Intraoperative renal desaturation and postoperative acute kidney injury in older patients undergoing liver resection: A prospective cohort study

The Association Between Renal Desaturation Measured Using Near-Infrared Spectroscopy and Postoperative Acute Kidney Injury: A Systematic Review

OBJECTIVES

The objective of this systematic review was to clarify the status of near-infrared spectroscopy (NIRS) in monitoring perioperative renal regional tissue oxygen saturation (rSO2) and determine whether there is evidence supporting its use in predicting postoperative acute kidney injury (AKI).

DESIGN

A systematic search of electronic databases was conducted to identify all clinical studies that utilized NIRS to monitor renal rSO2 during the perioperative period to observe postoperative AKI.

SETTING

Studies published online as of May 31, 2024, were included in the review.

PARTICIPANTS

Studies involving human participants undergoing surgery with a predefined outcome of AKI were included.

INTERVENTIONS

Regional tissue oxygen saturation was measured using NIRS.

MEASUREMENTS AND MAIN RESULTS

A total of 144 records were identified in the primary search after removing duplicates. After screening, 18 studies were included in the analysis, consisting of 3 case-control studies and 15 prospective cohort studies. Thirteen reports focused on pediatric surgery, whereas five reports focused on adult surgery. Sixteen studies involved cardiovascular surgery with cardiopulmonary bypass, and two studies focused on liver surgery. All studies received a quality score of 7 or above. Significant heterogeneity and mostly short follow up periods were noted.

CONCLUSION

Renal desaturation may indicate AKI in patients; however, further studies are required to substantiate this relationship. Additional clinical trials are necessary to evaluate normal values and establish the exact threshold of renal rSO2 that signifies a meaningful decline in renal function.

Association between muscular tissue desaturation and acute kidney injury in older patients undergoing major abdominal surgery: a prospective cohort study

PURPOSE

Present study was designed to investigate the association between muscular tissue desaturation and acute kidney injury (AKI) in older patients undergoing major abdominal surgery.

METHOD

A total of 253 patients (≥ 65 years old) who underwent abdominal surgery with expected duration ≥ 2 h were enrolled. Muscular tissue oxygen saturation (SmtO2) was monitored at quadriceps and bilateral flanks during surgery. Muscular desaturation was defined as SmtO2 < 90% baseline lasting for > 60 s. The primary outcome was the incidence of AKI within postoperative 7 days. The association between muscular desaturation and AKI was analyzed by multivariable logistic regression model. The secondary outcomes indicated the other complications within postoperative 30 days.

RESULTS

Among 236 patients, 44 (18.6%) of them developed AKI. The incidence of muscular desaturation at quadriceps was 28.8% (68/236). Patients with muscular desaturation had higher incidence of AKI than those without desaturation (27.9% [19/68], vs. 14.9% [25/168], P = 0.020). After adjustment of confounders, multivariable analysis showed that muscular desaturation at quadriceps was significantly associated with an increased risk of AKI (OR = 2.84, 95% CI 1.21-6.67, P = 0.016). Muscular desaturations at left and right flank were also associated with an increased risk of AKI (OR = 6.38, 95% CI 1.78-22.89, P = 0.004; OR = 8.90, 95% CI 1.42-45.63; P = 0.019, respectively). Furthermore, patients with muscular desaturation may have a higher risk of pulmonary complications, sepsis and stroke at 30-day follow-up.

CONCLUSION

Muscular desaturation was associated with postoperative AKI in older patients undergoing major abdominal surgery which may serve as a predictor of AKI.

Urinary oxygen tension and its role in predicting acute kidney injury: A narrative review

Acute kidney injury occurs frequently in the perioperative setting. The renal medulla often endures hypoxia or hypoperfusion and is susceptible to the imbalance between oxygen supply and demand due to the nature of renal blood flow distribution and metabolic rate in the kidney. The current available evidence demonstrated that the urine oxygen pressure is proportional to the variations of renal medullary tissue oxygen pressure. Thus, urine oxygenation can be a candidate for reflecting the change of oxygen in the renal medulla. In this review, we discuss the basic physiology of acute kidney injury, as well as techniques for monitoring urine oxygen tension, confounding factors affecting the reliable measurement of urine oxygen tension, and its clinical use, highlighting its potential role in early detection and prevention of acute kidney injury.

The relationship between trajectories of renal oxygen saturation and acute kidney injury: a prospective cohort study with a secondary analysis

BACKGROUND

Acute kidney injury (AKI) is a major postoperative consequence, affecting prognosis of older patients. Effective prediction or intervention to predict or prevent the incidence of AKI is currently unavailable.

AIMS

Dynamic changes of renal tissue oxygen saturation (RSO2) during surgery process are understudied and we intended to explore the distinct trajectories and associations with postoperative AKI.

METHODS

This was a secondary analysis including data for older patients who underwent open hepatectomy surgery with informed consent. Latent class mixed models (LCMM) method was conducted to generate trajectories of intraoperative renal tissue RSO2 through different time points. The primary outcome was postoperative 7-day AKI. The univariate and multivariate regression analysis were performed to identify the relationship between distinct trajectories of renal tissue RSO2 and the risk of AKI. Meanwhile, the prediction efficacy of renal tissue RSO2 at different time points was compared to find potential intervention timing.

RESULTS

Postoperative AKI occurred in 14 (15.2%) of 92 patients. There are two distinct renal tissue RSO2 trajectories, with 44.6% generating "high-downwards" trajectory and 55.4% generating "consistently-high" trajectory. Patients with "high-downwards" trajectory had significantly higher risk of postoperative AKI than another group (Unadjusted OR [Odds Ratio] = 3.790, 95% CI [Confidence Interval]: 1.091-13.164, p = 0.036; Adjusted OR = 3.973, 95% CI 1.020-15.478, p = 0.047, respectively). Predictive performance was 71.4% sensitivity and 60.3% specificity for "high-downwards" trajectory of renal tissue RSO2 to identify AKI. Furthermore, the renal tissue RSO2 exhibited the lowest level and the best results in terms of the sensitivity during the hepatic occlusion period, may be considered as a "time of concern".

CONCLUSIONS

Older patients undergoing hepatectomy may show high-downwards trajectory of renal tissue RSO2, indicating a higher risk of AKI, and the lowest level was identified during the hepatic occlusion period. These findings may help to provide potential candidates for future early recognition of deterioration of kidney function and guide interventions.

Prevalence and time course of postoperative nausea and vomiting and severe pain in patients under general anesthesia with patient-controlled intravenous analgesia

Introduction

Postoperative nausea and vomiting (PONV) and pain are common and distressing complications in patients undergoing surgery. However, it remains uncertain whether timing of the postoperative course or the diel rhythm influences the occurrence of PONV or severe pain. Therefore, we aimed to explore the temporal distribution of PONV and severe pain.

Material and methods

In this prospective observational study, we enrolled patients aged 18-65 years with American Society of Anesthesiologists classifications I-III, who were scheduled for surgery under general anesthesia. Patients were visited postoperatively at regular intervals (every 6 h over a 24-h period). Incidence of PONV was recorded and categorized based on real-time divisions: before dawn (00:00-05:59), morning (06:00-11:59), afternoon (12:00-17:59), and evening (18:00-23:59) and as sequential periods (i.e., 0-6, 6-12, 12-18, and 18-24 h). Severe pain and use of additional remedies were also recorded.

Results

A total of 724 patients were included in the final analysis. Of these, 14.92 % experienced PONV within the first 6 h, and 8.29 % received antiemetic therapy. Occurrence of PONV and administration of remedies declined over the 24-h postoperative period. The lowest rate of PONV was observed during the pre-dawn hours (5.66 %). There was no statistically significant difference in the incidence of PONV 24-h postoperatively between surgeries with different end times. Patients underwent orthopedic surgeries had the highest incidence of PONV during 18:00-23:59, gynecological surgery patients had the highest incidence at 12:00-17:59, and 6:00-11:59 for other surgery patients. All patients had the lowest incidence during 0:00-5:59. During the initial 6-h postoperative period, 24.59 % of patients experienced severe pain, which declined in the remaining episodes. Patients who underwent orthopedic and gynecological surgeries exhibited similar temporal patterns and distribution characteristics of PONV and severe pain.

Discussion

Both PONV and severe pain declined within the 24-h postoperative period, particularly within the first 6 h. Additionally, the onset patterns of PONV vary among patients undergoing different types of surgeries, all patients demonstrated decreased susceptibility to PONV between 00:00-05:59. Our findings enhance prevention and treatment strategies within an optimized timeframe during the postoperative course.

Polystyrene microplastics exposure aggravates acute liver injury by promoting Kupffer cell pyroptosis

OBJECTIVE

To investigate the long-term effects of polystyrene (PS) exposure on acute liver injury.

METHODS

The carbon tetrachloride-induced acute injury mouse model was subjected to long-term PS exposure. Pyroptosis was inhibited by knocking out Gsdmd in mice or treating with the Gsdmd inhibitor necrosulfonamide (NSA) to evaluate the effect of PS on liver injury. Kupffer cells were used as a cellular model to examine the effects of PS on cell pyroptosis, lactate dehydrogenase release rate, structural integrity (propidium iodide staining), and inflammatory factor levels.

RESULTS

In mice, PS exposure exacerbated acute liver injury, which was mitigated upon Gsdmd knockout (KO) or NSA treatment along with the downregulation of tissue inflammatory response. In vitro studies demonstrated that PS promoted Kupffer cell pyroptosis, which was suppressed upon Gsdmd KO or NSA treatment along with the alleviation of inflammation.

CONCLUSION

These results suggest that long-term PS exposure exacerbates acute liver injury by promoting Kupffer cell pyroptosis, which is one of the hepatotoxic mechanisms of PS.