Maciej Babinski

Percutaneous transtracheal ventilation

The technique of percutaneous transtracheal ventilation (intermittent jets of oxygen under high pressure, 50 pounds per square inch [psi]) has been used for resuscitation during anesthesia and prior to tracheostomy, and has been established as an important adjunct to life-support techniques. The technical aspects are described together with experimental evidence that intermittent jet ventilation is necessary to eliminate carbon dioxide. The complications occurring with a series of 80 patients are reported along with experimental work in ventilation of dogs with compressed air sources, including truck tires. Emergency physicians should be familiar with this technique and equipment for its use should be readily available in the emergency department. The potential role of transtracheal ventilation in the mobile intensive care unit at accident sites has been explored and appears promising. Conventional airway support techniques should be applied prior to resorting to transtracheal ventilation.

Clinical Application of Continuous Flow Apneic Ventilation

Continuous flow apneic ventilation (CFAV) was studied in five adult female patients. After induction of anesthesia with thiopental sodium (5 mg/kg) and fentanyl (5 μg/kg), and paralysis with pancuronium bromide (0.12 mg/kg), the patients were ventilated with oxygen at an FIO2 of 1.0 by face mask. Two polyethylene catheters (outside diameter [OD] 2.5 mm) were each inserted into the right and left mainstem bronchi. Each catheter had a curved tip measuring 2 cm in length. The angulation of the catheter tip from the axis was 20° for the right side and 30° for the left side. The endobronchial position was checked by fiberoptic bronchoscopy. Subsequently, tracheal intubation was performed using a 7.5 mm OD tracheal tube. CFAV was started when both catheters were connected to the gas delivery system. Humidified oxygen was delivered at total flows between 0.6 and 0.7 1/min. Arterial blood gases were analyzed every 5 min for 30 min. Monitoring included electrocardiogram, indirect blood pressure, heart rate, temperature, and peripheral nerve stimulation. Adequate oxygenation was maintained in all patients, 39.76 ± 4.32 kPa (299 ± 37 mmHg) at 30 min. There was a significant rise in Paco2 (P<0.05) at 30 min compared to the control, 4.92 ± 0.25 kPa compared to 7.30 ± 0.53 kPa (37.0 ± 1.9 mmHg compared to 54.9 ± 4.0 mmHg). There was a mean rise in Paco2 of 0.03 kPa/min (0.6 mmHg/min) compared to 0.5 kPa/min (3.8 mmHg/min) with apneic diffusion ventilation. In one patient there was no increase in Paco2 during the 30 min of CFAV. The results demonstrate that CFAV can maintain blood gases in a clinically useful range for as long as 30 min.

Limits of high frequency percutaneous transtracheal jet ventilation using a fluidic logic controlled ventilator.

A study was undertaken on dogs to find the limit of carbon dioxide exchange with high frequency jet ventilation using a fluidic logic controlled oxygen jet ventilator. Fifteen dogs were ventilated through a transtracheal catheter at respiratory rates up to 600 per minute. The following were recorded: aortic, pulmonary artery, pulmonary arterial wedge, and central venous blood pressures; intratracheal pressure; electrocardiogram; inspiratory and expiratory time of the jet; arterial and central venous blood gases; intermittent cardiac output.Normal gas exchange was found up to a respiratory rate of 400 per minute with low tidal volume and low intratracheal pressures. There were no adverse circulatory effects up to a rate of 400 per minute. At rates of 500 and 600 per minute, cardiac contractility was unaffected, but a decreased heart rate and increased peripheral resistance produced a fall in cardiac output. There was no interference with the resumption of spontaneous ventilation during weaning.In a control series of five dogs, apnoeic oxygenation was used. The PaCO2 was allowed to reach 15.96 kPa (120 torr). High frequency jet ventilation was then started at arate of 600 per minute and decreased in increments to 100 per minute. Arterial blood gases were continuously recorded through an intra-arterial catheter connected to a mass spectrometer. The PaCO2 gradually declined to normal levels as the rate decreased.RésuméCette étude a été entreprise dans le but de déterminer les limitations aux échanges du gaz carbonique survenant lors de la ventilation à haute fréquence réalisée par un ventilateur fluidique à jet ďoxygène et à contrôle logique. Quinze chiens ont été ventilés par cathéter transtrachéal à des fréquences allant jusqu’à 600 à la minute. Les paramètres qui suivent ont été enregistrés: la pression aortique, artérielle pulmonaire, capillaire bloquée et veineuse centrale; la pression intra-trachéale; ľélectrocardiogramme; la durée des phases inspiratoire et expiratoire de ľinjecteur; les tensions des gaz artériels et veineux; le débit cardiaque.On a trouvé que les échanges gazeux restaient normaux jusqu’à la fréquence de 400 à la minute avec des petits volumes courants et de basses pressions intratrachéales et qu’à ces fréquences, il n’y avait pas de perturbations circulatoires. La contractilité cardiaque n’a pas été affectée par des fréquences de 500 et 600 à la minute, mais une diminution de la fréquence cardiaque associée à une augmentation de la résistance périphérique a été à ľorigine ďune baisse du débit cardiaque. Le retour à la respiration spontanée n’a pas été entravé pendant le sevrage.Dans une série-contrôle de cinq chiens, on a eu recours à ľoxygénation apnéique et on a laissé la PaCO2atteindre 120 torr (15.96 kPa). On a alors débuté la ventilation à haute fréquence par injecteur à la fréquence de 600 à la minute en ralentissant progressivement par paliers de 100 torr (13.3 kPa). Les gaz artériels ont été constamment analysés par sonde artérielle branchée sur un spectomètre de masse. La PaCO2 s’est abaissée progressivement jusqu’à la normale parellèmenent à la diminution de la fréquence.

Continuous-flow Apneic Ventilation during Thoracotomy

Continuous-flow apneic ventilation (CFAV) by endobronchial insufflation of conditioned gas was evaluated in dogs during thoracotomy. In Group 1 (n = 6), dogs were anesthetized with pentobarbital (25 mg/kg). An endobronchial catheter (2.5 mm ID) was introduced into each mainstem bronchus using a fiberoptic bronchoscope and held in place by an endotracheal tube. Before the onset of CFAV (total flow 1.0 1 · kg-1 · min-1, the animals were paralyzed with pan-curonium bromide and muscle relaxation was monitored with a peripheral nerve stimulator. The CFAV delivery system consisted of a flow meter, air/oxygen blender, oxygen analyzer, heated humidifier, and ultrasonic spirometer. Blood gas values were measured after 30 min of spontaneous ventilation, and CFAV with: 1) closed chest, fractional inspired O2 concentration (FIO2) 0.21; 2) open chest, FIO2 0.21; 3) open chest, FIO2 0.21, continuous positive airway pressure (CPAP) 5 mmHg; and 4) open chest FIO2 0.4, CPAP 5 mmHg. This last combination resulted in a mean PaO2 of 113.1 ± 5.5 (SEM) mmHg and a PaCO2 of 35.0 ± 2.1 (SEM) mmHg. In Group 2 (n = 6), animals with open chests were ventilated with CFAV (FIO2 0.4 and CPAP 5 mmHg) for 5 h. Adequate oxygenation and ventilation were achieved. PaCO2 after 5 h of CFAV was 41.8 ± 1.9 (SEM) mmHg compared with 40.8 ± 1.9 (SEM) mmHg during spontaneous breathing. PaO2 after 5 h of CFAV was 138.1 ± 11.7 (SEM) mmHg. There were no significant changes observed in vascular pressures. Significant differences in other hemodynamic parameters were probably due to pentobarbital anesthesia. Adequate gas exchange can be achieved during CFAV in dogs with open chests for 5 h.

A method for ventilating patients during laryngoscopy

A method of ventilating patients during laryngoscopy was described in 40 patients. The technique used a combination of a small endotracheal tube and a high pressure oxygen jet with general anesthesia. A plastic chest tube 3.5 mm internal diameter (I.D.) was used as an endotracheal tube. The patients were ventilated with intermittent high pressure oxygen jet (50 p.s.i.) using a 1.5 mm I.D. intravenous plastic catheter introduced into the end of the endotracheal tube. Three holes were made in the proximal end of the endotracheal tube to permit air entrainment which was measured. Anesthesia was obtained with sodium thiamylal and In‐novar®. Muscular relaxation was maintained with succinylcholine. Arterial blood gases were monitored and showed adequate ventilation in the majority of the patients. In 18 patients the endotracheal pressure was measured. In two instances the pressure was elevated (35 cm H2O). No postoperative complications occurred. This technique was useful, safe, and well accepted by the surgeons. The authors consider that this technique avoids the disadvantages of conventional endotracheal anesthesia as well as those of the ventilating laryngoscope. It is contraindicated in patients with poor lung and chest wall compliance, particularly the obese. Subsequent to this study, 85 additional patients were similarly anesthetized without complications.

THE EFFECT OF LIDOCAINE ON SUCCINYLCHOLINE-INDUCED RISE IN INTRAOCULAR PRESSURE

SummaryThe effect of lidocaine on the increase of intraocular pressure induced by succinylcholine was studied in patients 6 to 85 years of age. Three groups of patients were studied. One group of eight patients received lidocaine 1 mg·kg-1 before succinylcholine and a control group of ten patients did not have lidocaine. Anaesthesia was induced with thiopentone 5 mg·kg-1 and maintained with nitrous oxide 50 per cent with oxygen and halothane 1.0-1.5 per cent. The tracheae of all patients were intubated.Lidocaine in doses of 1.0 to 2.0 mg·kg-1 did not prevent transient rise in intraocular pressure following administration of succinylcholine and tracheal intubation.RésuméĽétude porte sur trois groupes de patients et évalue ľeffet de ľinjection de lidocaíne sur ľaugmentation de la tension intraoculaire dgmentationclenchgmentatione par la succinylcholine. Un premier groupe de huit patients a reçu lidocaíne 1 mg·kg-1 avant la succinylcholine, un deuxième de dix patients, lidocaíne 2 mg·kg1 avant la succinylcholine, et un troisième de dix patients n’a reçu que la succinylcholine et a servi de contrôle. Ľanesthísie fut réalisée avec du thiopental 5 mgékg-1 suivi de protoxyde ďazote-oxygène à 50 pour cent avec halothane 1.0 à 1.5 pour cent. Tous les patients furent intubés.La lidocaíne aux doses de 1.0 à 2.0 mg·kg-1 n’a pas empêché ľaugmentation transitoire de la tension intraoculaire provoquée par ľadministration de succinylcholine et ľintubation trachéale.

Regional Organ Blood Flow during High-frequency Positive-pressure Ventilation (HFPPV) and Intermittent Positive-pressure Ventilation (IPPV)

The effect of high-frequency ventilation (HFV) on cerebral blood flow (CBF) at normal and elevated intracranial pressure (ICP) was compared with flows measured under the same conditions during intermittent positive pressure ventilation (IPPV). Renal, lung (bronchial artery supply), and cardiac blood flows also were measured during HFV and compared with flows observed during IPPV. Measurements were made in canines with stable hemodynamic variables and arterial CO2 and O2 tensions in the normal range. CBF during HFV was comparable to the CBF during IPPV. Following an increase in ICP to a mean of 44 ± 18 mmHg (SD), mean CBF decreased to 22.5 ± 11 ml · 100 g-1 · min-1 (SD) during IPPV and 21.7 ± 13.2 ml · 100 g-1 · min-1 (SD) during HFV. No statistical differences could be noted in regional or global flow as a function of ventilatory mode. Renal, lung (bronchial artery supply), and cardiac blood flows also showed no statistical variation between HFV and IPPV. Ventilator-synchronous fluctuations in ICP observed during IPPV were reduced during HFV at normal ICP and eliminated by HFV at elevated ICP.

Effect of nitrogen on carbon dioxide elimination during continuous flow apneic ventilation in dogs

Continuous endobronchial insumation of air in paralyzed animals (continuous flow apneic ventilation ‐CFAV) has been shown to maintain adequate oxygenation and carbon dioxide removal. CFAV in patients using oxygen resulted in adequate oxygenation but a mean rise in Paco2 of 0.6 mmHg/min (0.08 kPa/min). This experiment compared carbon dioxide removal in dogs with air and oxygen. Ten dogs were anesthetized and paralyzed, and CFAV was used for 1 h with either air or oxygen in a randomized fashion. Adequate oxygenation was obtained with air and oxygen. Normal Pacos levels were obtained with air; however, in the animals where oxygen was used, Paco2 levels rose to a mean of 6.45 ± s.e.mean 0.4 kPa (48.5 ± s.e.mean 3.2 mmHg).

Acute Cervical Spinal Cord Injuries

Because of the significant mortality, CNS effects, and often overwhelming physiological responses from other organ systems, this report will deal with some of the critical care management problems associated with acute cervical cord trauma (ACCT).

Epidemiology, emergency and acute care: Advances in physiopathology and treatment

is Assistant Professor of Neurological Surgery, University of Pittsburgh, He received his basic neurosurgery training at Case Western Reserve Hospital and completed a year Fellowship in Microsurgery at the University of Pittsburgh. Dr. Yonass research areas mainly are centered on problems of cerebral ischemia; for that study he has developed a new primate stroke model. His special interests in problems of spasticity developed during his fellowship at the University of Pittsburgh, and continues to the present.