Optimization of Endotracheal Tube Cuff Pressure by Monitoring CO2 Levels in the Subglottic Space in Mechanically Ventilated Patients: A Randomized Controlled Trial.

BACKGROUND: Many of the complications of mechanical ventilation are related to inappropriate endotracheal tube (ETT) cuff pressure. The aim of the current study was to evaluate the effectiveness of automatic cuff pressure closed-loop control in patients under prolonged intubation, where presence of carbon dioxide (CO2) in the subglottic space is used as an indicator for leaks. The primary outcome of the study is leakage around the cuff quantified using the area under the curve (AUC) of CO2 leakage over time. METHODS: This was a multicenter, prospective, randomized controlled, noninferiority trial including intensive care unit patients. All patients were intubated with the AnapnoGuard ETT, which has an extra lumen used to monitor CO2 levels in the subglottic space.The study group was connected to the AnapnoGuard system operating with cuff control adjusted automatically based on subglottic CO2 (automatic group). The control group was connected to the AnapnoGuard system, while cuff pressure was managed manually using a manometer 3 times/d (manual group). The system recorded around cuff CO2 leakage in both groups. RESULTS: Seventy-two patients were recruited and 64 included in the final analysis. The mean hourly around cuff CO2 leak (mm Hg AUC/h) was 0.22 ± 0.32 in the manual group and 0.09 ± 0.04 in the automatic group (P = .01) where the lower bound of the 1-sided 95% confidence interval was 0.05, demonstrating noninferiority (>-0.033). Additionally, the 2-sided 95% confidence interval was 0.010 to 0.196, showing superiority (>0.0) as well. Significant CO2 leakage (CO2 >2 mm Hg) was 0.027 ± 0.057 (mm Hg AUC/h) in the automatic group versus 0.296 ± 0.784 (mm Hg AUC/h) in the manual group (P = .025). In addition, cuff pressures were in the predefined safety range 97.6% of the time in the automatic group compared to 48.2% in the automatic group (P < .001). CONCLUSIONS: This study shows that the automatic cuff pressure group is not only noninferior but also superior compared to the manual cuff pressure group. Thus, the use of automatic cuff pressure control based on subglottic measurements of CO2 levels is an effective method for ETT cuff pressure optimization. The method is safe and can be easily utilized with any intubated patient.

Detection of endobronchial intubation by monitoring the CO2 level above the endotracheal cuff.

Early detection of accidental endobronchial intubation (EBI) is still an unsolved problem in anesthesia and critical care daily practice. The aim of this study was to evaluate the ability of monitoring above cuff CO2 to detect EBI (the working hypothesis was that the origin of CO2 is from the unventilated, but still perfused, lung). Six goats were intubated under general anesthesia and the ETT positioning was verified by a flexible bronchoscope. The AnapnoGuard system, already successfully used to detect air leak around the ETT cuff, was used for continuous monitoring of above-the-cuff CO2 level. When the ETT distal tip was located in the trachea, with an average cuff pressure of 15 mmHg, absence of CO2 above the cuff was observed. The ETT was then deliberately advanced into one of the main bronchi under flexible bronchoscopic vision. In all six cases the immediate presence of CO2 above the cuff was identified. Further automatic inflation of the cuff, up to a level of 27 mmHg, did not affect the above-the-cuff measured CO2 level. Withdrawal of the ETT and repositioning of its distal tip in mid-trachea caused the disappearance of CO2 above the cuff in a maximum of 3 min, confirming the absence of air leak and the correct positioning of the ETT. Our results suggest that measurement of the above-the-cuff CO2 level could offer a reliable, on-line solution for early identification of accidental EBI. Further studies are planned to validate the efficacy of the method in a clinical setup.

Benefits and harms of perioperative high fraction inspired oxygen for surgical site infection prevention: a protocol for a systematic review and meta-analysis of individual patient data of randomised controlled trials.

INTRODUCTION: The use of high fraction of inspired oxygen (FiO2) intraoperatively for the prevention of surgical site infection (SSI) remains controversial. Promising results of early randomised controlled trials (RCT) have been replicated with varying success and subsequent meta-analysis are equivocal. Recent advancements in perioperative care, including the increased use of laparoscopic surgery and pneumoperitoneum and shifts in fluid and temperature management, can affect peripheral oxygen delivery and may explain the inconsistency in reproducibility. However, the published data provides insufficient detail on the participant level to test these hypotheses. The purpose of this individual participant data meta-analysis is to assess the described benefits and harms of intraoperative high FiO2compared with regular (0.21-0.40) FiO2 and its potential effect modifiers. METHODS AND ANALYSIS: Two reviewers will search medical databases and online trial registries, including MEDLINE, Embase, CENTRAL, CINAHL, ClinicalTrials.gov and WHO regional databases, for randomised and quasi-RCT comparing the effect of intraoperative high FiO2 (0.60-1.00) to regular FiO2 (0.21-0.40) on SSI within 90 days after surgery in adult patients. Secondary outcome will be all-cause mortality within the longest available follow-up. Investigators of the identified trials will be invited to collaborate. Data will be analysed with the one-step approach using the generalised linear mixed model framework and the statistical model appropriate for the type of outcome being analysed (logistic and cox regression, respectively), with a random treatment effect term to account for the clustering of patients within studies. The bias will be assessed using the Cochrane risk-of-bias tool for randomised trials V.2 and the certainty of evidence using Grading of Recommendations, Assessment, Development and Evaluation methodology. Prespecified subgroup analyses include use of mechanical ventilation, nitrous oxide, preoperative antibiotic prophylaxis, temperature (<35°C), fluid supplementation (<15 mL/kg/hour) and procedure duration (>2.5 hour). ETHICS AND DISSEMINATION: Ethics approval is not required. Investigators will deidentify individual participant data before it is shared. The results will be submitted to a peer-review journal. PROSPERO REGISTRATION NUMBER: CRD42018090261.

Professional stress in anesthesiology: a review.

Anesthesiology is a stressful medical profession. While anesthesia in particular has become safer for the patient in the last decades, anesthesiology as a profession represents a medical field in which the professionals are permanently tense. The various reasons for this situation include the fact that anesthesiology is a team profession that requires perfect cooperation with other specialists. It also entails great responsibility for the patient's life, the daily use of "blind" invasive techniques, and last but not least the production pressure that characterizes the activity in the operating room. There are various methods to quantify professional stress and this article emphasizes the place of measurement of salivary cortisol in order to identify those stressful moments that are part of the anesthesiologist's routine activity, in addition to those individuals who are more prone to develop negative aspects of stress. It seems that there is a strong correlation between the high level of salivary cortisol and stressful events during patient management and also a correlation between this level and a high score of implicit job-stress. This reality created the need to look for remedies; some authors recommend a long list of measures to be taken in order to prevent or reduce the magnitude of professional stress. This list includes a continuous self-care attitude, consisting of having a balanced professional and personal life; adequate sleep; avoiding drugs, obesity, and "workaholic" behavior; as well as better use of leisure. Finally, more studies are needed to find out which preventive means may potentially reduce the risk of professional stress among anesthesiologists.

Endotracheal tube cuff--small important part of a big issue.

Many of the complications related to prolonged ventilation are related to inappropriate handling of endotracheal tube (ETT) cuff. This article reviews the possible complications associated with the ETT cuff, and the landmark development made in that field. The article challenges the present paradigm of cuff use and reviews the current clinical practice in that area.

Do waking salivary cortisol levels correlate with anesthesiologist's job involvement?

Anesthetists' work carries great responsibility and can be very stressful. Cognitive appraisal plays a central role in stress responses; however, little is known about the relationship between stress appraisal and biological markers of stress, particularly among anesthesiologists. Stress response may be associated with increased levels of systemic cortisol, which can be conveniently measured in saliva and used as a marker for the extent of stress. The objective of this study was to examine the correlation between work-related cognitive variables and waking salivary cortisol, a possible stress marker, in anesthesiologists. Thirty-eight anesthesiologists were assessed for work-related thought intrusions and perceived "mental distance" between themselves and their work, using the pictorial representation of illness self-measure (PRISM), and underwent an implicit association test reflecting implicit job-stress associations. Salivary cortisol was measured twice upon awakening and an hour later, in saliva samples, using a kit based on chemoluminescence competition assay. Only implicit job-stress associations were correlated with waking cortisol (r = 0.35, p < 0.05). Furthermore, high implicit job-stress was related to elevated cortisol only among anesthesiologists reporting large "mental distance" from work, which may represent limited job involvement related to burnout. Anesthesiologists with a low degree of job involvement who have high implicit job-stress associations have higher levels of waking salivary cortisol. Further studies are necessary to assess the impact of stress management techniques on anesthesiologists' personal and professional behavior as well as on the quality of medical care.

Ventilator-associated pneumonia: current status and future recommendations.

OBJECTIVE: Ventilator-associated pneumonia (VAP) is a common hazardous complication in ICU patients. The aim of the current review is to give an update on the current status and future recommendations for VAP prevention. METHODS: This article gives an updated review of the current literature on VAP. The first part briefly reviews pathogenesis and epidemiology while the second includes an in-depth review of evidence-based practice guidelines (EBPG) and new technologies developed for prevention of VAP. RESULTS: VAP remains a frequent and costly complication of critical illness with a pooled relative risk of 9-27% and mortality of 25-50%. Strikingly, VAP adds an estimated cost of more than $40,000 to a typical hospital admission. An important aetiological mechanism of VAP is gross or micro-aspiration of oropharyngeal organisms around the cuff of the endotracheal tube (ETT) into the distal bronchi. Prevention of VAP is preferable. Preventative measures can be divided into two main groups: the implemen- tation of EBPGs and use of device-based technologies. EBPGs have been authored jointly by the American Thoracic Society and the Infectious Diseases Society of America. The Canadian Critical Care Trials group also published VAP Guidelines in 2008. Their recommendations are detailed in this review. The current device-based technologies include drainage of subglottic secretions, silver coated ETTs aiming to influence the internal bio-layer of the ETT, better sealing of the lower airways with ultrathin cuffs and loops for optimal cuff pressure control. CONCLUSIONS: EBPG consensus includes: elevation of the head of the bed, use of daily "sedation vacations" and decontamination of the oropharynx. Technological solutions should aim to use the most comprehensive combination of subglottic suction of secretions, optimization of ETT cuff pressure and ultrathin cuffs. VAP is a type of hospital-acquired pneumonia that develops more than 48 h after endotracheal intubation. Its incidence is estimated to be 9-27%, with a mortality of 25-50% [Am J Respir Crit Care Med 171:388-416 (2005), Am J Med 85:499-506 (1988), Chest 122:2115-2121 (2002), Intensive Care Med 35:9-29 (2009)]. The most important target in VAP handling is its prevention. The aim of this article is to review the pathogenesis, epidemiology and the different strategies/technologies for prevention of VAP.

[Organ transplantation in Israel of 2007--reality and vision].

The situation of organ transplantation in Israel has currently reached a crossroad. The number of patients on the waiting list increases from one year to another, but the availability of organs remains, more or less, the same as in the last decade. As a result, the medical condition of the patients on the waiting list deteriorates and each year some 7% of these patients died before an organ could be procured for saving their lives. Since 1994 the organ transplantation system in Israel is nationally controlled by the Israel Transplant Center (ITC) which employs transplantation teams (a physician and at least one registered nurse) acting in each general hospital. ITC and the teams proceed in the direction of identification of potential donors after brain death, hemodynamic stabilization, talks with the patient's family aiming to obtain acceptance for donating the deceased person's organs and the logistic aspects of organ harvesting and transplantation. This review presents the up to date parameters of organ transplantation in Israel and compares this information with some data from other countries. The data from last year placed Israel on the lower part of the list of developed countries regarding the availability of organs for transplantation: 9 donors per million inhabitants (in comparison to 35 in Spain or 25 in the USA). Furthermore, a lower percentage of the Israeli adult population (9.4% as per March 2008) signed a donor card, thereby expressing the intention to donate organs after death. Finally, some ideas for improving the situation of organ donation in this country are proposed, among them a continuous campaign for increasing population awareness regarding organ donation, the use of non-heart beating donor organs, the use of expanded criteria for donated organs, development of a system of pair exchange in case of immunologic incompatibility between the donor and the recipient or the use of solutions and machines for organ perfusion in order to increase the viability time of the harvested organ.

Acoustic monitoring of double-lumen ventilated lungs for the detection of selective unilateral lung ventilation.

One-lung intubation (OLI) is among the most common complications of endotracheal intubation. None of the monitoring tools now available has proved effective for its early detection. In this study we investigated the efficacy of acoustic analysis for the detection of OLI. We collected lung sounds from 11 patients undergoing thoracic surgery requiring the placement of a double-lumen tube. Recordings of separate lung ventilation were performed after induction and confirmation of adequate tube positioning, before surgery. Samples of lung sounds were collected by three piezoelectric microphones, one on each side of the chest and one on the right forearm, for background noise sampling. The samples were filtered, the signals' energy envelopes were calculated, and segmentation to breath and rest periods was performed. Each respiration was classified into one of the three categories: bilateral ventilation, selective right-lung ventilation, or selective left-lung ventilation, on the basis of the ratio between the energy signals of each lung. OLI was accurately identified in 10 of the 11 patients during right OLI and in all 11 patients during left OLI. This study suggests that acoustic monitoring is effective for the detection of selective lung ventilation and may be useful for early diagnosis of OLI.

Terlipressin facilitates transport of septic patients treated with norepinephrine.

BACKGROUND: Transport of hemodynamic unstable septic patients for diagnostic or therapeutic interventions outside the intensive care unit is complex but sometimes contributes to increasing the chance of survival. OBJECTIVES: To report our experience with terlipressin treatment for facilitation of transport to distant facilities for diagnostic or therapeutic procedures in septic patients treated with norepinephrine. METHODS: We conducted a retrospective analysis of the records of our ICU, identifying the patients with septic shock who required norepinephrine for hemodynamic support. RESULTS: Terlipressin was given to 30 septic shock patients (15 females and 15 males) who were on high dose norepinephrine (10 microg/min or more) in order to facilitate their transport outside the ICU. The dose of terlipressin ranged from 1 to 4 mg, with a mean of 2.13+/-0.68 mg. The dose of norepinephrine needed to maintain systolic blood pressure above 100 mmHg decreased following terlipressin administration, from 21.9+/-10.4 microg/min (range 5-52 microg/min) to 1.0+/-1.95 (range 0-10) (P < 0.001). No patients required norepinephrine dose adjustment during transport. No serious complications or overshoot in blood pressure values were observed following terlipressin administration. Acrocyanosis occurred only in eight patients receiving more than 1 mg of the drug. The overall mortality rate was 50%. CONCLUSIONS: Our data suggest that terlipressin is effective in septic shock. Because it is long-acting and necessitates less titration it might be indicated for patient transportation.

Management of the hopelessly ill patient: to stop or not to start?

The paper discusses the subject of futile treatment in the case of a hopelessly ill patient. The topic has many facets, among them the ethical precepts of preventing futile treatment, but also the economic and logistic impact of treating patients who do not have a fair chance of benefitting from managing their medical condition. A 75-year old patient, suffering from an advanced stage of Alzheimer's disease and a clinical picture of acute surgical abdomen, is presented and two approaches are discussed. The first scenario is the aggressive management, including immediate laparotomy and admission to an intensive care unit, a solution without a fair chance of saving the patient's life. The most favorable, but theoretical, output in this case would be the patient's return to his previous mental condition, without any connection with the reality and surroundings and in permanent need for help, supervision and assistance. The second option is letting the patient die in dignity, alleviating pain and surrounded by family. The role of the primary care physician and family is discussed and some ethical principles are presented in order to emphasize the importance of preventing futile treatment in a case of a terminally ill patient.

Helmet noninvasive ventilation for weaning from mechanical ventilation.

We saw a patient who presented with carbon dioxide narcosis and acute respiratory failure due to an exacerbation of chronic obstructive pulmonary disease. We intubated and 12 hours later he had recovered consciousness and could cooperate with noninvasive ventilation, at which point we extubated and used a helmet to provide noninvasive positive-pressure ventilation in assist/control mode, and then during the ventilator-weaning process, pressure support, and finally continuous positive airway pressure. The patient had no complications from the helmet, and he was discharged from intensive care 48 hours after helmet ventilation was initiated. Helmet noninvasive ventilation is a potentially valuable ventilator-weaning method for certain patients.

Emergency percutaneous tracheostomy is feasable in experienced hands.

One of most stressful situations for a physician occurs when a patient is unable to breathe and endotracheal intubation is not possible. The establishment of an open airway by surgery is indicated only if the physician is unable to do so with an endotracheal tube. Surgical tracheostomy is not indicated in emergency situations because it takes a long time and can result in death if respiratory support cannot be provided during the procedure. Percutaneous dilatational tracheostomy in experienced hands takes only a few minutes. We describe six patients, including two trauma patients, in whom emergency percutaneous tracheostomy was rapidly and successfully performed under conditions of the imminent loss of airway and inability to intubate the patient. As this procedure is safe and can be performed easily by experienced personnel, we propose its addition to the armamentarium of emergency airway management.

Fatal metabolic acidosis caused by thiamine deficiency.

Acute thiamine deficiency, an uncommon cause of hemodynamic instability in Western countries, may be manifested by acute heart failure and neurological deficits. Severe metabolic acidosis is one of its least recognized features. We present a report of foreign workers who complained of weakness and lower limb edema and were found to have acute thiamine deficiency. One died of refractory metabolic acidosis and shock, and the diagnosis was reached post mortem. Thiamine deficiency should be considered in every case of severe lactic acidosis without an obvious cause, especially in high-risk populations (malnourished, alcoholics, Far-East workers, etc). Whenever it is suspected, empiric treatment with thiamine should be initiated immediately. Physicians who care for populations at risk should be familiar with the clinical spectrum of nutritional deficits, and monitor the nutritional habits of these patients carefully. The treatment is inexpensive and devoid of adverse effects. Moreover, delaying thiamine administration in patients with deficiency may cause severe life-threatening metabolic acidosis and affect recovery. The prophylactic use of thiamine in a high-risk population, even before blood levels are received, may be cost effective.

The dilemma of immediate preoperative hypertension: to treat and operate, or to postpone surgery?

STUDY OBJECTIVE: To evaluate the efficacy and complications of immediate preoperative reduction of arterial blood pressure (BP) in patients with well-controlled hypertension but with diastolic blood pressure (DBP) between 110 and 130 mmHg on arrival at the operating room (OR). DESIGN: Prospective, randomized, large-sample study. SETTING: University-affiliated, 550-bed community hospital. PATIENTS: 989 patients with well-controlled hypertension, who were scheduled for surgery, and who had no previous myocardial infarction, unstable or severe angina pectoris, renal failure, pregnancy induced hypertension, left ventricular hypertrophy, previous coronary revascularization, aortic stenosis, preoperative dysrhythmias, conduction defects, or stroke. INTERVENTIONS: Patients with DBP between 110 and 130 mmHg were randomly allocated to two groups: 400 patients in the control group and 589 patients serving as the study group. The control group had their surgery postponed and they remained in hospital for BP control, and the study patients received 10 mg of nifedipine intranasally delivered. The patients were observed for cardiovascular and neurological complications during the intraoperative period and over the first three postoperative days. MEASUREMENTS AND MAIN RESULTS: The two groups were similar in age, gender, type of surgery, duration of anesthesia, and intraoperative fluid administration. There were no statistically significant differences in postoperative complications. The hospitalization time was considerable shorter in the study group than in the control group. CONCLUSIONS: Immediate preoperative reduction of DBP with intranasal nifedipine is safe in patients with well-controlled arterial hypertension but they presented with severe to very severe hypertension for patients in the OR. We were able to avoid unnecessary surgery postponement and attendant costs.

Factors encouraging and inhibiting organ donation in Israel: the public view and the contribution of legislation and public policy.

Although transplantation surgeries are relatively successful and save the lives of many, only few are willing to donate organs. In order to better understand the reasons for donation or refusing donation and their implications on and influence by public policy, we conducted a survey examining public views on this issue in Israel. Between January and June 2010, an anonymous questionnaire based on published literature was distributed among random and selected parts of Israeli society and included organ recipients, organ donors, soldiers, university and high school students, and the general population. The analysis of 799 questionnaires revealed that, although 74.7 percent have not signed a donor card, 60.8 percent of participants consider doing so. Additionally, 54.3 percent of respondents objected to giving or receiving compensation for donation, and, if at all, priority in transplantation care is the most desired form of such compensation. The health status of the donor and knowing that donation saves lives or that there exists a shortage of organs for transplantation are the two factors most affecting motivation to donate. Lack of information, relatives' views on donation, and type of organ involved in donation are factors most inhibiting donation. Willingness to donate is significantly affected by the proximity of the recipient to the donor. With regard to most organs, their contribution to one's sense of "self" and its symbolic role strongly affects motivation to donate, except for donation to relatives. Compensation for organ donation has little effect on motivation to donate during life and after death. Our findings suggest new ways to construct a more effective public policy on this issue.