Medical devices for the anesthetist: current perspectives

Jerry Ingrande, Hendrikus JM LemmensDepartment of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, CA, USAAbstract: Anesthesiologists are unique among most physicians in that they routinely use technology and medical devices to carry out their daily activities. Recently, there have been significant advances in medical technology. These advances have increased the number and utility of medical devices available to the anesthesiologist. There is little doubt that these new tools have improved the practice of anesthesia. Monitoring has become more comprehensive and less invasive, airway management has become easier, and placement of central venous catheters and regional nerve blockade has become faster and safer. This review focuses on key medical devices such as cardiovascular monitors, airway equipment, neuromonitoring tools, ultrasound, and target controlled drug delivery software and hardware. This review demonstrates how advances in these areas have improved the safety and efficacy of anesthesia and facilitate its administration. When applicable, indications and contraindications to the use of these novel devices will be explored as well as the controversies surrounding their use.Keywords: catheters, echocardiography, ultrasound, fiberoptic bronchoscope, laryngeal mask airway, closed-loop anesthesi

Peri-operative Medication Dosing in Adult Obese Elective Surgical Patients: A Systematic Review of Clinical Studies

Background: Despite the increasing numbers of obese patients undergoing elective surgery, there is a lack of evidence-based dosing guidelines for peri-operative medications in obesity. Objective: The objective was to systematically review the dosing and outcomes of peri-operative medications used in obese elective surgical patients. Methods: Medical subject headings and general keywords were used to systematically search multiple databases (PubMed, EMBASE, Cochrane Library and CINAHL). Studies of medications in obese surgical patients were included if they had a non-obese control or comparative dosing scalar group. The National Health and Medical Research Council GRADE tool was used to assess quality of evidence for each drug. Results: Thirty-three studies of six drug classes were identified: anaesthetics (n = 6), muscle relaxants (n = 10), neuromuscular reversal agents (n = 3), analgesics (n = 2), antibiotics (n = 5) and anticoagulants (n = 7). A variety of dose scalars and/or recommendations was observed for various medications. Lean body weight was proposed as a suitable weight scalar for induction of anaesthesia with propofol whereas total body weight for maintenance of anaesthesia with propofol and depolarizing muscle relaxants. Ideal body weight was reported as an appropriate dosing scalar for non-depolarizing muscle relaxants and neuromuscular reversal agents. Both corrected body weight 40% and ideal body weight were reported as suitable weight scalars for post-operative analgesia with morphine. The standard 2-g dose of cefazolin appeared effective in the prevention of surgical site infection. Body mass index stratified dosing of enoxaparin was effective for venous thromboembolism prevention. Conclusion: No drug recommendation achieved an “Excellent” quality of evidence. Limited data suggest that clinicians should consider each individual class of medication when selecting a dose for obese surgical patients. Routine use of fixed-dosing regimens is likely to under- or overdose obese patients thus predisposing them to adverse drug events or treatment failure leading to patient harm