Jeffrey Katz

A brief history of tracheostomy and tracheal intubation, from the Bronze Age to the Space Age

ObjectiveTo present axa0concise history of tracheostomy and tracheal intubation for the approximately forty centuries from their earliest description around 2000xa0BC until the middle of the twentieth century, at which time axa0proliferation of advances marked the beginning of the modern era of anesthesiology.Data sourcesReview of the literature.ConclusionsThe colorful and checkered past of tracheostomy and tracheal intubation informs contemporary understanding of these procedures. Often, the decision whether to perform axa0life-saving tracheostomy or tracheal intubation has been as important as the technical ability to perform it. The dawn of modern airway management owes its existence to the historical development of increasingly effective airway devices and to regular contributions of research into the pathophysiology of the upper airway.

Outflow pressure reduces lymph flow rate from various tissues

We previously reported that the very act of cannulating a lung lymph vessel could alter the unique flow characteristics that existed within the lymphatic before cannulation. We postulated that this phenomenon could hold true for lymphatics draining any organ within the body. Since it is frequently important to know the relationship between the transmicrovascular fluid flux and true lymph flow rate, it would be critical that a cannulated lymphatic vessel have the same flow characteristics as those uncannulated vessels draining the same organ. In order to test our hypothesis we cannulated lymph vessels draining the heart, liver, small intestine, kidney, and skeletal muscle. By altering the lymphatic outflow pressure (normally related to systemic venous pressure) and by using lymphatic cannulas of various resistance, we were able to demonstrate that lymph flow varied linearly with lymphatic outflow pressure in every organ. By increasing transmicrovascular fluid flux and lymph flow rate in each organ we were also able to demonstrate that effective resistance of the lymphatic vessels and the effective pressure driving lymph flow varied as a function of the physical characteristics of the organ under investigation. Characteristic effective resistances of the heart, liver, skeletal muscle, kidney, and small intestine lymphatics decreased by 83, 40, 61, 36, and 50%, respectively. Along with these changes in effective resistance, the effective lymph driving pressure in the same organs varied by 49, 0, 257, 0, and 63%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of the Trendelenburg Position on the Distribution of Arterial Air Emboli in Dogs

We examined the effects of buoyancy on the distribution of arterial gas bubbles using in vitro and in vivo techniques in dogs. A simulated carotid artery preparation was used to determine the effects of bubble size and vessel angle on the velocity and direction of bubble movement in flowing blood. Because buoyancy tends to float bubbles away from dependent areas, bubble velocity would be expected to decrease as the vessel angle increased. We found that larger bubbles increased in velocity in the same direction as the blood flow at 0-, 10-, and 30-degree vessel angles and decreased when the vessel was positioned at 90 degrees. Smaller bubbles did not change velocity from 0 to 30 degrees and increased in velocity in the same direction as blood flow at 90 degrees. In 10 anesthetized dogs, we studied the effects of 0-, 10-, 15-, and 30-degree Trendelenburgs position on carotid artery distribution of gas bubbles injected into the left ventricle or ascending aorta. Regardless of the degree of the Trendelenburg position, the bubbles passed into the carotid artery simultaneously with passage into the abdominal aorta. We conclude that the forces of buoyancy do not overcome the force of arterial blood flow and that the Trendelenburg position does not prevent arterial bubbles from reaching the brain.

Air embolism during cardiopulmonary bypass

Sudden and unexpected death during an operation is a calamity which never fails to strike terror to the heart of the boldest surgeon. Although death is a frequent and familiar visitor wherever human beings exist, nevertheless its sudden and unforeseen advent conveys with it more than the usual halo of sadness, and when such a scene transpires in the operating room it leaves impressions which neither time nor space can erase ... Believing that it is good practice to prepare for war in time of peace, I intend on this occasion to call your attention to one of the most dreaded and, I may add, one of the most uncontrollable causes of sudden death I

Bronchoscopic findings in post-obstructive pulmonary oedema

PurposeTo present the first photographed bronchoscopic findings associated with negative pressure pulmonary oedema (NPPE).Clinical featuresA previously healthy patient underwent anterior C3–C4 disc removal and arthrodesis. Following tracheal extubation he developed acute respiratory distress manifested as stridor, tachypnoea, restlessness, and desaturation. Once the trachea was reintubated, he displayed the classic findings of pulmonary oedema. Bronchoscopy was performed to confirm tracheal tube position and to rule out tracheal injury secondary to surgical manipulation. Diffuse punctate haemorrhages were noted throughout the visualised tracheobronchial tree.ConclusionWe believe that these haemorrhages represent disruption of the bronchial vasculature and may contribute to the clinical presentation of NPPE.RésuméObjectifPrésenter les premières photographies par bronchoscopie d’un oedème pulmonaire provoqué par une pression pulmonaire négative.Eléments clniquesUn patient jusque là bien portant subit une résection antérieure de disque à C3–C4 avec arthrodèse. Après l’extubation de la trachée, il développe une détresse respiratoire aiguë manifestée par du stridor, de la tachypnée, de l’agitation et de la désaturation. Une fois réintubé, il révèle les signes classiques d’un oedème pulmonaire. Une bronchoscopie est réalisée pour confirmer la position du tube endotrachéal et d’éliminer la possibilité de blessure trachéale secondaire à la manipulation chirurgicale. Des hémorragies diffuses ponctiformes sont notées sur l’arbre trachéobronchique.ConclusionNous croyons que ces hémorragies représentent la rupture de la vasculature bronchique et peuvent contribuer aux manifestations cliniques d’un oedème pulmonaire associé à une pression pulmonaire négative.

Massive Macroglossia After Posterior Fossa Surgery in the Prone Position

We describe an unusual case of severe postoperative macroglossia after posterior fossa surgery in the prone position, and review potential causative factors and prophylactic measures that may alleviate this serious complication.

A model of the lung interstitial-lymphatic system

Our model of the pulmonary interstitial-lymphatic system is based on the assumption that the lung interstitial space can be divided into two compartments. The first compartment (C1) contains the terminal lymph vessels. Increases in the fluid pressure within this compartment, along with increased pressure generated by lymph vessel pumping, cause the lymph flow rate to increase. The lymph vessels run through the second compartment (C2) which we believe represents the perivascular spaces. Increases in the fluid volume of C2 cause the lymph vessels to dilate and this causes lymph vessel resistance to decrease. Normally the lymph flow rate equals the microvascular filtration rate so that lung fluid volume is constant. According to our model, increases in filtration rate cause fluid to collect in C1 and C2. The resulting increase in fluid pressure in C1, increased lymph vessel pumping, and the decrease in lymph vessel resistance in C2 cause lymph flow to increase. Eventually, the lymph flow rises to equal the filtration rate and lung fluid volume becomes constant again. The results of simulations with our model indicate that decreases in lymph vessel resistance are essential for lymph flow to increase substantially as edema develops.

Arterial air embolism of venous origin in dogs: effect of nitrous oxide in combination with halothane and pentobarbitone

The effects of using nitrous oxide (N2O) with halothane or pentobarbitone anaesthesia on the filtration of venous air emboli (VAE) by the pulmonary circulation were studied in dogs. Dogs anaesthetized with either pentobarbitone, pentobarbitonelN2O, halothane, or halothanelN2O were embolized with venous air into the right atrium at 0.25 to 0.35 ml-kg-1 min-1 for 30 min. The animals were in a supine, head down position. A Doppler ultrasonic probe located over the suprarenal aorta detected arterial bubbles that escaped filtration by the lungs. No bubbles were detected at 0.25 ml.kg-1min-1,but at 0.30ml.kg-1.min-1 the incidence was 11 per cent (pentobarbitone), 0 per cent (pentobarbitonelN2O), 33 per cent (halothane), and 63 per cent (halothanelN2O) and at 0.35 ml-kg-1.min-1, 44 per cent (pentobarbitone), 14 per cent (pentobarbitonelN2O), and 56 per cent (halothane). Half of the dogs receiving VAE with halothanelN2O at 0.30 ml.kg-1.min-1 died within the first 10 min of the air infusion. Thus, no animals were studied at the next higher dose (0.35 ml-kg-1.min-1). The results suggest that the occurrence of VAE with nitrous oxide anaesthesia may result in greater haemodynamic consequence and increased likelihood for spillover of the venous bubbles into the arteries if used with halothane as compared to pentobarbitone.RésuméOn a étudié, chez les chiens, les effets qu’avait le protoxyde ďazote (N2O), utilisé lors ďune anesthésie à ľhalothane ou au pentobarbital, sur la filtration ďembolie gazeuse (EGV) par la circulation pulmonaire. On a causé des embolies gazeuses veineuses dans ľoreillette allant de 0.25 à 0.35 ml.kg-1.min-1 pendant 30 minutes, chez des chiens anesthésiés au pentobarbital, au pentobarbitallN2O, à ľhalothane, ouàľhalothanelN2O. Les animaux étaient en position de Trendelenburg en décubitus dorsal. Une sonde ultrason Doppler, localisée au-dessus de ľaorte suprarenale, détectait les bulles ďair artérielles qui échappaient à la filtration pulmonaire. On a décelé aucune bulles ďair à 0.25 ml.kg-1.min-1, mais à 0.30 ml.kg-1.min-1 ľincidence était de 11 pour cent (pentobarbital), 0 pour cent (pentobarbitallN2O), 33 pour cent (halothane), et 63 pour cent (halothanelN2O) et à 0.35 ml.kg-1.min-1, elle était 44 pour cent (pentobarbital), 14 pour cent (pentobarbitalN2O), et de 56 pour cent (halothane). La moitié des chiens recevant des EGV avec de ľhalothanelN2O àO.30 ml.kg-1 sont morts dans les dix minutes après ľinfusion de ľair. Nous n’avons donc pas étudié ďanimaux à la dose élevée qui suivait (0.35 ml.kg-1). Les résultats laissent entendre qu’il est possible que la conséquence hémodynamique soit plus importante et que la possibilité ďécoulement de bulles ďair veineuses dans les artères soit augmentée dans ľapparition de EGV avec protoxyde ďazote, si ce dernier est utilisé avec une anesthésie à ľhalothane en comparaison à une anesthésie au pentobarbital.

A comparison of different methods of lubrication of glass syringes used to identify the epidural space

Measurement of loss of resistance in glass syringes is a method widely used to locate the epidural space in epidural anaesthesia. Static and dynamic forces were measured under four experimental conditions in new glass syringes: unpolished, dry; polished, dry; unpolished, saline lubricated; and polished, saline lubricated. The unpolished saline lubricated syringes had a mean (SD) static force of 53.18 (15.0) g and dynamic force of 40.88 (15.2) g. These values were significantly greater than for polished dry syringes where the values were 5.27 (2.1) g and 4.38 (0.94) g, respectively. The results show that the least amount of resistance to plunger movement is obtained by dry polishing glass syringes.