Postbypass Treatment

Ischemia induced by cross-clamping the aorta during open-heart operations initiates progressive metabolic derangement. If the duration of ischemia is short, these derangements are easily reversed by restoring the flow of blood containing oxygen and substrate. If ischemia is prolonged, treatment designed to ameliorate ischemic damage may be necessary. Three problems are discussed: (1) loss of adenine nucleotides, particularly adenosine triphosphate, (2) impairment of calcium sequestration, and (3) formation of microemboli in coronary vessels. The rationale for postbypass treatment is presented.     

Biochemical Changes of Ischemia

Normothermic ischemic arrest by aortic cross-clamping, a widely used clinical technique, is associated with metabolic changes in the myocardium that are incompletely understood. The effects of aortic cross-clamping on glycolytic pathways as well as associated morphological changes are discussed. Emphasis is placed on the conservation of high-energy phosphate moieties during the period of cross-clamping as well as during reperfusion. A marked reduction in total high-energy phosphates (62%) and glycogen (63%) and an increase in lactate production (243%) denote a shift to anaerobic metabolism during the period of arrest. Despite reperfusion, total high-energy nucleotides remained depressed. The data suggest that persistent abnormal myocardial carbohydrate metabolism and low levels of high-energy nucleotides prevent recovery of contractility following normothermic ischemic arrest and reperfusion.     

Protection of the Myocardium with High-Energy Solutions

An approach to intraoperative protection of the myocardium is described that attempts to increase glucose utilization by infusion of high-energy solutions during aortic cross-clamping. Infusion of hypertonic glucose or glucose plus insulin prior to aortic cross-clamping has enhanced contractility and increased high-energy phosphate moieties in animals with induced ischemia. Recent pilot experiments in our laboratory suggest that infusions of creatine may result in increased production of creatine phosphate, which in turn induces phosphorylation of adenosine diphosphate to adenosine triphosphate, possibly enhancing myocardial contractility. The intraoperative clinical benefits of these infusions remain to be proved, however.     

Multiple level injuries of the cervical spine

In a group of 105 patients admitted to hospital with injuries of the cervical spine, the incidence of injuries at multiple levels was 24 per cent. Multi-level injuries occurred in 17 out of 54 patients (31 per cent) sustaining a noteworthy neurological injury and in 8 out of 51 when such an injury was absent. This incidence is higher than previously reported, probably due to increasingly elaborate investigations. In the majority of cases, treatment of the dominant injury was unchanged by the demonstration of injuries at other levels, but in a small number, serious errors in treatment arose or could have arisen. Careful multi-level assessment, including assessment of the cervicothoracic junction, is indicated before selecting management. While conventional or computerized axial tomography may occasionally be necessary to achieve this, good conventional radiography remains the most important investigation. Computerized axial tomography is particularly useful in establishing the anatomy of complex injuries in the upper cervical spine.     

Noncoronary collateral myocardial blood flow.

This study shows that noncoronary collateral flow occurs in normal hearts after chronic coronary occlusion and with left ventricular hypertrophy in variable amounts (0.2 to 16 ml/100 gm/min). Luminal--left ventricular flow is greatest when the heart is arrested by aortic cross-clamping, falls significantly when perfusion pressure is lowered to 50 mm Hg, and increases slightly when blood viscosity is reduced (hemodilution). Our findings indicate that the heart which is arrested by aortic cross-clamping may not be anoxic.     

Seminoma of the anterior mediastinum.

Primary pure cell seminoma of the mediastinum is a rare and potentially fatal lesion. Encroachment on or invasion of adjacent structures is common, as are distant metastases. The differentiation between pure cell seminomas and mixed germ cell tumors should be made since the extreme radiosensitivity of seminomas improves the prognosis. The presence of metastases from primary mediastinal seminomas, as with testicular germinomas, need not be a deterrent to long-term cure. Recommended therapy consists of total or subtotal removal, radiation therapy (2,500 to 3,500 rads delivered over 2 to 4 weeks), and, in some patients, chemotherapy. A patient who was successfully treated with subtotal removal and irradiation is presented.     

Viability of cryopreserved red blood cells studied over 96 hr post-thaw

The use of cryopreserved blood is of major importance in the transfusion of patients who are potential candidates for or who have already received a renal allograft. However, the use of this blood is limited because its present shelf life is only 24 hr. Should this shelf life be extended, which is very likely within the next 5 years, it would be essential to know the biologic viability of this blood beyond the 24-hr storage time.In this study, we have investigated the parameters of frozen-deglycerolized human blood that are indicative of red blood cell viability and rate of cell lysis up to 96 hr post-thaw. Our studies support the concept that frozen-thawed blood can be transfused safely after storage for 96 hr.     

Secundum atrial septal defect and mitral valve incompetence.

Mitral regurgitation associated with secundum atrial septal defect is described in 4 patients, each with a different mitral lesion: rheumatic valvular disease, congenitally cleft valve, subacute bacterial endocarditis with disruption of the chordae tendineae, and traumatic valve rupture. The pathological spectrum of mitral valve disease associated with atrial septal defect is reviewed, and it is suggested that structural abnormality of the mitral valve may accompany the atrial septal defect. More general awareness of this association will allow the surgeon more accuracy in defining and repairing this rather unusual combination of lesions.     

Clinical results with a new acoustic device to identify the epidural space

Fifty patients scheduled for surgery under lumbar epidural anaesthesia were included in a study to evaluate the possibility of localising the epidural space solely by means of an acoustic signal. With an experimental set-up, the pressure generated during the epidural puncture procedure was translated into a corresponding acoustic signal. One anaesthetist held the epidural needle with both hands and detected the epidural space by means of this acoustic signal. At the same time, a second anaesthetist applied the loss of resistance technique and functioned as control. In all patients the epidural space was located with the acoustic signal. This was confirmed by conventional loss of resistance in 49 (98%) of the patients; in one patient (2%) it was not. We conclude that it is possible to locate the epidural space using an acoustic signal alone.     

一种衡量机构传动质量的新指标——兼论机构的压力角

长期以来,在凸轮机构中用压力角α;在连杆机构中用传动角γ(因为丨90°-γ丨=α,实质上仍是压力角)作为衡量机构传动质量的指标和设计依据。本文通过分析,指出了压力角作为这种指标的缺陷和提出了新的机构传动质量指标Ψ'=tga'tgφ',其中α'为实际压力角,φ'为从动件与机架间的当量摩擦角。文章还阐述了新指标在机构分析和综合上的应用。     

A functional treatment method for interphalangeal pyogenic arthritis

A treatment plan for pyogenic arthritis has been devised in which the accessory collateral ligaments are resected through radial and ulnar midaxial incisions. The surgical wound is debrided and copiously irrigated with an antibiotic solution, and intravenous antibiotics are instituted before operation and continued after operation. Physical therapy is begun within 24 hours of surgery and includes active range of motion (ROM) of all joints, dynamic splinting, and hand therapy to ensure both full flexion and extension. Forty patients were treated with this method within a 6-year period. Of five interphalangeal (IP) joints of the thumb, four regained 0 degree to 60 degrees full ROM and one gained 15 degrees to 65 degrees limited ROM. Of the two distal IP joints, one regained full ROM and the other became fused. Among the 33 proximal IP joints, 13 regained full ROM of 110 degrees and 13 regained limited ROM. Good functional results were obtained with this treatment plan in lieu of amputation, which previously was the most likely treatment.     

Yersinia enterocolitis.

Human infection with Yersinia enterocolitica is being seen with increasing frequency. This disease has importance to the pediatric surgeon as it may mimic acute appendicitis in patients in the pediatric age group. Clinical suspicion should be high in the patient with right lower-quadrant symptoms suggestive of appendicitis with an inordinate amount of diarrhea. Serologic and microbiologic evidence should be sought, and tissues removed at the time of a negative exploration for appendicitis should be cultured for Yersinia enterocolitica. In general, the disease is associated with an excellent clinical response to simple antibiotic therapy and a good prognosis, but fatal cases have been reported, especially in older patients.     

Oral cholestyramine and paregoric therapy for intractable diarrhea following surgical correction of catastrophic disease of the GI tract in neonates

Ten surgical neonates with postoperative intractable diarrhea and secondary weight loss were treated with combination cholestyramine and paregoric therapy. Within 3–5 days all infants except two showed significant clinical improvement with a decreasing number of stools, an increase in the consistency of the stool, and gradual weight gain. The exact mechanism of action of cholestyramine is not clear. It may act by binding with bile salts and/or endotoxins in the bowel lumen or decreasing the motility of the bowel. Used in combination with paregoric, a known bowel motility depressant, the doses of each medication can be kept quite low thus avoiding undesirable side effects. Medium chain triglyceride formula is helpful in some of these infants to improve fat absorption further. Medication in all of these infants has been discontinued without any adverse effects.     

Thyroid abscess in a 14-month-old child

Suppurative thyroiditis occurring in childhood is rare. Progression to abscess formation is an even more uncommon occurrence. Only four thyroid abscesses occurring in children under 15 yr of age have been reported in the past 20 yr.^1–4A 14-mo-old white girl developed an enlarging mass in the anterior neck. Two weeks previously she was treated for otitis media by her local physician and subsequently was observed to develop a mass in the area of the thyroid gland. Her febrile course was not altered by antibiotics. Physical examination was entirely within normal limits except for the thyroid which was firm and hard with a 4-cm movable mass in the region of the left lobe of the thyroid. There was no associated erythema or apparent tenderness.Laboratory studies included a hemoglogin of 11.6 g/100 ml, hematocrit of 33.5 vol %, white blood cell count of 16,700/ml³ with a differential count of 65 neutrophils, 30 lymphocytes, and 5 monocytes. A urinalysis revealed no abnormalities. Stool culture grew normal enteric flora. A throat culture grew non-Group A beta hemolytic streptococci. A chest film revealed no abnormalities. Studies of thyroid function included a T-3 (30.4%) within normal limits and a T-4 (10.1 μg) in the high euthyroid range.The child received erythromycin 125 mg orally at 6-hr intervals without cessation of fever for 4 days. At this time, it was felt that the fever was related to the thyroid mass which appeared unchanged from the time of admission.At operation, an abscess cavity was noted in the superion of the left lobe of the thyroid gland. Approximately 10 cc of purulent material was removed from the cavity and a Penrose drain was placed in the abscess cavity. A biopsy specimen revealed inflammation and fibrosis consistent with the wall of the abscess. Bacterial, fungal, and acid-fast cultures of the pus were negative.The child became afebrile within 24 hr after operation. The postoperative course was uncomplicated except for the occurrence of a skin abscess at the site of the operative incision. Drainage of this abscess yielded 4 cc of purulent material from which staphylococcus epidermidis was grown. Subsequently the child has not experienced any further difficulty and remains euthyroid.     

Microvascular changes in Dupuytren's contracture

Previous studies of certain fibrotic lesions (hypertrophic scar, keloid, pseudotendon) have revealed pervasive microvascular occlusion. Lowered oxygen tension is considered to be a stimulus to excessive collagen production and, hence, the scar. Because its characteristics are similar to those of other lesions, Dupuytren's contracture appeared to be a good model in which to confirm the presence of occluded microvessels. Six cases were examined by light, electron, and polarizing microscopy. Most of the microvessels from the precontracture band area throughout the periphery of the body of the nodules were occluded by a bulging of the endothelial cells into the lumen. The microvessels were surrounded by extensive layers of basal laminae. The nodules were essentially avascular. The presence of another fibrotic lesion in which pervasive microvascular occlusion occurs is suggestive of an underlying biologic principle concerning the generation of all fibrotic lesions.     

Glomus tumor of the metacarpophalangeal joint: a case report

A case of a glomus tumor of the head of the third metacarpal bone is described. The metacarpophalangeal joint had to be opened to allow excision of the tumor.     

Topical povidone-iodine reduces mortality from bacterial peritonitis

The efficacy of topical 10 and 1.5% povidone-iodine was assessed in a rat fecal peritonitis model. Both solutions were bactericidal in vitro. An LD₉₀ preparation of fecal peritonitis in the rat was then assessed and rats were assigned to control or four treatment groups consisting of lavage with saline, 10% povidone-iodine (2.5 ml/kg), povidone-iodine plus saline (600 ml/kg), or 1% cephalothin (600 ml/kg). Twenty-four-hour mortality rates were recorded. Quantitative peritoneal cultures were obtained before and 3 and 6 hr after lavage. Lavage was effective only with 1.5% povidone-iodine or when cephalothin was added. Each of these lavage solutions significantly reduced mortality (P < 0.05). Delayed intravenous cephalothin (200 mg/kg) reduced mortality significantly following 10 or 1.5% povidone-iodine. Failure of povidone irrigation is due to uncontrolled infection rather than to drug toxicity.     

Microparticles from stored red blood cells promote a hypercoagulable state in a murine model of transfusion

Background

Red blood cell-derived microparticles are biologically active, submicron vesicles shed by erythrocytes during storage. Recent clinical studies have linked the duration of red blood cell storage with thromboembolic events in critically ill transfusion recipients. In the present study, we hypothesized that microparticles from aged packed red blood cell units promote a hypercoagulable state in a murine model of transfusion.

Management of immature teratoma of the ovary in children by conservative resection and chemotherapy

Six patients with immature teratoma of the ovary were treated with surgery and chemotherapy. Surgical management consisted of unilateral salpingooophorectomy, biopsy and conservation of the contralateral ovary, and biopsy of peritoneal implants. Triple-agent chemotherapy with vincristine, actinomycin D, and cyclophosphamide was given to four patients and appeared to be beneficial. Radiation therapy was not employed. Local resection of teratomatous recurrences was frequently necessary. Thorough sampling of this tumor is mandatory for establishment of an exact pathologic diagnosis. All six patients are surviving in good health at 1–8-yr follow-up. The prognosis of immature teratoma in the child or adolescent appears more favorable than previously appreciated.