Michael C. Townsend

Incidence and timing of hypothermia in trauma patients undergoing operations.

Hypothermia is a major problem in patients who have sustained trauma. We reviewed the cases of 100 consecutive trauma patients transferred directly to the operating room (OR) from the Emergency Department (ED) in a Level I trauma center; 26 cases could not be evaluated. Forty-two patients (57%) became hypothermic at some time between injury and leaving the OR. Fifty-five patients (74%) had a temperature (T) recorded on arrival to the ED; but only 7 (12%) were hypothermic (34.7 degrees +/- 1.5 degrees C). In contrast, 34 patients (46%) arrived in the OR hypothermic (34.8 degrees +/- 0.9 degrees C) and 26 (76%) of these left the OR hypothermic (34.8 degrees +/- 0.9 degrees C). Eight additional patients (20%) arriving in the OR with a T greater than 35.9 degrees C left the OR hypothermic (35.1 degrees +/- 0.4 degrees C). The mean T loss in the ED was significantly greater than that lost in the OR (-0.8 degrees +/- 0.7 degrees C vs. 0.0 degrees +/- 0.6 degrees C; p less than 0.0001, ANOVA). Ninety-two percent of the patients lost temperature in the ED, while 43% of the patients gained temperature in the OR. Hypothermia was associated with lower Trauma Scores, and those patients who were severely hypothermic received more intravenous fluids. However, the impact of fluid infusion was not independent from Trauma Score and did not fully explain the magnitude of the heat loss. These data suggest that hypothermia in trauma patients has a multifactoral etiology related to the magnitude of injury and that the major T loss occurs in the ED rather than in the OR.(ABSTRACT TRUNCATED AT 250 WORDS)

Experience with phenylephrine as a component of the pharmacologic support of septic shock.

ObjectiveTo evaluate the use of the selective α1-adrenergic receptor agonist phenylephrine in the hemodynamic support of patients with septic shock. DesignRetrospective analysis of clinical use of phenylephrine. SettingSurgical ICU in a university hospital. PatientsThirteen patients with septic shock (diagnosed by defined criteria) requiring pharmacologie support for the treatment of hypotension. Interventions and Main ResultsAll patients underwent invasive hemodynamic monitoring followed by volume resuscitation and inotropic support to reverse flow-dependent oxygen consumption and lactic acidosis. Patients with persistent hypotension (mean arterial pressure [MAP] <65 mm Hg) and vasodilation (systemic vascular resistance index [SVRI] <1500 dyne-sec/cm5-m2 received phenylephrine at iv infusion rates of 0.5 to 9 μg/kg·min to maintain MAP >70 mm Hg. MAP, SVRI, left ventricular stroke work index, and stroke volume index were significantly (p < .05) increased after phenylephrine administration and at the time of highest oxygen consumption (&OV0312;o2). Cardiac index was unchanged initially but increased at the time of highest &OV0312;o2 (p < .05). Pulmonary artery occlusion pressure and heart rate were unchanged. Average baseline &OV0312;o2 increased from 145 to 200 mL/min·m2 and oxygen delivery (&U1E0A;o2) increased from 447 to 597 mL/min-m2 during phenylephrine treatment (p < .05). Blood lactate concentrations decreased and urine output increased significantly (p < .05), while serum creatinine concentrations remained unchanged during phenylephrine therapy. ConclusionsTreatment with phenylephrine was associated with beneficial hemodynamic effects when used to maintain perfusion, while increasing &U1E0A;o2 and &OV0312;o2 in patients with septic shock.

Diagnostic laparoscopy as an adjunct to selective conservative management of solid organ injuries after blunt abdominal trauma.

To investigate the efficacy of diagnostic laparoscopy (DL) as an adjunct in patient selection for conservative management of solid organ injuries (SOI) following blunt abdominal trauma, 15 patients with injuries documented by computed tomographic (CT) scanning were prospectively evaluated. Diagnostic laparoscopy was performed in an attempt to characterize SOI, to evaluate the abdomen for associated occult injuries, and to select patients for conservative management or laparotomy. The 15 patients had CT evidence of 17 SOIs (nine spleen, eight liver), and DL allowed adequate visualization of 15 of the 17 injuries. Occult hollow viscus injury was discovered in 2 of 15 patients (one colon, one small bowel) and required laparotomy. In the remaining 13 patients, DL revealed ongoing hemorrhage in four patients and poor visualization in one patient that prompted laparotomy (four splenorrhaphy, one hepatorrhaphy). Conservative management was employed in the treatment of eight patients with findings of minor injury or adequate hemostasis on DL. The average transfusion requirement in this group was 1.8 U. No patient failed conservative management. There were no complications attributable to DL. These data demonstrate that DL may become an effective adjunct in patient selection for conservative management of SOI following blunt abdominal trauma.

In vivo [31P]NMR assessment of early hepatocellular dysfunction during endotoxemia

Hepatocellular dysfunction, as a result of sepsis or endotoxemia, plays a critical role in the pathogenesis of multiple systems organ failure. Conventional methods to assay hepatic ATP require large tissue samples, making repeat measurements in the same animal impossible, and are unable to detect the minimal changes in metabolism consistent with early or reversible cellular injury. 31P NMR is a modality available for the in vivo measurement of high energy phosphates. Inorganic phosphate (Pi) and phosphomonoester (PME) ratios (markers of cellular metabolism and viability) as well as fractionated ATP may be repeatedly quantitated. To assess the early effects of endotoxemia on hepatic function, phosphorus spectra of the liver were obtained using a 1.7-cm surface coil in six rats after the ip administration of 4 mg/kg Escherichia coli lipopolysaccharide. Conventional assay was performed on 24 matched controls. Pi, PME, alpha-, beta-, and gamma-ATP peaks (expressed as percentage total signal area) were collected over 20 min, integrated, and analyzed. Pi/beta-ATP decreased over time until 6 hr reflecting ongoing uptake of inorganic phosphate and continued cellular metabolism. PME/beta-ATP ratios, which indicate cellular viability, became significantly elevated at 6 hr. Using 31P NMR, beta-ATP best reflected the early subtle energy changes present prior to cell death and subsequent organ failure with significant decreases at 2, 4, and 6 hr. Conventional assay for ATP confirmed similar trends. We conclude that 31P NMR is a valuable tool for the study of reversible hepatic energy changes during early endotoxemia.

High-Dose Phenylephrine Infusion in the Hemodynamic Support of Septic Shock

A 75-year-old man with hyperdynamic septic shock and vasodilation was successfully supported hemodynamically for 88.5 hours through the use of a continuous infusion of phenylephrine at dosages up to 360 μg/min. The only other vasoactive compound administered was dopamine at a dosage of 3.4 μg/kg/min. Hemodynamic evaluation indicated improvements in mean arterial pressure, cardiac output, and oxygen transport parameters during the period of hemodynamic support, which did not indicate a detrimental effect on perfusion of vital organs and tissues despite the use of this vasoconstrictor. Phenylephrines pharmacologic properties may represent an advantage for its use as a vasoconstrictor over catecholamines such as norepinephrine and dopamine, particularly in patients who develop tachyarrhythmias with these agents. The pharmacology, dosage, and appropriate monitoring of therapy with phenylephrine in patients with septic shock are discussed.

CD-ROM source data uploaded to the operating and storage devices of an IBM 3090 mainframe through a PC terminal

A powerful method of processing MEDLINE and CINAHL source data uploaded to the IBM 3090 mainframe computer through an IBM/PC is described. Data are first downloaded from the CD-ROMs PC devices to floppy disks. These disks then are uploaded to the mainframe computer through an IBM/PC equipped with WordPerfect text editor and computer network connection (SONNGATE). Before downloading, keywords specifying the information to be accessed are typed at the FIND prompt of the CD-ROM station. The resulting abstracts are downloaded into a file called DOWNLOAD.DOC. The floppy disks containing the information are simply carried to an IBM/PC which has a terminal emulation (TELNET) connection to the university-wide computer network (SONNET) at the Ohio State University Academic Computing Services (OSU ACS). The WordPerfect (5.1) processes and saves the text into DOS format. Using the File Transfer Protocol (FTP, 130,000 bytes/s) of SONNET, the entire text containing the information obtained through the MEDLINE and CINAHL search is transferred to the remote mainframe computer for further processing. At this point, abstracts in the specified area are ready for immediate access and multiple retrieval by any PC having network switch or dial-in connection after the USER ID, PASSWORD and ACCOUNT NUMBER are specified by the user. The system provides the user an on-line, very powerful and quick method of searching for words specifying: diseases, agents, experimental methods, animals, authors, and journals in the research area downloaded. The user can also copy the TItles, AUthors and SOurce with optional parts of abstracts into papers under edition. This arrangement serves the special demands of a research laboratory by handling MEDLINE and CINAHL source data resulting after a search is performed with keywords specified for ongoing projects. Since the Ohio State University has a centrally founded mainframe system, the data upload, storage and mainframe operations are free.

A technique for rapid closure of traumatic small intestine perforations without resection

Small bowel perforation after blunt trauma is frequently associated with other intra-abdominal injuries. Typically, large luminal defects are encountered after blunt trauma that cannot be closed primarily without subsequent luminal compromise, necessitating formal resection with primary anastomosis. We describe a safe, rapid, and effective method by which traumatic small bowel perforations may be closed without resection using readily available gastrointestinal stapling devices. The speed of the closure allows for expedient management of associated injuries without fear of continued enteric spillage. No mesenteric resection or closure is needed, obviating the possibility of internal hernias.

An automatized computer-method utilizing Procomm Plus and DataEase (4.2) PC and SAS (6.06) mainframe software for isolated, perfused guinea-pig heart studies

A powerful, time sharing and automatized method of a comprehensive data analysis for isolated, perfused guinea-pig heart studies is described. Data are collected using DataEase PC software (version 4.2) into forms with data fields specified for vital parameters consistently recorded in isolated, perfused heart studies (HR, CBF, PEAKPRESSURE, DPDT, MVO2). After running, DataEase reports the data and information is uploaded to an IBM 3081D mainframe computer on each day of heart experiment and data collection. The uploading process, the data archival and the statistical analyses are automatized by Procomm Plus commands written in Aspect Source Program (.ASP) Files for logging, data transforming and file management procedures. The ASPCOMP.EXE compiler compiles these .ASP files into Aspect Script eXecutable (.ASX) programs, which run on the PC in our laboratory and activate WYLBUR (IBM 3081D Batch-job service and Command file processor) edited files in the mainframes electronic devices then upload, backup and save data into these files. SAS EXE files containing program instructions for the data analyzing system are then forced by Procomm Plus to operate over the data just uploaded. SAS reads the DATA files by its INFILE facility and performs comprehensive statistical analyses and produces hard output including graphics and JOB reports of dose-response- and logaritmic scale curves for delivery to team members. This computerized and automatized method developed for isolated, perfused guinea-pig heart studies is capable of performing multiple file transfer, sophisticated statistical analyses and graphic procedures after one keystroke on the PC (Alt-F5 in Procomm Plus section) and also facilitates a consistent and convenient method for planning, controlling and standardizing experiments. The method is based on an interactive computer conversation between the PC in the laboratory and the remotes WYLBUR editor. No human presence is needed; however, in case of failure, Procomm Plus gives one of the team members supervising the system a phone call in order to get human help.

DESPITE MAINTENANCE OF SYSTEMIC AND REGIONAL PERFUSION, ENDOTOXEMIA FOLLOWING COMPLEMENT DEPLETION PRODUCES HEPATOCELLULAR DYSFUNCTION

Experimental endotoxemia causes hypotension and a reduction in regional blood flow, including hepatic blood flow. Complement depletion prior to endotoxemia is known to attenuate these perfusion deficits. We depleted complement with cobra venom factor prior to the administration of Escherichia coli lipopolysaccharide in Sprague-Dawley rats and studied the effects of this treatment on systemic hemodynamics, regional hepatic perfusion, and hepatocellular integrity. Complement-depleted endotoxemic rats were compared with untreated rats, rats with complement depletion alone, and rats with endotoxemia alone. Systemic hemodynamics (cardiac index, mean arterial pressure), regional hepatic perfusion (effective hepatic blood flow), and hepatocellular integrity (adenosine triphosphate [ATP], lipid peroxidation) were determined 4-6 hr after the onset of endotoxemia. The endotoxemic animals exhibited a significant decrease in systemic hemodynamic performance and regional perfusion. Complement depletion prior to endotoxemia resulted in preservation of normal systemic and hepatic perfusion. ATP and lipid peroxide levels were significantly abnormal in both groups of endotoxemic animals. Complement depletion alone did not significantly affect any of the variables studied. The maintenance of systemic and regional perfusion during endotoxemia was not cytoprotective implicating direct cellular injury independent of perfusion deficits in the pathogenesis of hepatic failure during endotoxemia.