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Biomedical subjects

Carin A Hagberg

Publications and source records attributed to Carin A Hagberg.

14 recordsLinked to original sources

Comparison of direct and video-assisted views of the larynx during routine intubation.

OBJECTIVE: To compare the direct and indirect (video monitor) views of the glottic opening using a new Macintosh blade that is modified to provide a video image of airway structures during laryngoscopy. DESIGN: Prospective multicenter trial. SETTING: 11 university-affiliated hospitals. PATIENTS: 867 adults undergoing elective surgery requiring general anesthesia and tracheal intubation. INTERVENTIONS: Patients received general anesthesia and were paralyzed. Direct laryngoscopy was supervised by one of the investigators at each institution. The best possible view was obtained with a Macintosh video laryngoscope during direct vision using standard techniques such as external laryngeal manipulation and backward, upward, and rightward pressure, if necessary. The laryngoscopist then looked at the video monitor and performed any necessary maneuvers to obtain the best view on the video monitor. Thus, 2 assessments were made during the same laryngoscopy (direct naked-eye view vs video monitor view). Tracheal intubation was then performed using the monitor view. Glottic views were rated according to the Cormack-Lehane scoring system, as modified by Yentis and Lee. A questionnaire was completed for each patient. MEASUREMENTS AND MAIN RESULTS: Data from 865 patients were suitable for analysis. Visualization was considered easy (Cormack-Lehane score<3) in 737 patients and difficult (Cormack-Lehane score=3 or 4) in 21 for both direct and video-assisted views. In 7 patients, the view was considered easy during direct visualization yet difficult on the video monitor view. On the other hand, the view was considered difficult in 100 patients during direct visualization yet easy on the video monitor view (P<0.001). CONCLUSIONS: Video-assisted laryngoscopy provides an improved view of the larynx, as compared with direct visualization. This technique may be useful for cases of difficult intubation and reintubation as well as for teaching laryngoscopy and intubation.

Adult↗

A multicenter study of the Ambu laryngeal mask in nonparalyzed, anesthetized patients.

We designed this multicenter trial to evaluate the performance and safety of the Ambu laryngeal mask, a new disposable supraglottic airway device, in patients scheduled for elective surgery. One-hundred-eighteen nonparalyzed, anesthetized patients (ASA physical status I-II, age, 18-65 yr, body mass index, 18-30 kg/m(-2)) receiving total IV anesthesia were included in this study. After device insertion, fiberoptic position and oropharyngeal leak pressure were determined at an intracuff pressure of 60 cm H2O. Ease of ventilation was determined by controlling ventilation at 6 mL/kg tidal volume. Any complications were noted and recorded. Device placement was successful in all patients on the first or second attempt (92.4% or 7.6%, respectively) with an insertion time (removal of face mask until first tidal volume) of 44.9 +/- 37.91 s. Adequate ventilation was achieved in all patients and the vocal cords could be visualized by fiberoptic endoscopy in 91.5% of patients. Oropharyngeal leak pressures were 24.1 +/- 5.44 cm H2O. Blood was detected on the device in 8.5% of patients. Complications and patient complaints were minor and quickly resolved. The Ambu laryngeal mask is easy and quick to insert and provides a safe and efficient seal during positive pressure ventilation in nonparalyzed patients scheduled for elective surgery.

Adolescent↗

The incidence of gastroesophageal reflux and tracheal aspiration detected with pH electrodes is similar with the Laryngeal Mask Airway and Esophageal Tracheal Combitube--a pilot study.

PURPOSE: Aspiration as a result of gastroesophageal reflux (GER) and regurgitation remains a serious potential problem in anesthetized patients. The incidence of GER with either the Esophageal Tracheal Combitube (ETC) or the laryngeal mask airway (LMA) was investigated using tracheal and esophageal pH electrodes. METHODS: Following approval by the Institutional Review Board and written informed consent, 57 patients of ASA physical status I to III were randomly assigned to receive either an LMA (Group I, n = 28) or an ETC (Group II, n = 29) during general anesthesia. All patients were paralyzed and received positive pressure ventilation. Two monocrystalline antimony catheters were used for pH monitoring: one unipolar catheter with a single pH sensor for tracheal pH measurements and one bipolar catheter with proximal and distal sensors for pharyngeal and esophageal pH measurements, respectively. RESULTS: One episode of GER occurred in a patient in Group II, yet there were no pH changes reflected in the oropharyngeal or tracheal regions. There were 3/25 (12%) patients in Group I vs 1/25 (4%) patients in Group II that met the pH criterion for aspiration (pH below 4.0 that lasted at least 15 sec), yet no patient developed any clinical signs of aspiration. In all patients, hemodynamic and respiratory variables remained stable throughout the period of measurement (data not included). CONCLUSION: In this pilot study, the ETC appears comparable to the LMA regarding the incidence of GER and tracheal acid aspiration.

Adult↗

A randomized controlled trial comparing the ProSeal Laryngeal Mask Airway with the Laryngeal Tube Suction in mechanically ventilated patients.

BACKGROUND: The ProSeal Laryngeal Mask Airway (PLMA) (Laryngeal Mask Company, Henley-on-Thames, United Kingdom) is a new laryngeal mask with a modified cuff designed to improve its seal and a drain tube for gastric tube placement. Similarly, the Laryngeal Tube Suction (LTS) (VBM Medizintechnik Gmbh, Sulz a.N, Germany) is a new laryngeal tube that also has an additional channel for gastric tube placement. This study compared the placement and functions of these two devices. METHODS: One hundred fifty patients undergoing general anesthesia for elective surgery were randomly allocated to the PLMA (n = 75) or LTS (n = 75). Oxygenation and ventilation, ease of insertion, fiberoptic view, oropharyngeal leak pressure, ventilatory data, ease of gastric tube insertion, and postoperative airway morbidity were determined. RESULTS: After successful insertion of the devices in 96% of patients with the PLMA and in 94.4% with the LTS it was possible to maintain oxygenation, ventilation, and respiratory mechanics during the entire duration of surgery. Successful first and second attempt insertion rates were 57 patients (76%) and 15 patients (20%), respectively, for the PLMA and 60 patients (80%) and 11 patients (14.6%), respectively, for the LTS. Airway placement was unsuccessful with the PLMA in three patients and with the LTS in four patients. Time to achieve an effective airway was 36 +/- 24 s with the PLMA versus 34 +/- 25 s with the LTS. Gastric tube insertion was possible in 97.3% of patients with the PLMA and in 96% with the LTS. CONCLUSIONS: With respect to both physiologic and clinical function, the PLMA and LTS are similar and either device can be used to establish a safe and effective airway in mechanically ventilated anesthetized adult patients.

Adult↗

A new supraglottic airway, the Elisha Airway Device: a preliminary study.

We describe the Elisha Airway Device (EAD), a new reusable supraglottic ventilatory device. Its uniqueness consists of its ability to combine three functions in a single device: ventilation, blind and/or fiberoptic-aided intubation without interruption of ventilation, and gastric tube insertion. This study was performed in 70 ASA status I-II, Mallampati class I-II patients undergoing elective knee arthroscopy and receiving general anesthesia with mechanical ventilation. Anesthesia was induced with fentanyl and propofol and was maintained with isoflurane in N20/oxygen. Neuromuscular blockade was achieved with vecuronium. Blind insertion of the device was successful in 96% of patients, with a mean insertion time of 20 +/- 4 s. In these patients it was possible to maintain oxygenation and ventilation throughout the surgical procedure. Gastric tube insertion was successful in all cases. Endotracheal intubation via the EAD was attempted in 20 patients. Blind intubation was possible during the first and second attempts in 15 and 2 patients, respectively. Fiberoptic intubation was then successful in two of the remaining three patients. The EAD is a new alternative in the evolution of supraglottic ventilatory devices; however, further clinical studies are necessary to evaluate its efficacy.

Adult↗

Instruction of airway management skills during anesthesiology residency training.

BACKGROUND: Difficult airway management is a critical aspect of anesthesiology training and practice. A survey was conducted of American anesthesia residency programs to determine the prevalence of a specific airway rotation and its curriculum. METHODS: A questionnaire was sent by both e-mail and fax to all 132 directors of American anesthesiology residency programs. RESULTS: Of the 132 programs surveyed, 79 (60%) responded. Of the responders, 26 programs (33%) have a difficult airway rotation. The rotation was offered throughout the years of clinical training in 13 (49%) of the programs and was of 1-week duration in 16 (61%) of these programs who had a rotation. Formal instruction was administered before the rotation in 18 (69%) of the programs. Instruction was usually performed on surgical patients in 22 (85%) of the program, ASA status I and II patients in 20 (77%) of the programs, and taught by selected faculty in 20 (78%) of the programs. There was a 2- to 5-minute time limitation or a number of maximum attempts when using any of these devices in 16 (62%) programs. There was a case number requirement regarding the use of the devices in 5 (19%) of the programs. Residents were evaluated by both skills testing and written evaluation in 63% of these programs. DISCUSSION: Of the programs with an airway rotation, the flexible fiberoptic bronchoscope and the laryngeal mask airway represent the most frequently used devices, excluding the standard laryngoscopes. There is minimum emphasis on more invasive techniques. Traditional methods of instruction continue to be utilized more frequently than nontraditional methods.

Anesthesiology↗

Difficult airway management practice patterns among anesthesiologists practicing in the United States: have we made any progress?

STUDY OBJECTIVE: To determine the extent instruction and practice in the use of airway devices and techniques varies among anesthesiologists practicing in the United States. DESIGN: Survey questionnaire. SETTING: University medical center. MEASUREMENTS: Questionnaires were completed by American-trained anesthesiologists who attended the 1999 American Society of Anesthesiologists (ASA) Annual Meeting. Data collected included demographics, education, skills with airway devices/techniques, management of clinical difficult airway scenarios, and the use of the ASA Difficult Airway Algorithm. MAIN RESULTS: 1) DEMOGRAPHICS: 452 questionnaires were correctly completed; 62% attending anesthesiologists, 70% <50 years, 81% males, 44% from academic institutions, 63% >10 years of practice, 81% night duty, 77% board certified. 2) Education: 71% had at least one educational modality: difficult airway rotation, workshops, conferences, books, and simulators. 3) Skills: Miller blade 61%, Bullard laryngoscope 32%, LMA 86%, Combitube 43%, bougie 43%, exchangers 47%, cuffed oropharyngeal airway (COPA) 34%, retrograde 41%, transtracheal needle jet ventilation 34%, cricothyrotomy 21%, fiberoptics 59%, and blind nasal intubation 78%. The average reported use of special airway devices/techniques was 47.5%. 4) Management choices: failed intubation/ventilation: LMA (81%) and for all other situations: fiberoptic intubation. Use of ASA Difficult Airway Algorithm in clinical practice (86%). CONCLUSION: Fiberoptic intubation and the LMA are most popular in management of the difficult airway.

Anesthesia, Conduction↗

A two-person technique for fiberscope-aided tracheal extubation/reintubation in intensive care unit (ICU) patients.

The technique of fiberoptic-aided intubation for management of a difficult airway is often limited in the presence of blood or secretions and conditions in which the passage of a fiberoptic bronchoscope ("fiberscope") beneath the epiglottis and into the glottic opening may prove difficult. Direct laryngoscopy can be utilized in combination with the fiberscope as a two-person technique to overcome these challenges. We report the usefulness of a two-person technique using the flexible fiberscope in combination with direct laryngoscopy for extubation/reintubation in two intensive care unit patients with known difficult airways.

Adult↗

Effective use of the esophageal tracheal Combitube following severe burn injury.

We present the case of a patient status post previous burn injury, undergoing elective surgery in which the Combitube was used because contractural formation of the mouth and tracheal stenosis precluded tracheal intubation. The Combitube proved to be highly successful in this patient who had a very limited mouth opening.

Anesthesia, General↗

An evaluation of the Laryngeal Tube during general anesthesia using mechanical ventilation.

UNLABELLED: The Laryngeal Tube is a new supraglottic ventilatory device for airway management. It has been developed to secure a patent airway during either spontaneous or mechanical ventilation. In this study, we sought to determine the effectiveness of the Laryngeal Tube for primary airway management during routine surgery with mechanical ventilation. One-hundred-seventy-five subjects classified as ASA physical status I and II, scheduled for elective surgery, were included in the study. After the induction of general anesthesia and insertion of a Size 4 Laryngeal Tube, measurements of oxygen saturation, end-tidal CO(2) and isoflurane concentration, and breath-by-breath spirometry data were obtained every 5 min throughout surgery. The lungs were ventilated with volume-controlled mechanical ventilation. The number of attempts taken to insert the Laryngeal Tube and the insertion time were recorded. In 96.6% of patients, it was possible to maintain oxygenation, ventilation, and respiratory mechanics by using mechanical ventilation throughout the surgical procedure. The results of this study suggest that the Laryngeal Tube is an effective and safe airway device for airway management in mechanically ventilated patients during elective surgery. IMPLICATIONS: In 96.6% of patients intubated with the Laryngeal Tube, it was possible to maintain oxygenation, ventilation, and respiratory mechanics during mechanical ventilation.

Adolescent↗

Special devices and techniques.

Management of the difficult airway remains one of the most challenging tasks for anesthesia care providers. Most airway problems can be solved with relatively simple devices and techniques, but clinical judgment borne of experience is crucial to their application. As with any intubation technique, practice and routine use improve performance and may reduce the likelihood of complications. Each airway device has unique properties that may be advantageous in certain situations, yet limiting in others. Specific airway management techniques are greatly influenced by individual disease and anatomy, and successful management may require combinations of devices and techniques.

Anesthesia↗

Training of residents in peripheral nerve blocks during anesthesiology residency.

STUDY OBJECTIVE: To survey American anesthesiology residency program directors to determine the availability and extent of training in peripheral nerve block techniques. DESIGN: Survey questionnaire was mailed and faxed to 132 American anesthesiology residency program directors and followed up 4 weeks later with another mailing to nonresponders. SETTING: University medical center. MEASUREMENTS AND MAIN RESULTS: Of the 132 American anesthesiology residency program directors surveyed, 69 (52%) responded. Of the responders, 40 (58%) offered a specific peripheral nerve block rotation. The rotation was of 1 month's duration in 61% of these programs. Formal instruction was administered during the rotation in 69%. The regional instruction approach consisted of a nerve stimulator (98%), paresthesia (75%), and transarterial (85%). Multimedia, mannequins, and cadaver dissection were used infrequently (13-25%). During the rotation, residents performed a variety of blocks, but the number of each block varied from 2 (supraclavicular) to 10 (axillary). These blocks were performed in the operating room in 48% of programs. Finally, in the programs with a specific peripheral nerve block rotation, residents were evaluated. CONCLUSIONS: Specific peripheral nerve block rotations are not always included in anesthesiology residents' curriculum. In addition, residents in programs with a specific nerve block rotation are exposed to a greater number of peripheral nerve block techniques than those who do not have such a rotation included in their curriculum.

Academic Medical Centers↗