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Eighty-two patients with the acquired immunodeficiency syndrome (AIDS) were admitted to the intensive care units (ICUs) at San Francisco General Hospital (SFGH) between March 1981 and December 1985. Of these patients, 69% died in the hospital, as did 87% of patients who required mechanical ventilation because of Pneumocystis carinii pneumonia and respiratory failure. Although the number of hospital admissions of patients with AIDS has increased steadily since the fourth quarter of 1982 (12 admissions) through the fourth quarter of 1985 (158 admissions), the number of admissions to the ICUs peaked at 17 in the second quarter of 1984 and decreased steadily, averaging 5 per quarter in 1985. This decrease was not explained by a reduction in the number of patients with P. carinii pneumonia or an improvement in their treatment. A survey of physicians at SFGH indicated that physicians are aware of the poor prognosis of patients with AIDS with P. carinii pneumonia and respiratory failure, believe that mechanical ventilation is infrequently indicated for this condition, and have become increasingly likely to discuss issues of resuscitation with their patients with AIDS. Therefore, possible explanations for this trend in ICU utilization include changing physician attitudes, in addition to more effective patient counseling and increased availability of hospital and community-based support services that provide alternatives to terminal intensive care.

Numerous studies in recent years have documented the increased risk of perioperative complications in patients with pulmonary disease. In assessing lung function before anesthesia and surgery, history and physical examination may be helpful but spirometry and blood gas determination are more accurate indicators of significant pulmonary disease. Risk apparently can be minimized by intensive chest therapy before and after surgery. Low-dose heparin therapy, in particular, is rec-mmended to prevent deep venous thrombosis and pulmonary embolism.

SUMMARY A broad spectrum of lung disease occurs in association with HIV infection. Included are both infectious and neoplastic processes and idiopathic disorders. To insure prompt, accurate, and efficient diagnosis, a logical, staged sequence of tests should be applied. Chest films and, in some instances, pulmonary function tests and gallium-67 citrate lung scans serve to provide objective indications of lung disease. Each of these tests is sensitive but nonspecific. Specific infecting organisms, particularly P. carinn, can be identified by examining sputum induced by inhalation of 3 per cent saline. Bronchoscopic procedures, including BAL and TBB, are highly sensitive and should be performed in patients having non-diagnostic sputum examinations. Tests involving antigen and antibody detection are of little use in the evaluation of individual patients. Detection of recurrent episodes of PCP is difficult because abnormalities in the usual screening tests may be residual from previous episodes. Finding P. carinii in sputum or bronchoscopic specimens soon (within 2 to 3 months) after a confirmed episode of PCP likely represents residual organisms rather than recrudescence of the infection. Empiric diagnosis of P. carinii should be employed only in limited circumstances when specific diagnostic studies are not available, are contraindicated, or are refused.

Recent work on the genetics of DDT resistance in the house fly, Musca domestica L., has indicated the presence of a single autosomal dominant gene for high tolerance to DDT. Two laboratory strains of house flies have been shown to carry this gene, the Multi X strain, studied by Maelzer and Kirk (1953), and the DDT I strain, studied by Lichtwardt (1955). These two strains are essentially the same with respect to DDT resistance, the Multi X strain being a branch of the DDT I strain which was selected for resistance to DDT by Bruce (1950) and Bruce and Decker (1950). Maelzer and Kirk (1953) suggested that this gene was responsible for the high resistance to DDT in field populations of house flies and the present study was undertaken to investigate this possibility.

In this paper the fishes of the Kaskaskia have been taken up one by one and in the case of the larger and better known kinds points of interest and usefulness have been discussed, while the smaller, rarer and less important kinds are only mentioned. In the course of this survey quantitative collections were made of the small bottom animals which are the most important constituents of the food of all kinds of larger fishes.

Transbronchial biopsy with the flexible fiberoptic bronchoscope is usually performed with the assistance of fluoroscopy in order to increase diagnostic yield and decrease the incidence of pneumothorax. We have compared the results of transbronchial biopsy performed with or without fluoroscopic guidance in patients with diffuse roentgenographic infiltrates who had or were suspected of having the acquired immunodeficiency syndrome. Neither the sensitivity for Pneumocystis carinii (88.5 versus 92%) nor the percentage of patients developing pneumothoraces after transbronchial biopsy (8.6 versus 11.1%) was significantly different in those patients who had the procedure without fluoroscopic guidance compared with those in whom fluoroscopy was used. There were no patients with significant hemorrhage or deaths in either group. This complication rate compares favorably with other reports of transbronchial biopsy in immunocompromised patients in which fluoroscopy was used. "Blind" transbronchial biopsy is a safe and effective diagnostic procedure in this patient population.

SUMMARY Blindness following blowout fractures is an unfortunate complication. The ophthalmologist must be aware of the events and sites of injury to the optic nerve which lead to visual problems. Preventive measures include immediate recognition of the signs of impending optic nerve compression and execution of treatment without delay. The importance of monitoring vision cannot be overstressed. Judicious surgery involves a post-injury delay in cases that are improving daily. The avoidance of additional surgical trauma with implant insertion during that period may help prevent postoperative blowout blindness.

MSOF is a complicated disorder that can involve every organ system in the body. Whatever causes or perpetuates the syndrome, its management involves the prevention and treatment of infection, the maintenance of tissue oxygenation, nutritional and metabolic support, and the support of individual organ systems. Unfortunately, this therapy often is nonspecific and of little proven efficacy. It also is potentially harmful in that measures used to benefit some organ systems may be detrimental to others. Further research is needed both to understand MSOF and to improve its management.

We studied regional blood flow (QR) using radiolabeled microspheres and measured hemodynamic variables in 20 anesthetized dogs in normal sinus rhythm and during ventricular fibrillation treated with cardiopulmonary resuscitation (CPR). Nonsimultaneous compression and ventilation CPR (NSCV-CPR) was performed in seven dogs with a pneumatic piston that gave 50 chest compressions/min with an open airway with 10 ventilations at an airway pressure of 33 mm Hg interposed between each fifth and sixth compression. Simultaneous compression and ventilation (SCV-CPR) was performed in seven dogs with the piston and in six other dogs with a circumferential pneumatic vest. Both devices gave 30 compressions/min simultaneously with 30 ventilations that elevated airway pressure to 80 mm Hg., The abdomen was bound during SCV-CPR. Regional blood flow (mean +/- SD) to the cerebral hemispheres, cardiac ventricles, and kidneys, expressed as ml/min/100 g tissue, was 3.1 +/- 4.0, 3.4 +/- 3.3 and 1.5 +/- 1.5, respectively, during NSCV-CPR; 11.5 +/- 5.9, 4.9 +/- 4.7 and 2.7 +/- 2.7 during SCV-CPR (vest); and 16.2 +/- 7.2, 11.0 +/- 4.0 and 20.1 +/- 20.2 during SCV-CPR (piston) (all p less than 0.05 compared with NSCV-CPR). These results indicate that QR to all organs studied is reduced below normal sinus rhythm levels during CPR for ventricular fibrillation, QR to the brain is proportionately greater than QR to the heart and kidneys, and QR to the brain is greater with both forms of SCV-CPR than with NSCV-CPR.

To study the effect of increases in lung volume on solute uptake, we measured clearance of 99mTc-diethylenetriaminepentaacetic acid (Tc-DTPA) at different lung volumes in 19 healthy humans. Seven subjects inhaled aerosol (1 micron activity median aerodynamic diam) at ambient pressure; clearance and functional residual capacity (FRC) were measured at ambient pressure (control) and at increased lung volume produced by positive pressure [12 cmH2O continuous positive airway pressure (CPAP)] or negative pressure (voluntary breathing). Six different subjects inhaled aerosol at ambient pressure; clearance and FRC were measured at ambient pressure and CPAP of 6, 12, and 18 cmH2O pressure. Six additional subjects inhaled aerosol at ambient pressure or at CPAP of 12 cmH2O; clearance and FRC were determined at CPAP of 12 cmH2O. According to the results, Tc-DTPA clearance from human lungs is accelerated exponentially by increases in lung volume, this effect occurs whether lung volume is increased by positive or negative pressure breathing, and the effect is the same whether lung volume is increased during or after aerosol administration. The effect of lung volume must be recognized when interpreting the results of this method.

A 38-year-old leukemic patient developed pericarditis and cardiac tamponade due to Aspergillus niger one month after undergoing bone marrow transplantation. She failed to improve even though amphotericin B and rifampin therapy had been initiated before infection was evident. Her unique case illustrates both the unusual presentations of invasive aspergillosis and the difficulty of diagnosing and treating this increasingly common disease.

We determined the influence of several factors on lung solute clearance using aerosolized 99mTc-diethylenetriaminepentaacetate. We used a jet nebulizer-plate separator-balloon system to generate particles with an activity median aerodynamic diameter of 1.1 micron, administered the aerosol in a standard fashion, and determined clearance half times (t1/2) with a gamma-scintillation camera. The following serial studies were performed in five anesthetized, paralyzed, intubated, mechanically ventilated dogs: 1) control, with ventilatory frequency (f) = 15 breaths/min and tidal volume (VT) = 15 ml/kg during solute clearance; 2) repeat control, for reproducibility; 3) increased frequency, with f = 25 breaths/min and VT = 10 ml/kg; 4) positive end-expiratory pressure (PEEP) of 10 cmH2O; 5) unilateral pulmonary arterial occlusion (PAO); and 6) bronchial arterial occlusion (BAO). Control t1/2 was 25 +/- 5 min and did not change in the repeat control, increased frequency, or BAO experiments. PEEP markedly decreased t1/2 to 13 +/- 3 min (P less than 0.01), and PAO increased it to 37 +/- 6 min (P less than 0.05). We conclude that clearance from the lungs by our method is uninfluenced by increased frequency, increases markedly with PEEP, and depends on pulmonary, not bronchial, blood flow.

AIDS presents ethical dilemmas about intensive care. Even with intensive care the outcome for patients with AIDS is poor. Care givers have no ethical or medical obligation to provide futile care. Decisions concerning competent patients should be made jointly by physicians and the informed patients themselves. For incompetent patients decisions should be made jointly by physicians and appropriate patient-surrogates in light of the previously expressed wishes of the patients. Care givers should encourage patients with AIDS to express their preferences about life-sustaining treatment in order to avoid dilemmas should these patients later become incompetent. The AIDS epidemic may force more explicit discussions about the allocation of limited health-care resources, such as intensive care. Such allocation decisions should not discriminate against patients with AIDS.

The records of 35 adult male patients with suspected Pneumocystis carinii pneumonia and the acquired immune deficiency syndrome were reviewed to determine the diagnostic utility of fiberoptic bronchoscopy. Twenty-two of the 24 patients (92%) shown to have Pneumocystis pneumonia were diagnosed by bronchoscopy; 20 patients were diagnosed after 1 bronchoscopy and 2 patients after 2 bronchoscopies. The sensitivity of bronchoscopy specimens for diagnosing Pneumocystis pneumonia was 79% for transbronchial biopsies (19 of 24), 78% for transbronchial biopsy touch preparations (7 of 9), 55% for bronchial washings (11 of 20), and 39% for bronchial brushings (7 of 18). The overall sensitivity of fiberoptic bronchoscopy was 85% (22 positive of 26 total bronchoscopies). Complications, occurring during 6 of the 37 bronchoscopies, were slight hemoptysis (1 patient), fever (2 patients), septic shock (1 patient), and pneumothorax (2 patients). Fiberoptic bronchoscopy is a safe and effective procedure for making the early diagnosis of Pneumocystis carinii pneumonia in adult male patients with the acquired immune deficiency syndrome.

Approximately 12,000 Americans suffer traumatic spinal cord injuries each year. This article discusses the management of their neurologic, respiratory, cardiovascular, gastroenterologic, and genitourinary complications in the critical care setting.

JI he muscles of respiration comprise three groups: the diaphragm, the intercostal and accessory muscles, and the muscles of the abdomen (Fig 1). All three groups have inspiratory and expiratory function and work together in intricate ways. This article reviews respiratory muscle action and interaction. We also discuss respiratory muscle dysfunction and its treatment in several disease states, including chronic obstructive pulmonary disease, asthma, chest wall deformity, obesity, generalized neuromuscular disorders, cervical cord injury, and unilateral and bilateral diaphragmatic paralysis. We conclude with a discussion of how training may influence respiratory muscle fatigue. Other issues, including central nervous system control of the respiratory muscles, are covered by Derenne and colleagues.1 Their article contains an extensive bibliography.

Eighty-two patients with the acquired immunodeficiency syndrome (AIDS) were admitted to the intensive care units (ICUs) at San Francisco General Hospital (SFGH) between March 1981 and December 1985. Of these patients, 69% died in the hospital, as did 87% of patients who required mechanical ventilation because of Pneumocystis carinii pneumonia and respiratory failure. Although the number of hospital admissions of patients with AIDS has increased steadily since the fourth quarter of 1982 (12 admissions) through the fourth quarter of 1985 (158 admissions), the number of admissions to the ICUs peaked at 17 in the second quarter of 1984 and decreased steadily, averaging 5 per quarter in 1985. This decrease was not explained by a reduction in the number of patients with P. carinii pneumonia or an improvement in their treatment. A survey of physicians at SFGH indicated that physicians are aware of the poor prognosis of patients with AIDS with P. carinii pneumonia and respiratory failure, believe that mechanical ventilation is infrequently indicated for this condition, and have become increasingly likely to discuss issues of resuscitation with their patients with AIDS. Therefore, possible explanations for this trend in ICU utilization include changing physician attitudes, in addition to more effective patient counseling and increased availability of hospital and community-based support services that provide alternatives to terminal intensive care.

We investigated possible mechanisms by which positive end-expiratory pressure (PEEP) increased cerebrospinal fluid pressure (PCSF) in anesthetized mechanically ventilated dogs. In part I of the study, PEEP was applied in 5 cmH2O increments each lasting 1–2 min, before and after a snare separated the spinal from the cerebral subarachnoid space in each animal. Next, with the spinal cord still ligated, the dogs were ventilated without PEEP while superior vena cava pressure (PSVC) was raised in 5 cmH2O increments by means of a fluid reservoir connected with the superior vena cava. Cerebrospinal fluid pressure in the cisterna magna increased immediately and in parallel with PEEP before and after the spinal subarachnoid space was occluded and also increased when PSVC was raised independently; in all circumstances the increase in PCSF correlated closely with PSVC (r = 0.926). In part II of the study, arterial blood gases were drawn before and after PEEP was applied in the same increments and for the same duration as in part I. Cerebrospinal fluid pressure measured with a hollow skull screw again rose in parallel with PEEP, whereas arterial carbon dioxide tension rose only slightly at 60 s. In part III of the study, mean arterial pressure (Pa) was allowed to decrease with PEEP or was held constant by distal aortic obstruction and volume infusion. Cerebrospinal fluid pressure increased regardless of Pa, but the increase was greater when Pa was held constant than when it fell with PEEP. We conclude that PEEP increases PCSF primarily by increasing PSVC and decreasing cerebral venous outflow. This effect is augmented if cerebral arterial inflow is increased as well.

To test the value of dexamethasone acetate for ameliorating acute mountain sickness (AMS), we conducted a double-blind, randomized study that compared the effects of 4 mg of dexamethasone acetate or a placebo (given every six hours for six doses beginning at the time of exposure) at 2700 and 2050 m. Study subjects, who were recruited from health professionals who attended continuing medical education programs at ski resorts in the Rocky Mountains, were classified as having AMS when they reported three or more of the five usual symptoms (headache, insomnia, dyspnea, anorexia, and/or fatigue) on a single day. All symptoms with an intensity of at least grade 2 (moderate) out of 5 were analyzed. At 2700 m, there was a 50% decrease in the mean AMS symptom score in the dexamethasone group (0.94 +/- 1.11 vs 1.84 +/- 1.44 [mean +/- SD]) and the incidence of AMS was 20% of that in the control group (3/38 vs 14/35). At 2050 m, there was no difference between dexamethasone and a placebo in the mean AMS symptom score (1.52 +/- 1.50 vs 1.24 +/- 1.33) and the incidence of AMS (5/25 vs 4/25). Dexamethasone ameliorates the usual symptoms of AMS at 2700 m but not at 2050 m.

The use of aerosolized pentamidine was investigated in ten patients with the acquired immunodeficiency syndrome (AIDS) and Pneumocystis carinii pneumonia (PCP) who had previous or concurrent severe adverse reactions or contraindications to trimethoprim-sulfamethoxazole or parenteral pentamidine. A dose of 600 mg pentamidine in 6 ml sterile water, aerosolized in a small-particle producing jet nebulizer was administered for 25 minutes once daily for an average of 10.5 days to these ten patients. All patients improved their arterial O2 saturation and showed clinical and roentgenographic improvement within six to 21 days of aerosol pentamidine therapy. No adverse systemic reactions occurred. The results of this small open trial indicate that aerosolized pentamidine is effective and can be given safely to AIDS patients with PCP who have had adverse reactions to trimethoprim-sulfamethoxazole or parenteral pentamidine.

A patient with primary hyperparathyroidism underwent cervical exploration and hemithyroidectomy. Only one normal parthyroid gland was found and was removed. Hypercalcemia persisted and subsequent arteriography localized a large mediastinal adenoma which was excised. Parathyroid autotransplantation of a small part of this tissue was performed and the patient was well for over a year. He again became markedly hypercalcemic and graft-dependent elevation of parathromone levels was demonstrated. Autograft resection resulted in normocalcemia. Nineteen months later hypercalcemia and elevated parathormone levels prompted re-exploration of the graft site and another enlarged implant was removed. This restored normocalcemia and normal parathromone levels. Parathyroid adenomatous tissue has the potential for autonomous hyperfunction, and caution must be exercised in its use in autotransplantation.

We recently surveyed the medical house staff at the University of California, San Francisco, and found that residents had a good understanding of the poor prognosis of patients with the acquired immunodeficiency syndrome (AIDS) and Pneumocystis carinii pneumonia who require intensive care for respiratory failure, and tended to favor early discussions with patients regarding resuscitation and intensive care. We used the same questionnaire to survey the house staffs of four other programs varying in geography and exposure to patients with AIDS. We found a striking correlation between the number of patients with AIDS cared for by the residents, the assessment of the prognosis of patients with AIDS with P carinii pneumonia, and house-staff attitudes toward discussions about resuscitation and intensive care. The results of this study suggest that the intensity of exposure to patients with AIDS determines the assessment of prognosis, and that one or both of these factors strongly influences attitudes toward intensive care. Regardless of these attitudes, early discussion of resuscitation and intensive care between physicians and patients with AIDS and P carinii pneumonia seems warranted.

Under this umbrella are grouped a multitude of disorders--with broadly similar manifestations but widely differing etiologies--believed to affect more than 10 million people in the United States. Cases attributable to known causes are treatable. Most, however, are of uncertain etiology and respond poorly to treatment. An updated diagnostic and therapeutic approach is presented.

It is not known whether positive end-expiratory airway pressure (PEEP) merely improves gas exchange in patients with the adult respiratory distress syndrome (ARDS) or if it also affects the resolution of their lung injury. The present investigation was performed to determine whether expiratory positive airway pressure (EPAP), a form of PEEP, is prophylactic in preventing the lung injury induced by oleic acid in dogs or in enhancing its resolution. Arterial and mixed venous blood gases and functional residual capacity (FRC) were measured in 14 pairs of mongrel dogs with indwelling catheters and permanent tracheostomies. One member of each pair was treated with 10 cm H2O EPAP through a valve attached to the tracheostomy tube. Both dogs received 0.06 ml/kg oleic acid intravenously at hour 0. Measurements were made at three, 12, and 24 hours, when EPAP was discontinued, and over the next six days. Five dog pairs were sacrificed at 72 hours; the other surviving animals were sacrificed at 168 hours. FRC was higher at three, 12, and 24 hours in dogs receiving EPAP than in the untreated dogs. The arterial oxygen tension (PaO2) was higher and the venous admixture (Qva/Qt) was lower at three and 12 hours in the dogs receiving EPAP than in the untreated dogs. However, after 24 hours, no differences were noted between the two groups in FRC, PaO2, Qav/Qt, mortality, final lung compliance to initial lung compliance differences, lung water to dry lung weight ratios, or histology. It is concluded that EPAP improves gas exchange during its administration, but has no demonstrable prophylactic effect on the resolution of lung injury in the oleic acid model of human ARDS.

The wide range of pulmonary infections associated with human immunodeficiency virus (HIV)-seropositivity, coupled with the possible presence of HIV-related neoplasms and non-HIV-related pulmonary processes, requires that most patients who are known to be or suspected of being HIV-seropositive should undergo a thorough diagnostic evaluation. This usually should include a screening evaluation that includes history, physical examination, screening laboratory tests, chest radiography, and arterial blood gas measurements. Pulmonary function testing and lung scanning also may be sensitive in screening, although these and the other procedures are nonspecific. Specific infectious organisms, particularly Pneumocystis carinii, may be identified through examination of induced sputum and by bronchoscopic procedures, including bronchoalveolar lavage and transbronchial biopsy. Open lung biopsy is not a routine part of the diagnostic evaluation. Although detection of recurrent episodes of pneumonia due to P carinii is difficult, empiric diagnosis and treatment of this disorder should be employed primarily when specific diagnostic techniques are unavailable or are refused.

More than twenty years ago, Ashbaugh and coworkers, (1), in a now classic article, described. 12 patients whose striking but uniform clinical, physiologic, roentgenographic,and pathologic abnormalities distinguished them from among 272adult patients who had received respiratory support in the intensive care units of Colorado General Hospital and Denver General Hospital. The 12patients all had severedyspnea, tachypnea, cyanosis that was refractory to oxygen therapy, decreased respiratory system compliance, and diffuse alveolar infiltrations on their chest radiographs. Pathologic examination in seven patients who died revealed atelectasis, vascular congestion and hemorrhage, severe pulmonary edema and hyaline membranes. Shortly afterward, Petty and coworkers (2), called this constellation of findings the adult respiratory distress syndrome (ARDS). Since then, ARDS has been recognized as an entity throughout the world and has been the subject of numerous conferences, hundreds of articles, and several books. As a result of this activity, much descriptive information has been obtained about ARDS, and we have learned a lot about its clinical features, physiologic disturbances, prognosis, and pathologic findings. And yet formidable problems remain: there is disagreement about exactly what ARDS is and on what causes it; more importantly, available empiric treatment is inadequate, and mortality remains unacceptably high (600/0 or more) (3). This appears to be one of the few points of agreement among investigators, but even that statement is arguable (4). We believe that much of the controversy concerning ARDS is explained by the lack of a satisfactory definition of this elusivesyndrome. How can you collect, much less compare, epidemiologicdata and mortality figures when there is no uniformly accepted (and used) definition? How can you study basic pathophysiologic mechanisms, understand natural history, and above all, evaluate new therapeutic approaches in what appears now to be an amalgam of many different disorders? The purpose of this article, therefore, is to propose an expanded definition of ARDS that takes into account new knowledge about

A broad spectrum of lung disease occurs in association with HIV infection. Included are both infectious and neoplastic processes and idiopathic disorders. To insure prompt, accurate, and efficient diagnosis, a logical, staged sequence of tests should be applied. Chest films and, in some instances, pulmonary function tests and gallium-67 citrate lung scans serve to provide objective indications of lung disease. Each of these tests is sensitive but nonspecific. Specific infecting organisms, particularly P. carinii, can be identified by examining sputum induced by inhalation of 3 per cent saline. Bronchoscopic procedures, including BAL and TBB, are highly sensitive and should be performed in patients having nondiagnostic sputum examinations. Tests involving antigen and antibody detection are of little use in the evaluation of individual patients. Detection of recurrent episodes of PCP is difficult because abnormalities in the usual screening tests may be residual from previous episodes. Finding P. carinii in sputum or bronchoscopic specimens soon (within 2 to 3 months) after a confirmed episode of PCP likely represents residual organisms rather than recrudescence of the infection. Empiric diagnosis of P. carinii should be employed only in limited circumstances when specific diagnostic studies are not available, are contraindicated, or are refused.