Jones, Philip M.

Background: Pulse pressure variation (PPV) is widely used to guide fluid responsiveness in mechanically ventilated patients, but its accuracy in the prone position remains uncertain. Prone positioning alters respiratory mechanics and venous return, potentially diminishing the respiratory variation in stroke volume that PPV is designed to detect. We conducted a systematic review and meta-analysis to evaluate the diagnostic accuracy of PPV for predicting fluid responsiveness during prone spine surgery. Methods: We searched MEDLINE, Embase, Scopus, and Cochrane through July 2025 for prospective studies evaluating PPV in adults undergoing prone spine surgery. Two reviewers independently screened studies, extracted data, assessed risk of bias using QUADAS-2, and pooled diagnostic performance using a bivariate random-effects model. The protocol was registered with PROSPERO (CRD420251106134). Results: Of 599 records, 34 underwent full-text review, and 10 studies (433 patients) were included. PPV thresholds ranged from 7% to 15%. Most studies were at low risk of bias except for the index test because thresholds were determined post hoc. For predicting fluid responsiveness, PPV had a pooled sensitivity of 68% (95% CI: 61%-75%) and specificity of 76% (95% CI: 65%-84%), with a summary area under the receiver operating characteristic curve of 0.72 (95% CI: 0.64-0.80). Conclusions: PPV showed only moderate diagnostic performance for predicting fluid responsiveness during prone spine surgery. Its performance may have been influenced by threshold variability, heterogeneous reference standards, fluid-challenge protocols, ventilation strategies, and positioning systems. PPV should therefore be interpreted alongside complementary dynamic assessments rather than in isolation, particularly during lung-protective ventilation.

BACKGROUND: Spinal anesthesia with intrathecal morphine is often the preferred anesthetic modality for elective cesarean delivery. Side effects and drug shortages, however, prompted researchers to look into intrathecal hydromorphone as an alternative. These studies established the effective analgesic dose for 90% of patients (ED90) for both opioids for postcesarean analgesia, yet failed to demonstrate the superiority of morphine over hydromorphone. Nonetheless, the noninferiority of hydromorphone has yet to be determined. METHODS: In this noninferiority randomized blinded clinical trial, 126 patients undergoing elective cesarean delivery under spinal anesthesia received either morphine 150 µg or hydromorphone 75 µg (ED90). The primary outcome was the between-group difference of the mean Numeric Rating Scale (NRS) pain score (0–10) for the first 24 hours after cesarean delivery, with a preestablished threshold for noninferiority of 1. This 24-hour NRS pain score was defined as a single number obtained at the 24 hours postcesarean delivery interview, based on participant’s recall of their overall pain experience during this period. Secondary outcomes included differences in NRS pain scores every 6 hours, cumulative 24 hour opioid consumption, time-to-first opioid request, quality of recovery as measured by the Obstetric Quality of Recovery Score-11 (ObsQoR-11), frequency of interventions for side effects, and Apgar scores. RESULTS: The mean (standard deviation [SD]) of the 24-hour NRS pain score was 4.0 (1.7) for morphine and 3.6 (1.5) for hydromorphone (between-group difference –0.46 (95% confidence interval [CI], –1.0 to 0.1). Given that the upper limit of the 95% CI did not exceed 1, noninferiority of hydromorphone was established. No statistically significant differences were found in mean (SD) 24 hour oral morphine consumption (morphine: 4.2 mg (6.5) vs hydromorphone: 4.1 (8.0) mg; P = .98), median [interquartile range {IQR}] ObsQoR-11 score (morphine: score 87 [75–97.5] vs hydromorphone: score 90 [80–96.5]; P = .51), median [IQR] time to first opioid request (morphine: 10.2 [3.2–15.5] h versus hydromorphone: 6.2 [3.1–12.4] h; P = .35), or proportion of patients requiring interventions for opioid-related pruritus (morphine: 0.316 (variance 0.216) vs hydromorphone: 0.321 (variance 0.218) ( P = .96) and opioid-related nausea and vomiting (morphine: 0.333 (variance 0.222) vs hydromorphone: 0.393 (variance 0.238) ( P = .51). CONCLUSIONS: Intrathecally, hydromorphone is noninferior to morphine for analgesia after elective cesarean delivery when using the previously established ED90 for both opioids (morphine: 150 µg versus hydromorphone: 75 µg); hydromorphone provides effective analgesia and may be a suitable alternative to morphine.

Background: The perioperative management of chronic aspirin therapy in patients undergoing elective brain surgery is challenging due to the risk of bleeding and thromboembolic events. Although aspirin discontinuation reduces the bleeding risk, it can increase thrombotic complications, particularly in patients at high risk of cardiovascular complications. This Delphi study aimed to develop consensus-based guidelines to address these clinical challenges. Methods: A 2-round Delphi survey was conducted among an international panel of 42 experienced anesthesiologists and neurosurgeons. Participants assessed the risks and benefits of perioperative aspirin management, including bleeding risk, thrombotic risk, timing of cessation and resumption, and the utility of platelet function testing. Consensus was defined as ≥80% agreement in round 2. Results: Round 1 highlighted significant variability in practice patterns. In round 2, consensus was reached on several key areas. Most experts (84%) agreed that continuing aspirin increases perioperative bleeding risk in high-risk procedures, with 87% recommending discontinuing aspirin 5 to 7 days before surgery. Nearly all experts (97%) supported continuing low-dose aspirin in high-thrombotic-risk patients. Conversely, for low-thrombotic-risk patients, only 65% agreed on aspirin continuation, reflecting an ongoing debate. No consensus was reached regarding routine platelet function testing. Conclusions: This Delphi study provides experience-based recommendations for managing chronic aspirin therapy in neurosurgical patients. The panel strongly supports aspirin continuation in high-thrombotic-risk patients, with cessation 5 to 7 days before high-bleeding-risk surgeries. Individualized management is advised for low-bleeding-risk procedures and low-thrombotic-risk patients. Future research should further clarify aspirin management in these groups and explore the role of platelet function testing in neurosurgical settings.

OBJECTIVE: To determine the impact of point-of-care ultrasound (POCUS)-guided resuscitation on clinical outcomes in adult patients with shock. DATA SOURCE: We searched MEDLINE, Embase, and unpublished sources from inception to December 2023. STUDY SELECTION: We included randomized controlled trials (RCTs) that examined the use of POCUS to guide resuscitation in patients with shock. DATA EXTRACTION: We collected data regarding study and patient characteristics, POCUS protocol, control group interventions, and outcomes. DATA SYNTHESIS: We identified 18 eligible RCTs. POCUS slightly influences physicians’ plans for IV fluid (IVF) and vasoactive medication prescription (moderate certainty), but results in little to no changes in the administration of IVF (low to high certainty) or inotropes (high certainty). POCUS may result in no change in the number of CT scans performed (low certainty) but probably reduces the number of diagnostic echocardiograms performed (moderate certainty). POCUS-guided resuscitation probably reduces 28-day mortality (relative risk [RR] 0.88; 95% CI, 0.78–0.99), the duration of vasoactive medication (mean difference –0.73 d; 95% CI, –1.16 to –0.30), and the need for renal replacement therapy (RRT) (RR 0.80; 95% CI, 0.63–1.02) (low to moderate certainty evidence), and lactate clearance (high certainty evidence). POCUS-guided resuscitation may results in little to no difference in ICU or hospital admissions, ICU and hospital length of stay, and the need for mechanical ventilation (MV) (low to moderate certainty evidence). There is an uncertain effect on the risk of acute kidney injury and the duration of MV or RRT (very low certainty evidence). CONCLUSIONS: POCUS-guided resuscitation in shock may yield important patient and health system benefits. Due to lack of sufficient evidence, we were unable to explore how the thresholds of operator competency, frequency, and timing of POCUS scans impact patient outcomes.