Implementation Science: Incorporating Obstructive Sleep Apnea Screening and Capnography Into Everyday Practice.

PURPOSE: This article describes the implementation and maintenance of obstructive sleep apnea (OSA) screening and capnography monitoring. DESIGN: A quality improvement project. METHODS: A multidisciplinary team provided staff education to three perianesthesia care units. Using the STOP-Bang screening tool, five or more positive responses indicated high risk for OSA. A postanesthesia care unit audit tool tracked STOP-Bang scores, capnography use, hypoventilation events, nursing interventions, and respiratory complications. FINDINGS: Among 314 patients with OSA, 36% were identified as high risk. Nurses used capnography on 76% of OSA patients and were able to readily identify hypoventilation and intervene. Respiratory complications occurred in 10.8% (n = 34) requiring a higher level of care. Postimplementation, all six postanesthesia care units employ this best practice. CONCLUSIONS: Perianesthesia nurses found OSA screening and capnography easy to incorporate into nursing practice. This process can reduce respiratory complications in the surgical patient with OSA. An Evidence-Based Practice Fellowship Program facilitated this practice change.

An abnormal capnography trace due to air embolism in the lateral position.

Venous air embolism occurs when air is entrained into the venous system and travels to the right heart and pulmonary circulation, and commonly occurs as a complication in laparoscopic, neurosurgical and cardiac surgeries. We present a case of abnormal end-tidal carbon dioxide capnography tracing in the lateral position in a laparoscopic major liver procedure and discuss the potential novel use of this as a red flag in aiding the medical practitioner to diagnose air embolism.

Investigating Capnography Innovation for Better Patient Monitoring in the Resource Limited Surgical Setting.

BACKGROUND: Access to basic anesthetic monitoring in the developing world is lacking, which contributes to the 100 times greater anesthesia-related mortality in low- and middle-income countries. We hypothesize that an environmental sensor with a lower sampling rate could provide some clinical utility by providing CO2 levels, respiratory rate, and support in detection of clinical abnormalities. MATERIALS AND METHODS: A bench-top lung simulation was created to replicate CO2 waveforms, and an environmental sensor was compared with industry-available technology. Sensor response time and respiratory rates were compared between devices. Additionally, an in silico model was created to replicate capnography pathology as waveforms would appear using the environmental sensor. RESULTS AND CONCLUSION: Breath simulations using the bench-top lung simulation produced similar results to industry standards with a degree of variability. Respiratory rates did not differ between the environmental sensor and all other devices tested. Finally, pathological waveforms created in silico carried a certain level of detail regarding ventilatory pathology, which could provide some clinical insight to an anesthesiologist. We believe our prototype is the first step toward making low-cost and portable capnography available in the resource-limited setting, and future efforts should focus on bridging the gap to safer anesthesia and surgery globally.

Performance of a second generation pulmonary capnotracking system for continuous monitoring of cardiac output.

Technologies for minimally-invasive cardiac output measurement in patients during surgery remain little used in routine practice. We tested a redeveloped system based on CO2 elimination (VCO2) by the lungs for use in ventilated patients, which can be seamlessly integrated into a modern anesthesia/monitoring platform, and provides automated, continuous breath-by-breath cardiac output monitoring. A prototype measurement system was constructed to measure VCO2 and end-tidal CO2 concentration with each breath. A baseline measurement of non-shunt cardiac output was made during a brief oscillating change in ventilator rate, according to the differential CO2 Fick approach and repeated at 5-10 min intervals. Continuous breath-by-breath monitoring of cardiac output was performed between these intervals from measurement of VCO2, using a derivation of the Fick equation applied to pulmonary CO2 elimination and cardiac output displayed in real time. Measurements were compared with simultaneous measurements by thermodilution in 50 patients undergoing cardiac surgery or liver transplantation. Overall mean bias [sd] for agreement in cardiac output measurement was - 0.3 [1.1] L/min, percentage error ± 38.7%, intraclass correlation coefficient = 0.91. Concordance in measurement of changes of at least 15% in cardiac output was 81.4%, with a mean angular bias of - 1.7°, and radial limits of agreement of ± 76.2° on polar plot analysis. The accuracy and precision compared favourably to other clinical techniques. The method is relatively seamless and automated and has potential for continuous, cardiac output monitoring in ventilated patients during anesthesia and critical care.

Research: Continuous Surveillance of Sleep Apnea Patients in a Medical-Surgical Unit.

This report consists of two separate studies on the use of continuous capnography monitoring conducted in an effort to improve patient safety at Virtua Health System. The desire for improved patient safety is motivating continuous monitoring and improved surveillance in clinical areas not traditionally equipped for such monitoring. We explored the use of remote monitoring of capnography, using enterprise middleware, in patients recovering from surgery in a medical-surgical unit. Continuous monitoring traditionally has been used in higher-acuity settings, such as intensive care units. Patients diagnosed or suspected to have obstructive or central sleep apnea may benefit from the increased surveillance afforded by continuous monitoring. Pain management in this cohort of patients, recovering from bariatric, joint replacement, or other major surgery, often involves administration of opioids (e.g., hydromorphone, morphine sulfate), which are known to increase risk of respiratory depression. Continuous monitoring of these patients increases the likelihood of detecting adverse clinical events. Our goal was to implement continuous monitoring in order to identify alarm conditions caused by adverse clinical events requiring intervention (e.g., opioid-induced respiratory depression) and artifacts related to patient movement, suspect measurements, or other medical device-generated alarm signals.

[Airway management in intensive care units in Rhineland-Palatinate : Evolution over five years]. / Atemwegssicherung auf Intensivstationen in Rheinland-Pfalz : Entwicklung über fünf Jahre.

BACKGROUND: Securing the airway in severely ill patients is associated with a high rate of complications. So far, no information exists about the equipment readily available for airway management in German intensive care units (ICUs). It is also unknown if the range of material has improved over time. OBJECTIVES: In the present trial the availability of equipment for airway management in ICUs in Rhineland-Palatinate was evaluated at two different times. MATERIALS AND METHODS: Using a structured questionnaire, all ICUs in the state were contacted in the years 2010 and 2015. The availability of different types of equipment for airway management, as well as the presence of a training program for airway management, was evaluated. RESULTS: For 2010 data from 64 ICUs were evaluated and for 2015 data sets from 63 ICUs were collected. In 2010 indirect laryngoscopes were available in eight ICUs; in 2015 these devices were directly accessible in 43 units (p < 0.0001). Extraglottic devices were available in all but one ICU in 2010 and all ICUs in 2015. Equipment for emergency surgical airway procedures was available in nearly every ICU (n = 60). The availability of capnography increased significantly from 2010 (n = 12) to 2015 (n = 56; p < 0.0001). In 2010 and 2015, frequent training with a focus on airway management was performed in 23 and 32 units, respectively (p > 0.05). CONCLUSION: Most ICUs in Rhineland-Palatinate have a broad range of equipment for airway management available, and the range has significantly improved over the time period evaluated. The availability of indirect laryngoscopes and capnometers improved significantly. However, it is remarkable that in some ICU's there is still a lack of equipment for advanced airway management.

Capnography as a tool to detect metabolic changes in patients cared for in the emergency setting / Capnografia como ferramenta para detectar alterações metabólicas em pacientes atendidos em situações de emergência / Capnografía como herramienta para detectar alteraciones metabólicas de los pacientes atendidos en situaciones de urgência

ABSTRACT Objective: to evaluate the usefulness of capnography for the detection of metabolic changes in spontaneous breathing patients, in the emergency and intensive care settings. Methods: in-depth and structured bibliographical search in the databases EBSCOhost, Virtual Health Library, PubMed, Cochrane Library, among others, identifying studies that assessed the relationship between capnography values and the variables involved in blood acid-base balance. Results: 19 studies were found, two were reviews and 17 were observational studies. In nine studies, capnography values were correlated with carbon dioxide (CO2), eight with bicarbonate (HCO3), three with lactate, and four with blood pH. Conclusions: most studies have found a good correlation between capnography values and blood biomarkers, suggesting the usefulness of this parameter to detect patients at risk of severe metabolic change, in a fast, economical and accurate way.

RESUMO Objetivo: avaliar a utilidade da capnografia para a detecção de alterações metabólicas em pacientes com respiração espontânea, no contexto das emergências e dos cuidados intensivos. Método: pesquisa bibliográfica estruturada aprofundada, nas bases de dados EBSCOhost, Biblioteca Virtual em Saúde, PubMed, Cochrane Library, entre outras, identificando estudos que avaliavam a relação entre os valores da capnografia e as variáveis envolvidas no equilíbrio ácido-base sanguíneo. Resultados: foram levantados 19 estudos, dois eram revisões e 17 eram estudos observacionais. Em nove estudos, os valores capnográficos foram correlacionados com o dióxido de carbono (CO2), em oito com o bicarbonato (HCO3), em três com o lactato, e em quatro com o pH sanguíneo. Conclusões: na maioria dos estudos foi observada uma correlação adequada entre os valores capnográficos e os biomarcadores sanguíneos, sugerindo a utilidade deste parâmetro para a identificação de pacientes com risco de sofrer uma alteração metabólica grave, de uma forma rápida, econômica e precisa.

RESUMEN Objetivo: explorar la utilidad de la capnografía para la detección de alteraciones metabólicas ante pacientes en respiración espontánea, en el ámbito de las emergencias y los cuidados críticos. Método: búsqueda bibliográfica estructurada en profundidad, en bases de datos EBSCOhost, Biblioteca Virtual de la Salud, PubMed, Cochrane Library, entre otras, identificando estudios que evaluaban la relación entre valores de la capnografía y variables implicadas en el equilibrio ácido-base sanguíneo. Resultados: se recopilaron 19 estudios, dos eran revisiones y 17 observacionales. En nueve estudios, se correlacionaron los valores capnográficos junto al dióxido de carbono (CO2), en ocho con el bicarbonato (HCO3), tres con el lactato, y cuatro con el pH sanguíneo. Conclusiones: la mayoría de estudios han obtenido una correlación adecuada entre los valores capnográficos y biomarcadores sanguíneos, sugiriendo la utilidad de este parámetro para la detección de pacientes en riesgo de padecer una alteración metabólica grave, de forma rápida, económica y precisa.

Accuracy of CO2 monitoring via nasal cannulas and oral bite blocks during sedation for esophagogastroduodenoscopy.

Esophagogastroduodenoscopy procedures are typically performed under conscious sedation. Drug-induced respiratory depression is a major cause of serious adverse effects during sedation. Capnographic monitoring of respiratory activity improves patient safety during procedural sedation. This bench study compares the performance of the nasal cannulas and oral bite blocks used to monitor exhaled CO2 during sedation. We used a spontaneously breathing mechanical lung to evaluated four CO2 sampling nasal cannulas and three CO2 sampling bite blocks. We placed pneumatic resistors in the mouth of the manikin to simulate different levels of mouth opening. We compared CO2 measurements taken from the sampling device to CO2 measurements taken directly from the trachea. The end tidal CO2 concentration (PETCO2) measured through the bite blocks and nasal cannulas was always lower than the corresponding PETCO2 measured at the trachea. The difference became larger as the amount of oxygen delivered through the devices increased. The difference was larger during normal ventilation than during hypoventilation. The difference became larger as the amount of oral breathing increased. The two nasal cannulas without oral cups failed to provide sufficient CO2 for breath detection when the mouth was fully open and oxygen was delivered at 10 L/min. Our simulation found that respiratory rate can be accurately monitored during the procedure using a CO2 sampling bite block or a nasal cannula with oral cup. The accuracy of PETCO2 measurements depends on the device used, the amount of supplement oxygen, the amount of oral breathing and the patient's minute ventilation.

PET(CO2) measurement and feature extraction of capnogram signals for extubation outcomes from mechanical ventilation.

Capnography is a continuous and noninvasive method for carbon dioxide (CO2) measurement, and it has become the standard of care for basic respiratory monitoring for intubated patients in the intensive care unit. In addition, it has been used to adjust ventilatory parameters during mechanical ventilation (MV). However, a substantial debate remains as to whether capnography is useful during the process of weaning and extubation from MV during the postoperative period. Thus, the main objective of this study was to present a new use for time-based capnography data by measuring the end-tidal CO2 pressure ([Formula: see text]), partial pressure of arterial CO2 ([Formula: see text]) and feature extraction of capnogram signals before extubation from MV to evaluate the capnography as a predictor of outcome extubation in infants after cardiac surgery. Altogether, 82 measurements were analysed, 71.9% patients were successfully extubated, and 28.1% met the criteria for extubation failure within 48 h. The ROC-AUC analysis for quantitative measure of the capnogram showed significant differences (p < 0.001) for: expiratory time (0.873), slope of phase III (0.866), slope ratio (0.923) and ascending angle (0.897). In addition, the analysis of [Formula: see text] (0.895) and [Formula: see text] (0.924) obtained 30 min before extubation showed significant differences between groups. The [Formula: see text] mean value for success and failure extubation group was 39.04 mmHg and 46.27 mmHg, respectively. It was also observed that high CO2 values in patients who had returned MV was 82.8 ± 21 mmHg at the time of extubation failure. Thus, [Formula: see text] measurements and analysis of features extracted from a capnogram can differentiate extubation outcomes in infant patients under MV, thereby reducing the physiologic instability caused by failure in this process.

Evaluation of an oxygen mask-based capnometry device in subjects extubated after abdominal surgery.

BACKGROUND: For early detection of respiratory and hemodynamic changes during anesthesia, continuous end-tidal carbon dioxide concentration (PETCO2) is monitored by capnometry. However, the accuracy of CO2 monitoring during spontaneous breathing in extubated patients remains undetermined. Therefore, we aimed to compare P(ETCO2) measured by capnometry using an oxygen mask with a carbon dioxide sampling port (capnometry-type oxygen mask) and P(CO2) in extubated subjects who had undergone abdominal surgery. Furthermore, we investigated whether spontaneous deep breathing affected dissociation between P(aCO2) and P(ETCO2). METHODS: Adult post-abdominal surgery subjects admitted to the ICU were enrolled in this study. After extubation, oxygen was supplied at 6 L/min using the capnometry-type oxygen mask. After 30 min of oxygen supply, P(aCO2) blood gas analysis was performed, and P(ETCO2) was measured under resting and deep-breathing conditions. For both resting and deep-breathing conditions, the correlation between P(aCO2) and P(ETCO2) was analyzed. Furthermore, bias, precision, and limits of agreement were calculated using the Bland-Altman method. RESULTS: Twenty-five subjects (15 men, 10 women) with a mean age of 62 y (interquartile range of 57-76 y) and body mass index of 20-24 kg/m(2) were studied. The correlation (r) between P(aCO2) and P(ETCO2) under resting and deep-breathing conditions was 0.50 and 0.56, respectively. Compared with P(aCO2), the bias and limits of agreement were -12.6 (-20.6 to -4.6) for resting P(ETCO2) and -9.1 (-16.0 to -2.1) for deep-breathing P(ETCO2). The association between P(aCO2) and deep-breathing P(ETCO2) was significantly smaller compared with resting P(ETCO2) (P = .002). CONCLUSIONS: It is possible to measure the P(ETCO2) under varying breathing conditions with the capnometry-type oxygen mask in subjects receiving oxygen supplementation after extubation following upper abdominal surgery to determine whether they are properly ventilating. (ClinicalTrials.gov registration UMIN000011925.).

Cardiovascular and cerebrovascular responses to progressive central hypovolemia in young smokers: a preliminary study.

The purpose of this study was to describe cardiovascular and cerebrovascular responses of smokers and nonsmokers to progressive central hypovolemia. Twenty subjects participated (equal male and female). We recorded the electrocardiogram, beat-to-beat arterial pressure (Finometer), cerebral blood velocity of the middle cerebral artery (transcranial Doppler), and end-tidal CO2. Lower body negative pressure (LBNP) was applied at 3 mm Hg · min(-1) for 20 minutes to an ending pressure of -60 mm Hg, and data were averaged in 2-minute bins. Arterial pressures were similar between groups at baseline, but heart rates tended to be higher, and stroke volumes and cerebral velocities tended to be lower in smokers at baseline and during LBNP (all p ≥ 0.17). Heart rates increased, and arterial pressures, stroke volumes, and cerebral velocities decreased during LBNP (all p ≤ 0.05), but responses were not different between smokers and nonsmokers. During the final stage of LBNP, systolic pressures and mean middle cerebral artery velocities were substantially lower in smokers than nonsmokers: these preliminary data may suggest clinical relevance of smoking status, but the magnitude of differences between groups were not distinguishable statistically. We therefore conclude that smokers and nonsmokers respond similarly to progressive central hypovolemia.

Anesthesia equipment for the oral and maxillofacial surgery practice.

The physical design of an oral and maxillofacial surgeon's office is highly individualized and unique. Every office must incorporate certain essential equipment and features to safely deliver office anesthesia, regardless of the scope of anesthesia services provided. Furthermore, the office design and anesthesia armamentarium must take into account patient safety and comfort. This article discusess the necessary elements, ranging from preanesthesia assessment forms and intraoperative records to office design, anesthesia monitors, and equipment related to the safe and successful administration of office-based anesthesia by oral and maxillofacial surgeons and their staff.

Propofol drip infusion anesthesia for MRI scanning: two case reports.

The magnetic resonance imaging (MRI) room is a special environment. The required intense magnetic fields create unique problems with the use of standard anesthesia machines, syringe pumps, and physiologic monitors. We have recently experienced 2 oral maxillofacial surgery cases requiring MRI: a 15-year-old boy with developmental disability and a healthy 5-year-old boy. The patients required complete immobilization during the scanning for obtaining high-quality images for the best diagnosis. Anesthesia was started in the MRI scanning room. An endotracheal intubation was performed after induction with intravenous administration of muscle relaxant. Total intravenous anesthesia via propofol drip infusion (4-7 mg/kg/h) was used during the scanning. Standard physiologic monitors were used during scan pauses, but special monitors were used during scanning. In MRI scanning for oral maxillofacial surgery, general anesthesia, with the added advantage of having a secured airway, is recommended as a safe alternative to sedation especially in cases of patients with disability and precooperative chidren.

Preoperative, intraoperative, and postoperative anesthesia assessment and monitoring in oral surgery.

This article discusses the general methods used to assess patients before, during, and after operative procedures, sedation, or general anesthesia by the oral and maxillofacial surgery team. The details about specific disease processes will be discussed in other articles. These methods and modalities are not standards, but are commonly used in offices and clinics in the United States where sedation and anesthesia are provided.

Accuracy of end-tidal CO2 capnometers in post-cardiac surgery patients during controlled mechanical ventilation.

BACKGROUND: The determination of end-tidal carbon dioxide (etCO2) is very helpful in cardiac resuscitation for confirmation and monitoring of endotracheal tube placement and as an indicator of return of circulation and effectiveness of chest compressions. There is now also widespread use of capnometry on-site at emergency and trauma fields. OBJECTIVE: We studied the accuracy and correlation of three capnometers (EMMA, Medtronic, and Evita) with partial pressure of arterial CO2 (PaCO2) measurements. METHODS: The three capnometers were placed in-line in the ventilator tubing of the patient. Forty sedated and mechanically ventilated post-cardiac surgery patients were studied. Twenty consecutive etCO2 values were collected simultaneously from all three monitors while drawing an arterial blood sample. Paired sample t-test and Pearson correlation were used to compare the capnometers and their correlation with PaCO2. RESULTS: The correlation of etCO2 measurements between all three capnometers was good (Emma vs. Evita: 0.874, Emma vs. Medtronic: 0.949, Evita vs. Medtronic: 0.878). The correlation of PaCO2 with the Evita is the lowest (0.671) as compared to the EMMA (0.693) and the Medtronic (0.727). The lowest dispersion of the difference between etCO2 and PaCO2 was seen in EMMA (3.30), the highest in Evita (3.98). CONCLUSIONS: A good correlation between etCO2 and PaCO2 was shown with the three capnometers in the present study. However, etCO2 measurements were not valid to estimate PaCO2 in these patients. Therefore, capnometry cannot be used to replace serial blood gas analyses completely, but may be a good cardiopulmonary trend monitor and alerting system in catastrophic events.