Arthur N. Thomas

Prevention of complications from prolonged tracheal intubation

Abstract Eight commercially available soft cuff endotracheal tubes were studied to determine the relationship between inflation pressure distention of the cuff. Although the balloon cuff may be easily distensible in open air, when confined within the trachea small increments in the inflation volume may produce high pressures. This means that continuous external control of cuff pressure is required to prevent ischemia of the tracheal wall. Major tracheal complications in a busy ICU were examined before and after the introduction of a controlled pressure tube. Control of intratracheal cuff pressures decreased major tracheal complications tenfold and eliminated complications specifically related to the cuff.

The role of emergency room thoracotomy in Trauma

The charts of 175 patients who underwent emergency thoracotomy (ET) in the emergency room (ER) between 1972 and 1978 were reviewed to determine the efficacy of this procedure. Seven cases of nontraumatic cardiac arrest were excluded from analysis. Although 150 patients were transported to the ER within 1 hour of injury, 60% either had no vital signs (91 cases) or were agonal (20 cases) on admission to the ER. The trauma was blunt in 60 cases and penetrating in 108. The major sites of injury were heart, major vessels, head, liver, and lung. Thirty-six patients died in the ER, 83 died in the operating room, and eight of the remaining 49 patients who survived operation died acutely in the immediate postoperative period. Of the patients who survived beyond 24 hours after injury 80% recovered and left the hospital: overall 19.6% survived. If patients with irreversible head injuries are eliminated, 24% survived. Correlation of admission status with outcome revealed the following survival rates: no vital signs (6.6%); agonal (20%); profound shock (34.1%); and mild shock with subsequent deterioration (56.3%). Survival rates were higher for patients with stab wounds (40%), pericardial tamponade (38%), and injury to the heart (30%), or lungs (57%). A cost-benefit analysis revealed that total benefits were 2.4 times greater than total costs. Performing early thoracotomy in the ER is a life-saving measure for a substantial number of trauma patients who present to the ER in extremis.

Transient bacteremia: A cause of infection in prosthetic vascular grafts

Abstract To test the theory that freshly implanted vascular prosthetic grafts are susceptible to infection via circulating bacteria, the infrarenal aortas of twelve dogs were replaced with Dacron grafts during experimentally induced bacteremia from Staph. aureus. Three weeks after graft placement, all grafts showed infection with Staph. aureus. The results of this study indicate that a prosthetic vascular graft, unprotected by pseudointima, is vulnerable to circulating bacteria in the blood stream. It is suggested that prophylactic antibiotics be used in patients who are scheduled to receive a prosthetic vascular graft.

LIGATION TREATMENT OF AN ABDOMINAL AORTIC ANEURYSM.

Summary Surgical therapy of abdominal aortic aneurysms is well established, and surgical mortality has progressively lessened to as little as 4 per cent in one major clinic. Arteriosclerosis, the most common cause of aneurysm, is a generalized disease and an occasional patient with aneurysm and severe associated cardiovascular or pulmonary disease may be a significant risk for abdominal aortic surgery. A case of symptomatic abdominal aneurysm in a poor risk patient is presented. It was thought that predictable surgical mortality was greater than 10 per cent and for this reason a staged operation was performed. The initial procedure consisted of a subcutaneous graft from the axillary to the femoral artery and an additional graft from one femoral artery to the other. At a second operation the aorta was ligated; the previously placed graft now provided the entire circulation to the lower half of the body. There was minimal morbidity from the operation, the circulation in the lower half of the body has been excellent, and the large aneurysm is no longer palpable four months after surgery. Conventional resection of an aneurysm with plastic prosthetic replacement is optimal therapy. It may be well to consider the occasional patient with recent myocardial infarction or associated chronic degenerative disease as a candidate for this staged reconstruction rather than to abandon consideration of surgical therapy.

ACUTE TRACHEOBRONCHIAL INJURY

We reviewed our experience with tracheal and bronchial trauma from 1977 to 1988. There were 22 patients with tracheobronchial injuries treated in this period. Seventeen (77%) of the injuries were due to penetrating trauma and five (23%) were due to blunt trauma. Thirteen patients had major associated injuries, including six esophageal injuries. The most common physical findings were tachypnea (13 patients) and subcutaneous emphysema (nine patients). Eight patients presented with airway obstruction. All patients with penetrating cervical tracheal injuries underwent neck exploration and primary repair. All blunt injuries were diagnosed by bronchoscopy. Three patients with blunt injuries were treated with primary repair. Two patients with blunt chest trauma and small bronchial tears were treated nonoperatively with good results. All three deaths (14% mortality rate) were due to associated injuries. We conclude that patients with penetrating tracheobronchial injuries should be managed by surgical exploration and primary repair, although selected patients with blunt injury may be treated nonoperatively.

Reentry confined to the atrioventricular node: Electrophysiologic and anatomic findings

A patient with recurrent disabling, paroxysmal supraventricular tachycardia refractory to drug treatment underwent electrophysiologic studies. The paroxysmal supraventricular tachycardia was found to be due to atrioventricular (A-V) nodal reentry. The patient died shortly after surgical His bundle section and detailed anatomic studies were performed. These showed fatty infiltration of the approaches to the sinoatrial node, atrial preferential pathways, and A-V node and common bundle. The A-V node was mechanically damaged and the common His bundle was completely severed. These abnormalities were clearly delineated and there was no evidence of an atrio-His bundle bypass tract to an accessory A-V node. Specifically, the central fibrous body and pars membranacea were defined and no atrial muscular fibers pierced these structures to joint the A-V bundle. It is concluded that paroxysmal supraventricular tachycardia due to A-V nodal reentry can be confined to the A-V node.

Radiofrequency-Triggered Pacemakers: Uses and Limitations: A Long-Term Study

Seven patients with either recurrent paroxysmal supraventricular tachycardia (five), alternatinng bradycardiatachycardia (one), or ventricular tachycardia (one) underwent insertion of permanent radiofrequency-triggered pacemakers. Follow-up evaluation (36 +/- 24 months, mean +/- SD) revealed that arrhythmias were well controlled in five of seven patients, although three of the five required medication to decrease frequency of arrhythmias. Overdrive pacing was ineffective in one patient with Wolff-Parkinson-White syndrome who had recurrent bouts of atrial fibrillation or atrial flutter. One additional patient with ventricular tachycardia became refractory to overdrive atrial pacing. These studies document the long-term effectiveness of radiofrequency pacemakers in some patients with recurrent refractory arrhythmias. Careful patient selection and electrophysiologic studies are mandatory before implantation of a permanent radiofrequency pacemaker. Physicians must be aware of both the benefits and possible limitations of radiofrequency pacemakers in order to choose between pacemaker versus surgical intervention in patients with cardiac arrhythmias refractory to standard drug therapy.

Unusual complications of epicardial pacemakers: Recurrent pericarditis, cardiac tamponade and pericardial constriction

Three patients with unusual complications after insertion of an epicardial pacemaker are described. In one patient pericarditis and severe cardiac tamponade developed that required emergency pericardiocentesis 8 weeks after pacemaker insertion. No evidence of myocardial perforation was observed at operation. In another patient two unusual complications developed: (1) migration of the pulse generator from the epigastric site of implantation into the pelvis, and (2) recurrent pericarditis with occult signs of constriction. In another patient recurrent pericarditis and clinical evidence of constriction developed. All three patients required pericardiectomy. Recurrent pericarditis after insertion of an epicardial pacemaker requires careful medical follow-up because either life-threatening tamponade or chronic constrictive pericarditis may develop.

Revascularization of severely ischemic extremities with an arteriovenous fistula

Abstract Patients with severely ischemic extremities frequently have multiple occlusive lesions. The surgeons ability to salvage these limbs is frequently compromised by impaired “runoff” at the level of the popliteal artery which results in early thrombosis of endarterectomies or bypass grafts. This is ascribed to low rates of flow through the areas of reconstruction resulting from obstruction of the arterial outflow by disease. One method of artificially augmenting the outflow and thus preventing failure of an operation is the production of a “leak” or arteriovenous fistula immediately distal to the reconstruction. In the four cases we have reported, extensive disease prevented the use of standard operations and peripheral arteriovenous fistulas were placed to increase flow artificially through the critical vessel. This has resulted in an immediate success of the operation. The fundamental aspect of the technic is control of flow through the fistula. By so doing, it is possible to ensure flow in the arterial bed distal to the fistula and simultaneously prevent any adverse systemic effects of the fistula. This technic will permit vascular reconstruction to be used on arteries formerly considered inoperable as it provides a means of assuring blood flow through the operated area.

Management of tracheoesophageal fistula caused by cuffed tracheal tubes

Abstract Seven cases of tracheoesophageal fistula caused by cuffed tracheal tubes are presented. The diagnosis should be suspected when patients who require prolonged tracheal intubation develop symptoms of aspiration or findings of air leak around the cuff. Early repair of the tracheoesophageal fistula is advocated whenever possible. The technic of repair used was interposition of a pedicled sternothyroid or sternohyoid muscle graft between the trachea and esophagus. This operation was carried out in four patients, three of whom survived. Two patients died without operative repair of the fistula and one patient has had operation delayed because of other complications.