Use of a Beck Airway Airflow Monitor and controllable-tip endotracheal tube in two cases of nonlaryngoscopic oral intubation.

Alternative techniques and equipment for intubation may be particularly useful in settings such as air-medical transport, prehospital on-scene care, mass casualty incidents, or incidents in which there may be a lack of medications or equipment. Once traditional techniques of endotracheal intubation and tube verification have been mastered, emergency medicine residents and other intubators should be encouraged to learn alternative techniques, such as these, that may be of use in some special situations, even within the ED. Neither of these two techniques of BAAM-assisted blind oral intubation can be considered essential, nor should it be contended that these techniques supplant learning of more conventional methods of endotracheal intubation and tube placement verification. However, particularly in the setting of residency training, multiple methods of endotracheal intubation should be taught in order to allow the clinician alternative methods if unable to intubate by traditional means in a particular setting. Use of a BAAM to assist in blind oral intubation of a spontaneously breathing patient may allow for oral intubation of awake patients without the additional use of paralytic medications. Use of the BAAM with a digital technique during external cardiac massage may facilitate intubation by the digital technique and help to verify endotracheal tube position. These two additional uses for the BAAM should be noted and these two additional methods of airway control be recognized as backup methodologies in the armamentarium for situations in which they may be needed.

Small intrapulmonary artery lung prototypes: design, construction, and in vitro water testing.

Blind-ended, hollow fibers mounted on a pulmonary artery catheter may allow O2 and CO2 transfer in the vena cava, right ventricle, and pulmonary artery. The effects of fiber length, manifold number, and gas oscillation on mass and momentum transfer with water perfusate using mass spectrometry and mass flow controllers were studied. Manifolds with 112-196 microporous polypropylene fibers were mounted on 8 Fr multiple lumen, commercially available pulmonary artery catheters. Fiber lengths varied from 0.5 to 16 cm and surface areas from 7 to 220 cm2. Prototypes with 2 cm long fibers were constructed with 1-15 manifolds. A two manifold prototype with 8 cm long fibers and a surface area of 378 cm2 was also studied. The transfer failed to scale with manifold number because the steady gas flow was maldistributed to the manifolds. Oscillating gas pressures from 780 to 76 mmHg absolute at a rate of 40 cycles/min increased CO2 transfer up to 15-fold and O2 transfer up to 2.5-fold. Oscillation also corrected the maldistribution. Optimal fiber lengths of 3 and 1 cm for O2 and CO2, respectively, were seen with steady gas flow, and 8 cm for both with oscillatory gas flow.

The BAAM and endotrol endotracheal tube for blind oral intubation. Beck Airway Air Flow Monitor.

Blind oral intubation in a spontaneously breathing patient can be facilitated with a combination of two devices used mainly for nasotracheal intubation, the BAAM (Beck Airway Air Flow Monitor, Great Plains Ballistics, Lubbock, TX) and the Endotrol endotracheal tube (Mallinckrodt Critical Care, Inc., St. Louis, MO). We describe a case in which intubation of a spontaneously breathing intensive care unit patient was unsuccessful by traditional methods. In the successful approach we describe, the tube was passed through the oral cavity and pharynx in a blind fashion, using the BAAM's whistling sound for guidance and the plastic ring of the Endotrol tube to help positioning. This equipment combination may be useful in certain difficult intubation situations.

Clinical trials of an intravenous oxygenator in patients with adult respiratory distress syndrome.

In patients with severe adult respiratory distress syndrome, mechanical ventilation may not be able to ensure gas exchange sufficient to sustain life. We report the use of an intravenous oxygenator (IVOX) in five patients who were suffering from severe adult respiratory distress syndrome as a result of aspiration, fat embolism, or pneumonia. IVOX was used in an attempt to provide supplemental transfer of CO2 and O2 and thereby reduce O2 toxicity and barotrauma. All patients were tracheally intubated, sedated, and chemically paralyzed and had a PaO2 < 60 mmHg when the lungs were ventilated with an FIO2 = 1.0 and a positive end expiratory pressure of > or = 5 cmH2O. The right common femoral vein was located surgically, and the patient was systemically anticoagulated with heparin. A hollow introducer tube was inserted into the right common femoral vein, and the furled IVOX was passed into the inferior vena cava and advanced until the tip was in the lower portion of the superior vena cava. IVOX use ranged from 2 h to 4 days. In this group of patients, IVOX gas exchange ranged from 21 to 87 ml x min-1 of CO2 and from 28 to 85 ml x min-1 of O2. One of the five patients survived and was discharged from the hospital. The IVOX transferred up to 28% of metabolic gas-exchange requirements. One patient with a small vena cava showed signs of caval obstruction. Three other patients demonstrated signs of a septic syndrome after the device was inserted.(ABSTRACT TRUNCATED AT 250 WORDS)

Trauma anesthesia and critical care: the concept and rationale for a new subspecialty.

Proper care of the severely injured patient will require the development of a new anesthesia specialist. The trauma anesthesiologist, like the cardiovascular anesthesiologist, must become thoroughly familiar with one disease. The anesthesiologist who manages patients with traumatic disease must become an expert in critical care, high-risk anesthesia practice, and emergency resuscitation of the trauma patient. An outline for a fellowship in trauma anesthesia and critical care is included.

Renal failure in the trauma patient.

Acute renal failure is a serious complication of the resuscitation and post-traumatic critical care of the severely injured patient. Renal ischemia secondary to shock is the most common cause of post-traumatic renal failure. The unrecognized or untreated renal ischemic state can lead to nephrotoxic damage in the post-traumatic patient. Prevention of acute failure by rapid resuscitation and restoration of circulating volume to prevent ongoing renal ischemia and prerenal azotemia is imperative for reducing the incidence of post-traumatic renal failure. Once post-traumatic renal failure is established, aggressive dialysis can reduce the mortality resulting from post-traumatic renal failure.

Airway management: considerations in the trauma patient.

The five components integral to modern, sophisticated airway management in trauma patients include equipment, pharmacologic adjuncts, manual techniques, physical circumstances, and patient profile. Although there is a finite number of pieces and types of equipment, pharmacologic adjuncts, and manual techniques, the last two components are variable. For purposes of brevity and clarity, this article has presented definitive airway management in terms of a well-organized, fully-equipped admitting (resuscitation) area of a trauma center, but a trauma patient may require airway management in a variety of physical circumstances, including the field, the transport vehicle, and numerous locations within the trauma center. We believe that the commonly used airway management algorithms are a poor substitute for a conceptual understanding of the basic principles of the five components of airway management, although these decision trees may be useful as learning tools. The construction of a truly complete decision tree is virtually impossible because of the high number of individual patient profiles.

General anesthesia: management considerations in the trauma patient.

Endotracheal intubation and mechanical ventilation are vital components of the resuscitation of the most seriously injured patients and those suffering from multisystem trauma. Therefore, general anesthesia administered both intravenously and endotracheally becomes the anesthetic of choice for most of this patient population. Endotracheal intubation and anesthetic induction techniques are designed to protect the patient's cervical spinal cord from injury and his or her airway from aspiration of gastric contents. Anesthetic drugs are chosen to minimize cardiovascular depression, to maximize oxygen delivery to the tissues, and to decrease intracranial pressure. Monitoring techniques include the basic noninvasive monitoring set forth in the American Society of Anesthesiologist's standards, as well as invasive cardiac monitoring via arterial catheters and pulmonary artery catheters. Attention to detail in the recovery room will continue the success of a well-conducted general anesthetic for the trauma patient.

Nalbuphine analgesia in the prehospital setting.

Forty-six patients with moderate to severe pain caused by orthopedic injuries, burns, multiple trauma, or intraabdominal conditions were treated with intravenous (IV) nalbuphine hydrochloride (Nubain; DuPont Pharmaceuticals, Wilmington, DE) by paramedics before arrival at the hospital. Patients who weighed less than 60 kg received 15 mg nalbuphine, and patients weighing greater than 60 kg received 20 mg nalbuphine. Forty-one of 46 patients (89%) experienced pain relief from nalbuphine, with maximum relief occurring within 15 minutes after the administration of the drug. Two addicted patients received no pain relief. There were no untoward side effects following nalbuphine administration, and the patients' heart rates, mean arterial pressures, and respiratory rates remained constant and stable throughout the study period. Repeated assessment of the patient by paramedics in the field was not impaired by nalbuphine treatment. In summary, nalbuphine hydrochloride is a useful and safe analgesic drug for IV use by paramedics in the prehospital setting.

Increased cardiac output following occlusion of the descending thoracic aorta in dogs.

Occlusion of the thoracic aorta (AO) in dogs with a constant volume right ventricular extracorporeal bypass increased cardiac output (Q) by 43% and mean arterial pressure by 46%, while mean systemic pressure (MSP) was unchanged. We compared AO with occlusion of the brachiocephalic and left subclavian arteries (BSO) which decreased cardiac output by 5%, increased mean arterial pressure by 32%, and increased MSP by 11%. We feel these results confirm that AO elevates preload by transferring blood volume from the splanchnic veins to the vascular system drained by the superior vena cava. If the heart is competent to keep right arterial pressure at or near zero, this increase in preload will elevate Q above control levels. Comparing our data with results of other authors who have not controlled right atrial pressure, emphasizes the importance of a competent right ventricle in allowing venous return to determine Q.

Changes in lung membrane diffusing capacity for oxygen produced by halothane.

The effect of halothane on membrane diffusing capacity for O2 (DMO2) was measured in isolated left lower lobes of dog lungs using the sodium dithionite method. At 25 degrees C, halothane reduced DMO2 according to the regression equation: per cent control DMO2 = -4.85(per cent halothane) + 97.5 (r = -0.55, P = 0.0007). Although DMO2 was reduced from control by halothane administration, lung volume (VL) increased at higher halothane concentrations and tended to restore DMO2 by increasing surface area. There was a better correlation between the DMO2/VL ratios and per cent halothane: per cent (DMO2/VL) = -5.76 (per cent halothane) + 95.6 (r = -0.65, P = 0.00003). Effects of halothane on DMO2 and VL were reversible and were not influenced by gas mixing efficiency since argon dilution half-times over two decades were unchanged by halothane. It is unlikely that altered vascular recruitment affected the measured DMO2 since resistance to blood flow was unchanged. We conclude that halothane decreases DMO2 by either decreasing the physical diffusion coefficient (D') for O2 or decreasing the effective O2 solubility (alpha), or both, in the alveolar-capillary membrane.