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Unexpected cardiorespiratory compromise has been reported during ophthalmic arterial chemotherapy in pediatric patients with retinoblastoma. Although the underlying mechanisms remain unclear, autonomic responses are presumed to contribute to these events. We hypothesized that periprocedural heart rate variability would differ between patients with and without events. Between April 2018 and September 2019, 38 patients (age under 7 years) were included. Heart rate variability was analyzed using electrocardiogram, and oxygen reserve index was also monitored. Cardiorespiratory events were defined as > 30% changes in blood pressure or heart rate, > 20% changes in end-tidal carbon dioxide, > 40% changes in peak inspiratory pressure, or pulse oxygen saturation < 90% during ophthalmic artery catheterization. Heart rate variability and oxygen reserve index were compared between patients with and without cardiorespiratory events. Cardiorespiratory events occurred in 13/38 (34%) patients. During the events, end-tidal carbon dioxide was significantly lower (median difference [95% CI], - 2 [- 4 to - 1] mmHg, p = 0.006) and the maximum peak inspiratory pressure was higher (30 [25-37] vs. 15 [14-16] hPa, p < 0.001), compared to patients without events. Standard deviation of normal-to-normal R-R interval, total power, and very low-frequency power domain increased during selection of the ophthalmic artery in patients with events (all adjusted p < 0.0001), without predominancy of specific autonomic nervous alterations. Oxygen reserve index was significantly lower in patients with events than those without throughout the procedure (mean difference [95% CI], - 0.19 [- 0.32 to - 0.06], p = 0.005). Enhanced compensatory autonomic regulation without specific autonomic predominancy, and reduced oxygen reserve index was observed in patients with cardiorespiratory events than in patients without events., (© 2021. The Author(s), under exclusive licence to Springer Nature B.V.)

When hemoglobin (Hb) is fully saturated with oxygen, the additional gain in oxygen delivery (DO 2 ) achieved by increasing the fraction of inspired oxygen (FiO 2 ) is often considered clinically insignificant. In this study, we evaluated the change in DO 2 , interrogated by mixed venous oxygen saturation (SvO 2 ), in response to a change in FiO 2 of 0.5 during cardiac surgery. When patients were hemodynamically stable, FiO 2 was alternated between 0.5 and 1.0 in on-pump cardiac surgery patients (pilot study), and between 0.3 and 0.8 in off-pump coronary artery bypass grafting patients (substudy of the CARROT trial). After the patient had stabilized, a blood gas analysis was performed to measure SvO 2 . The observed change in SvO 2 (ΔSvO 2 ) was compared to the expected ΔSvO 2 calculated using Fick's equation. A total 106 changes in FiO 2 (two changes per patient; total 53 patients; on-pump, n = 36; off-pump, n = 17) were finally analyzed. While Hb saturation remained near 100% (on-pump, 100%; off-pump, mean [SD] = 98.1% [1.5] when FiO 2 was 0.3 and 99.9% [0.2] when FiO 2 was 0.8), SvO 2 changed significantly as FiO 2 was changed (the first and second changes in on-pump, 7.7%p [3.8] and 7.6%p [3.5], respectively; off-pump, 7.9%p [4.9] and 6.2%p [3.9]; all P < 0.001). As a total, regardless of the surgery type, the observed ΔSvO 2 after the FiO 2 change of 0.5 was ≥ 5%p in 82 (77.4%) changes and ≥ 10%p in 31 (29.2%) changes (mean [SD], 7.5%p [3.9]). Hb concentration was not correlated with the observed ΔSvO 2 (the first changes, r =  - 0.06, P = 0.677; the second changes, r =  - 0.21, P = 0.138). The mean (SD) residual ΔSvO 2 (observed - expected ΔSvO 2 ) was 0%p (4). Residual ΔSvO 2 was more than 5%p in 14 (13.2%) changes and exceeded 10%p in 2 (1.9%) changes. Residual ΔSvO 2 was greater in patients with chronic kidney disease than in those without (median [IQR], 5%p [0 to 7] vs. 0%p [- 3 to 2]; P = 0.049). DO 2 , interrogated by SvO 2 , may increase to a clinically significant degree as FiO 2 is increased during cardiac surgery, and the increase of SvO 2 is not related to Hb concentration. SvO 2 increases more than expected in patients with chronic kidney disease. Increasing FiO 2 can be used to increase DO 2 during cardiac surgery., (© 2021. The Author(s).)

Background: Cerebral oximetry has been widely used to measure regional oxygen saturation in brain tissue, especially during cardiac surgery. Despite its popularity, there have been inconsistent results on the use of cerebral oximetry during cardiac surgery, and few studies have evaluated cerebral oximetry during off pump coronary artery bypass graft surgery (OPCAB)., Methods: To evaluate the relationship between intraoperative cerebral oximetry and postoperative delirium in patients who underwent OPCAB, we included 1439 patients who underwent OPCAB between October 2004 and December 2016 and among them, 815 patients with sufficient data on regional cerebral oxygen saturation (rSO 2 ) were enrolled in this study. We retrospectively analyzed perioperative variables and the reduction in rSO 2 below cut-off values of 75, 70, 65, 60, 55, 50, 45, 40, and 35%. Furthermore, we evaluated the relationship between the reduction in rSO 2 and postoperative delirium., Results: Delirium occurred in 105 of 815 patients. In both univariable and multivariable analyses, the duration of rSO 2 reduction was significantly longer in patients with delirium at cut-offs of < 50 and 45% (for every 5 min, adjusted odds ratio (OR) 1.007 [95% Confidence interval (CI) 1.001 to 1.014] and adjusted OR 1.012 [1.003 to 1.021]; p = 0.024 and 0.011, respectively). The proportion of patients with a rSO 2 reduction < 45% was significantly higher among those with delirium (adjusted OR 1.737[1.064 to 2.836], p = 0.027)., Conclusions: In patients undergoing OPCAB, intraoperative rSO 2 reduction was associated with postoperative delirium. Duration of rSO 2 less than 50% was 40% longer in the patients with postoperative delirium. The cut-off value of intraoperative rSO 2 that associated with postoperative delirium was 50% for the total patient population and 55% for the patients younger than 68 years.

Background: One-lung ventilation during thoracic surgery frequently disturbs normal systemic oxygenation. However, the effect of anesthetics on arterial oxygenation during one-lung ventilation has not been well established in human study. In this clinical trial, we investigated whether a difference between desflurane-remifentanil and propofol-remifentanil anesthesia can be observed with regard to oxygenation during one-lung ventilation for thoracoscopic surgery., Methods: Adult patients with lung cancer, scheduled for video-assisted thoracoscopic lobectomy without preoperative oxygen support, were screened and randomized to receive desflurane or propofol, with remifentanil continuous infusion in both groups. Mechanical ventilation was performed with tidal volume of 8 ml/kg and F I O 2 0.5 during two-lung ventilation, and 6 ml/kg and 1.0 during one-lung ventilation, both with positive end-expiratory pressure of 5 cmH 2 O. Arterial blood gas analysis was performed preoperatively, during two-lung ventilation, and after 15, 30, 45, and 60 min of one-lung ventilation. The primary endpoint was PaO 2 at 30 min after initiating one-lung ventilation. Statistical analyses included the independent t-test for the primary endpoint and a mixed model with a post-hoc analysis to evaluate the serial changes in values., Results: Patients were recruited between July 9 and December 2, 2014. In total, 103 patients were analyzed (n = 52 in desflurane group and n = 51 in propofol group). The primary endpoint, PaO 2 at 30 min of one-lung ventilation was lower in the desflurane group than the propofol group (170 ± 72 vs. 202 ± 82 mmHg; p = 0.039). Serial changes in PaO 2 during one-lung ventilation showed lower levels during desflurane anesthesia compared with propofol anesthesia (mean difference, 45 mmHg; 95% confidence interval, 16-75 mmHg; p = 0.003)., Conclusions: In conclusion, desflurane-remifentanil anesthesia resulted in decreased arterial oxygenation compared with that of propofol-remifentanil anesthesia during one-lung ventilation for thoracoscopic surgery in patients with lung cancer., Trial Registration: ClinicalTrials.gov identifier: NCT02191371 , registered on July 7, 2014.

Background: To maintain adequate oxygenation is of utmost importance in intraoperative care. However, clinical evidence supporting specific oxygen levels in distinct surgical settings is lacking. This study aimed to compare the effects of 30% and 80% oxygen in off-pump coronary artery bypass grafting (OPCAB). Methods: This multicenter trial was conducted in three tertiary hospitals from August 2019 to August 2021. Patients undergoing OPCAB were cluster-randomized to receive either 30% or 80% oxygen intraoperatively, based on the month when the surgery was performed. The primary endpoint was the length of hospital stay. Intraoperative hemodynamic data were also compared. Results: A total of 414 patients were cluster-randomized. Length of hospital stay was not different in the 30% oxygen group compared to the 80% oxygen group (median, 7.0 days vs 7.0 days; the sub-distribution hazard ratio, 0.98; 95% confidence interval [CI] 0.83–1.16; P = 0.808). The incidence of postoperative acute kidney injury was significantly higher in the 30% oxygen group than in the 80% oxygen group (30.7% vs 19.4%; odds ratio, 1.94; 95% CI 1.18–3.17; P = 0.036). Intraoperative time-weighted average mixed venous oxygen saturation was significantly higher in the 80% oxygen group (74% vs 64%; P < 0.001). The 80% oxygen group also had a significantly greater intraoperative time-weighted average cerebral regional oxygen saturation than the 30% oxygen group (56% vs 52%; P = 0.002). Conclusions: In patients undergoing OPCAB, intraoperative administration of 80% oxygen did not decrease the length of hospital stay, compared to 30% oxygen, but may reduce postoperative acute kidney injury. Moreover, compared to 30% oxygen, intraoperative use of 80% oxygen improved oxygen delivery in patients undergoing OPCAB. Trial registration ClinicalTrials.gov (NCT03945565; April 8, 2019). [ABSTRACT FROM AUTHOR]

Optimal oxygen management during cardiac surgery has not been established, and studies on the effects of perioperative hyperoxia on postoperative acute kidney injury (AKI) are scarce. The association between intraoperative hyperoxia and AKI after cardiac surgery involving cardiopulmonary bypass was evaluated for the present study. Retrospective observational study. A tertiary teaching hospital. Adult patients who underwent cardiac surgery with cardiopulmonary bypass from November 2006–December 2018. None. The area above arterial oxygen partial pressure (PaO 2) threshold of 300 mmHg (AOT 300 , mmHg × h) was used as a metric of intraoperative hyperoxia and was associated with postoperative AKI, using the logistic regression analysis. Data also were fitted using the restricted cubic spline model. Sensitivity analyses were conducted using different PaO 2 thresholds (150, 200, 250, and 350 mmHg). A total of 2,926 patients were analyzed. Intraoperative AOT 300 independently was associated with the risk of AKI (odds ratio 1.0009; 95% confidence interval 1.0002-1.0015). A PaO 2 increment of 100 mmHg above PaO 2 300 mmHg for an hour was associated with an increased risk of AKI by 9.4% (1.0009100 ≈ 1.094). In the spline model, the log-odds of AKI increased as AOT 300 increased. In the sensitivity analyses, AOT 250 and AOT 350 also significantly were associated with the risk of AKI, whereas AOT 150 and AOT 200 were not. As the PaO 2 threshold increased from 150 to 350 mmHg, the odds ratio gradually increased. Intraoperative hyperoxia significantly was associated with the risk of AKI after cardiac surgery involving cardiopulmonary bypass. [ABSTRACT FROM AUTHOR]

Background: General anesthesia may induce inadvertent hypothermia and this may be related to perioperative cardiovascular complications. Microvascular reactivity, measured by the recovery slope during a vascular occlusion test, is decreased during surgery and is also related to postoperative clinical outcomes. We hypothesized that microvascular changes during surgery may be related to intraoperative hypothermia. To evaluate this, we conducted a randomized study in patients undergoing off-pump coronary artery bypass surgery, in which the effect of prewarming on microvascular reactivity was evaluated. Methods: Patients scheduled for off-pump coronary artery bypass surgery were screened. Enrolled patients were randomized to the prewarming group to receive forced-air warming during induction of anesthesia or to the control group. Measurement of core and skin temperatures and vascular occlusion test were conducted before anesthesia induction, 1, 2, and 3 h after induction, and at the end of surgery. Results: In total, 40 patients were enrolled and finished the study (n = 20 in the prewarming group and n = 20 in the control group). During the first 3 h of anesthesia, core temperature was higher in the prewarming group than the control group (p < 0.001). The number of patients developing hypothermia was lower in the prewarming group than the control group (4/20 vs. 13/20, p = 0.004). However, tissue oxygen saturation and changes in recovery slope following a vascular occlusion test at 3 h after anesthesia induction did not differ between the groups. There was no difference in clinical outcome, including perioperative transfusion, wound infection, or hospital stay, between the groups. Conclusions: Prewarming during induction of anesthesia decreased intraoperative hypothermia, but did not reduce the deterioration in microvascular reactivity in patients undergoing off-pump coronary artery bypass surgery. Trial Registration: ClinicalTrials.gov [ABSTRACT FROM AUTHOR]