Evaluation of N95 respirators, modified snorkel masks and low-cost powered air-purifying respirators: a prospective observational cohort study in healthcare workers.

Disposable N95 respirator masks are the current standard for healthcare worker respiratory protection in the COVID-19 pandemic. In addition to shortages, qualitative fit testing can have low sensitivity for detecting poor fit, leading to inconsistent protection. Multiple groups have developed alternative solutions such as modified snorkel masks to overcome these limitations, but validation of these solutions has been lacking.

Accelerated ethanol elimination via the lungs.

Ethanol poisoning is endemic the world over. Morbidity and mortality depend on blood ethanol levels which in turn depend on the balance between its rates of absorption and clearance. Clearance of ethanol is mostly at a constant rate via enzymatic metabolism.

Hyperbaric oxygen therapy for spinal cord ischaemia after complex aortic repair - a retrospective review.

Background: Complex aortic repair (CAR) carries high rates of debilitating postoperative complications, including spinal cord injury. The rate of spinal cord deficits post-CAR is approximately 10%, with permanent paraplegia in 2.9% and paraparesis in 2.

Technology III: in-line vaporizer with reflector.

As the clinical advantages of vapor anesthesia (VA) for sedation of patients in ICU become more apparent, the ergonomics, economy and safety issues need to be better addressed. Here we describe the use of a new commercial digital in-line anesthetic vaporizer that can be attached to the inspiratory limb of a ventilator. If used with a simple, and easily assembled secondary circuit and anesthetic reflector, the circuit remains remote from the patient, the VA consumption approaches a physical minimum, VA level is controlled and monitored, and the tidal volume size is not limited.

High volatile anaesthetic conservation with a digital in-line vaporizer and a reflector.

Background: A volatile anaesthetic (VA) reflector can reduce VA consumption (VAC) at the cost of fine control of its delivery and CO accumulation. A digital in-line vaporizer and a second CO absorber circumvent both of these limitations. We hypothesized that the combination of a VA reflector with an in-line vaporizer would yield substantial VA conservation, independent of fresh gas flow (FGF) in a circle circuit, and provide fine control of inspired VA concentrations.

Cerebral oximetry and postoperative delirium after cardiac surgery: a randomised, controlled trial.

Postoperative delirium is associated with increased morbidity and mortality. We hypothesised that restoration of regional cerebral oxygen desaturation would reduce the incidence of postoperative delirium in elderly patients after cardiac surgery. After institutional ethics review board approval and informed consent, a double-blinded, prospective, randomised, controlled trial was conducted in patients ≥ 60 years of age undergoing cardiac surgery with cardiopulmonary bypass.

Relationship between hyperbaric oxygen therapy and quality of life in participants with chronic diabetic foot ulcers: data from a randomized controlled trial.

Aims: To investigate the effect of hyperbaric oxygen therapy on health-related quality of life (HRQoL) in participants with diabetes and chronic foot ulcers.

Methods: Using data from a randomized controlled trial, we included 103 participants (49 in hyperbaric oxygen therapy group and 54 in sham group) for analyses. The primary outcome was HRQoL as measured by the EQ-5D-3L instrument, while secondary outcomes included quality of life evaluated by the Short Form 36 (SF-36) and Diabetic Foot Ulcers Scale-Short Form (DFS-SF).

Hyperbaric Oxygen Therapy Does Not Reduce Indications for Amputation in Patients With Diabetes With Nonhealing Ulcers of the Lower Limb: A Prospective, Double-Blind, Randomized Controlled Clinical Trial.

Objective: Hyperbaric oxygen therapy (HBOT) is used for the treatment of chronic diabetic foot ulcers (DFUs). The controlled evidence for the efficacy of this treatment is limited. The goal of this study was to assess the efficacy of HBOT in reducing the need for major amputation and improving wound healing in patients with diabetes and chronic DFUs.

Dexmedetomidine versus Propofol Sedation Reduces Delirium after Cardiac Surgery: A Randomized Controlled Trial.

Background: Postoperative delirium (POD) is a serious complication after cardiac surgery. Use of dexmedetomidine to prevent delirium is controversial. The authors hypothesized that dexmedetomidine sedation after cardiac surgery would reduce the incidence of POD.

Rates of carbon monoxide elimination in males and females.

The purpose of this study was to verify the previously reported shorter half-time of elimination (t½) of carbon monoxide (CO) in females compared to males. Seventeen healthy subjects (nine men) completed three sessions each, on separate days. For each session, subjects were exposed to CO to raise the carboxyhemoglobin percentage (COHb) to ~10%; then breathed in random order, either (a) 100% O2 at poikilocapnia (no CO2 added), or (b) hyperoxia while maintaining normocapnia using sequential gas delivery, or (c) voluntary hyperpnea at~4x the resting minute ventilation.

Post-operative hypercapnia-induced hyperpnoea accelerates recovery from sevoflurane anaesthesia: a prospective randomised controlled trial.

Background: The time to recovery from vapour anaesthesia is shortened by an increase in ventilation while maintaining normocapnia. Hypercapnia during emergence from anaesthesia in spontaneously breathing patients also increases anaesthetic clearance from the brain by increasing cerebral blood flow. We hypothesised that hypercapnia-induced hyperpnoea accelerates emergence from sevoflurane anaesthesia compared to the standard anaesthesia protocol.

The interaction of carbon dioxide and hypoxia in the control of cerebral blood flow.

Both hypoxia and carbon dioxide increase cerebral blood flow (CBF), and their effective interaction is currently thought to be additive. Our objective was to test this hypothesis. Eight healthy subjects breathed a series of progressively hypoxic gases at three levels of carbon dioxide.

Early benefit of preserved cognitive function is not sustained at one-year after cardiac surgery: a longitudinal follow-up of the randomized controlled trial.

Purpose: Recently, we showed that processing of shed blood with a continuous-flow cell saver during cardiopulmonary bypass resulted in a clinically significant reduction in postoperative cognitive decline (POCD) six weeks after coronary artery bypass graft (CABG) surgery. The current study examined if the early benefit of reduced POCD was sustained in the same patient population at one-year follow-up.

Methods: One hundred seventy patients (cell saver group, n = 84; controls, n = 86) underwent neuropsychological testing at baseline and one year after surgery.

Rapid elimination of CO through the lungs: coming full circle 100 years on.

At the start of the 20th century, CO poisoning was treated by administering a combination of CO(2) and O(2) (carbogen) to stimulate ventilation. This treatment was reported to be highly effective, even reversing the deep coma of severe CO poisoning before patients arrived at the hospital. The efficacy of carbogen in treating CO poisoning was initially attributed to the absorption of CO(2); however, it was eventually realized that the increase in pulmonary ventilation was the predominant factor accelerating clearance of CO from the blood.

Increased lung clearance of isoflurane shortens emergence in obesity: a prospective randomized-controlled trial.

Background: There is a concern that obesity may play a role in prolonging emergence from fat-soluble inhalational anaesthetics. We hypothesized that increased pulmonary clearance of isoflurane will shorten immediate recovery from anaesthesia and post-anaesthesia care unit (PACU) stay in obese patients.

Methods: After Ethics Review Board approval, 44 ASA I-III patients with BMI>30 kg/m(2) undergoing elective gynaecological or urological surgery were randomized after completion of surgery to either an isocapnic hyperpnoea (IH) or a conventional recovery (C) group.

A prospective, double-blind, randomized, controlled clinical trial comparing standard wound care with adjunctive hyperbaric oxygen therapy (HBOT) to standard wound care only for the treatment of chronic, non-healing ulcers of the lower limb in patients with diabetes mellitus: a study protocol.

Background: It has been suggested that the use of adjunctive hyperbaric oxygen therapy improves the healing of diabetic foot ulcers, and decreases the risk of lower extremity amputations. A limited number of studies have used a double blind approach to evaluate the efficacy of hyperbaric oxygen therapy in the treatment of diabetic ulcers. The primary aim of this study is to assess the efficacy of hyperbaric oxygen therapy plus standard wound care compared with standard wound care alone in preventing the need for major amputation in patients with diabetes mellitus and chronic ulcers of the lower limb.

Isocapnic hyperpnoea shortens postanesthetic care unit stay after isoflurane anesthesia.

Background: We conducted a prospective controlled clinical trial of the effect of isocapnic hyperpnoea (IH) on the times-to-recovery milestones in the operating room (OR) and postanesthetic care unit (PACU) after 1.5 to 3 hours of isoflurane anesthesia.

Methods: Thirty ASA grade I-III patients undergoing elective gynecological surgery were randomized at the end of surgery to either IH or the conventional recovery (control).

Preoperative use of statins is associated with reduced early delirium rates after cardiac surgery.

Background: Delirium is an acute deterioration of brain function characterized by fluctuating consciousness and an inability to maintain attention. Use of statins has been shown to decrease morbidity and mortality after major surgical procedures. The objective of this study was to determine an association between preoperative administration of statins and postoperative delirium in a large prospective cohort of patients undergoing cardiac surgery with cardiopulmonary bypass.

The pharmacokinetic profile of recombinant human erythropoietin is unchanged in patients undergoing cardiac surgery.

Background: In anticipation of future studies, we examined the pharmacokinetics profile of erythropoietin (EPO) in patients undergoing cardiac surgery.

Methods: Cardiac surgical patients were enrolled into one of six groups: four cardiopulmonary bypass (CPB) groups [placebo (n = 6), 250 IU/kg EPO (n = 3), 500 IU/kg EPO (n = 3), and 500 IU/kg EPO, two doses (n = 6)] and two off-pump coronary artery bypass (OPCAB) groups [placebo (n = 3) and 500 IU/kg EPO (n = 3)]. The EPO was administered prior to anesthesia and 10 min after CPB (if required).

Prevalence of claustrophobia and magnetic resonance imaging after coronary artery bypass graft surgery.

Background: The purpose of this study was to determine the prevalence of claustrophobia in patients undergoing magnetic resonance imaging (MRI) after coronary artery bypass graft (CABG) surgery.

Methods: After IRB approval, we conducted a substudy of a prospective randomized controlled clinical trial of 311 patients evaluating administration of tranexamic acid and early saphenous vein graft patency with MRI after conventional CABG surgery. Chest tube drainage was measured at 6, 12, and 24 hours after surgery.