthesia management. However, peak creatinine levels, needed for renal replacement therapy, and in-hospital mortality were higher, and 28-day hospital-free days were lower in patients receiving HES ≥ 1000 mL than those receiving HES < 1000 mL (p < 0.05). CONCLUSIONS: Intraoperative use of HES was not associated with postoperative AKI following CPB. However, administration of large volumes of HES may be associated with kidney-related adverse clinical outcomes.

Acute cerebral infarction in a patient with an epidural catheter after left upper lobectomy: a case report.

BACKGROUND: There are several recent reports that left upper lobe lung resection is a risk factor for the development of postoperative thromboembolism. Although administering epidural analgesia is common in thoracic surgery, anesthesiologists should be alert when administering epidural analgesia to a patient undergoing left upper lobectomy, considering the increased risk of postoperative thromboembolism and the potential need for anticoagulation or fibrinolytic therapy in the immediate postoperative period. CASE PRESENTATION: A seventy-one-year-old female with a metastatic lung lesion developed a cerebral infarction approximately 30 h after video-assisted thoracoscopic left upper lobectomy. Cerebral intravascular therapy was indicated and the epidural catheter was removed immediately to avoid formation of an epidural hematoma. Approximately four hours after onset, reperfusion was successfully established by aspiration of endovascular thrombi. She recovered with mild residual paralysis of the left upper extremity and was transferred to a rehabilitation facility. CONCLUSIONS: We present a patient with a cerebral infarction after left upper lobectomy. Left upper lobectomy is associated with an increased risk of postoperative thromboembolism. Although the exact mechanism of thrombosis after left upper lobectomy is unclear, a judicious decision should be made regarding epidural catheter placement for postoperative analgesia.