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Analysis of deaf college students' (N=100) performance on the Degrees of Reading Power test (which assesses reading comprehension with use of a modified cloze procedure) revealed that postlingually deaf students scored higher than prelingually deaf students. Scores correlated with degree of hearing loss for prelingually deaf students and articulation ability. (Author/CB)

The objective of this study was to discuss the case of a patient with severe smoke inhalation-related respiratory failure treated with extracorporeal support. The study was set in a 12-bed multi-trauma intensive care unit at a level one trauma center and hyperbaric medicine center. The patient under investigation had carbon monoxide poisoning, and developed acute respiratory distress syndrome and cardiovascular collapse following smoke inhalation. Rapid initiation of extracorporeal support, extreme inverse-ratio ventilation and intermittent prone positioning therapy were carried out. Admission and serial carboxyhemoglobin levels, blood gases, and computerized tomography of the chest were obtained. The patient developed severe hypoxia and progressed to cardiovascular collapse resistant to resuscitation and vasoactive infusions. Veno-venous extracorporeal support was initiated. Cardiovascular parameters of blood pressure, cardiac output, and oxygen delivery were maximized; oxygenation and ventilation were supported via the extracorporeal circuit. Airway pressure release ventilation and intermittent prone positioning therapy were instituted. Following 7 days of extracorporeal support, the patient was decannulated and subsequently discharged to a transitional care facility,neurologically intact. Smoke inhalation and carbon monoxide poisoning may lead to life-threatening hypoxemia associated with resultant cardiovascular instability. When oxygenation and ventilation cannot be achieved via maximal ventilatory management, extracorporeal support may prevent death if initiated rapidly.

Diffuse alveolar hemorrhage secondary to systemic lupus erythematosus (SLE) may cause life-threatening respiratory failure and may be associated with multiple organ failure. Extensive support may be necessary to sustain life while systemic therapy becomes effective. We report here a patient with profound respiratory failure secondary to SLE associated with multiorgan failure, who was supported with veno-arterial extracorporeal lung assist (ECLA), veno-venous ECLA, and multiple continuous renal replacement therapies during plasmapheresis. The full spectrum of extracorporeal life support and treatment modalities was performed seamlessly by a single service within the critical care department.

Group A streptococcus has emerged as a major cause of aggressive life-threatening deep-seated infections. In addition, toxic shock syndrome caused by Group A streptococcus was recognized in 1983. Group A streptococcus produces several potent exotoxins which explain the pathophysiology of these invasive infections. Other virulence factors such as M protein, which can impede phagocytosis, are associated with some Group A streptococcus. M protein and streptococcal pyrogenic exotoxins may act as super antigens. Host factors may influence the severity of infection. Blood purification techniques such as continuous renal replacement therapy and plasmapheresis can remove streptococcal exotoxins as well as inflammatory mediators. Replacement with fresh-frozen plasma corrects coagulopathy and may provide some antibody protection. Four patients with Group A streptococcus-toxic shock syndrome treated with continuous renal replacement therapy, plasmapheresis, or both showed dramatic, rapid improvement in cardiovascular dynamics and respiratory parameters. Two patients died. The mainstay of treatment for Group A streptococcus-toxic shock syndrome remains early diagnosis, aggressive surgical control of the infection, and appropriate antibiotics (i.e., penicillin and clindamycin). Flush resuscitation may rescue some patients from profound toxic shock. The mechanisms of action need to be delineated.

The Seldinger technique is commonly used to change central venous access catheters in the Intensive Care Unit. These catheters are routinely being changed to prevent septic complications. Some of these changes are performed by an "over-wire" technique. To assess the utility of postprocedural chest X-rays on critically ill patients after an over-wire catheter change, we followed 68 patients after they had 80 catheter changes. This study assesses catheter position by use of a postprocedural X-ray. During the study, we found no misplaced catheters and minimum symptomatology in 80 patients. The trauma/critical care fellows performing the procedures rated them as easy in 97.5 percent of the changes. The conclusion of the study is that, if the catheter change is technically easy and the patient has no symptoms, a postprocedural X-ray is not necessary.

Continuous arterial-venous and veno-venous hemodiafiltration are reliable methods of renal replacement therapy and are particularly suited to critically ill patients in acute renal failure. Fluid and uremic toxin removal from continuous hemodiafiltration is sufficient to allow unrestricted nutrition support. However, the hemodiafilter cannot discriminate between uremic toxins and nutrients. Therefore, the potential exists for significant nutrient loss during continuous hemodiafiltration. Amino acid loss during continuous hemodiafiltration is approximately 10-15 g/day, although in individual cases > or = 30 g/day can be lost. Neither lipids nor intact proteins are lost to any appreciable degree during continuous hemodiafiltration. Small amounts of glucose are lost if dextrose-free dialysate is used for dialysis. If dextrose-containing dialysate is used, significant amounts of glucose can be absorbed (35-45% of the infused glucose). Fluid replacement with dextrose-containing electrolyte solutions can also lead to significant infusion of glucose. Vitamin and mineral losses during continuous hemodiafiltration are not known; neither are the vitamin requirements for patients receiving continuous hemodiafiltration. Effects of continuous hemodiafiltration on vitamin and mineral loss and status remain an important research question.

Extracorporeal life support (ELS) systems may be run by certified perfusionists, specially trained nurses or respiratory therapy staff. Guidelines for the training, certification and retraining of ELS operators have been established by the Extracorporeal Life Support Organization. Recommendations include "... a well defined program for staff training, certification, and retraining". Some clinicians have suggested that ELS operators be certified and recertified in an animal laboratory. But such practice involves veterinary expenses, animal use issues and considerable clean-up and disposal. We describe an alternative method of training, using an in vitro physiologic model designed to simulate various pathophysiologic states. In addition, the in vitro physiologic model may be used to evaluate membrane lung characteristics. This model's ease of construction, maintenance and use for training compared with live animal techniques are discussed. Research capabilities may be more flexible than with the use of the live animal technique. The in vitro physiologic model can be a useful and convenient asset to an extracorporeal membrane oxygenation/extracorporeal carbon dioxide removal (ECMO/ECCO2R) program.

Objective: To compare urea nitrogen removal by continuous hemodiafiltration vs. functional native kidneys in critically ill, septic patients receiving > 2 g of amino acids/kg body weight per day., Design: Prospective, comparative, unblinded study., Setting: Trauma critical care units of a Level I adult trauma hospital., Patients: Fifteen septic patients with multiple organ failure including renal failure who were receiving continuous hemodiafiltration; 11 septic patients with multiple organ failure without renal failure (control group). Ages of patients ranged from 18 to 60 yrs., Interventions: Collection of effluent (dialysate + ultrafiltrate) from hemodiafilters. Collection of urine from control patients., Measurements: Urea nitrogen and creatinine concentrations in blood, urine, and the hemodiafiltration effluent, measured every 24 hrs for 6 days. Effluent and urine volumes were measured., Main Results: Hemodiafilters were operational for 21.8 +/- 3.0 hrs/day. Mean urea nitrogen removal in the renal failure group was 28 +/- 10 g/day. Blood urea nitrogen was stable over the 6-day study period. In control subjects, urea nitrogen removal was 27 +/- 9 g/day, which was not significantly different from the continuous hemodiafiltration group. Blood urea nitrogen concentrations in control patients increased over the 6-day study period (p < .05). Urea nitrogen removal correlated moderately well with amino acid intake in the control group (r2 = .30), but not in the continuous hemodiafiltration group (r2 = .0004). In patients receiving continuous hemodiafiltration, effluent volume was most significantly correlated with urea nitrogen removal (r2 = .69)., Conclusions: The technique of continuous hemodiafiltration can remove substantial amounts of urea nitrogen, similar to that of normal native kidneys. In addition, at amino acid intake rates of > 2 g/kg body weight/day, urea nitrogen removal during continuous hemodiafiltration remains a function of effluent volume, so there is no need to restrict amino acid intake in acute renal failure patients supported with continuous hemodiafiltration.

Standard care for patients with renal failure while in an intensive care unit involves traditional hemodialysis or peritoneal dialysis and protein restriction. We present a case of a patient with renal failure supported with continuous arteriovenous hemofiltration with dialysis (CAVH-D) who was given full protein alimentation. Total daily urea clearance was measured from the CAVH-D output. Protein load was 196 +/- 34 g/day while receiving total parenteral nutrition and 164 +/- 30 g/day while receiving enteral alimentation. Serum blood urea nitrogen was controlled between 40 and 75 mg/dL, except during septic episodes. Nitrogen balance was estimated based upon known alimentation protein load and measurable and estimated nitrogenous losses. The patient was potentially in nitrogen equilibrium during most of the dialysis period. The cumulative nitrogen balance was positive by 5.2 g after 67 days of dialysis. Volume of alimentation was 3.49 +/- 0.7 liters/day. With CAVH-D, the renal failure patient can receive full alimentation without volume or protein load limitations. Furthermore, nitrogen balances can be estimated easily while the patient is on CAVH-D.

Objective: To document the efficacy of continuous arteriovenous hemofiltration with dialysis following renal failure, without protein restriction, and to explore the magnitude and clinical applications of total daily urea clearance., Design: A noncomparative, descriptive account of a case series. Data were collected prospectively and analyzed retrospectively., Setting: A tertiary care facility in a statewide emergency medical services system., Patients: Twenty-eight patients with renal failure were supported by continuous arteriovenous hemofiltration with dialysis in a critical care unit during a 14-month period (21 patients with multitrauma; three patients with soft tissue infections; and four patients with multisystem organ failure who had been transferred from other hospitals). Renal failure was most commonly due to multisystem organ failure or associated with adult respiratory distress syndrome., Results: Continuous arteriovenous hemofiltration with dialysis days totaled 308 (mean 10.9). All patients received full protein alimentation (mean protein load 131 g/day). The blood urea nitrogen concentration was controlled, generally to 40 to 75 mg/dL (14.3 to 26.7 mmol/L) within 3 to 5 days. Total daily urea clearance ranged from 15 to 21 g/day. Five (18%) of the 28 patients survived., Conclusion: Continuous arteriovenous hemofiltration with dialysis appears to be effective for the control of blood urea nitrogen and clearance of urea. This modality also permits full protein alimentation. Total daily urea clearance can be calculated easily and may have important clinical uses and implications.

Objective: To describe the hospital course and outcomes of trauma patients requiring ICU stays greater than 30 days and the charges they incur., Design: A retrospective case series analysis of data collected from patient charts and trauma registry., Setting: A Level I regional trauma center that is part of a statewide trauma system., Patients: Over a 3-yr period, 87 patients (3% of all trauma ICU admissions) had prolonged stays (greater than 30 days) in the ICU; they constitute the study group. Blunt trauma was responsible for 90% of injuries, and the mean Injury Severity Score was 34 +/- 16 SD., Results: Mechanical ventilation was required for 78.5% of the time spent in the ICU. The mean time spent on mechanical ventilators was 47 +/- 23 days; in the ICU, 60 +/- 27 days; and in the hospital, 72 +/- 29 days. Infectious complications occurred in 90% and organ dysfunction was seen in 76% of patients. The overall mortality rate was 17.2% (31% for patients greater than 65 yr). Patients less than 40 yr had lower mortality rates despite a significantly higher Injury Severity Score and lower Glasgow Coma Scale score compared with those greater than 65 yr. More patients greater than 65 yr were discharged to chronic care facilities than those younger (23% vs. 5%). The number of patients followed at 3 and 12 months after discharge was 74% and 54%, respectively, with only two deaths. The mean hospital and professional charges to the patients were $101,000 +/- 61,000 and $35,000 +/- 13,000, respectively., Conclusion: Length of ICU stay was most closely associated with the need for mechanical ventilation. The presence of premorbid illness, age greater than 65 yr, and organ dysfunction was associated with increased mortality. Although trauma patients requiring prolonged ICU stays utilize many resources, the ultimate outcome may be fairly good.

Renal failure is a common sequela of mass casualty, particularly when crush injury is involved. Traditional management of renal failure with hemodialysis equipment may be difficult or inaccessible due to lack of electricity and water supply or damage to existing equipment. Furthermore, a sudden new population of renal failure patients may overwhelm an existing dialysis program. The rapid mobilization of traditional hemodialysis equipment may be delayed due to limited supply, manufacturing delays, or inventory shortages. For these reasons, we propose the use of continuous arteriovenous hemofiltration with dialysis (CAVH-D) as an alternative renal support modality for the mass casualty situation.