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Biomedical subjects

D H Wisner

Publications and source records attributed to D H Wisner.

At least 37 records · Page 2Linked to original sources
PubMed1997

Use of ultrasonography in the patient with acute abdominal trauma.

The purpose of this study was to assess the use of ultrasonography in patients with acute abdominal trauma. Five hundred prospective patients, who came to the Emergency Department with acute trauma, were evaluated with ultrasonography and included in this study. The ultrasonographic examination focused on detection of free fluid but included evaluation of parenchymal organs for injury. The physical examination was not used in the statistical analysis of the sonographic findings. In comparing ultrasonography to computed tomography, diagnostic peritoneal lavage, or operative findings, we obtained 24 true positive, 79 true negative, four false positive, and 14 false negative results. Sensitivity of ultrasonography in detecting free fluid in comparison to computed tomography, diagnostic peritoneal lavage, and surgery was 63%, specificity was 95%, accuracy was 85%, positive predictive value was 86%, and negative predictive value was 85%. The most common reason for false negative sonographic results was identification of free fluid in the pelvis on computed tomograms but not on ultrasonograms owing to lack of a full bladder. In none of these instances were the sonographic false negative results of clinical significance. Ultrasonography allowed detection of solid organ injury of the liver in one of seven cases, of the kidney in one of four cases, and in the bowel in zero of three cases. In the three instances of bowel injury, free fluid was noted on ultrasonograms. Ultrasonography fared better in cases of splenic laceration, permitting detection in nine of 14 cases. The emergent ultrasonogram may be used to detect free fluid in the abdomen of the acutely traumatized patient. However, sonography is limited in detecting free fluid in the pelvis using the present technique and does not allow visualization of organ injury. Limitations of this examination should be recognized for appropriate triage of the acutely traumatized patient.

Abdomen↗
PubMed1997

Jehovah's Witnesses: unique problems in a unique trauma population.

BACKGROUND: Jehovah's Witnesses can create perplexing treatment problems by their refusal of blood transfusions. This dilemma is especially difficult for the trauma surgeon faced with critically low hemoglobin levels or life-threatening blood loss in an injured Jehovah's Witness. STUDY DESIGN: Retrospective review of the records of 58 Jehovah's Witnesses admitted to a single trauma center between July 1992 and June 1995. RESULTS: There were 53 blunt and 5 penetrating injuries. Four patients (7 percent) received blood transfusions; one received banked blood and three received autotransfusions. Two patients were sedated and paralyzed to optimize oxygen utilization; one patient received erythropoietin. Eighteen patients had a general anesthetic and underwent an operative procedure; one underwent controlled hypotensive anesthesia with normovolemic hemodilution. The records of 21 patients (36 percent) included documentation of absolute refusal of blood or blood products; the exact status of consent for blood transfusion was not documented in the records of 33 patients (57 percent). One death and six complications occurred, none of which were attributed to acute blood loss or anemia. Treatment options and special techniques for the severely anemic patient refusing blood transfusions are discussed. CONCLUSIONS: Documentation of religious status and beliefs about blood transfusion, as well as knowledge of special treatment options available for anemic Jehovah's Witnesses, is necessary to provide quality care to this unique trauma population.

Adolescent↗
PubMed1996

The feasibility of organ salvage from non-heart-beating trauma donors.

BACKGROUND: Blunt trauma patients without vital signs on admission are potential non-heart-beating donors. OBJECTIVE: To review the feasibility of postmortem visceral perfusion and organ donation in blunt trauma patients without vital signs. DESIGN: A retrospective case series of blunt trauma victims who were declared dead in the emergency department. SETTING: A level I trauma center. MAIN OUTCOME MEASURES: Factors potentially precluding donation and potential donor yield. RESULTS: The mean trauma-to-death interval was 71 minutes (< 60 minutes in 57% of the cases). Injuries likely to interfere with in situ perfusion were present in 41% of the cases. The tissue donation consent rate was 45%. Assuming a similar organ donation consent rate, the potential donor yield was 9% after excluding victims who were younger than 60 years of age, warm ischemia times that were less than 60 minutes, and patients who had injuries precluding perfusion. CONCLUSIONS: The potential organ yield from non-heart-beating, blunt trauma victims is low, which highlights the ethical and legal problems of this approach.

Adolescent↗
PubMed1996

Cerebral effects of resuscitation with hypertonic saline and a new low-sodium hypertonic fluid in hemorrhagic shock and head injury.

OBJECTIVES: A 2400-mOsm/L hypertonic solution (isosal) with a lower sodium content, compared with conventional 7.5% hypertonic saline, was formulated using a mixture of sodium chloride, glucose, and mixed amino acids. This solution was developed to minimize hypernatremia during resuscitation. We assessed the effects of isosal on hemodynamics, brain edema, and plasma sodium concentration after head injury associated with hemorrhagic shock. DESIGN. Prospective, randomized laboratory study. SETTING: University research laboratory. SUBJECTS: Twenty-one adult female Suffolk sheep, weighing 39 to 49 kg. INTERVENTIONS: Animals were subjected to a 2-hr period of hemorrhagic shock to a mean arterial pressure (MAP) of 40 to 45 mm Hg in the presence of a freeze injury to the cerebral cortex. The hemorrhagic shock/head injury phase was followed by 2 hrs of resuscitation with isosal, a new 2400-mosm/L low-sodium hypertonic fluid, 2400 mosm/L of 7.5% hypertonic saline, or lactated Ringer's solution. Initial resuscitation was with a bolus injection of 8 mL/kg of the study solution; subsequent resuscitation in all three groups was with lactated Ringer's solution as needed to maintain baseline cardiac output. MEASUREMENTS AND MAIN RESULTS: Serial hemodynamics, intracranial pressure, electrolytes, and osmolarity were measured. AT the end of resuscitation, the animals were killed and brain water content (mL H2O/g dry weight) of the injured and uninjured areas was determined. Resuscitation volumes were significantly lower in the isosal (19 +/- 5 mL/kg) and 7.5% hypertonic saline (14 +/- 2 mL/mg) groups compared with the lactated Ringer's solution (35 +/- 5 mL/kg) group. Intracranial pressure after 2 hrs of resuscitation was significantly lower in the isosal (7 +/- 1 mm Hg) and hypertonic saline groups (4 +/- 1 mm Hg). Water content in all areas of the brain was significantly lower in the hypertonic saline group compared with the lactated Ringer's solution group. Brain water content in the isosal group was lower than in the lactated Ringer's solution group only in the cerebellum. Plasma sodium content was lower in the isosal group than in the hypertonic saline group. CONCLUSIONS: After combined head injury and shock, isosal and 7.5% hypertonic saline have similar effects on hemodynamics and intracranial pressure. Hypertonic saline induces a greater degree of brain dehydration; isosal resuscitation results in smaller increases in plasma sodium.

Animals↗
PubMed1996

Uncontrolled hemorrhage from parenchymal injury: is resuscitation helpful?

UNLABELLED: Fluid resuscitation increases blood pressure and may increase hemorrhage. We tested this hypothesis in a model of liver injury. After standardized injury, rats were randomized into four groups: no resuscitation (NR, n = 30), small volume lactated Ringer's solution (SVLR, 4 mL/kg, n = 30), large volume lactated Ringer's solution (LVLR, 24 mL/kg, n = 30), and hypertonic saline (HS, 4 mL/kg, n = 30). Terminal circulating volume was estimated using controlled hemorrhage experiments. Survival times and mortality rates were significantly lower in HS animals (10%) than in NR (50%) or SVLR (47%) animals. Blood pressure was significantly higher after HS, and this difference was sustained. Intraperitoneal blood volume was significantly higher with HS (26.0 +/- 0.7 mL/kg) and LVLR (26.9 +/- 0.6 mL/kg) compared with NR (21.5 +/- 0.7 mL/kg) and SVLR (22.5 +/- 0.7 mL/kg). Estimated terminal blood volume was significantly decreased in LVLR (29.3 +/- 0.6 mL/kg) compared with NR (33.3 +/- 0.7 mL/kg), SVLR (33.7 +/- 0.8 mL/kg), and HS (31.7 +/- 0.7 mL/kg). CONCLUSION: Vigorous resuscitation increases bleeding from solid viscus injury. Small volume HS improves blood pressure and survival compared with no resuscitation. Results of large vessel hemorrhage models may not apply to parenchymal viscus injury.

Animals↗
PubMed1996

Resuscitation of uncontrolled liver hemorrhage: effects on bleeding, oxygen delivery, and oxygen consumption.

Using a standardized liver injury model of uncontrolled hemorrhage, we tested the effect of different fluid resuscitation regimens on hemodynamics, oxygen delivery, oxygen consumption, bleeding volume, and fluid resuscitation requirements. Rats were randomized into three bolus resuscitation groups 15 minutes after liver injury: lactated Ringer's solution (LR, n = 10), hypertonic saline (HS, n = 10), and hypertonic sodium acetate (HA, n = 10). In all resuscitation groups, a 4 mL/kg bolus was first infused at a rate of 0.4 mL/min. Continuous supplemental LR infusion was then given for 90 minutes to maintain a mean arterial pressure of 80 mm Hg. An initial bolus of LR led to minimal changes in hemodynamics. Initial resuscitation with HS markedly increased blood pressure and cardiac index. The bolus of HA increased cardiac index but did not increase blood pressure; systemic vascular resistance was significantly decreased and bleeding significantly increased. Resuscitation with HS did not increase bleeding compared with LR and resulted in the smallest total resuscitation volume requirement. Resuscitation with HS and HA both resulted in a rapid increase in oxygen consumption; LR did not increase oxygen consumption. Animals in the HS group had significantly higher oxygen extraction ratios at the conclusion of the experiment. The use of different bolus fluids for the resuscitation of uncontrolled hemorrhage resulted in significant differences in hemodynamics, oxygen metabolism, and blood loss even when subsequent resuscitation was the same in all groups. Results from large vessel injury animal models and clinical studies of patients with penetrating trauma may not apply to solid parenchymal injuries.

Animals↗
PubMed1996

Complications after negative laparotomy for trauma: long-term follow-up in a health maintenance organization.

OBJECTIVE: To assess short-term and long-term complication rates after trauma laparotomy in a group of health maintenance organization (Kaiser Permanente) patients. DESIGN: Retrospective cohort study of patients belonging to Kaiser Permanente. MATERIALS AND METHODS: Eighty Kaiser patients who underwent a negative or nontherapeutic laparotomy for trauma at a Level I trauma center (University of California, Davis Medical Center (UCDMC)) between April 1989 and May 1994 were identified. Demographic data, past medical history, mechanism of injury, indications for surgery, findings at laparotomy, and short-term complications were abstracted from the UCDMC record. Long-term complications were taken from the Kaiser record. MEASUREMENTS: Long-term complications, including small bowel obstruction, hernia, and cosmesis. Short-term complications, including pneumonia, cellulitis, wound infection, prolonged ileus, and urinary tract infection. RESULTS: The single death in the early postoperative period was not related to the laparotomy. Mean follow-up was 36 +/- 2 months (median, 36 months); 86% had follow-up of at least 1 year. The incidence of short-term complications was 43% in patients with associated extra-abdominal injuries and 20% in patients without associated extra-abdominal injuries (p = 0.17). On long-term follow-up, there were no small bowel obstructions, incisional hernias, or cosmetic problems requiring correction. One patient developed a stitch abscess 6 weeks after the operation. CONCLUSIONS: The incidence of long-term complications after negative or nontherapeutic laparotomy for trauma is low.

Abdominal Injuries↗
PubMed1995

Liver injury as a model of uncontrolled hemorrhagic shock: resuscitation with different hypertonic regimens.

Using a standardized liver injury model of uncontrolled hemorrhage, we tested the effect of different hypertonic solutions on mortality, blood pressure, intra-abdominal bleeding, and circulating blood volume. After liver injury, rats were randomized to 4 groups: lactated Ringer's (LR, n = 10), Isosal (ISO, n = 10), hypertonic saline (HS, n = 10), and hypertonic sodium acetate (HA, n = 10). In all resuscitation groups, 4 mL/kg was infused at a rate of 0.4 mL/min. Blood volume was evaluated both directly and by estimation. Mortality was highest after HA resuscitation (40%) and lowest after HS resuscitation (0%), but this difference was not significant. Blood pressure was significantly higher after HS resuscitation, and this difference was sustained for 4 hours. The HA resuscitation did not increase blood pressure compared with LR resuscitation. Intraperitoneal blood volume was significantly higher with HS (25.5 +/- 0.7 mL/kg) and HA (26.8 +/- 1.2 mL/kg) than with LR (22.5 +/- 0.4 mL/kg). The HA resuscitation led to a significantly larger drop from baseline values of estimated terminal circulating blood volume than LR resuscitation. Nonparametric analysis combining survival time and directly measured change in blood volume demonstrated a significant advantage to HS, compared with LR. HA and HS resuscitations increased bleeding from uncontrolled solid viscus injury. The HS resuscitation restored blood pressure better than the other hypertonic solutions and maintained circulating blood volume in spite of increased bleeding. The HA and ISO resuscitations did not exhibit any advantage over LR in resuscitation of solid viscus injury.

Acetates↗
PubMed1995

Blood-to-tissue albumin transport in rats subjected to acute hemorrhage and resuscitation.

Hemorrhage induces a rapid redistribution of protein from extravascular spaces into the blood. We studied the effects of acute, nontraumatic hemorrhage on tracer-albumin clearances into individual tissues of rats to determine if reduced protein extravasation could account for intravascular protein gain. Three groups were studied: 1) HEM animals were anesthetized with pentobarbital sodium and bled to a mean arterial pressure of 50 mmHg for 90 min; 2) HEM-RS animals were treated identical to group 1 and then resuscitated with 5% bovine serum albumin (BSA) until baseline arterial pressures were regained; 3) SHAM animals served as time controls. Hemodynamic variables were measured periodically throughout hemorrhage and clearance periods, and plasma samples were collected prior to death for protein and hormone analysis. Plasma clearance of 131I-BSA into individual tissues was measured over the final 30 min of each protocol with a terminal injection of 125I-BSA used to correct for intravascular volume. Reduction of blood volume by 35% in HEM-treated animals resulted in a marked decrease in albumin transport relative to the SHAM group (p < or = .05) in the following tissues: skeletal muscle (-65%), skin (-49%), ileum (-75%), cecum (-66%), colon (-67%), heart (-67%), and lung (-71%). Significant changes were not observed in the remaining tissues sampled: pancreas, kidney, and cerebrum. Albumin clearances in the HEM-RS group were slightly but not significantly lower than SHAM animals except for skeletal muscle, where transport remained depressed following resuscitation.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1994

Use of Carmeda-coated femoral-femoral bypass during repair of traumatic aortic pseudoaneurysms.

OBJECTIVE: To compare the results and outcomes of three different approaches to posttraumatic pseudoaneurysm repair: clamp and sew, left heart bypass, and the most recent approach, cardiopulmonary support using femoral-femoral bypass. DESIGN: Retrospective series. SETTING: A university-based, level 1 trauma center. PATIENTS: Forty-two consecutive patients treated for posttraumatic aortic pseudoaneurysm whose mean (+/- SEM) Injury Severity Score was 37 +/- 1.7. INTERVENTION: Methods of repair included clamp and sew in nine patients, left heart bypass in 24 patients, and cardiopulmonary support in nine patients. METHODS: Student's t test was used to compare interoperative blood loss, need for blood transfusion, and aortic cross-clamp time. Complications and mortality were also reviewed. RESULTS: Mean (+/- SEM) aortic cross-clamp time for clamp and sew was 28.1 +/- 3.3 minutes vs 52.5 +/- 3.7 for left heart bypass and 49.3 +/- 5.6 for cardiopulmonary support. Blood loss and the need for transfusion were comparable between groups. Complications were also comparable. CONCLUSION: Femoral-femoral cardiopulmonary support is safe to use, has a very low risk of complications, and should provide protection for the spinal cord during aortic repair. We encourage a randomized prospective trial to determine if cardiopulmonary support has a significantly lower rate of paraplegia than the clamp- and -sew technique.

Adolescent↗
PubMed1993

Splenic abscess in the intensive care unit.

BACKGROUND AND METHODS: From 1980 through 1990, nine patients developed de novo splenic abscess during their stay in our intensive care unit (ICU), representing the first series of such reported cases. RESULTS: All nine patients were septic prior to the diagnosis of splenic abscess. The signs and symptoms of splenic abscess commonly described in the literature were of little help in detecting this pathology in ICU patients. Mean +/- SD platelet count, however, increased significantly, from 274 x 10(9)/L +/- 50 x 10(9)/L at admission to 647 x 10(9)/L +/- 94 x 10(9)/L at diagnosis. At diagnosis, left pleural effusion was present in all patients. Only three patients had detectable left upper quadrant tenderness. Abdominal computed tomographic scans, when used, were diagnostic in all cases. All patients were treated by splenectomy; eight had a solitary abscess. Six abscesses were caused by enteric organisms, two by Staphylococcus aureus, and one by Streptococcus epidermidis. Eight patients (89%) had had the offending organism previously isolated from their blood or from another infected site. Mortality was 45%. CONCLUSIONS: Splenic abscess, although a rare clinical entity, does occur de novo in ICU patients and is associated with significant mortality. Unexplained thrombocytosis in a septic ICU patient with persistent left pleural effusion is suggestive of splenic abscess. Previous culture and sensitivity results are useful in guiding perioperative antibiotic choices.

Abscess↗
PubMed1993

Effects of hypertonic and isotonic fluid infusion on the flash evoked potential in rats: hemorrhage, resuscitation, and hypernatremia.

In resuscitation from hemorrhagic shock, very small volumes of hypertonic saline (HS) improve blood pressure while reducing intracranial pressure and edema formation. The effects of hypertonic resuscitation fluids and hypernatremia on electrophysiologic brain function have not been studied. The present study was done in two parts. First we examined the effects of hemorrhagic shock and resuscitation with either 7.5% HS or lactated Ringer's (LR) solution on the flash evoked potential (FEP). Rats were bled to a mean arterial pressure (MAP) of 35 mm Hg for 1 hour, then resuscitated with HS (n = 10) or LR (n = 10) to a MAP of 80 mm Hg for another hour. Resuscitation required 3.8 +/- 0.5 mL/kg HS and 42.9 +/- 7.5 mL/kg LR (p < 0.05). During hemorrhage, FEP latencies increased and amplitudes decreased. During resuscitation, these variables returned toward baseline values. There were no significant differences between groups, although HS tended to restore the FEP better than LR. We next examined the effects on the FEP of hypernatremia and hyperosmolarity produced by two different hyperosmotic fluids. Over a 1-hour period, 16 mL/kg HS (n = 8), 16 mL/kg IsoSal (4.5% saline, 5.9% glucose, 6.4% mixed amino acids; n = 8), or 40 mL/kg LR (n = 8) was infused into normovolemic rats. Plasma sodium levels increased in both hyperosmotic groups (baseline = 145.2 +/- 0.7 mEq/L; after infusion, HS = 202.4 +/- 9.8 mEq/L, IsoSal = 163.3 +/- 4.2 mEq/L; p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Priorities in the management of multiple trauma: intracranial versus intra-abdominal injury.

UNLABELLED: Setting priorities in the management of patients with suspected injuries to both the head and the abdomen is difficult and depends on the likelihood of different injuries. Eight hundred trauma patients were retrospectively reviewed to determine the likelihood of a surgically correctable cerebral injury. All 800 patients, at the time of initial evaluation, were thought to have potentially correctable injuries to both the head and the abdomen. Of these, 52 had a head injury requiring craniotomy; 40 required a therapeutic celiotomy. Only three patients required both craniotomy and therapeutic celiotomy. There were more cases of delay in therapeutic celiotomy because of negative results of computed tomographic (CT) scanning of the head (13 cases) than there were delays in craniotomy because of nontherapeutic celiotomy (four cases). Need for craniotomy, based on emergency department evaluation, was indicated by the presence of lateralizing neurologic signs. Low Glasgow Coma Scale score, anisocoria, fixed/dilated pupils, loss of consciousness, facial or scalp injuries, and age were of no independent value in predicting the need for craniotomy. CONCLUSIONS: Patients with surgically correctable injuries of both the head and the abdomen are rare. In stable patients with altered mental status and potential injuries to both the head and the abdomen, the abdomen is best evaluated first by diagnostic paracentesis. If paracentesis does not return gross blood, CT scanning of the head should be done.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdominal Injuries↗
PubMed1993

Hypertonic saline (7.5%) versus mannitol: a comparison for treatment of acute head injuries.

Hypertonic saline (7.5% NaCl = HS) was compared with 20% mannitol (MAN), for the treatment of increased intracranial pressure (ICP), in a large animal model of head injury. Sheep were instrumented for hemodynamic and ICP monitoring and fluid administration. Elevated ICP (20-25 mm Hg) was produced by inflating an epidural balloon for 1 hour. Animals were then given a bolus of 250 mL of either HS (n = 7) or MAN (n = 7) and monitored for 2 hours. No significant differences in hemodynamic variables were noted between groups. The ICP decreased to the same degree in both groups during the 2 hours of observation (HS = 11 +/- 3.8 mm Hg; MAN = 8 +/- 2 mm Hg). Brain water contents were also similar (HS = 3.68 +/- 0.09 mL H2O/g dry wt; MAN = 3.83 +/- 0.08 mL H2O/g dry wt). The 7.5% NaCl was equally effective in treating elevated ICP caused by a space-occupying lesion when compared with 20% mannitol. Hypertonic saline has the additional benefit of rapid cardiovascular resuscitation of associated hemorrhagic shock with small-volume infusion.

Acute Disease↗
PubMed1993

Secondary survey following blunt trauma: a new role for abdominal CT scan.

Computerized tomographic (CT) scanning for blunt abdominal trauma has focused on initial emergency department evaluation. At our institution, CT scanning is often used on a delayed basis for unexplained drops in hematocrit, investigation of bony injuries, or subtle abdominal findings. We reviewed 268 such scans. Over 32 months, 487 CT scans were done for 5258 blunt trauma admissions. Of these scans, 268 (55%) were done 8-72 hours after admission on patients under observation. Scanning indications were a falling hematocrit (67%), associated injuries (28%), and abdominal tenderness (5%). Fifty of the 268 scans (19%) were positive for intra-abdominal abnormalities. Pleural effusions were seen in 82 (31%). Sixteen abdominal explorations were done. There was no difference in the pre-scan hematocrit drop in patients with normal scans (6.6%), positive scans (6.8%), and those who were explored (6.4%). There was one false positive (0.4%) and two false negative scans (0.8%). Conclusions. (1) A significant number of occult injuries, some life threatening, are detected by delayed CT scans. (2) Hematocrit drop under observation is not a good predictor of occult intra-abdominal injury. (3) Delayed CT scanning for occult abdominal injury is cost effective.

Abdominal Injuries↗
PubMed1992

History and current status of scoring systems for critical care.

Scoring systems for quantifying critical illness and predicting outcome are being used increasingly for resource utilization analysis and quality assurance purposes. The history of the development of these systems, the rationale for their use, and the data elements and statistical methods involved in these systems were reviewed. There are obvious advantages of scoring systems for the analysis of large groups of patients. At the same time, there are limitations of such systems in the treatment of individual patients. While improvement and refinement of existing scoring systems is likely to occur with time, these limitations must be kept in mind.

Critical Care↗
PubMed1992

Visceral injuries.

Abdominal visceral injuries are encountered by every surgeon who deals with trauma. It is simple and useful to divide abdominal visceral injuries into those caused by penetrating mechanisms of injury and those due to blunt mechanisms. Determination of the need for operative intervention is generally easier after penetrating trauma. Gunshot wounds to the abdomen should be explored, as should stab wounds to the anterior abdomen that penetrate the fascia. A midline incision is the standard approach to abdominal visceral injuries because of its ease and versatility. Abdominal exploration should be consistent and systemic so as not to miss significant injuries. Hollow viscus injury is most common after penetrating injury, while blunt injury most often results in injury to solid viscera. Diagnostic and operative aspects of the treatment of specific visceral injuries are reviewed.

Abdominal Injuries↗