SEARCH · Search PubMed

Results for “Capnography”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 361 records · Page 20Linked to original sources

PubMed1997

Accidental bronchial intubation. An analysis of AIMS incident reports from 1988 to 1994 inclusive.

Accidental bronchial intubation was examined in the first 3947 cases reported to the Australian Incident Monitoring Study and was found to have accounted for 154 (3.7%) of the total incidents reported. Most incidents were detected in the operating theatre (93.5%) and during maintenance of anaesthesia (77.9%), by unexplained oxygen desaturation alone (63.6%). Capnography remained normal or unremarkable during 88.5% of the episodes. One-third of cases were associated with head or neck surgery and possible flexion of the patient's head. A RAE tube was used in 20% of incidents, a greater frequency than occurred in the study overall. A third party was implicated in 36 (23.4%) of cases. Ninety per cent of cases were considered preventable. Major morbidity occurred in three cases and unplanned intensive care admission was required in a further five. Almost two-thirds (61.1%) of the incidents might have been avoided by the proposed markings on the tracheal tube. We conclude that when arterial desaturation occurs at any stage during anaesthesia the possibility of bronchial intubation must be considered. Asymmetrical ventilation may be difficult to detect clinically and in most cases there is no change in capnography.

Australia↗

PubMed2002

End-tidal carbon dioxide predicts the presence and severity of acidosis in children with diabetes.

BACKGROUND: Patients with diabetic ketoacidosis (DKA) hyperventilate, lowering their alveolar (PACO(2)) and arterial carbon dioxide (PaCO(2)). This ventilatory response lessens the severity of their acidemia in a predictable way. Because end-tidal CO(2) (ETCO(2)) closely approximates PaCO(2), measured ETCO(2) levels should allow for predictions about the presence and severity of acidosis in diabetic patients. OBJECTIVES: 1) To evaluate the relationship between measured serum bicarbonate (HCO(3)) and ETCO(2) measured via nasal capnography in children with suspected DKA; and 2) to assess the ability of capnography to predict DKA. METHODS: Children being evaluated in a pediatric emergency department for suspected DKA (known or suspected diabetes presenting with hyperglycemia with or without ketonuria) were enrolled in a cross-sectional, prospective, observational study. Prior to the availability of venous HCO(3) results, ETCO(2) values were measured using a Nellcor NPB-70 Handheld Capnograph. RESULTS: Forty-two patients were enrolled. Linear regression analysis revealed a significant relationship between HCO(3) and ETCO(2) (R(2) = 0.80, p < 0.0001). Mean ETCO(2) was 37 torr (95% CI = 35.5 to 37.9 torr) in the children without DKA and 22 torr (95% CI = 17.4 to 26.9 torr) in the children with DKA (p < 0.0001). An ETCO(2) cut-point of <29 torr correctly classified the most patients (95%), with a sensitivity of 0.83 (95% CI = 0.52 to 0.98) and a specificity of 1.0 (95% CI = 0.88 to 1.0). No patient with an ETCO(2) of > or =36 torr had DKA, for a sensitivity of 1.0 (95% CI = 0.74 to 1.0). CONCLUSIONS: End-tidal CO(2) is linearly related to HCO(3) and is significantly lower in children with DKA. If confirmed by larger trials, cut-points of 29 torr and 36 torr, in conjunction with clinical assessment, may help discriminate between patients with and without DKA, respectively.

Adolescent↗

PubMed2003

Ventilatory response during dissociative sedation in children-a pilot study.

OBJECTIVES: It is unclear whether ketamine induces subclinical respiratory depression when administered in dissociative doses intravenously (IV). The authors report a pilot study of capnography in emergency department (ED) pediatric patients receiving ketamine alone for procedural sedation, and describe serial measures of ventilatory response [end-tidal carbon dioxide (EtCO(2)), respiratory rate, pulse oximetry]. METHODS: The authors performed continuous capnography on a convenience sample of 20 ED pediatric patients who received ketamine 1.5 mg/kg IV for procedural sedation. RESULTS: Continuous EtCO(2) and pulse oximetry remained essentially unchanged following ketamine injection, and no EtCO(2) levels > 47 mm Hg were noted at any point throughout sedation. CONCLUSIONS: No hypoventilation was observed in 20 ED pediatric patients receiving ketamine 1.5 mg/kg administered IV over 1 minute. The authors found no evidence of respiratory depressant properties for this dissociative agent.

Anesthetics, Dissociative↗

PubMed1998

[Simultaneously monitoring end tidal CO2 and other parameters versus anesthesia management].

OBJECTIVE: To investigate the significance of end tidal CO2(ETCO2) combined with other techniques in anesthesia management. METHODS: Twenty two patients undergoing general anesthesia were monitored with electromyocardiogram (ECG), invasive arterial blood pressure (IABP), plethysmogram and capnography simultaneously. Ten patients undergoing epidural anesthesia and cervical plexus block were monitored with ETCO2. RESULTS: During general anesthesia the depth of general anesthesia, status of ventilation and the degree of muscle relaxation could be grossly evaluated by simultaneously monitoring ETCO2, capnography, plethysmogram, ECG and IABP. ETCO2 could also provide an objective standard for the assessment of respiratory function during spontaneous ventilation. CONCLUSIONS: ETCO2 combined with other monitoring techniques can increase the safety of anesthesia and the accuracy of anesthesia management.

Anesthesia, Epidural↗

PubMed2003

[Detection of esophageal intubation-assessment of several methods in clinical anesthesia].

OBJECTIVE: To evaluate the sensitivity and reliability of several widely used tests for prompt detection of inadvertent esophageal intubation. METHODS: Both endotracheal and esophageal intubations were made on 40 adult patients undergoing general anesthesia. The tests such as auscultation of bilateral apex of lungs and epigastrium by inexperienced examiners, capnography, SpO2, chest and upper abdomen movements, and airway resistance were evaluated. RESULTS: 90% and 96.25% cases in esophageal intubation were correctly diagnosed via auscultation of bilateral apex of lungs or epigastrium respectively. During esophageal ventilation, abdominal distension was found in 87.5% of cases, but none of them showed chest movements. Meanwhile, PetCO2 fluctuated between 1-2 mmHg, in association with a quick decline of SpO2 in 156 +/- 11 seconds. The airway mean resistance increased, whereas the period of plateau decreased significantly. CONCLUSIONS: (1) Auscultation of epigastrium in combination with bilateral apex of lungs is recommended because of the improved accuracy in tube positioning. (2) Capnography is the most reliable technique for the prompt detection of esophageal intubation, whereas other parameters do not seem to be of comparable value.

Adult↗

PubMedDate not supplied

Relationship of tonsil size on an airway blockage maneuver in children during sedation.

A previous report suggested that airway compromise without self-correction may occur in pediatric dental patients sedated with chloral hydrate (CH) and nitrous oxide (N2O) and may be interpreted as "deep" sedation. The purpose of this institutionally approved study was to determine 1) the association between the size of the tonsils and 2) the degree of expired carbon dioxide (CO2) and oxygen saturation (SaO2) changes to simulated airway obstruction using the Moore head-tilt maneuver for 30 sec or less. Thirty healthy children (ASA I), aged 22-40 months, were evaluated for tonsil size and sedated with CH (50 mg/kg) and hydroxyzine (2 mg/kg) and supplemented with N2O. Pulse oximetry and capnography were used to monitor the child. During the restorative phase when the patient appeared asleep, the head was rolled forward with the chin touching the chest for a period of 30 sec. Changes in SaO2 and CO2 waveform were observed during this period. The results indicated that seven children who had enlarged tonsils had blocked airways (as determined by capnography) lasting approximately 15 sec. The remaining children did not have enlarged tonsils and continued to exchange air appropriately. O2 levels did not change during this period. The results suggest that the likelihood of airway blockage increases with enlarged tonsils. In children without airway blockage, ventilation occurs unimpeded, and attempts to readjust the head may not occur. The association between airway blockage and patient responsiveness is discussed in relation to sedation levels.

Airway Obstruction↗

PubMed1982

Arterial to end-tidal carbon dioxide tension difference in children under halothane anaesthesia.

Using blood gas determinations and capnography, the relationship between arterial and end-tidal PCO2 was investigated in 20 children under halothane anaesthesia with spontaneous respiration. A median arterial to end-tidal carbon dioxide tension difference of 0.66 kPa (5 mm Hg) was found. There was a close correlation between PaCO2 and the magnitude of the carbon dioxide difference. Our findings may largely be explained by an increase in VD/VT (presumably mainly due to a reduction of VT) causing admixture of dead space air throughout expiration. It is concluded that though end-tidal carbon dioxide does not exactly reflect PaCO2 capnography may be of value as a monitor of respiration in paediatric anaesthesia at normal or near-normal values of end-tidal carbon dioxide.

Adenoidectomy↗

PubMed1995

[Preclinical control of intubation and artificial respiration. Animal experiment and literature review].

Oesophageal malposition of an endotracheal tube is among the leading causes of anaesthesia incidents. While clinical manoeuvres for detection of tube malposition are unreliable, monitoring (i.e. capnography) can prevent such incidents. The problem is particularly important in prehospital care, where capnography is not (yet) widely available. We tested three devices used for differentiating oesophageal from endotracheal intubation: 1. Non-CO2-dependent Oesophageal Detector Device (ODD) as described by Pollard and Wee, 2. Semi-quantitative chemical disposable capnometer EasyCAP (Nellcor), 3. Non-quantitative infrared miniaturised capnometer MiniCAP (MSA). METHODS. 50 anaesthetised minipigs were intubated with a Magill tube. An identical additional tube was placed in the oesophagus. The cuffs of both tubes were inflated. Unexperienced personnel (students, laboratory technicians) were asked to determine the position of one of the tubes by using one of the devices according to the randomisation plan. The decision had to be taken within 30 s. Using the ODD, the proband first injected 100 ml air into the lung (or stomach) and then tried to aspirate the same volume. EasyCAP and MiniCAP were used according to manuals. RESULTS. Each device was used 25 times with a tracheal tube and 25 times with an oesophageal tube. All tube position identifications were correct. When ventilating the oesophagus/stomach for capnometric control, regurgitation into the tube occurred six times (five times with the EasyCAP and once with the MiniCAP). In these cases, the decision was based on this occurrence and not on the display of the device. While using the ODD no regurgitation occurred. CONCLUSION. These devices are useful for preclinical practice. According to the literature and our experience, the ODD is superior for the initial control of tube position, especially in cardiac arrest. Capnometry is needed, however, for continuous control of ventilation.

Anesthesiology↗

PubMed1996

[Preclinical blood gas analysis. Technical description--initial experiences--indications].

OBJECTIVE: A new portable device for blood gas analyses (BGA) has been examined for prehospital application. METHODS: After a 1 h introduction to the procedure, two physicians used the blood gas analyzer in the emergency medical system in Graz, Austria, for 7 months. The indications for prehospital BGA were prolonged cardiopulmonary resuscitation, mechanical ventilation, hyperventilation for reducing increased intracranial pressure, respiratory failure and metabolic disorders. All patients tested were also checked with pulse oximetry and capnography. TECHNICAL SPECIFICATION: The device measures pO2, pCO2 and pH using the fluorescence method. The innovation of a single-use cassette system makes it unnecessary to do any calibrations or transport any test substances. The storage battery measures eight samples without recharge. The time spent on one measurement is 3-6 min. RESULTS: We took 49 samples from 24 patients and found 16 indications for therapeutical intervention, such as buffering metabolic acidosis and adjusting mechanical ventilation by means of BGA. In all cases the analyzer worked reliably. CONCLUSIONS: One advantage of BGA over the non-invasive methods pulse oximetry and capnography is that it does not interfere with factors like peripheral vasoconstriction or inequality of the pulmonary ventilation/ perfusion ratio. Moreover, it is the only method for controlled buffering of acid-base disturbances. This means more security in diagnostics and therapeutical interventions for the patient in danger of dying. The device has proved to be a useful addition to the monitoring methods for prehospital application.

Acid-Base Equilibrium↗

PubMed1994

Pulmonary function and sleep disordered breathing in patients with traumatic tetraplegia: a longitudinal study.

The purpose of this study was to determine longitudinal changes in nocturnal blood gas tensions in individuals with stable traumatic tetraplegia. Ten individuals initially evaluated at least 6 months postinjury were reevaluated 5 years later. When initially evaluated, all the patients had normal daytime blood gases. Six (60%), however, had nocturnal oxyhemoglobin desaturations (dSATs) below 90%, 3 (30%) had mean nocturnal oxyhemoglobin saturation (SAT) below 90% for 10% or more of at least 1 hour, and 4 had maximum end-tidal carbon dioxide tensions (EtCO2) greater than 45mmHg. At 5-year follow-up evaluation, then a mean of 11.6 +/- 5.7 years postinjury, the vital capacities (VCs) of these individuals had improved significantly by a mean of 1242 +/- 545mL without treatment, and daytime blood gases were still normal for 9 out of 10 patients. Five of the individuals (50%), however, had an increased number of transient nocturnal dSATs and 8 of 9 (88%) re-studied by capnography were hypercapnic. We conclude that nocturnal dSAT and hypercapnia appear to be common in tetraplegia and may increase as the patient ages, despite significant increases in VC. Oximetry and capnography are useful in diagnosing nocturnal dSAT and in monitoring treatment.

Adult↗

PubMed2006

Pilot study to evaluate the accuracy of ultrasonography in confirming endotracheal tube placement.

STUDY OBJECTIVE: Visualization of the vocal cords and end-tidal capnography are the usual standards in confirming endotracheal tube placement. Vocal cord visualization is, however, not always possible, and capnography is not 100% reliable and requires ventilation of the lungs to confirm placement. The goal of this study is to determine the accuracy of ultrasonography for detecting endotracheal tube placement into the trachea and esophagus in real time. METHODS: This was a prospective, randomized, controlled study. Eligible patients were adults undergoing elective surgery requiring intubation. Exclusion criteria were a history of difficult intubation, abnormal airway anatomy, aspiration risk factors, and esophageal disease. Thirty-three patients were enrolled. After induction of anesthesia and neuromuscular blockade, the anesthesiologist placed the endotracheal tube in the trachea and esophagus in random order with direct laryngoscopy. During the intubations, a high-frequency, linear transducer was placed transversely on the neck at the suprasternal notch. Two emergency physicians, blinded to the order and performance of the intubations, independently recorded the location of the endotracheal tube according to the real-time ultrasonographic image. A 2-by-2 table was used to calculate sensitivity and specificity of the emergency physicians' ability to detect placement of the endotracheal tube. RESULTS: For each physician, the sensitivity for identifying the first intubation as tracheal was 100% (95% confidence interval [CI] 77% to 100%) with a specificity of 100% (95% CI 82% to 100%). One endotracheal tube was unintentionally placed twice in the esophagus, but both tube placements were identified as esophageal by the emergency physicians. CONCLUSION: In this pilot study, 2 emergency physicians experienced in ultrasonography accurately detected placement of endotracheal tubes during intubation with ultrasonography in select patients in the controlled environment of the operating room. Future studies should examine the use of ultrasonography to visualize endotracheal tube placement in real time by emergency physicians with less ultrasonographic training; use of the technique in the emergency department on a wider range of patients, including patients with difficult airways; and assessment of the utility of ultrasonography in confirmation of endotracheal tube position in already intubated patients.

Adult↗

PubMed2003

[The sitting position in neurosurgical anaesthesia: a survey of French practice].

INTRODUCTION: It remains a French and international controversy about the use of the sitting position in neurosurgery. The aim of this study was to evaluate the frequency of sitting position use, perioperative monitoring and procedures for air embolism detection and treatment. STUDY DESIGN: National postal survey. PATIENTS AND METHODS: The survey was sent in may 2000 to the anaesthesiologists in 53 french public neurosurgical centers. Responses were collected during 9 months. RESULTS: Among the 44 centers (83%), 33 (75%) used the sitting position. In 20 centers (61%) it was limited for the surgical procedures for which the surgeon was unable to operate in other position. Perioperative monitoring for air embolism was: capnography (100%), Swan-Ganz catheter (21%), precordial Doppler ultrasonography (15%) and transoesophageal echocardiography (6%). Only 12 centers (36%) used 2 or more techniques of detection for perioperative air embolism. In the 25 centers (76%) of those, which used the sitting position systematic pre-operative identification of patent foramen ovale by contrast echocardiography was performed. Prevention procedures of air embolism were: plasma volume expansion (94%), antigravity suit (61%), mechanical ventilation with positive end-expiratory pressure (42%), and abdominal compression (24%). No protocol of air embolism prophylaxis was used in 18 centers. CONCLUSION: The survey concerned 83% of the centers. The number of centers using the sitting position was larger than in other countries like United Kingdom, Germany and Japan. Despite its lack of sensitivity capnography was universally practised. Preoperative contrast echocardiography for patent foramen ovale detection was not considered as necessary in all centers. Expert recommendations may be required.

Blood Gas Analysis↗

PubMed2003

[French national survey of the use of monitoring devices during cardiopulmonary bypass in 2001].

OBJECTIVES: To study the different monitoring devices used during cardiopulmonary bypass (CPB) and to determine the factors, which may influence the choice of these equipments. STUDY DESIGN: Survey. METHODS: A postal questionnaire was send to the 66 French cardiac surgery centres. Results have been analysed about the economic status (public health service or private institution) and the business of the centre (less than 500, between 500 to 800 and more than 800 cardiopulmonary bypass/year). RESULTS: The rate of answer reached 73%. In 40% of centres, the cardiovascular perfusionist was not alone during the procedure. The percentage of centres using a checklist was 80%, a neurologic monitoring 42%, anaesthesia depth monitoring 40%, venous reservoir level detector 52%, arterial line bubble detector 38%, cardioplegia circuit bubble detector 6%, transoesophageal echocardiography 48%, pipe's temperature monitoring 90%; oxymetry 44%, capnography 25%, SvO2 98%, blood gas analysis outside the OR 46% and computer records 35%. No difference was observed between public and private institution for these latter devices. However, a significant difference was noticed among the low, intermediate and highly busy centres for the use of checklist, the EEG monitoring, the pipe and water circuit temperature monitoring, capnography and location of the biologic analysers. CONCLUSION: Equipments were not similar among the different French cardiac surgery centres. Furthermore, the French practice seems different from American, UK and Australian's one. These results highlight the need of establishing French guidelines, which are absent.

Blood Pressure Determination↗

PubMed1999

Evaluation of a new fibre-optical monitor for respiratory rate monitoring.

OBJECTIVES: To present further development of a fibre-optical respiratory rate monitor and evaluate the function in the final version. METHODS: Respiration was recorded in 18 healthy volunteers of ages 9-83 years by three different methods simultaneously: fibre-optical monitoring, capnography and manually. The recordings were made-breath by breath in four 3-minute periods in each subject. In total there were 54 observations, corresponding to 648 minutes. The recordings were fed simultaneously into a computer. Two subjects were excluded because of pronounced differences between all three methods. One person was later diagnosed as having a nasal septum deviation. Recordings with any kind of technical problem were also excluded. RESULTS: In total 516 minutes were analysed. Students' paired t-test showed a mean of 0.5 and 0.3 more breaths were recorded by fibre-optical monitor compared with the manual method and capnography respectively. The 95% confidence interval of the differences between the fibre-optical monitor and the other two methods was -0.5 to +1.5 when the mean respiratory frequency was 14 breaths per minute. Analysis of variance revealed that the fibre-optical monitor tended to overestimate the mean respiratory rate (p < 0.001). CONCLUSION: The fibre-optical monitor has sufficient accuracy for clinical monitoring. It is easy to use and inexpensive. Combinations with pulse oximetry seem attractive, to use especially for application outside "high tech areas," for example when respiratory depressant drugs are used or in ambulances.

Adolescent↗

PubMed1999

The measurement of respiratory and metabolic parameters of patients and controls before and after incremental exercise on bicycle: supporting the effort syndrome hypothesis?

Hyperventilation (HV) occurring out of appropriate context, under some circumstances, can be potentially harmful to health. Nixon (1994) discusses convincingly the negative effects of long-term HV on the alkaloid buffering system and the potential challenge to a person's health status. Using capnography to measure respiration, percent expired CO2, to determine the anaerobic threshold during incremental exercise (the Effort Test), Nixon (1994) documented the onset of metabolic acidosis followed by alkalosis, secondary to the alkaloid buffering system response. Nixon (1994) hypothesized that recurring HV can lead to depletion of the alkaloid buffering system. By combining capnography, during the Effort Test, with analysis of blood gases and specific electrolytes, the effort-syndrome hypothesis was further tested in the present study. Thirteen patients with various kinds of stress-related problems were compared with four control participants. Pretest blood gases, from capillary blood, were collected after 10 minutes rest and 10 minutes of incremental exercise. Exhalation CO2, oxygen saturation, and traditional psychophysiological parameters were measured continuously during the experimental condition. Data from capillary blood and exhalation CO2 are reviewed. Change in patients' alkali buffering system supports the prediction made by Nixon (1994). The complexity of the data as well as methodological procedures of this study warrant a more sophisticated design, with more clearly defined functional analysis.

Adult↗

PubMed2002

Gastroenterologist-administered propofol versus meperidine and midazolam for advanced upper endoscopy: a prospective, randomized trial.

BACKGROUND & AIMS: Propofol is increasingly used for gastrointestinal endoscopy because of its rapid recovery profile. There has been no prospective, randomized comparison of gastroenterologist-administered propofol to meperidine and midazolam for endoscopic retrograde cholangiopancreatography and endoscopic ultrasonography. Additionally, its cost-effectiveness has not been studied. METHODS: Seventy-five randomized patients received either gastroenterologist-administered propofol (n = 38) or meperidine/midazolam (n = 37) for endoscopic retrograde cholangiopancreatography and endoscopic ultrasonography. Monitoring with capnography allowed for rapid titration of propofol at the earliest signs of respiratory depression. Visual analogue scales measured tolerance and satisfaction. A cost-effectiveness analysis was performed by using return to baseline for both activity and food intake 24 hours after the procedure as the effectiveness measure. RESULTS: The groups had similar physiological outcomes and satisfaction. Patients receiving propofol had shorter recovery times (P < 0.001) and a higher recovery of both baseline activity level and dietary intake 24 hours after the procedure (P = 0.028). With incremental cost-effectiveness analysis, gastroenterologist-administered propofol cost an additional $403.00 per additional patient at 100% of baseline for both activity level and food intake when compared with standard sedation and analgesia. Sensitivity analysis indicated that the only model in which propofol administration would become the dominant strategy was with its administration by a registered nurse. CONCLUSIONS: Gastroenterologist-administered propofol using monitoring with capnography is similar to meperidine/midazolam for both physiological outcomes and patient/endoscopist satisfaction. Propofol leads to significantly improved recovery of baseline activity and food intake 24 hours after the procedure. Our model suggests that propofol would be more cost-effective than meperidine and midazolam for endoscopic retrograde cholangiopancreatography and endoscopic ultrasonography if registered nurse administration were possible.

Analgesics, Opioid↗

PubMed1994

[Pneumothorax in laparoscopic cholecystectomy (II)].

This case report deals with pneumothorax during elective laparoscopic cholecystectomy in a young woman with no history of severe pulmonary disease. After inflating the capnoperitoneum, pulse oximetry and capnography raised suspicion of pneumothorax whereas the physical examination showed no irregularities. Surgical drapes provided a lack of information from percussion and auscultation. Changing respiratory parameters including the use of pressure-controlled ventilation in absence of tension pneumothorax enabled sufficient ventilation until the insertion of a chest tube. There were no further postoperative complications. Pulse oximetry, capnography and relaxometry proved helpful in monitoring. There may be a benefit from the use of pressure-controlled-ventilation in certain situations, if all changes in volume-controlled-ventilation fail.

Carbon Dioxide↗

PubMed1993

Experimental evaluation of two new sensors for respiratory rate monitoring.

Visual observation was chosen as the reference method for measuring the respiratory rate in ten healthy volunteers. The new fibre-optic and acoustic sensors were simultaneously compared with capnography and transthoracic impedance plethysmography during normoventilation in the respiratory rate range of 6-24 breaths per minute and at a fixed respiratory rate of 13 breaths per minute. In addition a simulation of central apnoea was performed. All the measurements were recorded on an analogue tape recorder and a strip-chart recorder and analysed off line. The analyses of the recordings were performed by a person who was unable to see the monitoring systems. There was no discrepancy in the results of these methods. Each of the methods responded rapidly to an apnoeic event. The new fibre-optic and acoustic sensors correlate well with more traditional methods such as capnography and transthoracic impedance plethysmography for respiratory rate monitoring.

Acoustics↗