Early outcomes of twin-peg mobile-bearing unicompartmental knee arthroplasty compared with primary total knee arthroplasty.

AIMS: Since redesign of the Oxford phase III mobile-bearing unicompartmental knee arthroplasty (UKA) femoral component to a twin-peg design, there has not been a direct comparison to total knee arthroplasty (TKA). Thus, we explored differences between the two cohorts. PATIENTS AND METHODS: A total of 168 patients (201 knees) underwent medial UKA with the Oxford Partial Knee Twin-Peg. These patients were compared with a randomly selected group of 177 patients (189 knees) with primary Vanguard TKA. Patient demographics, Knee Society (KS) scores and range of movement (ROM) were compared between the two cohorts. Additionally, revision, re-operation and manipulation under anaesthesia rates were analysed. RESULTS: The mean follow-up for UKA and TKA groups was 5.4 and 5.5 years, respectively. Six TKA (3.2%) versus three UKAs (1.5%) were revised which was not significant (p = 0.269). Manipulation was more frequent after TKA (16; 8.5%) versus none in the UKA group (p < 0.001). UKA patients had higher post-operative KS function scores versus TKA patients (78 versus 66, p < 0.001) with a trend toward greater improvement, but there was no difference in ROM and KS clinical improvement (p = 0.382 and 0.420, respectively). CONCLUSION: We found fewer manipulations, and higher functional outcomes for patients treated with medial mobile-bearing UKA compared with TKA. TKA had twice the revision rate as UKA although this did not reach statistical significance with the numbers available. Cite this article: Bone Joint J 2016;98-B(10 Suppl B):28-33.

Type 1 autoimmune pancreatitis and IgG4-related sclerosing cholangitis is associated with extrapancreatic organ failure, malignancy, and mortality in a prospective UK cohort.

OBJECTIVES: Type I autoimmune pancreatitis (AIP) and IgG4-related sclerosing cholangitis (IgG4-related SC) are now recognized as components of a multisystem IgG4-related disease (IgG4-RD). We aimed to define the clinical course and long-term outcomes in patients with AIP/IgG4-SC recruited from two large UK tertiary referral centers. METHODS: Data were collected from 115 patients identified between 2004 and 2013, and all were followed up prospectively from diagnosis for a median of 33 months (range 1-107), and evaluated for response to therapy, the development of multiorgan involvement, and malignancy. Comparisons were made with national UK statistics. RESULTS: Although there was an initial response to steroids in 97%, relapse occurred in 50% of patients. IgG4-SC was an important predictor of relapse (P<0.01). Malignancy occurred in 11% shortly before or after the diagnosis of IgG4-RD, including three hepatopancreaticobiliary cancers. The risk of any cancer at diagnosis or during follow-up when compared with matched national statistics was increased (odds ratio=2.25, CI=1.12-3.94, P=0.02). Organ dysfunction occurred within the pancreas, liver, kidney, lung, and brain. Mortality occurred in 10% of patients during follow-up. The risk of death was increased compared with matched national statistics (odds ratio=2.07, CI=1.07-3.55, P=0.02). CONCLUSIONS: Our findings suggest that AIP and IgG4-SC are associated with significant morbidity and mortality owing to extrapancreatic organ failure and malignancy. Detailed clinical evaluation for evidence of organ dysfunction and associated malignancy is required both at first presentation and during long-term follow-up.

The effect of trauma program registry on reported mortality rates.

BACKGROUND: This study assesses the relationship that the brand of trauma program registry (TPR) has on mortality rate (MR) in the reports prepared by the American College of Surgeons Committee on Trauma (ACSCOT) trauma center (TC) site surveyors. METHODS: Data from 242 ACSCOT adult TC survey reports (88 Level I, 115 Level II, and 39 Level III) were analyzed for annual trauma volume, injury severity score (ISS), MR, and TPR. Six TPR (A through F) were identified; group F was a composite of several infrequently used TPRs. This report focuses on the ISS range 16-24 because of the likelihood that the mean for each TC would be near 20 and MR is high enough so that a difference, if present, could be statistically documented. RESULTS: For the total group, MR showed no correlation with TC volume or TC level for ISS 16-24. MR was significantly different according to which TPR was used by the TCs. The MR is less (4.8%) for 14 high volume TCs (over 1200 admits) using TPR A compared with 33 low volume TCs (below 800 admits) using TPR A (6.34%). CONCLUSION: The MR for ISS 16-24 in ACSCOT-surveyed TCs differs within subgroups based on type of TPR utilized. This may reflect improper use of the software programs. Enhanced skill in the application of software programs designed to generate ISS scores is essential if meaningful studies on the effects of improved trauma care on MR are to be conducted. Hand scored ISS by trained personnel may circumvent this problem.

Mathematical modeling to define optimum operating room staffing needs for trauma centers.

BACKGROUND: Level II trauma centers may be verified (1999, American College of Surgeons Committee on Trauma) with an on-call operating room team if the performance-improvement program shows no adverse outcomes. Using queuing and simulation methodology, this study attempted to add a volume guideline. STUDY DESIGN: Data from 72 previously verified trauma centers identified multiple demographic factors, including specific information about the first trauma-related operation that was done between 11:00 PM and 7:00 AM each month for 12 consecutive months. RESULTS: The annual admissions averaged 1,477 for 37 Level I trauma centers, 802 for 28 Level II trauma centers, 481 for 4 Level III trauma centers, and 731 for 3 pediatric trauma centers. The annual admissions correlated with the number of operations done between 11:00 PM and 7:00 AM (p < 0.001). These 946 operations were performed by general surgery (39%), neurosurgery (8%), orthopaedic surgery (33%), another specialty (9%), or multiple services (10%). Admission to operation time was within 30 minutes for 12.1% of patients (2.6% for blunt and 24.1% for penetrating injuries). The probability of operation within 30 minutes of arrival varied with the number of admissions and with the percentage of penetrating versus blunt injuries. The likely number of operations from 11:00 PM to 7:00 AM would be 19 for 500 annual admissions, 26 for 750 annual admissions, and 34 for 1,000 annual admissions, with 5.83, 7.98, and 10.13 patients, respectively, going to operation within 30 min. The probability that two rooms would be occupied simultaneously was 0.14 and 0.24 for centers admitting 500 and 1,000 patients, respectively. CONCLUSIONS: Trauma centers performing fewer than six operations between 11:00 PM and 7:00 AM per year could conserve resources by using an immediately available on-call team, with responses monitored by the performance-improvement program.

The risk assessment profile score identifies trauma patients at risk for deep vein thrombosis.

BACKGROUND: The identification of trauma patients at risk for the development of deep venous thrombosis (DVT) at the time of admission remains difficult. The purpose of this study is to validate the risk assessment profile (RAP) score to stratify patients for DVT prophylaxis. METHODS: All patients admitted from November 1998 thru May 1999 were evaluated for enrollment. We prospectively assigned patients as low risk or high risk for DVT using the RAP score. High-risk patients received both pharmacologic and mechanical prophylaxis. Low-risk patients received none. Surveillance duplex Doppler scans were performed each week of hospitalization or if symptoms developed. Hospital charges for prophylaxis were used to determine the savings in the low-risk group. Statistical differences between the risk groups for each factor of the RAP and development of DVT were determined by the chi-squared test, with significance at a probability value of less than .05. RESULTS: There were 102 high-risk (64%) and 58 low-risk (36%) individuals studied. Eleven of the high-risk group (10.8%) experienced the development of DVT (asymptomatic, 64%). None of the low-risk group was diagnosed with DVT. Five of the 16 RAP factors were statistically significant for DVT. Eliminating prophylaxis and Doppler scans in low-risk patients resulted in a total savings of $18,908 in hospital charges. CONCLUSIONS: The RAP score correctly identified trauma patients at increased risk for the development of DVT. Despite prophylaxis, the high-risk group warrants surveillance scans. Withholding prophylaxis in low-risk patients can reduce hospital charges without risk.

Dynamic helical computed tomography scan accurately detects hemorrhage in patients with pelvic fracture.

BACKGROUND: The purpose of this study was to evaluate the use of dynamic helical computed tomography (CT) scan for screening patients with pelvic fractures and hemorrhage requiring angiographic embolization for control of bleeding. METHODS: Patients admitted to the trauma service with pelvic fractures were identified from the trauma registry. Data retrieval included demographics, hemodynamic instability, Injury Severity Score, blood transfusion requirement, length of stay, and mortality. CT scans obtained during the initial evaluation were reviewed for the presence of contrast extravasation and correlated with angiographic findings. Data are reported as mean +/- SEM, with P<.05 considered significant. RESULTS: Seven thousand seven hundred eighty-one patients were admitted from June 1994 to May 1999. A pelvic fracture was diagnosed in 660 (8.5%). Two hundred ninety (44.0%) dynamic helical CT scans were performed, of which 13 (4.5%) identified contrast extravasation. Nine (69%) were hemodynamically unstable and had pelvic arteriography performed. Arterial bleeding was confirmed in all and controlled by embolization. Patients with contrast extravasation had significantly greater Injury Severity Score, blood transfusion requirement and length of stay. Sensitivity, specificity, and accuracy of CT scan for identifying patients requiring embolization were 90.0%, 98.6%, and 98.3%, respectively. CONCLUSIONS: Early use of dynamic helical CT scanning in the multiply injured patient with a pelvic fracture accurately identifies the need for emergent angiographic embolization.

Effects of body temperature on accuracy of continuous cardiac output measurements.

Intermittent measurement of cardiac output is routine in the critically ill surgical patient. A new catheter allows real-time continuous measurement of cardiac output. This study evaluated the impact of body temperature variation on the accuracy of these measurements compared to standard intermittent bolus thermodilution technique. This prospective study in a university hospital surgical intensive care unit included 20 consecutive trauma patients. Data were collected with pulmonary artery catheters, which allowed both continuous (COC) and bolus (COB) thermodilution measurements. The catheter was placed through either the subclavian or internal jugular vein. Measurements for COB were performed using a bolus (10 cm3) of ice-cold saline with a closed-injectate delivery system at end-expiration. Computer-generated curves were created on a bedside monitor, and the average of three measurements within 10% of one another was used as COB. COC was determined as the average of the displayed CO before and after thermodilution CO measurements. Body temperature was measured from the pulmonary artery catheter and was grouped as < or =36.5 degrees C, 36.6-38.4 degrees C, and > or =38.5 degrees C. COB and COC were compared for agreement by plotting the mean of the differences (COB - COC) between the methods. The differences were plotted against the average of each pair and analyzed with linear regression. One hundred seventy-eight paired measurements were made over a period of 1 to 3 days. CO ranged from 3.7 to 15.5 L/min. Eighty-one percent of measurements were at a temperature of 36.5-38.4 degrees C. Approximately 7% of measurements were at a temperature below 36.5 degrees C and 11.2% were in patients with a core temperature above 38.5 degrees C. Correlation between the two techniques was 0.96, 0.91, and 0.82 for temperatures of < or =36.5 degrees C, 36.6-38.4 degrees C, and > or = 38.5 degrees C, respectively. In conclusion, the COC measurements correlate well with COB in trauma patients with a core temperature < or =38.5 degrees C. The accuracy degraded at higher temperatures, which may be related to the smaller signal-to-noise ratio at elevated body temperatures.

Institutional and individual learning curves for focused abdominal ultrasound for trauma: cumulative sum analysis.

OBJECTIVE: To evaluate both institutional and individual learning curves with focused abdominal ultrasound for trauma (FAST) by analyzing the incidence of diagnostic inaccuracies as a function of examiner experience for a group of trauma surgeons performing the study in the setting of an urban level I trauma center. SUMMARY BACKGROUND DATA: Trauma surgeons are routinely using FAST to evaluate patients with blunt trauma for hemoperitoneum. The volume of experience required for practicing trauma surgeons to be able to perform this examination with a reproducible level of accuracy has not been fully defined. METHODS: The authors reviewed prospectively gathered data for all patients undergoing FAST for blunt trauma during a 30-month period. All FAST interpretations were validated by at least one of four methods: computed tomography, diagnostic peritoneal lavage, celiotomy, or serial clinical evaluations. Cumulative sum (CUSUM) analysis was used to describe the learning curves for each individual surgeon at target accuracy rates of 85%, 90%, and 95% and for the institution as a whole at target examination accuracy rates of 85%, 90%, 95%, and 98%. RESULTS: Five trauma surgeons performed 546 FAST examinations during the study period. CUSUM analysis of the aggregate experience revealed that the examiners as a group exceeded 90% accuracy at the outset of clinical examination. The level of accuracy did not improve with either increased frequency of performance or total examination experience. The accuracy rates observed for each trauma surgeon ranged from 87% to 98%. The surgeon with the highest accuracy rate performed the fewest examinations. No practitioner demonstrated improved accuracy with increased experience. CONCLUSIONS: Trauma surgeons who are newly trained in the use of FAST can achieve an overall accuracy rate of at least 90% from the outset of clinical experience with this modality. Interexaminer variations in accuracy rates, which are observed above this level of performance, are probably related more to issues surrounding patient selection and inherent limitations of the examination in certain populations than to practitioner errors in the performance or interpretation of the study.

Zone I retroperitoneal hematoma identified by computed tomography scan as an indicator of significant abdominal injury.

OBJECTIVE: All zone I retroperitoneal hematomas (Z1RPHs) identified at laparotomy for blunt trauma traditionally require exploration. The purpose of this study was to correlate patient outcome after blunt abdominal trauma with the presence of Z1RPH diagnosed on admission computed tomography (CT) scan. METHODS: This is a retrospective review of patients with blunt trauma who were admitted to a Level 1 trauma center and who underwent CT scan during a 40-month period. All scans with a traumatic injury were reviewed to identify and grade Z1RPH as mild, moderate, or severe. Patients requiring operative treatment were compared with those who were observed. Statistical analysis was performed with Student's t test and chi-square test, with P < .05 considered significant. RESULTS: Eighty-five (15.5%) of the CT scans were positive for Z1RPH. None of the 50 patients with a mild Z1RPH had their treatment altered. Of the 29 patients with a moderate or severe Z1RPH, 8 required celiotomy. The patients requiring celiotomy had significant elevations of solid viscus score (SVS) (4.9 +/- 1.6 versus 1.8 +/- 0.3), abdominal Abbreviated Injury Scale (3.8 +/- 0.3 versus 2.6 +/- 0.3), and transfusion requirements (13 +/- 4 versus 2 +/- 1). All patients (N = 4) with an SVS >4 required operative treatment. Seventy-two percent of patients with more than 1 intra-abdominal injury required abdominal exploration. CONCLUSIONS: The presence of a moderate or severe Z1RPH and more than 1 intra-abdominal injury or an SVS >4 on admission CT scan is an important radiographic finding. This injury pattern should be considered a contraindication for nonoperative treatment of the associated solid organ injury.

A prospective comparison of laparoscopic ultrasound vs intraoperative cholangiogram during laparoscopic cholecystectomy.

BACKGROUND: The laparoscopic ultrasound (US) probe provides a new modality for evaluating biliary anatomy during laparoscopic cholecystectomy (LC). METHODS: We performed a laparoscopic US examination in 65 patients without suspected common bile duct (CBD) stones prior to the performance of a laparoscopic cholangiogram (IOC). We then compared the cost, time required, surgeon's assessment of difficulty, and interpretations of findings. RESULTS: There was a significant difference in the cost of US versus the cost of IOC ($362 +/- 12 versus $665 +/- 12; p < 0.05). Surgeons who had performed >10 US (EXP) were compared with those who had performed 10 US exams.

Prospective, randomized comparison of epidural versus parenteral opioid analgesia in thoracic trauma.

OBJECTIVE: To evaluate systemic versus epidural opioid administration for analgesia in patients sustaining thoracic trauma. SUMMARY BACKGROUND DATA: The authors have previously shown that epidural analgesia significantly reduces the pain associated with significant chest wall injury. Recent studies report that epidural analgesia is associated with a lower catecholamine and cytokine response in patients undergoing elective thoracotomy compared with patient-controlled analgesia (PCA). This study compares the effect of epidural analgesia and PCA on pain relief, pulmonary function, cathechol release, and immune response in patients sustaining significant thoracic trauma. METHODS: Patients (ages 18 to 60 years) sustaining thoracic injury were prospectively randomized to receive epidural analgesia or PCA during an 18-month period. Levels of serum interleukin (IL)-1beta, IL-2, IL-6, IL-8, and tumor necrosis factor-alpha (TNF-alpha) were measured every 12 hours for 3 days by enzyme-linked immunosorbent assay. Urinary catecholamine levels were measured every 24 hours. Independent observers assessed pulmonary function using standard techniques and analgesia using a verbal rating score. RESULTS: Twenty-four patients of the 34 enrolled completed the study. Age, injury severity score, thoracic abbreviated injury score, and length of hospital stay did not differ between the two groups. There was no significant difference in plasma levels of IL-1beta, IL-2, IL-6, or TNF-alpha or urinary catecholamines between the two groups at any time point. Epidural analgesia was associated with significantly reduced plasma levels of IL-8 at days 2 and 3, verbal rating score of pain on days 1 and 3, and maximal inspiratory force and tidal volume on day 3 versus PCA. CONCLUSIONS: Epidural analgesia significantly reduced pain with chest wall excursion compared with PCA. The route of analgesia did not affect the catecholamine response. However, serum levels of IL-8, a proinflammatory chemoattractant that has been implicated in acute lung injury, were significantly reduced in patients receiving epidural analgesia on days 2 and 3. This may have important clinical implications because lower levels of IL-8 may reduce infectious or inflammatory complications in the trauma patient. Also, tidal volume and maximal inspiratory force were improved with epidural analgesia by day 3. These results demonstrate that epidural analgesia is superior to PCA in providing analgesia, improving pulmonary function, and modifying the immune response in patients with severe chest injury.

Use of the rapid/shallow breathing index as an indicator of patient work of breathing during pressure support ventilation.

BACKGROUND: Measuring patient work of breathing (WOBpt) has been suggested to provide safe, aggressive weaning from mechanical ventilation. We compared WOBpt and pressure-time-product (PTP) to routine weaning parameters [breath rate (f), tidal volume (VT), frequency/tidal volume ratio (f/VT)] at different levels of pressure support ventilation (PSV). METHODS: Fifteen patients in the surgical intensive care unit requiring prolonged weaning (more than 3 days) were entered in the study. A balloon-tipped esophageal catheter was placed and position confirmed by inspection of pressure and flow waveforms. Each patient was randomly assigned to breathe with 5, 10, 15, and 20 cm H2O of PSV. After 30 minutes, 40 breaths were recorded and analyzed. Measurement of WOBpt PTP, f, VT, and f/VT were made using the Bicore CP-100 monitor. Mean values for each parameter were calculated. PTP and WOBpt were plotted against f/VT to determine correlation coefficient. RESULTS: PTP, WOBpt and f/VT decreased in a stepwise fashion as PSV was increased. The f/VT correlated most closely with WOBpt (r = 0.983) and PTP (r = 0.972). Monitoring f alone also correlated with WOBpt (r = 0.894) and PTP (r = 0.881). All patients were weaned from the ventilator (mean duration, 22 +/- 5.9 days). Nine patients required tracheostomy before final liberation from the ventilator (mean duration, 22 +/- 5.9 days). Nine patients required tracheostomy before final liberation from the ventilator. CONCLUSIONS: Direct measurement of WOBpt is invasive, expensive, and' may be confusing to clinicians. Monitoring f/VT may be useful when changing PSV during weaning.

The effect of early versus late fasciotomy in the management of extremity trauma.

BACKGROUND: Recent reports have demonstrated an increase in the number of complications associated with delayed timing of fasciotomy for trauma. This study examines the effectiveness of early (less than 12 hours) versus late (more than 12 hours) fasciotomy in the injured extremity. METHODS: This is a retrospective review of 88 patients undergoing fasciotomy for extremity trauma admitted to the University of Cincinnati from January 1990 through December 1995. Records were reviewed for demographics, compartment pressures, time and type of fasciotomy, complications, limb salvage, and mortality. Statistical analysis was determined with chi-squared, multivariant regression analysis, and Student's t test with significance at p less than 0.05. RESULTS: Sixty-one (69%) patients had fasciotomy performed before 12 hours and twenty-seven (31%) after 12 hours. Although the rates of infection differed significantly between the two groups (7.3% for early versus 28% for late), the rates of limb salvage and neurologic sequelae were similar. Age, mechanism, shock, associated injuries, and time to fasciotomy were not predictive of complications. CONCLUSIONS: Fasciotomy for trauma is most efficacious when performed early. However, when performed late, it results in similar rates of limb salvage as compared with early fasciotomy but at the increased risk of infection. These results support aggressive use of fasciotomy in extremity trauma regardless of time of diagnosis.

Blunt carotid artery injuries.

BACKGROUND: Blunt carotid artery trauma remains a rare but potentially devastating injury. Early detection and treatment remain the goals of management. Our objective was to identify patients sustaining blunt carotid injuries at a regional trauma center and report on the incidence, demographics, diagnostic workup, management, and outcome. STUDY DESIGN: A retrospective chart review was performed of patients sustaining blunt carotid artery injury between 1990 and 1996. RESULTS: Twenty patients were identified during the 7-year period. All patients suffered blunt trauma, with motor vehicle accidents being the most common mechanism, and the internal carotid the most frequently injured vessel. Associated injuries were present in all patients, with head (65%) or chest (65%) injuries being the most common. The combination of head and chest trauma (45%) was found to be associated with a 14-fold increase in the likelihood of carotid injury. Cerebral angiography was diagnostic in all patients and the majority were treated nonoperatively with anticoagulation. Twenty percent of patients were discharged with a normal neurologic exam, while 45% left with a significant neurologic deficit. Overall mortality was 5%. CONCLUSIONS: Blunt carotid injuries are rare but are associated with significant morbidity and mortality. The combination of craniofacial and chest wounds should raise the index of suspicion for blunt carotid injury. Anticoagulation was associated with the least morbidity.

Discrimination of late apoptotic/necrotic cells (type III) by flow cytometry in solid tumors.

A method is described for the discrimination of Type III, late apoptotic, and necrotic cells, to improve the accuracy of proliferation and ploidy determinations of breast tumors. We selected an immunological probe, antitubulin antibody, and a DNA specific stain, propidium iodide (PI), both capable of crossing the permeable membranes of Type III, late apoptotic, and necrotic cells. This study utilized MDA-MB-175-VII breast carcinoma cells deprived of oxygen for up to 11 d to simulate intratumoral hypoxia, and 10 human breast tumors and mouse-human breast tumor xenografts disassociated by mechanical or enzymatic means. After 24 h under hypoxic conditions, the MDA cells displayed characteristics associated with both apoptosis and necrosis. Approximately 50% of day 1 cells showed membrane permeability by trypan blue and absence of DNA laddering; however, by day 3-4 characteristic apoptotic DNA laddering by gel electrophoresis was evident. Substantial DNA content loss, further evidenced by a reduction in PI staining and fluorescent microscopy, was obvious by day 5. By day 10, 98% of cells showed no propidium iodide staining by conventional PI live/dead cell gating, but were positive for antitubulin antibody staining. When the study was extended to the analysis of ten tumors, antitubulin antibody showed a range of 78%-96% staining with a median value of 87.5%, while PI staining showed a range of 8%-74% with a median value of 11.5%. This study demonstrates that a large percentage of cells in tumors and hypoxic cell populations have significantly reduced DNA content, such that conventional live/dead cell gating using PI may include many Type III cells as live cells, thus significantly altering data involving multicolor investigations.

Respiratory support of the head-injured patient.

Approximately 500,000 patients present with a CHI annually in the United States alone. Up to 20% of these injuries are classified as severe. Appropriate and aggressive intensive care of CHI patients will certainly reduce both the morbidity and mortality rates. Early therapy includes provision of adequate ventilation and oxygenation and definitive care based on clinical assessment. Once the acute phase of the injury has passed, supportive therapy should be maintained as long as secondary injury or complications are avoided. Respiratory care of CHI patients is important though different in each phase of the disease. Proper placement of and maintenance of airways, efficient use of and withdrawal from the mechanical ventilator, and providing adequate pulmonary toilet in order to treat or avoid pneumonia are but a few of the very important respiratory care practices necessary to provide optimal outcomes in patients with CHI.

Combined differential lung ventilation and inhaled nitric oxide therapy in the management of unilateral pulmonary contusion.

Unilateral pulmonary contusion after blunt thoracic trauma can prove to be a devastating injury. Regional disturbances in blood flow and alveolar ventilation can significantly alter pulmonary function. We present a case report of unilateral pulmonary contusion that resulted in significant pulmonary dysfunction. This patient was successfully managed with multimodality therapy consisting of differential lung ventilation and inhaled nitric oxide. The effect of nitric oxide applied to the "normal" lung, the "injured" lung, and both lungs is described. The use of inhaled nitric oxide was associated with an increase in oxygenation when applied to the normal or both lungs. The use of nitric oxide in conjunction with differential lung ventilation appeared to offer benefit in this patient with severe unilateral pulmonary contusion.

Inhaled nitric oxide in acute respiratory distress syndrome.

BACKGROUND: Inhaled nitric oxide has been shown to improve oxygenation in select patients with acute respiratory distress syndrome (ARDS). OBJECTIVE: The purpose of this study was to evaluate the clinical response to four concentrations of inhaled nitric oxide (NO) in 20 patients with ARDS. METHODS: All patients with ARDS were eligible for the study. ARDS was defined as (1) the presence of a predisposing factor; (2) a PaO2/FiO2 ratio < 200; (3) bilateral infiltrates on chest radiograph; and (4) absence of evidence of congestive heart failure and pulmonary artery wedge pressure < 18 mm Hg. Patients received each of four doses (1, 15, 30, and 60 ppm) in random order, each for a 3-hour period. Cardiovascular variables were continuously monitored, and arterial and mixed venous blood gas measurements were obtained at 30 minutes and 3 hours. RESULTS: Thirteen of the 20 patients demonstrated a significant increase in their PaO2/FiO2 (> 20% increase) when treated with inhaled NO. The administration of inhaled NO was associated with an increase in oxygenation at doses of 1, 15, and 30 ppm, but not 60 ppm. Increasing NO dose to more than 1 ppm did not significantly improve response. Mean pulmonary artery pressure decreased with increasing NO concentration, but this did not reach statistical significance. Nine of the 13 responding patients and 2 of the 7 nonresponding patients survived. CONCLUSION: Inhaled NO was successful in increasing PaO2/FiO2 by > 20% in 65% of the surgical patients in this trial. Response to NO could not be predicted by initial PaO2/FiO2 or pulmonary artery pressures. A trial of inhaled NO at a dose of < 10 ppm may be helpful in ARDS patients requiring increasing FiO2 and positive end-expiratory pressure.

Out-of-hospital administration of mannitol to head-injured patients does not change systolic blood pressure.

OBJECTIVE: To determine the effect of out-of-hospital mannitol administration on systolic blood pressure (BP) in the head-injured multiple-trauma patient. METHODS: This was a prospective, randomized, double-blind, placebo-controlled clinical trial involving a university-based helicopter air medical service and level-1 trauma center hospital. Endotracheally intubated head-trauma victims with Glasgow Coma Scale (GCS) scores < 12 were enrolled from November 22, 1991, to November 20, 1992, if evaluated by the participating aeromedical transport team within 6 hours of injury. Patients were excluded if they were < 18 years old, had already received mannitol or another diuretic, were potentially pregnant, or were receiving CPR. All patients were intubated prior to study drug (mannitol [1 g/kg] or normal saline) use. Pulse and BP were measured every 15 minutes for 2 hours following study drug administration. RESULTS: A total of 44 patients were enrolled. After exclusion of 3 patients who did not meet all inclusion criteria, there were 20 patients in the mannitol group and 21 patients in the placebo group. The groups were similar at baseline in age, pulse, systolic BP (baseline mannitol: 124 +/- 47 mm Hg; placebo: 128 +/- 32 mm Hg), GCS score, and Injury Severity Scale score. Systolic BP did not change significantly throughout the observation period in either group. This study had 83% power to detect a mean systolic BP drop to < 90 mm Hg. CONCLUSION: Out-of-hospital administration of mannitol did not significantly change systolic BP in this group of head-injured multiple-trauma patients.