Effect of a Perioperative Hypotension-Avoidance Strategy Versus a Hypertension-Avoidance Strategy on the Risk of Acute Kidney Injury: A Clinical Research Protocol for a Substudy of the POISE-3 Randomized Clinical Trial.

BACKGROUND: Most patients who take antihypertensive medications continue taking them on the morning of surgery and during the perioperative period. However, growing evidence suggests this practice may contribute to perioperative hypotension and a higher risk of complications. This protocol describes an acute kidney injury substudy of the Perioperative Ischemic Evaluation-3 (POISE-3) trial, which is testing the effect of a perioperative hypotension-avoidance strategy versus a hypertension-avoidance strategy in patients undergoing noncardiac surgery. OBJECTIVE: To conduct a substudy of POISE-3 to determine whether a perioperative hypotension-avoidance strategy reduces the risk of acute kidney injury compared with a hypertension-avoidance strategy. DESIGN: Randomized clinical trial with 1:1 randomization to the intervention (a perioperative hypotension-avoidance strategy) or control (a hypertension-avoidance strategy). INTERVENTION: If the presurgery systolic blood pressure (SBP) is <130 mmHg, all antihypertensive medications are withheld on the morning of surgery. If the SBP is ≥130 mmHg, some medications (but not angiotensin receptor blockers [ACEIs], angiotensin receptor blockers [ARBs], or renin inhibitors) may be continued in a stepwise manner. During surgery, the patients' mean arterial pressure (MAP) is maintained at ≥80 mmHg. During the first 48 hours after surgery, some antihypertensive medications (but not ACEIs, ARBs, or renin inhibitors) may be restarted in a stepwise manner if the SBP is ≥130 mmHg. CONTROL: Patients receive their usual antihypertensive medications before and after surgery. The patients' MAP is maintained at ≥60 mmHg from anesthetic induction until the end of surgery. SETTING: Recruitment from 108 centers in 22 countries from 2018 to 2021. PATIENTS: Patients (~6800) aged ≥45 years having noncardiac surgery who have or are at risk of atherosclerotic disease and who routinely take antihypertensive medications. MEASUREMENTS: The primary outcome of the substudy is postoperative acute kidney injury, defined as an increase in serum creatinine concentration of either ≥26.5 µmol/L (≥0.3 mg/dL) within 48 hours of randomization or ≥50% within 7 days of randomization. METHODS: The primary analysis (intention-to-treat) will examine the relative risk and 95% confidence interval of acute kidney injury in the intervention versus control group. We will repeat the primary analysis using alternative definitions of acute kidney injury and examine effect modification by preexisting chronic kidney disease, defined as a prerandomization estimated glomerular filtration rate <60 mL/min/1.73 m2. RESULTS: Substudy results will be analyzed in 2022. LIMITATIONS: It is not possible to mask patients or providers to the intervention; however, objective measures will be used to assess acute kidney injury. CONCLUSIONS: This substudy will provide generalizable estimates of the effect of a perioperative hypotension-avoidance strategy on the risk of acute kidney injury.

CONTEXTE: La plupart des patients qui prennent des médicaments antihypertenseurs continuent de les prendre le matin d'une intervention chirurgicale et pendant la période périopératoire. De plus en plus de preuves suggèrent que cette pratique pourrait entraîner l'hypotension périopératoire et augmenter le risque de complications. Ce protocole décrit une sous-étude sur l'insuffisance rénale aiguë (IRA) découlant de l'essai Perioperative Ischemic Evaluation-3 (POISE-3). Cet essai teste l'effet d'une stratégie d'évitement de l'hypotension périopératoire par rapport à une stratégie d'évitement de l'hypertension chez des patients qui subissent une chirurgie non cardiaque. OBJECTIFS: Cette sous-étude de l'essai POISE-3 vise à déterminer si une stratégie d'évitement de l'hypotension périopératoire réduit le risque d'IRA comparativement à la stratégie d'évitement de l'hypertension. TYPE D'ÉTUDE: Essai clinique randomisé à répartition 1:1 au groupe intervention (stratégie d'évitement de l'hypotension périopératoire) ou au groupe témoin (stratégie d'évitement de l'hypertension). GROUPE INTERVENTION: Si la pression artérielle systolique (PAS) avant l'opération est <130 mmHg, tous les médicaments antihypertenseurs sont suspendus le matin de la chirurgie. Si la PAS est ≥130 mmHg, certains médicaments (excluant les inhibiteurs de l'enzyme de conversion de l'angiotensine [IECA], les antagonistes du récepteur de l'angiotensine [ARA] ou les inhibiteurs de la rénine) peuvent être poursuivis de façon graduelle. Pendant la chirurgie, la pression artérielle moyenne (PAM) du patient est maintenue à ≥80 mmHg. Dans les 48 heures suivant l'intervention chirurgicale, certains médicaments antihypertenseurs (excluant les IECA, les ARA ou les inhibiteurs de la rénine) peuvent être réintroduits par étapes si la PAS est ≥130 mmHg. GROUPE TÉMOIN: Les patients reçoivent leurs médicaments antihypertenseurs habituels avant et après la chirurgie. La PAM du patient est maintenue à ≥60 mmHg de l'induction de l'anesthésie à la fin de l'intervention chirurgicale. CADRE: Recrutement à partir de 108 centres dans 22 pays entre 2018 à 2021. SUJETS: Des patients (~6 800) âgés de 45 ans et plus atteints d'athérosclérose, ou présentant un risque de l'être, devant subir une chirurgie non cardiaque et prenant des médicaments antihypertenseurs sur une base régulière. MESURES: Le principal critère d'évaluation de cette sous-étude est une IRA postopératoire définie par une hausse d'au moins 26,5 µmol/L (≥0,3 mg/dL) de la créatinine sérique dans les 48 heures suivant la randomisation ou d'au moins 50 % dans les 7 jours suivant la randomisation. MÉTHODOLOGIE: L'analyse primaire (par intention de traiter) examinera le risque relatif d'une IRA et l'intervalle de confiance à 95 % dans le groupe intervention par rapport au groupe témoin. Nous répéterons l'analyse primaire en utilisant d'autres définitions de l'IRA et nous examinerons la modification de l'effet en présence d'une insuffisance rénale préexistante (définie par un DFGe prérandomisation <60 ml/min/1,73 m2). RÉSULTATS: Les résultats de cette sous-étude seront analysés en 2022. LIMITES: Il n'est pas possible de procéder à l'insu des patients ou des prestataires de soins pour cette intervention; des mesures objectives seront toutefois utilisées pour évaluer l'IRA. CONCLUSION: Cette sous-étude fournira des estimations généralisables de l'effet d'une stratégie visant à éviter l'hypotension périopératoire sur le risque d'insuffisance rénale aiguë.

A prospective randomized comparison of ultrasound and neurostimulation as needle end points for interscalene catheter placement.

BACKGROUND: In this prospective, randomized study, we tested the hypothesis that interscalene catheters placed for shoulder surgery using an ultrasound needle end point provide postoperative analgesia similar in quality to those placed using a neurostimulation needle end point. Secondary end points included needle time under the skin, procedure-related pain, and the incidence of early neurological complications. METHODS: Patients presenting for shoulder surgery were recruited. Needles introduced for catheter insertion were initially guided with out-of-plane ultrasound imaging but were prospectively randomized to either sonographic placement immediately lateral to the interscalene interface (n = 41) or to an appropriate motor response at <0.5 mA (n = 40). Catheters were then advanced blindly 2-3 cm beyond needle tip. All surgery was conducted under general anesthesia. At the end of surgery, an infusion of ropivacaine 0.2% 2 mL/h with as-required hourly 5 mL boluses was instituted and continued at home for 2-5 days. Needle time under the skin and numerical rating pain score (NRPS) during insertion were recorded. Patients recorded worst NRPS, the need for supplementary ropivacaine boluses and tramadol on postoperative days 1 and 2. All patients were questioned at Day 10 for new neurological symptoms. RESULTS: There was no significant difference in the worst NRPS at rest and on movement and the requirement for supplementary ropivacaine boluses or tramadol during the first 48 postoperative hours. In one patient in group ultrasound, a satisfactory ultrasound image was unobtainable. An appropriate motor response was obtained in all subjects in group neurostimulation. The median (quartiles) needle time under the skin was 78 (65-101) s in group ultrasound and 108 (94-129) s in group neurostimulation (P < 0.001). The median (quartiles) insertion NRPS was 2 (0-4) in group ultrasound and 3 (1-5) in group neurostimulation (P < 0.048). There was no difference in the frequency of neurological complications between groups. CONCLUSIONS: Interscalene catheters placed for shoulder surgery using an ultrasound needle end point provide postoperative analgesia that is of similar quality to that obtained when using a neurostimulation needle end point. The ultrasound end point was associated with a reduction in needle under the skin time and procedure-related pain.

Dosing ketamine for pediatric procedural sedation in the emergency department.

OBJECTIVE: To describe intravenous ketamine dosing regimens for children requiring brief procedural sedation. METHODS: Time-concentration and sedation profiles were simulated in children (2, 6, and 12 years old) using published pediatric pharmacokinetic and pharmacodynamic parameter estimates. Single-dose, repeat-dosing, and infusion regimens to achieve sedation level of less than 2 (arouses slowly to consciousness, with sustained painful stimulus) for 15 minutes were investigated. RESULTS: A single bolus dose of 1.5 and 1.75, 2, and 2.125 mg/kg (for adult and 12-, 6-, and 2-year-olds, respectively) was required to achieve the desired sedation. Anticipated recovery would be slow, and a sedation level of 4 (drowsy, eyes open or closed but easily arouses to consciousness with verbal stimulus) was reached only after 70 minutes. The use of a smaller initial bolus with a subsequent half-dose "top-up" at 8 minutes achieves the same sedation level but with earlier recovery. A smaller initial dose of 0.25 and 0.275, 0.3, and 0.35 mg/kg followed by an infusion 2.5 and 2.75, 3, and 3.5 mg/kg per hour (for adult and 12-, 6-, and 2-year-olds, respectively) for 15 minutes gives a more even sedation level and rapid recovery (20 minutes to sedation level 4). CONCLUSIONS: Dosing increases with decreasing age. A large single dose is associated with deep sedation, possible adverse effects, and delayed recovery. Between-subjects variability is large, and dose should be tailored to clinical monitoring and requirement. Intermittent pain insult is better suited to a top-up technique, whereas continuous pain is better suited to an infusion technique.

The state of health hardware in Aboriginal communities in rural and remote Australia.

INTRODUCTION: Many of the health problems faced by rural and remote Aboriginal people have been attributed to a poor living environment. In the mid 1980s we began a process of defining problems with the immediate living environment that would affect health. These related particularly to safety, washing and hygiene practice. METHODS: Between January 1999 and November 2006 we undertook a standardised and detailed assessment of housing in Aboriginal communities. This involved an initial assessment of 250 items in each house and living area, focusing on performance and their impact on these healthy living practices. At the first survey-fix we implemented a limited cost repair of non-functioning health hardware and then six months later returned to the communities for a repeat assessment to examine improvement in performance. RESULTS: Between January 1999 and November 2006 we assessed 4,343 houses in 132 communities in four States and the Northern Territory during survey-fix 1 (SF1) and have repeated that survey-fix assessment (SF2) in 3,448 houses in 112 of those communities. This survey demonstrates extraordinarily poor performance of Aboriginal houses. In the survey period, 71,869 items referred for repair by survey teams were inspected by licensed electricians or plumbers and 49,499 of these have so far been fixed. Only 10% of these house items requiring repair were due to vandalism or misuse. CONCLUSION: Improvements in the living environment for Aboriginal people will require a sustained commitment to the planning, funding and implementation of maintenance programs in addition to adherence to the design, construction and supervision detail outlined in the National Indigenous Housing Guide.

A comparison of 4 common methods of hand-measured techniques with a computerized technique to measure the first intermetatarsal angle.

Measurement of the intermetatarsal (IM) angle on plain dorsoplantar radiographs is considered a standard in the surgical evaluation of hallux valgus. The angle formed in this measurement helps determine the selection of surgical procedure. A study was performed to determine the most consistent method to radiographically measure the first IM angle. The IM angle was measured manually with a tractograph by using 4 different techniques on 50 preoperative dorsoplantar radiographs. The techniques used were 1) bisecting the shaft of the first and second metatarsals, 2) bisecting the head and base of the first and second metatarsals (center-of-head method), 3) measuring the angle from the tangent of the medial aspect of the first and the second metatarsal shaft, and 4) measuring the angle formed by the tangent of the lateral aspects of the first and second metatarsal shafts. In addition, the same 50 radiographs were evaluated by a Java software program designed by 1 of the authors to specifically measure the IM angle by bisecting the areas of the first and second metatarsals. A statistical analysis was applied to determine which IM angle of the 4 methods measured by hand was most consistent with the computer-generated IM angle. The median absolute deviation error test was applied to interpret the results. The results showed that the bisection of the shaft of the first and second metatarsals had the smallest mean absolute value of 2.8 degrees (22.37% error), with the other techniques ranging from 3.0 degrees to 3.8 degrees. It appears that the method of bisection of the shafts of the first and second metatarsals provides the most accurate technique compared with the computer-determined technique.