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Fractures of the hook of the hamate are traditionally thought to be caused by direct trauma. A review of the anatomy and function of the hamate hook suggests that fracture is more likely as a result of a fatigue response that develops in the hook from repetitive load applied by the adjacent deep flexor tendons. Additional vascular compromise, from direct pressure of the tendons on critical local vessels, reduces blood flow leading to both mechanical and vascular effects that create pathological osseous change and weakening. These changes are likely to predispose to stress fracture and nonunion in repetitive gripping activities and are consistent with radiological findings. [ABSTRACT FROM AUTHOR]

Introduction: The pupillary light reflex (PLR) is the constriction of the pupil in response to light. The PLR in response to a pulse of light follows a complex waveform that can be characterized by several parameters. It is a sensitive marker of acute neurological deterioration, but is also sensitive to the background illumination in the environment in which it is measured. To detect a pathological change in the PLR, it is therefore necessary to separate the contributions of neuro-ophthalmic factors from ambient illumination. Illumination varies over several orders of magnitude and is difficult to control due to diurnal, seasonal, and location variations. Methods and results: We assessed the sensitivity of seven PLR parameters to differences in ambient light, using a smartphone-based pupillometer (Al Pupillometer, Solvemed Inc.). Nine subjects underwent 345 measurements in ambient conditions ranging from complete darkness (<5 Ix) to bright lighting (<10,000 Ix). Lighting most strongly affected the initial pupil size, constriction amplitude, and velocity. Nonlinear models were fitted to find the correction function that maximally stabilized PLR parameters across different ambient light levels. Next, we demonstrated that the lighting-corrected parameters still discriminated reactive from unreactive pupils. Ten patients underwent PLR testing in an ophthalmology outpatient clinic setting following the administration of tropicamide eye drops, which rendered the pupils unreactive. The parameters corrected for lighting were combined as predictors in a machine learning model to produce a scalar value, the Pupil Reactivity (PuRe) score, which quantifies Pupil Reactivity on a scale 0-5 (0, non-reactive pupil; 0-3, abnormal/'sluggish" response; 3-5, normal/brisk response). The score discriminated unreactive pupils with 100% accuracy and was stable under changes in ambient illumination across four orders of magnitude. Discussion: This is the first time that a correction method has been proposed to effectively mitigate the confounding influence of ambient light on PLR measurements, which could improve the reliability of pupillometric parameters both in pre-hospital and inpatient care settings. In particular, the PuRe score offers a robust measure of Pupil Reactivity directly applicable to clinical practice. Importantly, the formulae behind the score are openly available for the benefit of the clinical research community. [ABSTRACT FROM AUTHOR]

Registration: Australian New Zealand Clinical Trials Registry: ACTRN12619001274167p Rationale: Cerebral blood flow is blood pressure-dependent when cerebral autoregulation is impaired. Cerebral ischemia and anesthetic drugs impair cerebral autoregulation. In ischemic stroke patients treated with endovascular thrombectomy, induced hypertension is a plausible intervention to increase blood flow in the ischemic penumbra until reperfusion is achieved. This could potentially reduce final infarct size and improve functional recovery. Aim: To test if patients with large vessel occlusion stroke treated with endovascular thrombectomy will benefit from induced hypertension. Design: Prospective, randomized, parallel group, open label, multicenter clinical trial with blinded assessment of outcomes. Procedures: Patients with anterior circulation stroke treated with endovascular thrombectomy with general anesthesia within 6 h of symptom onset, and patients with 'wake up' stroke or presenting within 6 to 24 h with potentially salvageable tissue on computed tomography perfusion scanning, are included. Participants are randomized to a systolic blood pressure target of 140 mmHg or 170 mmHg from procedure initiation until recanalization. Methods to maintain the blood pressure are at the discretion of the procedural anesthesiologist. Study outcomes: The primary efficacy outcome is improvement in disability measured by modified Rankin Scale score at 90 days. The primary safety outcome is all-cause mortality at 90 days. Analysis: The Mann-Whitney U test will be used to test the ordinal shift in the seven-category modified Rankin Scale score. All-cause mortality will be estimated using the Kaplan-Meier method and compared using a log-rank test. [ABSTRACT FROM AUTHOR]

Fractures of the hook of the hamate are traditionally thought to be caused by direct trauma. A review of the anatomy and function of the hamate hook suggests that fracture is more likely as a result of a fatigue response that develops in the hook from repetitive load applied by the adjacent deep flexor tendons. Additional vascular compromise, from direct pressure of the tendons on critical local vessels, reduces blood flow leading to both mechanical and vascular effects that create pathological osseous change and weakening. These changes are likely to predispose to stress fracture and nonunion in repetitive gripping activities and are consistent with radiological findings., Competing Interests: Declaration of conflicting interestsThe authors declare no potential conflicts of interest with respect to the research, authorship and/or publication of this article.

Background: The Gompertz-Makeham law describes a characteristic pattern of mortality in human populations where death rate is near constant between age 18 and 30 years (Makeham's Law) and rises exponentially thereafter (Gompertz Law). This pattern has not been described in surgical populations, but if true, would have important implications for understanding surgical risk and design and interpretation of surgical risk models. The aim of this study was to determine if the Gompertz-Makeham law applies to perioperative mortality risk and the conditions under which it may apply., Methods: We examined the relationship between age and 1-month postoperative all-cause mortality risk in a 10-year New Zealand administrative dataset comprising of 5,615,100 surgical procedures from 2007 to 2016. The dataset includes patient and surgical factors including procedures, American Society of Anesthesiologist's physical status score (ASA-PS), diagnoses and other relevant details. Semi-logarithmic graphs of mortality risk and age were plotted. Linear regression models were fitted, with regression line slope and Pearson's correlation coefficient calculated., Results: The primary outcome occurred in 114,782 (2.0%) of 5,615,100 included participants. The Gompertz-Makeham law seems to apply to the national surgical population as a whole (slope = 0.0241, R2 = 0.971). The law applies in all subgroups studied including sex, ASA-PS, surgical acuity, surgical severity category, cancer status and ethnicity (slopes 0.0066 to 0.0307, R2 0.771 to 0.990). Important interactions were found between age, mortality risk and three high risk groups (cancer diagnosis, ASA-PS 4-5 and high surgical severity)., Conclusions: The Gompertz-Makeham law seems to apply in a national cohort of surgical patients. The inflection point for increased 1-month risk is apparent at age 30 years. A strict exponential rise in mortality risk occurs thereafter. This finding improves our understanding of surgical risk and suggests a concept-driven approach to improve modelling of age and important interactions in future surgical risk models., Competing Interests: Conflicts of interests: MW and MM declare no competing interests. LB received a PhD stipend from Precision Driven Health, a research funding organization. Precision Driven Health is a research collaboration between the New Zealand Ministry of Health, District Health Boards, New Zealand Universities and Orion Health (vendors of a "health data platform"). LB was previously an employee of Orion Health and was employed by them on completion of his PhD. DC has done funded research for Route 92. TS has done funded research for Beckton Dickinson and Roche Pharmaceuticals., (Copyright © 2024 American Society of Anesthesiologists. All Rights Reserved.)

Background: Deep learning using clinical and imaging data may improve pre-treatment prognostication in ischemic stroke patients undergoing endovascular thrombectomy (EVT)., Methods: Deep learning models were trained and tested on baseline clinical and imaging (CT head and CT angiography) data to predict 3-month functional outcomes in stroke patients who underwent EVT. Classical machine learning models (logistic regression and random forest classifiers) were constructed to compare their performance with the deep learning models. An external validation dataset was used to validate the models. The MR PREDICTS prognostic tool was tested on the external validation set, and its performance was compared with the deep learning and classical machine learning models., Results: A total of 975 patients (550 men; mean±SD age 67.5±15.1 years) were studied with 778 patients in the model development cohort and 197 in the external validation cohort. The deep learning model trained on baseline CT and clinical data, and the logistic regression model (clinical data alone) demonstrated the strongest discriminative abilities for 3-month functional outcome and were comparable (AUC 0.811 vs 0.817, Q=0.82). Both models exhibited superior prognostic performance than the other deep learning (CT head alone, CT head, and CT angiography) and MR PREDICTS models (all Q<0.05)., Conclusions: The discriminative performance of deep learning for predicting functional independence was comparable to logistic regression. Future studies should focus on whether incorporating procedural and post-procedural data significantly improves model performance., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Objectives: To measure differences at various deciles in days alive and out of hospital to 90 days (DAOH 90 ) and explore its utility for identifying outliers of performance among district health boards (DHBs)., Methods: Days in hospital and mortality within 90 days of surgery were extracted by linking data from the New Zealand National Minimum Data Set and the births and deaths registry between 1 January 2011 and 31 December 2021 for all adults in New Zealand undergoing acute laparotomy (AL-a relatively high-risk group), elective total hip replacement (THR-a medium risk group) or lower segment caesarean section (LSCS-a low-risk group). DAOH 90 was calculated without censoring to zero in cases of mortality. For each DHB, direct risk standardisation was used to adjust for potential confounders and presented in deciles according to baseline patient risk. The Mann-Whitney U test assessed overall DAOH 90 differences between DHBs, and comparisons are presented between selected deciles of DAOH 90 for each operation., Results: We obtained national data for 35 175, 52 032 and 117 695 patients undergoing AL, THR and LSCS procedures, respectively. We have demonstrated that calculating DAOH without censoring zero allows for differences between procedures and DHBs to be identified. Risk-adjusted national mean DAOH 90 Scores were 64.0 days, 79.0 days and 82.0 days at the 0.1 decile and 75.0 days, 82.0 days and 84.0 days at the 0.2 decile for AL, THR and LSCS, respectively, matching to their expected risk profiles. Differences between procedures and DHBs were most marked at lower deciles of the DAOH 90 distribution, and outlier DHBs were detectable. Corresponding 90-day mortality rates were 5.45%, 0.78% and 0.01%., Conclusion: In New Zealand after direct risk adjustment, differences in DAOH 90 between three types of surgical procedure reflected their respective risk levels and associated mortality rates. Outlier DHBs were identified for each procedure. Thus, our approach to analysing DAOH 90 appears to have considerable face validity and potential utility for contributing to the measurement of perioperative outcomes in an audit or quality improvement setting., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)