Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700

Prevention and treatment of noncognitive complications

Patients aged 65 and older are the fastest growing segment in the population of many countries. Based on evolving demographics showing increasing life expectancies, it is expected that there will be a concurrent rise in the demand for a large variety of surgical and anesthesia services. Surgery offers definitive management of many age-related diseases and provides symptom-relieving (morbidity) and life-extending (mortality) benefits. However, elderly adult surgical patients, especially the frail ones, often require a different level of care than younger patients during the perioperative period. As many have chronic illnesses and acquired deconditioning and functional decline, older patients are prone to develop untoward outcomes such as postoperative complications and loss of independence. This manuscript focuses on the holistic quality person-centered care, supported by a wide stakeholder team of health-care workers, ensuring fidelity to comprehensive geriatric assessment and optimization services where possible, offering a systematic approach to early health risk assessment and risk modification in the perioperative period, with the ultimate goal of reducing postoperative complications and health-care costs. The “comprehensive geriatric assessment and optimization” cost-effective approach builds on robust evidence with older people more likely to be alive, a shorter length of hospital stay due to fewer postoperative medical complications, and improved rates of return to usual residence. Prehabilitation programs are delivered focusing on primary (through counseling) and secondary prevention (through screening) with an aim to improve fitness for surgery, by evaluating functional capacity, nutritional and psychological health, prompting interventions, targeting physical exercise, lifestyle and nutritional advice, and psychological support

The Baska Mask® -A new concept in Self-sealing membrane cuff extraglottic airway devices, using a sump and two gastric drains: A critical evaluation

Background: In this study, we evaluated the performance of the Baska Mask® , a new extraglottic airway device (EAD) for use in anesthesia in adult patients undergoing a variety of surgical interventions. Materials and Methods: The self-recoiling membrane distally open cuff silicone mask consists of an anatomically curved airway tube with: (1) a bite block over the full length of the airway; (2) a self-sealing membranous variable-pressure cuff which adjusts to the contours of the mouth and pharynx; (3) a large sump cavity with two aspiratable gastric drain tubes; together with a number of special features such as (4) a tab for manually curving the mask to ease insertion; and (5) a suction elbow integral to one port with a second port acting as a free air flow access. The cuff of the Baska Mask® is not an inflatable balloon, but a membrane which inflates on every breath during intermittent positive pressure ventilation (IPPV) to achieve a superior seal when opposed to the larynx. An increase in IPPV pressure increases the oropharyngeal seal. With existing extraglottic airway devices, an increase in IPPV merely increases the leak. Results: Fifty patients with American Society of Anesthesiologists (ASA) physical status I-III were enrolled. We evaluated the "first attempt" and "overall insertion" success rates, insertion time, ease of insertion and removal of the device, oropharyngeal leak pressure, and anatomical position at fiberoptic view. The "first attempt" success rate was high (88%) and "overall insertion" success rates was considered "easy" to "very easy" by the operators in 92% of patients. Removal of the device was considered easy in all cases. The oropharyngeal leak pressure was above 30 cm H 2 O in all patients and the maximum of 40 cm H 2 O was achieved in 82% of the patients. In two patients, no adequate capnogram was obtained, so a smaller size mask was inserted with correction to adequate function. At fiberoptic evaluation of the anatomical position of the masks, the vocal cords could be seen, except in six patients (12%), where only the epiglottis could be visualized. Conclusion: The new EAD Baska Mask® has many novel features which should improve safety when used in both spontaneously breathing and IPPV anesthesia

Comparison of cuff-pressure changes in silicone and PVC laryngeal masks during nitrous oxide anaesthesia in spontaneously breathing children

BACKGROUND: The purpose of this study was to evaluate the cuff pressures of four different laryngeal masks in paediatric patients undergoing routine surgery and to determine whether there is a substantial increase in cuff pressure when silicone masks are used compared to PVC laryngeal mask airways.METHODS: Hundred and forty patients aged < 16 yr were randomly allocated to receive one of four extraglottic airway devices: LMA-Classic; LMA-Unique; Soft Seal; or Cobra-PLA. Intracuff pressure was monitored continuously throughout the operative intervention. The primary outcome was measurement of an increase in cuff pressure. First attempt success rate, effective airway time, anatomical position of the airway and incidence of airway morbidity data were monitored.RESULTS: Mean cuff pressure increased within 5 min of N2O exposure, and was substantially higher in the silicone LMA-C, compared to the PVC-based extraglottic airway devices tested, reaching a plateau of the cuff pressure after 45 min. The overall first attempt success rate (97%) and the mean effective airway time (24 ± 9 sec) were very satisfactory and all patients underwent successful surgery. Anatomical position was adequate in most airways, although in 34% of the patients in the Cobra group herniation of either the epiglottis or arytenoids were detected. Airway morbidity due to the devices was insignificant.CONCLUSIONS: This study demonstrated a substantial increase in cuff pressure during anaesthesia for children in whom a silicone-based LMA-C was used, whereas PVC-based extraglottic airway devices showed a much lower increase.BACKGROUND: The purpose of this study was to evaluate the cuff pressures of four different laryngeal masks in paediatric patients undergoing routine surgery and to determine whether there is a substantial increase in cuff pressure when silicone masks are used compared to PVC laryngeal mask airways.METHODS: Hundred and forty patients aged < 16 yr were randomly allocated to receive one of four extraglottic airway devices: LMA-Classic; LMA-Unique; Soft Seal; or Cobra-PLA. Intracuff pressure was monitored continuously throughout the operative intervention. The primary outcome was measurement of an increase in cuff pressure. First attempt success rate, effective airway time, anatomical position of the airway and incidence of airway morbidity data were monitored.RESULTS: Mean cuff pressure increased within 5 min of N2O exposure, and was substantially higher in the silicone LMA-C, compared to the PVC-based extraglottic airway devices tested, reaching a plateau of the cuff pressure after 45 min. The overall first attempt success rate (97%) and the mean effective airway time (24 ± 9 sec) were very satisfactory and all patients underwent successful surgery. Anatomical position was adequate in most airways, although in 34% of the patients in the Cobra group herniation of either the epiglottis or arytenoids were detected. Airway morbidity due to the devices was insignificant.CONCLUSIONS: This study demonstrated a substantial increase in cuff pressure during anaesthesia for children in whom a silicone-based LMA-C was used, whereas PVC-based extraglottic airway devices showed a much lower increase

Inverting nonminimum-phase systems from the perspectives of feedforward and ILC

System inversion is at the basis of many feedforward and learning control algorithms. This paper aims to analyze several of these approaches in view of their subsequent use, showing inappropriate use that is previously overlooked. This leads to new insights and approaches for both feedforward and learning. The methods are compared in various aspects, including finite vs. infinite preview, exact vs. approximate, and quality of inversion in various norms which directly relates to their use. The results are validated on a nonminimum-phase benchmark system