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Biomedical subjects

J A Johannigman

Publications and source records attributed to J A Johannigman.

At least 19 recordsLinked to original sources
PubMed2001

Work of breathing characteristics of seven portable ventilators.

Portable ventilators (PVs) are used for patient transport with increasingly frequency. Due to design differences it would not be unexpected to find differences among these ventilators in the imposed work of breathing (WOBI) during spontaneous respiratory efforts. The purpose of this investigation was to compare the WOBI characteristics during spontaneous breathing of seven PVs; Bird Avian, Bio-Med Crossvent 4, Pulmonetics LTV 1000, Hamilton Max, Drägerwerk Oxylog 2000, Impact Uni-Vent 750, and Impact Uni-Vent 754 using a model of spontaneous breathing. Differences between the PVs in regards to the measured parameters increased with increases in simulated breathing demand. WOBI, peak inspiratory pressure, and pressure-time product were consistently less with the LTV 1000 over the range of simulated breathing conditions. During pressure support ventilation these parameters were significantly less with the LTV 1000 compared with the Crossvent 4. Only the WOBI produced by the LTV was consistently lower than the physiologic work of breathing across the simulated spontaneous breathing conditions. Based on these results it is predicted PVs with flow triggering and positive end-expiratory pressure compensation will consistently offer the least WOBI. Clinicians should be aware of these characteristics when using PVs with spontaneous breathing patients.

Equipment Design↗
PubMed2001

Adaptive support ventilation.

Adaptive support ventilation (ASV) is a newer form of closed-loop ventilation control available on the Galileo ventilator (Hamilton Medical). ASV provides automated selection of initial ventilator parameters based on measurements of patient lung mechanics and breathing effort. After initiation, ASV will "titrate" ventilator output (mandatory breath rate, tidal volume, inspiratory pressure, inspiratory time, and I to E ratio) to maintain a calculated optimal breathing pattern that ensures delivery of a clinician selected minute ventilation target. ASV may be thought of as an "electronic" ventilator management protocol that may improve the safety and efficacy of mechanical ventilation. Additional clinical investigations regarding the effect of ASV on outcome, ventilator days, and so forth are forthcoming.

Algorithms↗
PubMed2001

Prone positioning and inhaled nitric oxide: synergistic therapies for acute respiratory distress syndrome.

BACKGROUND: Inhaled nitric oxide (INO) and prone positioning have both been advocated as methods to improve oxygenation in patients with acute respiratory distress syndrome (ARDS). This study was designed to evaluate the relative contributions of INO and prone positioning alone and in combination on gas exchange in trauma patients with ARDS. METHODS: Sixteen patients meeting the consensus definition of ARDS were studied. Patients received mechanical ventilation in the supine position, mechanical ventilation plus INO at 1 part per million in the supine position, mechanical ventilation in the PP, and mechanical ventilation in the prone positioning plus INO at 1 part per million. A stabilization period of 1 hour was allowed at each condition. After stabilization,hemodynamic and gas exchange variables were measured. RESULTS: INO and prone positioning both increased PaO2/FIO2 compared with ventilation in the supine position. PaO2/FIO2 increased by 14% during use of INO, and 10 of 16 patients (62%) responded to INO in the supine position. PaO2/FIO2 increased by 33%, and 14 of 16 patients (87.5%) responded to the prone position. The combination of INO and prone positioning resulted in an improvement in PaO2/FIO2 in 15 of 16 patients(94%), with a mean increase in PaO2/FIO2 of 59%. Pulmonary vascular resistance was reduced during use of INO, with a greater reduction in pulmonary vascular resistance seen with INO plus prone positioning (175 +/- 36 dynes x s/cm5 vs. 134 +/- 28 dynes x s/cm5) compared with INO in the supine position (164 +/- 48 dynes x s/cm5 vs.138 +/- 44 dynes x s/cm5). There were no significant hemodynamic effects of INO or prone positioning and no complications were seen during this relative short duration of study. CONCLUSIONS: INO and prone positioning can contribute to improved oxygenation in patients with ARDS. The two therapies in combination are synergistic and may be important adjuncts to mechanical ventilation in the ARDS patient with refractory hypoxemia.

Administration, Inhalation↗
PubMed2001

Surface temperature of two portable ventilators during simulated use under clinical conditions.

During performance testing of portable ventilators, it was noted that an area on the case of one of the devices, the LTV 1000, was noticeably warm. This investigation examined the case temperatures of this portable ventilator and a portable ventilator currently in the Department of Defense inventory, the Uni-Vent 754, during simulated clinical conditions. Both have an integral method of producing compressed air. The hottest portion of the cases of the LTV 1000 and the Uni-Vent 754 reached temperatures of 39.9 to 46.7 degrees C and 35.4 to 35.9 degrees C, respectively, across a range of simulated clinical conditions. Investigations have found the risk of burns to increase with temperatures greater than 40 degrees C. The cases of these devices are not designed to be in contact with the skin. Personnel should properly position these and other devices during patient transport and not allow contact with the patient's skin.

Burns↗
PubMed2000

The acute effects of body position strategies and respiratory therapy in paralyzed patients with acute lung injury.

BACKGROUND: Routine turning of critically ill patients is a standard of care. In recent years, specialized beds that provide automated turning have been introduced. These beds have been reported to improve lung function, reduce hospital-acquired pneumonia, and facilitate secretion removal. This trial was designed to measure the physiological effects of routine turning and respiratory therapy in comparison with continuous lateral rotation (CLR). METHODS: The study was a prospective, quasi-experimental, random assignment, trial with patients serving as their own controls. Paralyzed, sedated patients with acute respiratory distress syndrome were eligible for study. Patients were randomized to receive four turning and secretion management regimens in random sequence for 6 h each over a period of 24 h: (1) routine turning every 2 h from the left to right lateral position; (2) routine turning every 2 h from the left to right lateral position including a 15-min period of manual percussion and postural drainage (P&PD); (3) CLR with a specialized bed that turned patients from left to right lateral position, pausing at each position for 2 min; and (4) CLR with a specialized bed that turned patients from left to right lateral position pausing at each position for 2 min, and a 15-min period of percussion provided by the pneumatic cushions of the bed every 2 h. RESULTS: Nineteen patients were entered into the study. There were no statistically significant differences in the measured cardiorespiratory variables. There was a tendency for the ratio of partial pressure of arterial oxygen to fractional inspired oxygen concentration (PaO2/FIO2) to increase (174 +/- 31 versus 188 +/- 36; P = 0.068) and for the ratio of deadspace to tidal volume (Vd/Vt) to decrease (0.62 +/- 0.18 versus 0.59 +/- 0.18; P = 0.19) during periods of CLR, but these differences did not achieve statistical significance. There were statistically significant increases in sputum volume during the periods of CLR. The addition of P&PD did not increase sputum volume for the group as a whole. However, in the four patients producing more than 40 ml of sputum per day, P&PD increased sputum volume significantly. The number of patient turns increased from one every 2 h to one every 10 min during CLR. CONCLUSION: The acute effects of CLR are undoubtedly different in other patient populations (spinal cord injury and unilateral lung injury). The link between acute physiological changes and improved outcomes associated with CLR remain to be determined.

Adult↗
PubMed2000

Positive end-expiratory pressure and response to inhaled nitric oxide: changing nonresponders to responders.

BACKGROUND: Inhaled nitric oxide (INO) has been shown to improve oxygenation in two thirds of patients with acute respiratory distress syndrome (ARDS). Failure to respond to INO is multifactorial. We hypothesized that the addition of positive end expiratory pressure (PEEP) might modify the response to INO in patients who had previously failed to respond to INO. METHODS: Patients with ARDS who failed to respond to INO at 1 ppm (PaO2 increase of < 20%) were selected. Each patient underwent a PEEP trial using an improvement in static lung compliance as the end point. One hour after the new PEEP level was reached, hemodynamic and blood gas values were obtained. INO was then reinstituted at 1 ppm, and hemodynamic and blood gas variables were obtained 1 hour later. RESULTS: Six of nine patients demonstrated an increase in PaO2/FIO2 (161 +/- 27 to 186 +/- 29) with a mean increase in PEEP of 3.7 cm H2O. Each patient responding to PEEP further improved PaO2/FIO2 (186 +/- 29 to 223 +/- 36) with INO at 1 ppm. The three patients who failed to improve after the PEEP increase also failed to respond to a second trial of INO. There were no changes in cardiac output or systemic vascular resistance. Pulmonary artery pressures decreased slightly (39 +/- 5 vs 38 +/- 7 vs 35 +/- 9 mm Hg). Pulmonary vascular resistance decreased significantly after reintroduction of INO (298 +/- 131 vs 310 +/- 122 vs 249 +/- 105 dynes/sec/cm-5) in patients who responded positively. CONCLUSIONS: The response of ARDS patients to INO can be improved if optimum alveolar recruitment is achieved by the addition of PEEP. PEEP and INO have a synergistic effect on PaO2/FIO2. Patients who fail to respond to INO may benefit from an optimum PEEP trial.

Administration, Inhalation↗
PubMed2000

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.

Abdominal Injuries↗
PubMed2000

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.

Adult↗
PubMed2000

Prone positioning for acute respiratory distress syndrome in the surgical intensive care unit: who, when, and how long?

BACKGROUND: We evaluated the effects of prone positioning (PP) on surgery and trauma patients with acute respiratory distress syndrome (ARDS). METHODS: Patients with ARDS were studied. Exclusion criteria were contraindications to PP. Patients were evaluated in the supine position and after being turned to the PP. After 6 hours, patients were returned to the supine position for 3 hours. One hour after each position change, arterial and mixed venous blood was drawn and analyzed for blood gases and pH, and hemodynamics were measured. RESULTS: Over 20 months, 27 patients met the criteria, and 20 of the patients were entered into the study. On day 1, 18 of 20 patients (90%) responded with an increase in PaO(2) during PP. On day 2, 16 of 17 patients (94%) responded; on day 3, 15 of 16 patients responded (94%); on day 4, 11 of 13 patients responded (85%); on day 5, 8 of 8 patients responded (100%); and on day 6, 4 of 5 patients responded (80%). Pao(2)/Fio(2) and Qs/Qt were significantly improved (P<.05) during PP. There were 91 periods of PP, lasting 10.3+/-1.2 hours. Of 91 changes to PP, 78 changes (86%) resulted in an improvement in Pao(2)/Fio(2) of more than 20%. CONCLUSIONS: PP improves oxygenation in ARDS for 6 days with few complications.

Adult↗
PubMed2000

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.

Abdominal Injuries↗
PubMed2000

Prolonged use of heat and moisture exchangers does not affect device efficiency or frequency rate of nosocomial pneumonia.

OBJECTIVE: To determine whether use of a single heat and moisture exchanger (HME) for < or =120 hrs affects efficiency, resistance, level of bacterial colonization, frequency rate of nosocomial pneumonia, and cost compared with changing the HME every 24 hrs. DESIGN: Prospective, controlled, randomized, unblinded study. SETTING: Surgical intensive care unit at a university teaching hospital. PATIENTS: A total of 220 consecutive patients requiring mechanical ventilation for >48 hrs. INTERVENTIONS: Patients were randomized to one of three groups: a) hygroscopic HME (Aqua+) changed every 24 hrs (HHME-24); b) hydrophobic HME (Duration HME) changed every 120 hrs (HME-120); and c) hygroscopic HME (Aqua+) changed every 120 hrs (HHME-120). Devices in all groups could be changed at the discretion of the staff when signs of occlusion or increased resistance were identified. MEASUREMENTS AND MAIN RESULTS: Daily measurements of inspired gas temperature, inspired relative humidity, and device resistance were made. Additionally, daily cultures of the patient side of the device were accomplished. The frequency rate of nosocomial pneumonia was made by using clinical criteria. Ventilatory support variables, airway care, device costs, and clinical indicators of humidification efficiency (sputum volume, sputum efficiency) were also recorded. Prolonged use of both hygroscopic and hydrophobic devices did not diminish efficiency or increase resistance. There was no difference in the number of colony-forming units from device cultures over the 5-day period and no difference between colony-forming units in devices changed every 24 hrs compared with devices changed after 120 hrs. The average duration of use was 23+/-4 hrs in the HHME-24 group, 73+/-13 hrs in the HME-120 group, and 74+/-9 hrs in the HHME-120 group. Mean absolute humidity was greater for the hygroscopic devices (30.4+/-1.1 mg of H2O/L) compared with the hydrophobic devices (27.8+/-1.3 mg of H2O/L). The frequency rate of nosocomial pneumonia was 8% (8:100) in the HHME-24 group, 8.3% (5:60) in the HME-120 group, and 6.6% (4:60) in the HHME-120 group. Pneumonia rates per 1000 ventilatory support days were 20:1000 in the HHME-24 group, 20.8:1000 in the HME-120 group, and 16.6:1000 in the HHME-120 group. Costs per day were $3.24 for the HHME-24 group, $2.98 for the HME-120 group, and $1.65 for the HHME-120 group. CONCLUSIONS: Changing the hydrophobic or hygroscopic HME after 3 days does not diminish efficiency, increase resistance, or alter bacterial colonization. The frequency rate of nosocomial pneumonia was also unchanged. Use of HMEs for >24 hrs, up to 72 hrs, is safe and cost effective.

Adult↗
PubMed2000

The effects of passive humidifier dead space on respiratory variables in paralyzed and spontaneously breathing patients.

BACKGROUND: Passive humidifiers have gained acceptance in the intensive care unit because of their low cost, simple operation, and elimination of condensate from the breathing circuit. However, the additional dead space of these devices may adversely affect respiratory function in certain patients. This study evaluates the effects of passive humidifier dead space on respiratory function. METHODS: Two groups of patients were studied. The first group consisted of patients recovering from acute lung injury and breathing spontaneously on pressure support ventilation. The second group consisted of patients who were receiving controlled mechanical ventilation and were chemically paralyzed following operative procedures. All patients used 3 humidification devices in random order for one hour each. The devices were a heated humidifier (HH), a hygroscopic heat and moisture exchanger (HHME) with a dead space of 28 mL, and a heat and moisture exchanger (HME) with a dead space of 90 mL. During each measurement period the following were recorded: tidal volume, minute volume, respiratory frequency, oxygen consumption, carbon dioxide production, ratio of dead space volume to tidal volume (VD/VT), and blood gases. In the second group, intrinsic positive end-expiratory pressure was also measured. RESULTS: Addition of either of the passive humidifiers was associated with increased VD/VT. In spontaneously breathing patients, VD/VT increased from 59 +/- 13 (HH) to 62 +/- 13 (HHME) to 68 +/- 11% (HME) (p < 0.05). In these patients, constant alveolar ventilation was maintained as a result of increased respiratory frequency, from 22.1 +/- 6.6 breaths/min (HH) to 24.5 +/- 6.9 breaths/min (HHME) to 27.7 +/- 7.4 breaths/min (HME) (p < 0.05), and increased minute volume, from 9.1 +/- 3.5 L/min (HH) to 9.9 +/- 3.6 L/min (HHME) to 11.7 +/- 4.2 L/min (HME) (p < 0.05). There were no changes in blood gases or carbon dioxide production. In the paralyzed patient group, VD/VT increased from 54 +/- 12% (HH) to 56 +/- 10% (HHME) to 59 +/- 11% (HME) (p < 0.05) and arterial partial pressure of carbon dioxide (PaCO2) increased from 43.2 +/- 8.5 mm Hg (HH) to 43.9 +/- 8.7 mm Hg (HHME) to 46.8 +/- 11 mm Hg (HME) (p < 0.05). There were no changes in respiratory frequency, tidal volume, minute volume, carbon dioxide production, or intrinsic positive end-expiratory pressure. DISCUSSION: These findings suggest that use of passive humidifiers with increased dead space is associated with increased VD/VT. In spontaneously breathing patients this is associated with an increase in respiratory rate and minute volume to maintain constant alveolar ventilation. In paralyzed patients this is associated with a small but statistically significant increase in PaCO2. CONCLUSION: Clinicians should be aware that each type of passive humidifier has inherent dead space characteristics. Passive humidifiers with high dead space may negatively impact the respiratory function of spontaneously breathing patients or carbon dioxide retention in paralyzed patients. When choosing a passive humidifier, the device with the smallest dead space, but which meets the desired moisture output requirements, should be selected.

Analysis of Variance↗
PubMed1999

Changes in respiratory mechanics after tracheostomy.

OBJECTIVE: To determine the effects of tracheostomy on respiratory mechanics and work of breathing (WOB). DESIGN: A before-and-after trial of 20 patients undergoing tracheostomy for repeated extubation failure. SETTING: Surgical intensive care unit at a university teaching hospital and a level I trauma center. PATIENTS: A consecutive sample of 20 patients who met extubation criteria (Pa(O2), >55 mm Hg; pH >7.30; and respiratory rate, <30/min on room air continuous positive airway pressure after 20 minutes) but failed extubation on 2 occasions were eligible for the study. INTERVENTIONS: Respiratory mechanics, lung volumes, and WOB were measured before and after tracheostomy. MAIN OUTCOME MEASURES: Patients in whom extubation fails often progress to unassisted ventilation after tracheostomy. The study hypothesis was that tracheostomy would result in improved pulmonary function through changes in respiratory mechanics. RESULTS: Data are given as means +/- SDs. After tracheostomy, WOB per liter of ventilation (0.97+/-0.32 vs. 0.81+/-0.46 J/L; P<.09), WOB per minute (8.9+/-2.9 vs. 6.6+/-1.4 J/min; P<.04), and airway resistance (9.4+/-4.1 vs. 6.3+/-4.5 cm H20/L per second; P<.07) were reduced compared with breathing via an endotracheal tube. These findings, however, do not fully explain the ability of patients to be liberated from mechanical ventilation after tracheostomy. In 4 patients who were extubated before tracheostomy, WOB was significantly greater during extubation than when breathing through an endotracheal or tracheostomy tube (1.2+/-0.19 vs. 0.81+/-0.24 vs. 0.77+/-0.22 J/L). CONCLUSIONS: We believe that the rigid nature of the tracheostomy tube represents reduced imposed WOB compared with the longer, thermoliable endotracheal tube. The clinical significance of this effect is small, although as respiratory rate increases, the effects are magnified. In patients in whom extubation failed, WOB may be elevated because of incomplete control of the upper airway. Future studies should evaluate the cause of increased WOB after extubation.

Adult↗
PubMed1999

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 (NOV). There were significant differences between the EXP and NOV groups in ease of examination, visualization of biliary anatomy, and accuracy of measurement of the CBD. CONCLUSIONS: The use of laparoscopic US for the accurate evaluation of the CBD and biliary anatomy requires that the surgeon has surpassed the learning curve, which we have defined as having performed >10 US exams.

Adult↗
PubMed1999

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.

Adolescent↗
PubMed1999

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.

Abdominal Injuries↗
PubMed1998

The detection of microbial DNA in the blood: a sensitive method for diagnosing bacteremia and/or bacterial translocation in surgical patients.

OBJECTIVE: The purpose was to determine the sensitivity of detecting microbial DNA in the blood of surgical patients as a measure for diagnosing systemic infection and/or translocation from the gut. SUMMARY BACKGROUND DATA: Microbial infections and translocation of intestinal bacteria are thought to contribute to multiple system organ failure, but bacterial cultures are often negative in patients with this complication. METHODS: DNA was extracted from the blood of 40 surgical patients and 20 healthy controls. Polymerase chain reaction (PCR) techniques were used to amplify genes from Escherichia coli, Bacteroides fragilis, and a region of 16S ribosomal RNA found in many gram-positive and -negative bacteria. RESULTS: Bacterial DNA genes were not detected in healthy volunteers but were found in all patients with positive blood cultures. All eight transplant patients receiving OKT3 therapy had microbial DNA in their blood, possibly indicating translocation from the gut. Sixty-four percent of critically ill patients had microbial DNA detected in their blood, but only 3 (14%) had positive blood cultures. CONCLUSIONS: The PCR method is more sensitive than blood cultures for detecting bacterial components in the blood of critically ill surgical patients and may detect microbial translocation from the intestine.

Adolescent↗