Maximal erythrocyte and hemoglobin catabolism.

A series of experiments were performed on anesthetized dogs in which varying quantities of normal canine erythrocytes damaged by incubation with N-ethylmaleimide were injected into the circulation. Cell sequestration and catabolism of hemoglobin to carbon monoxide remained normal after injections that contained from 0.058 to 0.154 g of hemoglobin per kg of body weight. After administration of larger quantities of these cells, from 0.154 to 0.364 g of hemoglobin per kg of body weight, sequestration remained normal but the rate of catabolism of hemoglobin to carbon monoxide reached a maximum. Large quantities of hemoglobin entered the plasma in these experiments at a time when cell sequestration in the reticuloendothelial system appeared to be virtually complete. After injection of even larger quantities of damaged erythrocytes, 0.545 and 0.552 g of hemoglobin per kg, sequestration became slightly delayed, but was complete. These data appear to indicate that (a) the maximal rate of hemoglobin catabolism in normal anesthetized dogs averages approximately 0.07 g/kg of body weight per hr; (b) hemoglobinemia can result from "overloading" the reticuloendothelial system with damaged sequestered cells and, therefore, may not always indicate "intravascular" hemolysis; and (c) the sequestering function of the reticuloendothelial system appears not to limit the maximal rate of catabolism of hemoglobin. The limiting parameter or parameters were not defined in these studies.

Bronchiolitis obliterans organizing pneumonia and rheumatoid arthritis.

The case of a 68-year-old woman who presented with dyspnea and upper lobe pulmonary infiltrates and shortly thereafter developed seropositive, erosive polyarticular rheumatoid arthritis (RA) is presented. An open-lung biopsy to evaluate progression of infiltrates showed bronchiolitis obliterans-organizing pneumonia (BOOP). Both lung and articular disease responded rapidly to corticosteroid therapy. Interrelationships between BOOP, bronchiolitis obliterans, and interstitial fibrosis with connective tissue disease are discussed.

Prevention of pulmonary insufficiency through prophylactic use of PEEP and rapid respiratory rates.

This study evaluated the effectiveness of prophylactic positive end-expiratory pressure (PEEP) rapid respiratory rates (RRR), and high tidal volume (HTV) in prevention of congestive atelectasis. Measurements of pulmonary hemodynamics, mechanics, gas exchange, functional residual capacity (FRC), pathology, and cinemicroscopy were performed in 45 anesthetized dogs subjected to hemorrhagic hypotension. Randomly, the animals received control ventilation, HTV (20 ml. per kilogram), RRR (32 breaths per minute), or PEEP (5 cm. of water). Carbon dioxide was added as needed to maintain normocapnia. Control and HTV animals showed characteristic changes of congestive atelectasis (capillary congestion, stasis, interstitial edema, periarterial hemorrhage, alveolar edema, and hemorrhage). These microscopic and cinemicroscopic changes were prevented by PEEP and RRR and correlated with decreased physiological shunting (PEEP 10 percent, RRR 13 percent, HTV 22 percent; p less than 0.01) in the postshock phase. PEEP increased FRC by 40 percent (p less than 0.02) and reduced the pulmonary artery--small pulmonary vein gradient (PA-SPV), suggesting a direct effect on the capillary bed. RRR did not affect FRC but minimized the SPV-LA gradient. This effect on the pulmonary venules theoretically could be mediated by stimulating lymphatic flow, thereby decreasing interstitial edema. Thus PEEP and RRR are beneficial when used prophylactically but may work by widely differing mechanisms.

The role of carbon dioxide in the development of pulmonary insufficiency.

The effects of carbon dioxide (PCO2 = 40 versus PCO2 = 20) on pulmonary function changes during 2 hours of hemorrhagic hypotension followed by resuscitation are evaluated in 21 dogs. Pulmonary hemodynamics, mechanics, gas exchange, functional residual capacity, and morphology are studied. In the preshock period, hypocapnia is associated with a decreased cardiac output, increased dead space, and increased alveolar-arterial (A-a) gradiant (room air). During the period of hypotension, all parameters in both groups changed similarly. After resuscitation, the A-a gradients in the two groups further widened. Following the return to control levels of normocapnia in all animals, the group which had been hypocapnic during the hypotensive episode continued to show increased shunting (20 versus 13 percent, p less than 0.05). These results correlated well with cinemicroscopic findings, which showed the normocapnic group to have less interstitial edema and better capillary flow.

Correlation of viral infection, histology, and mortality in immunocompromised patients with pneumonia. Analysis by in situ hybridization and the polymerase chain reaction.

The purpose of this study was to determine the occurrence and histologic correlates of viral infections in immunocompromised patients with pneumonia. Of the 44 immunocompromised patients studied, 37 had AIDS. Lung tissue from these patients, including 34 with pneumocystis pneumonia, was evaluated by in situ hybridization for the presence of cytomegalovirus (CMV), adenovirus, Epstein-Barr virus, and herpes simplex virus. Fifteen of the 44 patients were positive for at least one virus (34%); CMV (13 cases) was the most common. In an additional seven cases, CMV DNA was detected using the polymerase chain reaction (PCR), for an overall viral detection rate of 22 of 44 (50%). Histologic features were diagnostic of a viral infection in nine of 15 cases (60%) of the in situ positive cases and in nine of 22 (41%) of the tissues where viral DNA was detected by PCR. Mortality rate was significantly correlated with viral detection: 77% for the viral-positive cases and 27% for the viral-negative cases (p < 0.05). We concluded that in immunocompromised patients with pneumonitis, the detection of viral DNA is strongly correlated with survival and that histologic features of the inflamed lung tissue are a specific but insensitive means of diagnosing viral presence.

Comparison of patients with coronary artery or valve disease: intraoperative differences in blood volume and observations of vasomotor response.

A review of 296 patients undergoing cardiac operations has shown that those with coronary artery disease have a blood volume deficit. The 148 patients with valve disease had a normal blood volume of 78 ml/kg (normal range, 68--88 ml/kg), while the 148 coronary artery disease had a blood volume of 69 ml/kg (p less than 0.001). Infusion of plasma prior to cardiopulmonary bypass as well as the total transfusion required afterward to maintain blood pressure indicated an important clinical difference in these two groups. Another finding was that the requirement for a drug to control blood pressure prior to use of cardiopulmonary bypass was greater in the coronary patients (p less than 0.01). Comparison of the requirement for a hypotensive agent before and after bypass showed a greater predictability in the valve group. This experience leads us to conclude that patients with coronary artery disease and angina not only have a low blood volume, but they also have a marked vasoactive lability which shows up in their hemodynamic response to the conduct of an operation and to anesthesia.

Ultrastructure of the proliferating cells in pulmonary lymphangiomyomatosis.

Pulmonary lymphangiomyomatosis occurs almost exclusively in women and is characterized by a widespread proliferation of spindle-shaped cells within the lung. Although these cells have been considered to be vessel-associated smooth muscle cells, their origin remains undefined. In this case of pulmonary lymphangiomyomatosis studied by electron microscopy, the proliferating cells were found to vary morphologically and to differ from typical smooth muscle cells. The ultrastructure suggests that the cell of origin might be the pulmonary interstitial cell rather than vascular smooth muscle. It is also possible that the cells are derived from pericytes. Accumulations of glycogen were seen in the proliferating cells and are suggested to be a reflection of an estrogenic hormonal dominance.

Recurrent chondromyxoid fibroma of the thoracic spine 30 years after primary excision: case report and review of the literature.

We report a case of late recurrence of chondromyxoid fibroma (CMF) arising in a thoracic vertebra in an 11-year-old male. This was treated by curettage, and 30 years later, the patient noticed shoulder pain and leg weakness. A recurrent mass appeared at the same site in the spinous process of T6. The histologic features of the recurrent tumor were similar to those of the primary lesion. A total of 38 cases of CMF of the vertebra have been reported. Only 3 of 38 previously reported vertebral CMF recurred. Tumors recurred 2 years after operation in 2 cases, and 7 years after operation in 1 case.

High-performance liquid chromatography as a diagnostic tool in prolonged neuromuscular blockade.

We report the use of high-performance liquid chromatography (HPLC) to identify the cause of prolonged neuromuscular blockade in a child who had received 2 mg.kg-1 of succinylcholine. Upon analysis by HPLC the syringe was found to contain succinylcholine (10 mg.ml-1) and also atracurium (5 mg.ml-1), so that a diagnosis was established. In situations where medication errors are suspected, we recommend saving syringe contents for analysis for confirmation of the agent.

Hypokalaemia and respiratory acidosis following partial obstruction of the airway.

An 87-year-old female, with a history of hypertension controlled with hydrochlorothiazide, was scheduled for excision of a cystic mass of the left lobe of the thyroid. In the course of the anaesthetic, she developed partial airway obstruction that resulted in respiratory acidosis (PaCO2 108 mmHg, pH 7.06), developed premature ventricular contractions and experienced a reduction in plasma potassium concentration from 3.9 to 2.9 mmole X L-1. We interpret this hypokalaemia as a consequence of the epinephrine discharge due to hypercapnia. The case is reported to emphasize the importance of minimizing the sympathetic response to induction of anaesthesia, intubation and surgery in patients with marginal potassium stores.

Anaesthesia for open-heart surgery in haemodialysis-dependent patients: a report of two cases.

Two cases are presented in which patients in chronic renal failure underwent successful open heart surgery. The additional problems chronic renal failure imposes on the anaesthetic management of patients requiring cardiac surgery are discussed, with recommendations on choice of agents and techniques.

A PSRO record-keeping system for anesthesiologist.

To meet the requirements for Professional Standards Review Organization (PSRO) auditing, a new anesthesia record-keeping system was designed. The forms are also well adapted for use in an anesthesia teaching department.

Electrocautery-induced pacemaker malfunction during surgery.

We report a case of electrocautery-induced pacemaker failure that resulted in asystole in a 15-year-old girl scheduled for cardiac surgery. Her pacemaker was converted to the asynchronous mode the night before surgery. Electromagnetic interference from the unipolar electrocautery caused a reduction in the battery voltage, which allowed the digital circuitry, but not the voltage control oscillator (VCO), to work properly. Eventually the battery current drain caused VCO "lock-out," and pacemaker and battery failure. This report demonstrates that electrocautery-induced pacemaker failure can occur, even after conversion to asynchronous mode.

Fatty infiltration: another restrictive cardiomyopathic pattern.

Restrictive cardiomyopathies have been shown to occur as result of infiltrative processes from a variety of sources. The current report describes an obese male, who was found to have hemodynamic evidence of a restrictive cardiac process. His pericardium was proven to be normal and an incisional biopsy obtained of the myocardium during coronary artery bypass surgery demonstrated histologic evidence of fatty infiltration of myocardium. Review of the restrictive and pathology literature is discussed and indicates that this is the first report to demonstrate the association between fatty infiltration and hemodynamic findings consistent with a restrictive cardiomyopathy.

Isolated pulmonary microangiitis mimicking pneumonia in a patient infected with human immunodeficiency virus.

We describe the first case, to our knowledge, of apparently isolated pulmonary vasculitis mimicking bacterial pneumonia in a patient infected with human immunodeficiency virus (HIV). Patients presenting with fever, cough, and pulmonary infiltrates present a diagnostic challenge. As a result of severe T cell mediated immunosuppression and humoral dysregulation, the differential diagnosis is diverse. One must consider both noninfectious and infectious etiologies. Noninfectious etiologies such as pulmonary lymphoma, endobronchial Kaposi's sarcoma, and adverse drug reactions are common. Recent recognition of the paradoxical association between HIV and systemic vasculitis requires additional acknowledgment of this problem in diagnosis.

Does a mid-lumbar block level provide adequate anaesthesia for transurethral prostatectomy?

In this prospective, randomized study, 23 patients having spinal anaesthesia for transurethral prostatectomy (TURP) were evaluated for the adequacy of their block using a visual analog pain score (VAPS). Each patient with a "standard" (> or = T10) block level (n = 5) or "intermediate" (L1 or T12) block level (n = 5) found the block adequate. Sixty-two percent (8/13) of patients with a "low" (< or = L3) block level found their block adequate. The VAPS was assessed every five minutes or whenever pain abruptly increased during TURP; an "inadequate block" was defined as a VAPS > or = 5/10 during prostatic resection. Intravesical pressure was monitored and kept < 15 mmHg to distinguish between pain from bladder distension and from prostatic resection. "Low" block patients (LBP) who found their block inadequate (n = 5) received supplemental intrathecal local anaesthetic given through a spinal catheter. The subsequent L1 block level was adequate for TURP. In LBP, who found their block adequate (n = 8), a higher (P < 0.01) VAPS was observed than in patients with a "standard" block level. However, a smaller (P < 0.05) maximum percent decrease in diastolic blood pressure was found in LBPs, than in "intermediate" or "standard" block patients. It is concluded that a spinal block > or = L1 is adequate during TURP when bladder pressure is monitored and kept low. Mid-lumbar block levels should be reserved for patients in whom the benefit of minimizing haemodynamic changes outweighs the risk of a "less complete" anaesthetic.

Diagnosis of asbestosis by transbronchial biopsy. A method to facilitate demonstration of ferruginous bodies.

The diagnosis of asbestos-associated pulmonary fibrosis was established in 3 patients by finding ferruginous bodies in transbronchial lung biopsies. Ferruginous bodies may be difficult to identify in histologic preparations when they are not oriented parallel to the plane of tissue section or when camouflaged by anthracotic pigment. We describe a simple method to enhance diagnostic sensitivity by digesting biopsy tissue and examining the filtered residue for ferruginous bodies.

Artifacts in the measurement of pulmonary artery wedge pressure.

Pulmonary artery wedge pressure (PAWP) will only reflect left atrial pressure (LAP) if continuity of fluid exists from the catheter tip to the left atrium. Either increased airway pressure or decreased hydrostatic pressure may lead to discontinuity of the fluid column and midinterpretation of PAWP. Simultaneous measurements of PAWP and LAP were made in 19 anesthetized dogs. Placement of the pulmonary artery wedge catheter above the left atrium (West Zone I) in combination with the incremental addition of 5 cm H2O of PEEP caused a 5 mm Hg gradient between PAWP and LAP in the normovolemic animal. Augmenting PEEP further or hypovolemia (i.e., decrease in LAP) increased the gradient. Hypervolemia (increase in LAP) diminished the gradient. Fluid continuity between the PAW catheter and LA is a prerequisite for monitoring LAP with the Swan-Ganz catheter. Increases in PEEP, placement of the catheter above the left atrium and hypovolemia may occlude the fluid column and cause artifacts in the PAWP obtained.

Effects of DDT on stable laboratory mouse populations.

Four stable laboratory mouse populations were established; each contained approximately 400 mice of both sexes and all ages postweaning living in a single cage, as well as neonates caged in separate nesting boxes with their dams. Two were used to determine the effects of continuous exposure to a dietary level of 100 ppm DDT while the other two served as controls. The results indicated a significant decrease (p less than or equal to 0.05) in neonatal survival (lactation index) within 20 wk after the beginning of exposure to the toxicant in one of the exposed populations and by 30 wk in the other. This deleterious effect of the DDT continued through each succeeding generation. On the other hand, improved postweaning survival in DDT-fed mice was noted. Histological examination showed no tumors in test or control animals; other pathology was seen more frequently in control than in test animals.