Prospective, randomized evaluation of early removal of nasogastric tubes in postceliotomy trauma patients.

The objective of this study is to compare early (24-hour) removal of nasogastric tubes (NGTs) in trauma patients who have undergone emergency celiotomy to removal based on clinical signs of return of bowel function. All trauma patients who underwent an emergency celiotomy between November 1994 and August 1997 were randomized to 24-hour NGT removal, or removal when flatus and decreased NG output indicated. Exclusion criteria included patients with duodenal or esophageal injuries, those with airway intubations that were >24 hours, or those who had undergone same-hospitalization repeat celiotomy. Gastric or severity of intestinal injury were not exclusion criteria. Failure of NGT removal was defined as pain, abdominal distention, and vomiting. Mechanisms of injury, Injury Severity Score, operative findings, NGT removal times, morbidity, laboratory data, and reasons for failure were evaluated. A total of 177 patients qualified for the study. Two patients were inappropriately randomized and subsequently excluded. Of the remaining 175 patients, 151 sustained penetrating injuries and 24 sustained blunt injuries. Of the 151 patients in the penetrating injury group, 68 were randomized to the 24-hour pull (study) group and 83 were randomized to the clinical pull (control) group. There were three failures in the study group [3 of 68 patients (4.4%)] and three failures in the control group [3 of 83 patients (3.6%)]. Of the 24 blunt injury patients, 10 were randomized to the study group and 14 were randomized to the control group. There was one failure in the study group [1 of 10 patients (10.0%)] and one failure in the control group [1 of 14 patients (7.1%)]. Overall failure rate for the study group was 5.1 per cent [(3+1)/(68+10) = 5.1%] versus 4.1 per cent for the control group. Overall failure for all patients in the study was 4.6 per cent. Injury severity score, morbidity, and lab values were not significantly different. It is safe to remove NGTs at 24 hours in most trauma patients regardless of the severity of injury (failure rate, 5.1%). The surgical dogma of the need to have an NGT in longer for blunt trauma was not revealed in this study, however, a larger study would be needed to determine this with significance.

Method of urinary diversion in nonurethral traumatic bladder injuries: retrospective analysis of 70 cases.

Management of intraperitoneal, nonurethral bladder injuries by urinary diversion using suprapubic (SP) catheters versus transurethral (TU) Foley catheters was examined retrospectively in a attempt to determine which were most effective. A total of 8500 trauma admissions (6/89-1/96) were screened for bladder injuries. Mechanism, degree, treatment, and morbidity of injury in association with SP or TU Foley catheter placement were evaluated. Of the total of 70 bladder injuries identified, the diagnosis in 40 patients (57%) whose injuries resulted from blunt trauma was made by cystogram (55%), CT scan alone (15%), or by exploration (30%). Of these, 22 patients (55%) were treated nonoperatively with a TU catheter for extraperitoneal extravasation or partial bladder wall laceration. Gunshot wounds accounted for 43 per cent (30 patients); of these patients, all but one had celiotomies and bladder repair. SP catheters were placed in three blunt trauma patients, preoperatively in 1 patient, and intraoperatively in 17 patients who had sustained penetrating trauma. A total of 50 patients (71%), 27 with repair and TU catheter and 23 with TU catheter alone, were treated without an SP catheter. All bladder or urethral morbidity occurred in the SP group (35%): 3 strictures, 2 urinary retentions, 1 SP infection, and 1 urinary infection. Degree of bladder injury was no different with or without an SP catheter. No urethral strictures, urinary tract infections, or retention occurred in isolated bladder injuries treated with TU catheters alone. Average SP and TU catheter duration was 42 and 13 days, respectively. TU catheters for management of blunt and penetrating bladder trauma are effective, cause fewer strictures and less morbidity, and may be removed more rapidly than SP catheters for any degree of bladder injury.

Mechanism of suppression of natural killer cell activity in trauma patients.

Trauma patients develop a severe immunosuppression that includes suppression of natural killer (NK) cell activity although numbers of NK cells are not reduced. The mechanism of suppression of NK cell activity after major trauma is not known. The aim of the present study was to investigate the in vitro effect of plasma samples from trauma patients (TP) on the cytotoxic activity of normal NK cells. Buffycoat mononuclear cells (5x10(5)/well) were preincubated with either TP or plasma samples from age and sex matched healthy controls (CP) for 0, 16 or 40 h. These effector cells were then cultured with 51Cr labeled K-562 cells (2x10(4)/well) for 4 h at 37 degrees C and % lysis was calculated. No significant differences in % lysis between CP and TP were found with 0 or 16 h preincubation, however 40 h preincubation with TP severely suppressed NK cell function (p=0.003) as compared to preincubation with CP for the same period. Addition of neutralizing anti-IL-4, anti-TGF-beta1, or anti-IL-10 antibodies did not reverse the NK cell suppression. There was a partial reversal of NK cell suppression by catalase but not by SOD or L-NMMA. Removal of monocytes from buffycoat mononuclear cells also significantly reversed the NK cell suppression. These data suggest that suppression of NK cell activity in trauma patients may be an accessory cell dependent phenomenon and may partially depend on production of reactive oxygen metabolites (ROM).

Expression of inducible nitric oxide synthase in human lungs.

The aim of this study was to investigate the expression of inducible nitric oxide synthase (iNOS) in lungs of patients with or without adult respiratory distress syndrome (ARDS). We compared the expression of iNOS by immunohistochemical analysis and polymerase chain reaction in the human lungs collected during open-lung biopsy or at autopsy. The expression of iNOS mRNA was present in all lung samples; however, only 3 out of 11 lung samples showed weak staining for iNOS. Although the involvement of nitric oxide in animal models of ARDS is reported, production of nitric oxide in human lungs is still controversial. The data presented here suggest that human lungs express iNOS mRNA but that the production of iNOS protein may be tightly regulated and is expressed in pulmonary inflammation.

Psychopathologic risk factors for intentional and nonintentional injury.

OBJECTIVE: Trauma has a high rate of recurrence, suggesting that some people are more injury-prone than others. This study was performed to evaluate some of the psychological and social factors that might influence the likelihood of traumatic injury. METHODS: A case-control study was conducted to evaluate the relationship between selected psychosocial factors and traumatic injury. At a Level I trauma center, victims of intentional trauma (excluding attempted suicide), victims of nonintentional trauma, and patients undergoing elective surgery were interviewed by a person blinded to the purposes of the study. They were given an intelligence test and underwent a structured interview, yielding psychiatric diagnostic categories established in the third edition of the Diagnostic and Statistical Manual of Mental Disorders, Revised (DSM-III-R). RESULTS: Trauma patients were younger than elective surgery patients (p < 0.01) and were more likely to be men (p < 0.01). Victims of intentional injury had a higher probability of alcohol use (p < 0.01) and admitted illicit drug use (p < 0.001) than either nonintentional injury victims or elective surgery patients. Victims of intentional injury were more likely to be unemployed than those in the other two groups (p < 0.02), whereas elective surgery patients were more likely to be retired (p < 0.05) or to be disabled (p < 0.0001). The average intelligence score was slightly above the median in the nonintentional trauma group and in the control group (55th percentile and 54th percentile, respectively), compared with a mean intelligence score equivalent to the 35th percentile in the victims of intentional trauma (p < 0.001). Thirty percent of elective surgery patients met diagnostic criteria for at least one category of psychopathology, compared with 50% of nonintentional trauma patients, and 63% of intentional trauma patients (p < 0.01, trauma vs. elective surgery). Logistic regression analysis identified six variables that were independently associated with an increased tendency to be a victim of trauma: younger age, lower intelligence, antisocial personality, mental retardation, depression, and low income. CONCLUSIONS: Victims of trauma, both nonintentional, and especially intentional, have a high incidence of psychopathology. Victims of intentional trauma have significantly lower intelligence scores than either nonintentional injury or elective surgery patients. The high incidence of unemployment, alcohol abuse, and illicit drug use in victims of intentional injury might provide several opportunities for trauma prevention programs. Underlying psychological disorders will have to be addressed to reduce the likelihood of becoming a victim of trauma.

Randomized blinded study of aprotinin infusion for liver crush injuries in the pig model.

Repeat exploratory laparotomies for intra-abdominal bleeding in patients who sustain severe blunt intra-abdominal trauma are common. Reexploration usually reveals no single site of bleeding and the abdomen is closed with laparotomy pad packing, with a presumed diagnosis of coagulopathy. These postoperative coagulational defects may be the result of dilution, consumption, dysfunction, or acquired defects of either the coagulation, fibrinolytic, or platelet systems. The liver plays a major role in the balance of hemostatic systems, and this balance is disrupted by liver trauma. This study investigates the use of intravenous aprotinin, a naturally occurring serine protease inhibitor, in a pig liver crush model to evaluate its effectiveness in reducing intra-abdominal bleeding in experimentally induced shock and non-shock states.

Laparoscopy in trauma.

Laparoscopy is a nearly century-old technique that has experienced a resurgence of interest from surgeons since the development of technology that has broadened its applications. Although laparoscopy has been used to evaluate patients with possible abdominal trauma, its use for this purpose is limited by the availability of other diagnostic procedures that may be more suitable for particular circumstances and are more accurate for certain injuries. Laparoscopy is contraindicated in patients who are hypovolemic or hemodynamically unstable and should not be performed in patients with clear indications for celiotomy. It may not be appropriate for patients with cardiac dysfunction, nor for those with significant head injuries who are at risk for intracranial hypertension. Its best applications may be in stable patients with stab wounds or those with tangential gunshot wounds of the abdomen. The likelihood of missing hollow visceral injuries depends upon the indications for conversion to celiotomy. If peritoneal violation or the presence of a small amount of blood in the peritoneal cavity is used as an indication for celiotomy, then the missed injury rate will be low but the unnecessary celiotomy rate will be diminished only slightly compared with a policy of mandatory celiotomy. Excessive enthusiasm for laparoscopy in trauma might result in its use when other diagnostic measures or simple observation are more appropriate. The desire to perform a procedure can be compelling, especially in circumstances in which the general surgeon would not operate upon a patient but simply provide postoperative care after other surgeons have operated. The use of laparoscopy for these purposes can only be condemned, as it increases the costs and risks of care without improving the outcome. The role of laparoscopy in trauma is evolving, and further research into its diagnostic role and therapeutic applications is clearly needed.

Abbreviated Injury Scale does not reflect the added morbidity of multiple lower extremity fractures.

OBJECTIVES: To determine if patients with multiple lower extremity fractures have worse outcomes than do patients with isolated femur fractures, and to determine if the Abbreviated Injury Scale (AIS) should distinguish between single and multiple lower extremity fractures. DESIGN: A retrospective study. MATERIALS AND METHODS: All blunt trauma patients at least 15 years of age treated at a level 1 trauma center from January 1990 through December 1993. Three groups of patients were selected. Group 1 included 50 patients whose only significant injury was a diaphyseal femur fracture. They had no other long bone fractures, minimal injuries to other body areas, and an Injury Severity Score (ISS) < or = 14. Group 2 was consisted of 29 patients with a femur fracture, at least one other diaphyseal lower extremity fracture, and also an ISS < or = 14. Group 3 consisted of 23 patients who had fracture patterns similar to those of group 2, but also had more severe nonextremity injuries (ISS > or = 15). Hospital morbidity and mortality rates were compared with t tests or chi-square analysis. Type 1 error probability was established at p < 0.05. MEASUREMENTS AND MAIN RESULTS: Compared with patients in group 1, patients in group 2 had an identical ISS (10.1 vs. 10.6, respectively), but had higher transfusion requirements (0.3 vs. 3.9 units), more days in the intensive care unit (ICU) (0.02 vs. 1.4), a higher incidence of adult respiratory distress syndrome (ARDS) (0 vs. 14%), longer hospital stays (6.0 vs. 14.8 days), greater disability at discharge (disability score 2.2 vs. 3.2), and a higher mortality rate (0 vs. 3.4%; p < 0.05 all variables). Patients in group 3 had worse outcomes than the other two groups: ISS = 30.1; transfusions = 11.9 units; ICU days = 9.1; ARDS incidence = 26%; hospital days = 29.9; disability score = 3.9; mortality = 26% (p < 0.05). CONCLUSIONS: Although AIS and ISS appropriately reflect the impact of extraskeletal injuries in patients with femur fractures, they do not adequately reflect the increased morbidity associated with multiple lower extremity fractures. The AIS-Extremity Score may need to be upgraded for multiple long bone fractures of the lower extremities.

Thoracic outlet syndrome reconsidered.

During a four year period, 50 patients were evaluated for possible thoracic outlet syndrome (TOS). These 11 men and 39 women ranged in age from 27 to 60 years, with a mean age of 38.6 years. Their symptoms had been present from 3 months to 10 years (mean = 2.1 years). Twenty-seven had previously undergone 33 operations, including carpal tunnel release, shoulder arthroscopy, rotator cuff repair, cervical discectomy, and first rib resection, all without benefit. Patients were evaluated by history, physical examination, and radiographs of the cervical spine and chest. Additional studies such as electromyography/nerve conduction studies, computed tomography, magnetic resonance imaging, angiography, and myelography were obtained selectively. Only 12 patients were thought to have TOS, seven of whom underwent operation. Four had complete resolution of symptoms; three were improved but had residual symptoms for associated problems. Three patients who were not thought to have TOS underwent first rib resection in other hospitals; none was improved after surgery. The only study of positive value was evidence of unilateral subclavian artery compression with shoulder positioning on physical examination. All other studies were of value only if they demonstrated some other cause of the patient's symptoms. Of the 35 patients without TOS in whom long-term follow-up was obtained, four underwent appropriate operations with benefit, and 20 had good results from physical therapy and nonoperative management. Patients whose symptoms were work-related, and those who had engaged the services of a lawyer, were less likely to demonstrate improvement, regardless of the treatment employed. TOS is a relatively unusual cause of upper extremity pain and dysfunction. History and physical examination are the most important diagnostic studies, and radiographs of the chest and cervical spine and electromyography/nerve conduction studies are useful to identify other causes of pain and disability. Careful selection of patients for surgery can yield satisfactory results. A coordinated team of surgeons, neurologists, and physical therapists is important in the management of these patients.

Laparoscopic surgery during pregnancy.

BACKGROUND: Animal studies have demonstrated fetal acidosis during carbon dioxide pneumoperitoneum. This finding suggests a potential adverse effect of CO2 pneumoperitoneum on fetal outcome in humans. PATIENTS AND METHODS: We reviewed our recent experience with laparoscopic surgery performed under general anesthesia and with the use of CO2 pneumoperitoneum, in pregnant women with appendicitis or cholecystitis. We compared these women's charts and pregnancy outcomes with those of pregnant women who underwent formal laparotomy during the same period of time. RESULTS: Seven pregnant patients underwent laparoscopic surgery, and there were 4 fetal deaths among them (3 during the first postoperative week, and another 4 weeks postoperatively). Five pregnant patients underwent formal laparotomy, of whom 4 subsequently progressed to term and 1 was lost to follow-up. CONCLUSIONS: Our recent experiences together with the available animal data suggest that caution should be used when considering nonobstetrical laparoscopic surgery in pregnant women. This experience suggests that additional clinical and laboratory investigations may be indicated to evaluate fetal risk associated with such surgery.

Effect of aminoguanidine on in vivo expression of cytokines and inducible nitric oxide synthase in the lungs of endotoxemic rats.

Endotoxemia results in the release of multiple mediators such as tumor necrosis factor alpha (TNF-infinity), interleukin-1 beta (IL-1 beta), and nitric oxide (NO), which is thought to be responsible for the hypotension of septic shock. Although there are many reports on the presence of these mediators in serum, in vivo expression of TNF-infinity, IL-1 beta and inducible nitric oxide synthase (iNOS) at the tissue level has not been studied extensively. We investigated in vivo expression of these cytokines and iNOS in the lungs of rats that were injected with saline, endotoxin or endotoxin plus aminoguanidine (AG), an inhibitor of iNOS. Expression of TNF-infinity, IL-1 beta and iNOS was absent in control (saline treated) but was increased in endotoxin treated animals. In animals treated with endotoxin plus AG (400 mg/kg), expression of iNOS was markedly inhibited whereas there was no effect on expression of TNF-infinity and IL-1 beta. The inhibitory effect of AG was probably dose dependent because a lower concentration of AG (50 mg/kg) showed no change in the expression of iNOS.

Nitric oxide produced by cytokine-activated pulmonary artery smooth muscle cells is cytotoxic to cocultured endothelium.

BACKGROUND: We recently demonstrated that rat pulmonary artery smooth muscle (RPASM) generates maximal nitric oxide (NO) when exposed to inflammatory cytokines, such as tumor necrosis factor (TNF)-alpha and interferon (IFN)-gamma. Our hypothesis is that NO produced by cytokine-stimulated RPASM has local cytotoxic effects on endothelium. Accordingly, we designed a pulmonary smooth muscle and endothelial coculture experiment in which the effects of NO on endothelium can be distinguished from the direct effects of cytokines. METHODS: RPASM cells were incubated with a mixture of TNF-alpha (500 units/ml) and IFN-gamma (100 units/ml) for 24 hours. This cytokine mixture was then removed and the NO-producing smooth muscle cells were incubated in a coculture transwell system with rat pulmonary artery endothelial (RPAE) cells. Subsequent NO production (as measured by nitrite concentration in cell supernatants), and the number of viable attached endothelial cells were then measured at 48 hours. RESULTS: RPASM continued to produce large amounts of NO, in the absence of further cytokine stimulation, after a 24-hour exposure to TNF-alpha and IFN-gamma. This RPASM-generated NO decreased the number of viable attached endothelial cells after 24 hour RPASM-RPAE coculture by 57%. The competitive stereospecific inhibitor of inducible NO synthase (iNOS), NG-monomethyl-L-arginine (NMA), returned the inducible NO production to basal levels and reversed the cytotoxic effects on endothelial cells. The number of viable attached endothelial cells returned to control levels. CONCLUSIONS: The NO produced by cytokine-activated RPASM has local cytotoxic effects on RPAE in coculture. Such NO produced in the vasculature may be a factor in the origin of acute lung injury under conditions of trauma and sepsis.

The effect of nitric oxide on fetal pulmonary artery smooth muscle growth.

Endothelium-derived nitric oxide (NO) relaxes fetal pulmonary arterial vessels through activation of guanylate cyclase and increasing smooth muscle cyclic guanosine 3', 5'-monophosphate (cGMP). Exogenous NO administered as a gas at low concentrations shares this effect, decreasing pulmonary artery resistance and increasing in pulmonary blood flow. NO, endogenously synthesized or inhaled as a gas, may affect cellular growth in the underlying pulmonary vascular smooth muscle media. We report the effects of NO and cGMP upon DNA synthesis and proliferation of passaged pulmonary vascular smooth muscle cells from fetal rats. Smooth muscle cells from rat fetal pulmonary artery (RFPASM; 18-19 day gestation; term 21 days) were treated in culture with sodium nitroprusside (SNP), isosorbide dinitrite (ISDN)--both NO-generating vasodilators--or 8-bromo-cGMP, a cell-permeant cGMP analog. All agents inhibited thymidine uptake at concentrations of 10(-3)-10(-2) M. Lower concentrations (10(-5)-10(-4) M) of SNP and ISDN increased [3H]-thymidine ([3H]TdR) uptake, an effect not seen with cGMP at similar concentrations. Exposing RFPASM to authentic NO gas in a deoxygenated medium inhibited [3H]TdR uptake only. NO appears to have a biphasic effect on DNA synthesis in passaged RFPASM, with stimulation at micromolar concentrations and inhibition at higher levels. NO may thus alter vascular smooth muscle growth and pulmonary vascular remodeling in conditions complicated by pulmonary hypertension and treated with inhaled NO.

Antisense oligodeoxynucleotide to inducible nitric oxide synthase inhibits nitric oxide synthesis in rat pulmonary artery smooth muscle cells in culture.

BACKGROUND: We recently demonstrated the induced expression of the inducible nitric oxide synthase (iNOS) gene in cultured rat pulmonary artery smooth muscle (RPASM) in response to lipopolysaccharide and cytokines, using a complementary DNA probe to murine macrophage iNOS. Because nitric oxide (NO) can be cytotoxic, iNOS in the pulmonary vasculature may contribute to lung injury in sepsis. We designed an antisense oligodeoxynucleotide complementary to the iNOS messenger RNA (mRNA) sequence to determine whether the probe prevented iNOS translation. METHODS: RPASM, preincubated in the presence of antisense and sense oligodeoxynucleotide to the first 18 bases after the initiation codon of iNOS mRNA, was exposed to interferon-gamma and tumor necrosis factor-alpha to induce NO production (as measured by NO2-, the stable end product of NO formation). RESULTS: Interferon-gamma and tumor necrosis factor-alpha induced NO production in RPASM: The antisense probe caused up to a 36% decrease in cytokine-induced NO2- production in a concentration-dependent manner (1 to 10 mumol/L). The sense probe had no effect. CONCLUSIONS: Increased transcription of iNOS mRNA is an essential step in the induced production of NO by RPASM: Antisense probes partially inhibit iNOS expression in vitro, suggesting its use to inhibit iNOS expression under pathologic conditions.