Differential lung ventilation and emergency hyperbaric oxygenation for repair of a tracheal tear.

PURPOSE: To report the anaesthetic management of a case of tracheal rupture, using different types of ventilation and additional hyperbaric oxygenation (HBO). CLINICAL FEATURES: An 8 cm postintubation tracheal tear was repaired in a 66-yr-old woman with acute myocardial reinfarction, mediastinal and subcutaneous emphysema, cardiac failure and unrecognized lymphoma. Intraoperative monitoring included dual oximetry: arterial (SaO2) and mixed venous saturations (SvO2). Maintenance of free surgical access and a series of life-threatening events like dislocation of the jet catheter required many ventilation modes. An episode of supraventricular tachycardia was interrupted by cardioversion. Differential lung ventilation with a combination of conventional and high-frequency jet ventilation (HFJV) modes preserved oxygenation (PO2 139.2 mm Hg, PCO2 42.4 mm Hg, FiO2 1.0) until acute tube obstruction and decrease of saturation values (SaO2 58%, SvO2 45%) required emergency HBO: immediate cardiac and respiratory stabilization was provided by double-lung HFJV and apneic oxygenation under hyperbaric conditions at 2.5 atmospheres absolute for 35 min (SaO2 100%). The patient recovered from surgery but died of non-Hodgkin lymphoma. CONCLUSION: The combination of different ventilation modes including HFJV and the additional use of HBO resulted in sufficient oxygenation during tracheal repair.

Fiberoptic intubation in 327 neurosurgical patients with lesions of the cervical spine.

In patients with lesions of the cervical spine, direct laryngoscopy for endotracheal intubation entails the risk of injuring the spinal cord. In an attempt to avoid this complication, the authors used flexible fiberoptic nasal intubation in a series of 327 patients with cervical lesions undergoing elective neurosurgical procedures. The nasal route was preferred for laryngeal intubation because it is easier than the oral route and a restraining collar or halo device does not impair the intubating maneuver. Bronchoscopic intubation was possible in all patients. In 12 patients (3.6%), anatomic abnormalities prevented transnasal insertion of the endotracheal tube, and transoral fiberoptic intubation was necessary. Endotracheal intubation was graded as slightly difficult in 85 patients (26%). The minimal peripheral oxygen saturation during intubation exceeded 90% in 289 patients (88%). In the other 38 patients, the mean O2 saturation was 84.2+/-4.3% (range, 72-89%). Intubation was well tolerated by all patients and none had recall of the procedure. Cervical stabilizers did not have to be removed for intubation in any patient. None of the patients had postoperative neurologic deficits attributable to the intubation procedure. The authors consider fiberoptic transnasal intubation to be a useful alternative to direct laryngoscopic tracheal intubation in patients undergoing elective surgical procedures on the cervical spine to avoid potential injury to the cervical spinal cord.

[Preclinical blood gas analysis. 2. Experience with three blood gas analyzers in emergency care]. / Die präklinische Blutgasanalyse. Teil 2: Erfahrungen mit 3 Blutgasanalysegeräten im Notarztdienst.

UNLABELLED: Within the last few years the use of Point-of-Care Analyzers increased. These testing is primarily performed in the emergency room, intensive care units, and in the operating room using small portable analyzers. The fact of being transportable and working with rechargeable or changable batteries and disposable cartridges caused us to use blood gas analysis in the prehospital setting. METHODS: We tested three available blood gas analyzers: AVL OPTI 1, IRMA Blood Analyzer and the i-Stat Portlab System. All analyzers work with single-use cartridges and the calibration procedure is automatic. The AVL OPTI 1 uses a calibration gas and sucks in the blood by itself. The IRMA and the i-Stat system use a containing calibration gel, which must be removed from the sensory by injecting the blood sample. In all analyzers the results appear within 2-4 min on the screen. The OPTI 1 and the IRMA are able to print out the results automatically, the i-Stat uses an additional printer connected over an infrared adapter. RESULTS: During the observation period of 2 years more than 320 prehospital blood gas analyses were performed (200 with the OPTI 1.70 with IRMA and 50 with the i-Stat). All devices served their purpose. The main problems appeared with the application of the blood samples at the IRMA and the i-Stat. Because of this intricate procedures 21.4% and 20% of all tries failed. The time spent on the measurement was 2 to 5 minutes. CONCLUSIONS: All tested devices worked satisfactorily. Relating to the safety, the performance and the use the AVL OPTI 1 has to become the best notes. But this system is much more bigger and heavier than the others, especially the i-Stat Blood analyzer.

Doppler color-flow imaging: screening of a patent foramen ovale in children scheduled for neurosurgery in the sitting position.

A patent foramen ovale (PFO) is the most common cause of paradoxical air embolism during neurosurgical procedures in the posterior fossa in the sitting position in both adults and children. To detect right-to-left shunting, we performed Doppler color-flow imaging preoperatively in 30 children scheduled for neurosurgical procedures in the sitting position. A PFO was diagnosed on the basis of color alterations indicating an immediate blood shunt through a PFO. Six of 30 children (20%) had a PFO; in 4 of these children the sitting position then was avoided, and 2 children were operated on in a special supine position with minimal elevation of the head. Venous air embolism occurred in 9 of 24 (37%) children operated on in the sitting position and in none of the 6 children operated on in a nonsitting position. We conclude that Doppler color-flow mapping could be a useful noninvasive technique to screen children scheduled for neurosurgery in the sitting position for the presence of a PFO.

[Education of the medical student in first aid, emergency and disaster medicine--the Graz model]. / Die Ausbildung des Medizinstudenten in Erster Hilfe, Notfall- und Katastrophenmedizin--Modell Graz.

In Austria emergency and disaster medicine is a young interdisciplinary subject. It is only a borderline discipline encompassing different medical subjects and was subdivided into emergency medicine for medical doctors only and first-aid for lay people and emergency technicians. In fact, since emergency medicine without first-aid can't be successful, the Department of Anaesthesiology at the University of Graz let all students of the medical faculty have a comprehensive education in the treatment of injured of acutely ill patients. According to the three steps of the study lectures and practices, all parts of first-aid, emergency and disaster medicine were offered. In spite of the short time since this has been running, we found a good acceptance and we hope to increase the interest evinced by medical students in our training programme.

Sitting position for neurosurgery: experience with preoperative contrast echocardiography in 301 patients.

A persisting foramen ovale (PFO) is the most common cause of paradoxical air embolism. To detect right-to-left shunting, transthoracic contrast echocardiography was performed preoperatively in 301 patients scheduled for neurosurgical procedures in the sitting position. Echocardiography yielded evaluable results in 285 patients (94.7%). In 72 of 285 patients (25.2%), a PFO was diagnosed on the basis of contrast echo signals appearing in the left atrium or ventricle within 5 heart cycles after application of contrast medium via a peripheral vein. If echo signals appeared in the left heart after more than 5 heart cycles, an intrapulmonary right-to-left shunt was considered (11 patients, 3.9%). Venous air embolism (VAE) occurred in 27.4% of 226 patients operated on in the sitting position and in none of the 59 patients operated on in a nonsitting position. We conclude that the sitting position during neurosurgery should be avoided in patients with preoperative evidence of a right-to-left shunt at contrast echocardiography to reduce the risk of paradoxical air embolism (PAE).

[Right ventricular assist device (RVAD) in septic, fulminating pulmonary artery embolism]. / Right ventricular assist device (RVAD) bei septischer, fulminanter Pulmonalarterienembolie.

We describe a 34-year-old male with pulmonary embolism. The patient had been admitted to a peripheral hospital for incision and drainage of a very large ischio-rectal abscess. Four days after successful surgical intervention and during a change of dressings he developed a massive pulmonary artery embolism. The patient was transferred to the Department of Cardiac Surgery in Graz; on arrival he had a cardiac arrest. Resuscitation was initiated and the patient was transferred to the operating theatre where emergency sternotomy and embolectomy revealed large thrombotic masses in the pulmonary circulation. Extracorporeal circulation was initiated, but despite aggressive medical measures (dopamine, dobutamine, isoproterenol, enoximone, and prostaglandin E1 in maximum therapeutic doses) and a long reperfusion time weaning was not possible. Despite the septic state, a right ventricular assist device (RVAD; ABIOMED BVS 5000) was installed. Weaning was finally accomplished with a pump flow of 2.2 l/min m2 and the patient transferred to the intensive care unit. On post-operative day 3 the pump flow was reduced to 2 l/min. The patient's condition remained stable, which made removal of the RVAD possible on postoperative day 5. The further course was uneventful, with secondary ischio-rectal wound closure. His initial psychomotor impairment had nearly disappeared and he was discharged 2 months later.