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Biomedical subjects

J A Marx

Publications and source records attributed to J A Marx.

At least 19 recordsLinked to original sources
PubMed1993

Effectiveness and safety of intravenous nalmefene for emergency department patients with suspected narcotic overdose: a pilot study.

STUDY OBJECTIVE: To evaluate the efficacy and safety of nalmefene, an investigational narcotic antagonist that has potential advantages over naloxone because of its four- to eight-hour half-life, in emergency department patients with possible narcotic overdose. DESIGN: Multi-institutional, prospective, phase II, open-label study. TYPE OF PARTICIPANTS: Complete data were available for 53 cases from two teaching hospitals. Men 18 years old or older who would otherwise receive naloxone were eligible (two women were enrolled inadvertently). METHODS: Over four hours, one to ten boluses (median, one) of 0.5 or 1.0 mg nalmefene IV were given as often as every two minutes based on clinical need. Respirations, blood pressure, pulse, pupil size, and overall clinical response were monitored. Overall clinical response (1, no change; 2, partial response; 3, complete response), first assessed at two minutes, was analyzed by the Mann-Whitney U test. RESULTS: Fifteen of 25 (0.5 mg) and nine of 28 (1.0 mg) cases were opiate positive. Twelve of 15 (0.5 mg) and six of nine (1.0 mg) opiate-positive cases had a rapid complete response. Coincident causes of depressed sensorium were identified in the remaining six opiate-positive cases. No difference in initial overall clinical response was seen between 0.5-mg and 1.0-mg opiate-positive cases (P = .59). No deterioration requiring repeat nalmefene occurred in opiate-positive cases, even if methadone (four), codeine (two), or pentazocine (one) was found. No serious adverse events were judged to be related to nalmefene. CONCLUSION: Nalmefene is effective in the reversal of opiate overdose and appears to be safe in the management of patients with altered sensorium.

Adolescent↗
PubMed1993

Comparison of intraosseous, central, and peripheral routes of crystalloid infusion for resuscitation of hemorrhagic shock in a swine model.

Venous access is often a clinical dilemma in severely hypovolemic children. This study compares fluid resuscitation by central vein, peripheral vein, and the intraosseous route in a hemorrhagic shock model. Hampshire piglets were bled to a mean arterial pressure of 30 mm Hg. This level of shock was sustained for 30 minutes. Resuscitation was carried out with normal saline delivered at 50 mL/min by a manual pressure of 450-475 mm Hg over the ensuing 20 minutes. Bone marrow from two intraosseous-infused animals was harvested immediately after the study for histologic examination. The hemodynamic response to crystalloid resuscitation was comparable among the three groups. There was no significant difference in mean arterial pressure, central venous pressure, cardiac output, pulmonary capillary wedge pressure, mixed venous oxygen saturation, or arterial oxygen saturation. Histologically, cellular washout and necrosis were found in bone marrow immediately adjacent to the intraosseous needle infusion site. For fixed-rate infusion, intraosseous crystalloid resuscitation is as efficacious as that delivered by peripheral or central venous routes in reversing hemorrhagic shock.

Animals↗
PubMed1993

Penetrating abdominal trauma.

Penetrating trauma of the abdomen no longer warrants automatic laparotomy. Reasonably accurate clinical predictors of the need for operation should first be employed. Patients who do not meet these clinical criteria undergo a selective diagnostic approach on the basis of mechanism and site of injury and the experience and expertise of the respective institution. The desire to avoid unnecessary laparotomy is laudable. Nevertheless marked morbidity or mortality caused by failure to conduct laparotomy in a timely manner can be a dreaded consequence. When clinical and diagnostic studies are unable to resolve the presence or severity of injury, laparotomy is often more prudent than expectant observation.

Abdominal Injuries↗
PubMed1993

Blunt neck injury.

Emergency physicians must diagnose or exclude cervical spine trauma in daily practice. This is a complicated task, as the presentation may be subtle and the manifestations obscured, and no imaging modality is completely sensitive or specific. The research of the past two decades serves as a guide as to which types of patients require cervical radiologic evaluation and which modalities of evaluation are appropriate.

Cervical Vertebrae↗
PubMed1992

Grand mal seizures temporally related to cocaine use: clinical and diagnostic features.

STUDY OBJECTIVES: To determine the appropriate diagnostic workup of the emergency department patient with an uncomplicated cocaine-related grand mal seizure. DESIGN SETTING: Retrospective analysis. A city and county ED with 45,000 selected visits per year. TYPE OF PARTICIPANTS: Thirty-seven patients with acute grand mal seizure after cocaine exposure were studied. All had historical or laboratory evidence of cocaine use and no history of prior seizure disorder. INTERVENTIONS: The diagnostic workup varied among patients. Most received computed head tomography (35), whereas fewer received-ECG (18), EEG (16), and lumbar puncture (six). MEASUREMENTS AND MAIN RESULTS: Thirty-three patients with an uncomplicated cocaine-related seizure had an unremarkable series of diagnostic tests. The four patients with remarkable neurologic manifestations were compared with the remainder of patients who were without neurologic abnormalities. Comparison of groups by route of cocaine intake revealed no significant difference in the time interval to seizure (P = .761). CONCLUSION: Diagnostic workup probably is not indicated for the patient experiencing a cocaine-related generalized seizure who will recover promptly and have a normal postictal examination.

Adolescent↗
PubMed1992

Lithium absorption prevented by sodium polystyrene sulfonate in volunteers.

STUDY OBJECTIVE: To determine if sodium polystyrene sulfonate prevents absorption of lithium in human beings. DESIGN: Prospective, crossover study. TYPE OF PARTICIPANTS: Healthy volunteers age 22 to 34 years (three women and three men). INTERVENTIONS: After an eight-hour fast, subjects ingested 0.5 mEq/kg (18.5 mg/kg) lithium carbonate. One hour later, they ingested either 857 mg/kg sodium polystyrene sulfonate in 4 mL water/g sodium polystyrene sulfonate (experimental) or an equal volume of water without sodium polystyrene sulfonate (control). MEASUREMENTS AND MAIN RESULTS: Serum lithium levels were drawn zero, one, two, three, four, six, eight, ten, 12, and 24 hours after lithium ingestion. The sodium polystyrene sulfonate group had a smaller mean area under the serum concentration curve (11.6 +/- 1.0 mEq/L.hr versus 13.6 +/- 1.5 mEq/L.hr, P < .001) and lower mean highest measured lithium level (0.85 +/- 0.11 mEq/L versus 1.05 +/- 0.10 mEq/L, P < .05) compared with the control group. There was no significant difference in 24-hour urine lithium excretion or in serum sodium and potassium levels. CONCLUSION: Sodium polystyrene sulfonate administration decreased absorption of lithium after a lithium carbonate overdose. Sodium polystyrene sulfonate may be useful clinically for gastric decontamination after lithium overdoses.

Absorption↗
PubMed1992

Frequently nebulized beta-agonists for asthma: effects on serum electrolytes.

STUDY OBJECTIVE: To determine the magnitude of the changes in serum potassium, magnesium, and phosphate during the treatment of acute bronchospasm with repeated doses of beta-adrenergic agonists. DESIGN: Prospective study of a convenience sample of asthmatic patients. SETTING: University teaching hospital emergency department. TYPE OF PARTICIPANTS: Twenty-three patients met the inclusion criteria of age of more than 16 years; a history of asthma or chronic obstructive pulmonary disease; and an acute exacerbation. INTERVENTIONS: Baseline peak expiratory flow rate and serum potassium, magnesium, and phosphate levels were measured. Nebulized albuterol (2.5 mg) was administered every 30 minutes until the patient was discharged from the ED. Before each albuterol treatment, repeat serum levels of potassium, magnesium, and phosphate were determined. MEASUREMENTS AND MAIN RESULTS: Baseline peak expiratory flow rate averaged 188 +/- 119 L/min. Serum potassium levels decreased significantly (P = .0001 by repeated-measures analysis of variance) from 4.10 +/- 0.468 (baseline) to 3.55 +/- 0.580 mmol/L (90 minutes) and 3.45 +/- 0.683 mmol/L (180 minutes). Potassium decreased to less than 3.0 mmol/L in 22% of patients at some point during the study. Magnesium decreased from 1.64 +/- 0.133 mmol/L (baseline) to 1.48 +/- 0.184 mmol/L (90 minutes) and 1.40 +/- 0.219 mmol/L (180 minutes) (P = .0001). Phosphate levels also decreased, from 3.74 +/- 1.029 (baseline) to 2.84 +/- 0.957 mmol/L (90 minutes) and 2.55 +/- 0.715 mmol/L (180 minutes) (P = .0001). CONCLUSION: Aggressive administration of nebulized albuterol during the emergency treatment of acute bronchospasm is associated with statistically significant decreases in serum potassium, magnesium, and phosphate. The mechanism and clinical significance of these findings are unknown and warrant further study.

Adolescent↗
PubMed1992

Invalidation of the APACHE II scoring system for patients with acute trauma.

The APACHE II scoring system has been promulgated as a useful tool in the assessment of the severity of injury and prognosis for acutely ill patients. The physiologic basis for stratification is weighted toward older patients with chronic medical conditions. Recently, the APACHE II system has been proposed as a method for determining diagnosis related group (DRG) reimbursement for individual trauma patients. The present study applied the APACHE II scoring system to 280 patients with blunt or penetrating trauma who had documented systolic blood pressure < 90 mm Hg. Fifty-seven (20%) died of their injuries within the first 24 hours. APACHE II scores were recorded both in the emergency room (ED) and at 24 hours following admission. Injury Severity Scores (ISS), Revised Trauma Scores (RTS), and TRISSCAN were calculated. The APACHE II (n = 223) recorded at 24 hours (2.5 +/- 0.2) was significantly less than that recorded in the ED (6.6 +/- 0.3, p < 0.05, Mann-Whitney analysis). Using regression analysis, there was no correlation between APACHE II and ISS if recorded in the ED (r2 = 0.06) or 24 hours following admission (r2 = 0.08). APACHE II also demonstrated a poor correlation with the length of hospital stay (r2 = 0.03 [ED], = 0.19 [24 hours]). Whereas APACHE II may be helpful in defining severity of disease among patients with acute-on-chronic medical conditions, the classification lacks an anatomic component, which is essential to assess the magnitude of acute injury in patients who are typically otherwise healthy.

Acute Disease↗
PubMed1991

Management of acute pyelonephritis in an emergency department observation unit.

STUDY OBJECTIVES: To determine whether moderately to severely ill patients with acute pyelonephritis can be treated successfully on an outpatient basis, and whether any aspect of history, physical examination, or initial laboratory data predicts failure of outpatient therapy and the need for hospitalization. DESIGN: Retrospective chart review of all patients with a diagnosis of acute pyelonephritis seen during a three-year period. SETTING: Emergency department observation unit of an urban teaching hospital serving residents of the city and county of Denver. TYPE OF PARTICIPANTS: Women between the ages of 15 and 50 with symptoms, physical examination, and initial laboratory data consistent with a diagnosis of pyelonephritis. INTERVENTIONS: Patients received IV antibiotics, rehydration, analgesics, and antiemetics in an observation unit for up to 12 hours, when they were either admitted to the hospital or discharged home on oral antibiotics. MEASUREMENTS AND MAIN RESULTS: Sixty-three of 87 patients (72%) with acute pyelonephritis were managed successfully as outpatients, nine (22%) were hospitalized directly from the observation unit because they were considered to be too ill to go home, and five (6%) returned with persistent symptoms after ED therapy and were hospitalized. No clinical or laboratory variable predicted success or failure of ED observation unit therapy at the time of initial presentation. CONCLUSION: In selected patients, the observation unit may be used to initiate therapy for acute pyelonephritis. Those with an adequate clinical response to initial treatment may be discharged on oral antibiotic therapy with appropriate follow-up.

Adolescent↗
PubMed1991

Contributions of peritoneal lavage enzyme determinations to the management of isolated hollow visceral abdominal injuries.

STUDY OBJECTIVE: To determine the role of lavage amylase (LAM) and lavage alkaline phosphatase (LAP) in the identification of intraperitoneal hollow visceral injuries. DESIGN: Retrospective. SETTING: Level I trauma center, city/county institution. TYPE OF PARTICIPANTS: Patients with hollow visceral organ injury following major blunt or penetrating trauma whose diagnostic peritoneal lavage was negative by lavage red blood cell and lavage white blood cell were negative. MEASUREMENTS AND MAIN RESULTS: Fifty-one patients with injury isolated to one or more hollow visceral structures underwent diagnostic peritoneal lavage; 28 were positive based on aspirate, lavage red blood cell count (greater than 100,000/mm3), or lavage white blood cell count (greater than 500/mm3). Of the remaining 23 patients, each of 11 with isolated small bowel injury had LAM greater than or equal to 20 IU/L and six of these had LAP levels greater than or equal to 3 IU/L. All six patients with colon injury and two of the patients with gallbladder injury had LAM less than 20 IU/L and LAP less than 3 IU/L. CONCLUSIONS: In patients with hollow visceral injury and otherwise normal diagnostic peritoneal lavage, elevation in LAM is highly specific for isolated small bowel injury. Lavage enzyme determinations appear unhelpful in the detection of colonic injury. We recommend routine enzyme determinations of lavage effluent as a marker for isolated small bowel injury.

Abdominal Injuries↗
PubMed1991

Prehospital hypertonic saline/dextran infusion for post-traumatic hypotension. The U.S.A. Multicenter Trial.

The safety and efficacy of 7.5% sodium chloride in 6% dextran 70 (HSD) in posttraumatic hypotension was evaluated in Houston, Denver, and Milwaukee. Multicentered, blinded, prospective randomized studies were developed comparing 250 mL of HSD versus 250 mL of normal crystalloid solution administered before routine prehospital and emergency center resuscitation. During a 13-month period, 422 patients were enrolled, 211 of whom subsequently underwent operative procedures. Three hundred fifty-nine patients met criteria for efficacy analysis, 51% of whom were in the HSD group. Seventy-two per cent of all patients were victims of penetrating trauma. The mean injury severity score (19), Trauma Score plus Injury Severity Score (TRISS) probability of survival, revised trauma scores (5.9), age, ambulance times, preinfusion blood pressure, and etiology distribution were identical between groups. The total amount of fluid administered, white blood cell count, arterial blood gases, potassium, or bicarbonate also were identical between groups. The HSD group had an improved blood pressure (p = 0.024). Hematocrit, sodium chloride, and osmolality levels were significantly elevated in the Emergency Center. Although no difference in overall survival was demonstrated, the HSD group requiring surgery did have a better survival (p = 0.02), with some variance among centers. The HSD group had fewer complications that the standard treatment group (7 versus 24). A greater incidence of adult respiratory distress syndrome, renal failure, and coagulopathy occurred in the standard treatment group. No anaphylactoid nor Dextran-related coagulopathies occurred in the HSD group. Although this trial demonstrated trends supportive of HSD in hypotensive hemorrhagic shock patients requiring surgery, a larger sample size will be required to establish which subgroups of trauma patients might maximally benefit from the prehospital use of a small volume of hyperosmolar solution. This study demonstrates the safety of administering 250 mL 7.5% HDS to this group of patients.

Adolescent↗
PubMed1991

Peritoneal lavage enzyme determinations following blunt and penetrating abdominal trauma.

Diagnostic peritoneal lavage (DPL) provides a rapid and sensitive means of investigating the peritoneal cavity following blunt and penetrating trauma. However, its shortcomings include insensitivity in the early identification of isolated hollow viscus injuries. We have routinely assayed lavage amylase (LAM) and alkaline phosphatase (LAP) in acutely injured patients for more than 4 years to assess the contribution of lavage enzyme analysis to the overall accuracy of DPL. From 1,969 DPLs, LAM was analyzed in 1,881 (96%) and LAP in 1,734 (88%) of 1,536 blunt and 433 penetrating trauma cases. Of 28 patients with negative lavage by LRBC but LAM greater than or equal to 20 IU/L, 13 (46%) had clinically significant injury requiring laparotomy. Seventy-seven percent of these cases involved the small bowel. In this group, LAM greater than or equal to 20 IU/L had a sensitivity of 87%, specificity of 75%, and positive predictive value of 46% for significant intra-abdominal injury. Seven patients had LAM greater than or equal to 20 IU/L and LAP greater than or equal to 3 IU/L. These values had a sensitivity of 54%, specificity of 98%, and positive predictive value of 88% for significant abdominal injury. Elevations of LAM (greater than or equal to 20 IU/L) and LAP (greater than or equal to 3 IU/L) mandate laparotomy where the history is consistent with possible small bowel injury. Elevation of either enzyme alone should raise the suspicion of hollow visceral organ injury and warrant close observation.

Abdominal Injuries↗
PubMed1990

Initial evaluation of the patient with blunt abdominal trauma.

Unrecognized abdominal injury remains a distressingly frequent cause of preventable death following blunt trauma. Peritoneal signs are often subtle, overshadowed by pain from associated injury, and masked by head trauma or intoxicants. The initial management of the patient with blunt abdominal trauma should parallel the primary survey of airway, breathing, and circulation. Diagnostic peritoneal lavage remains the cornerstone of triage in patients with life-threatening blunt abdominal trauma. The only absolute contraindication to the procedure is an existing indication for laparotomy. Computed tomography is useful as a complementary diagnostic tool in selected patients, and it is the critical test for guiding nonoperative management of known intraperitoneal trauma. Routine ancillary tests for potentially occult injuries include nasogastric-tube placement for ruptures of the left diaphragm, Gastrografin contrast study for duodenum perforation, and pyelography for urologic injury. Ultrasonography may become a valuable tool in the initial assessment of the injured abdomen. Ultimately, the most important principle in the management of blunt abdominal trauma is repeat physical examination by an experienced surgeon.

Abdominal Injuries↗
PubMed1990

Diagnostic peritoneal lavage: accuracy in predicting necessary laparotomy following blunt and penetrating trauma.

The purpose of this study was to evaluate the ability of diagnostic peritoneal lavage (DPL) to predict intra-abdominal injuries that required surgical repair. To do this, we retrospectively reviewed 944 patients with blunt and penetrating abdominal trauma who underwent 975 DPLs. Initial DPL in 608 patients sustaining blunt trauma had a sensitivity of 87%, a specificity of 97%, an accuracy of 95%, a positive predictive value (PPV) of 85%, and a negative predictive value (NPV) of 97%. Initial DPL in 336 patients with penetrating trauma had a sensitivity of 87%, a specificity of 89%, an accuracy of 89%, a PPV of 75%, and a NPV of 95%. When utilizing final lavage results on the 944 patients, DPL had a sensitivity of 91%, a specificity of 94%, an accuracy of 93%, a PPV of 80%, and a NPV of 98% in predicting intra-abdominal injury requiring surgical repair.

Abdominal Injuries↗
PubMed1989

Traumatic central cord syndrome in a patient with Os odontoideum.

We report the case of a 33-year-old man who presented to the emergency department the morning after a motor vehicle accident with physical findings consistent with central cord syndrome. Radiographs of the cervical spine revealed os odontoideum. This abnormality of the odontoid process has not previously been described in association with central cord syndrome.

Adult↗
PubMed1989

The use of an emergency department observation unit in the management of abdominal trauma.

Diagnostic peritoneal lavage (DPL) is a valuable triage tool in the evaluation of patients with abdominal trauma. Observation after a negative lavage is necessary to detect injuries not well discerned by DPL performed in the early postinjury period. We evaluated the use of 12 hours of monitoring in an emergency department observation unit in the management of 230 patients with abdominal trauma and a negative initial DPL. One hundred five of the patients had blunt and 125 had penetrating trauma. One hundred eighty-seven patients (81%) were discharged home from the observation unit without any reported significant complications. Thirty-eight patients (17%) required admission to our hospital; four of the 38 underwent necessary laparotomy. In the 230 patients evaluated, no deaths or complications could be assigned to the use of 12 hours of observation in the unit. The use of an observation unit in our study resulted in the potential savings of $51,329. Our study supports the concept that selected patients with significant abdominal trauma and a negative DPL can be managed safely and cost effectively in an ED observation unit.

Abdominal Injuries↗
PubMed1989

The benefits of 7.5% NaCl/6% dextran 70 (HSD) for prehospital resuscitation of hemorrhagic shock: improved oxygen transport.

The purpose of this study was to compare the benefit of small volume hypertonic saline/dextran (HSD) versus the risk of obligatory time to administer it on-scene in a model of acute hemorrhagic shock. Dogs were bled to a mean arterial pressure (MAP) of 20 mmHg and then randomized to either: a) direct transport to the emergency department (ED) or b) 10 min delay to insert an iv HSD (4 ml/kg) infusion over 5 min, and then transport. The animals receiving HSD had improved (P less than 0.05) cardiac work and oxygen consumption during transport (MAP = 59 +/- 3 vs 38 +/- 4 mmHg; cardiac index (CI) = 3.2 +/- 0.2 vs 1.3 +/- 0.1 L min-1 M-2; O2CI = 115 +/- 7 vs 104 +/- 7 ml min-1 M-2), paralleled by reduced serum lactate (5.3 +/- 0.8 vs 7.0 +/- 2.3 mmol/L) and decreased metabolic acidosis. The benefits of HSD in attenuating shock-induced oxygen debt were corroborated by lower O2CI (98 +/- 4 vs 112 +/- 5 ml min-1 M-2) and higher pH (7.30 +/- 0.01 vs 7.24 +/- 0.02) in the postresuscitation period.

Animals↗