Randomized controlled multicenter international clinical trial of self-gripping Parietex™ ProGrip™ polyester mesh versus lightweight polypropylene mesh in open inguinal hernia repair: interim results at 3 months.

PURPOSE: To compare clinical outcomes following sutureless Parietex™ ProGrip™ mesh repair to traditional Lichtenstein repair with lightweight polypropylene mesh secured with sutures. METHODS: This is a 3-month interim report of a 1-year multicenter international study. Three hundred and two patients were randomized; 153 were treated with Lichtenstein repair (L group) and 149 with Parietex™ ProGrip™ precut mesh (P group) with or without fixation. The primary outcome measure was postoperative pain using the visual analog scale (VAS, 0-150 mm); other outcomes were assessed prior to surgery and up to 3 months postoperatively. RESULTS: Compared to baseline, pain score was lower in the P group at discharge (-10%) and at 7 days (-13%), while pain increased in the L group at discharge (+39%) and at 7 days (+21%). The difference between groups was significant at both time points (P = 0.007 and P = 0.039, respectively). In the P group, patients without fixation suffered less pain compared to those with single-suture fixation (1 month: -20.9 vs. -6.15%, P = 0.02; 3 months: -24.3 vs. -7.7%, P = 0.01). The infection rate was significantly lower in the P group during the 3-month follow-up (2.0 vs. 7.2%, P = 0.032). Surgery duration was significantly shorter in the P group (32.4 vs. 39.1 min; P < 0.001). No recurrence was observed at 3 months in both groups. CONCLUSIONS: Surgery duration, early postoperative, pain and infection rates were significantly reduced with self-gripping polyester mesh compared to Lichtenstein repair with polypropylene mesh. The use of fixation increased postoperative pain in the P group. The absence of early recurrence highlights the gripping efficiency effect.

[Heterotopic pancreas in the gallbladder. Diagnosis, therapy, and course of a rare developmental anomaly of the pancreas]. / Heterotopes Pankreasgewebe in der Gallenblase. Diagnostik, Therapie und Verlauf einer seltenen Entwicklungsanomalie der Bauchspeicheldrüse.

Ectopic pancreas is a rare entity but the second most prevalent pancreatic anomaly. Heterotopic pancreas is defined as the presence of pancreatic tissue without any anatomic or vascular continuity with the main body of the pancreas. Its aetiology is not clearly established. In 1916, Poppi published for the first time evidence of heterotopic pancreas in the gallbladder. A review of the literature up to the present showed only 28 more cases worldwide of ectopic pancreas in the gallbladder. Aberrant pancreas is incidentally discovered in 2% of autopsies and has been estimated to occur once in every 500 upper abdominal explorations. Ninety per cent of ectopic pancreas is found in the stomach, duodenum, and jejunum. Mostly it is asymptomatic and benign. For this reason, therapy is indicated only in patients with symptoms such as pyloric obstruction, bleeding, and malignant transformation. Surgical resection or endoscopic mucosal resection as a newer method are recommended.

Selected in-treatment outcomes of long-term methadone maintenance treatment patients in New York State.

The New York State Office of Alcoholism and Substance Abuse Services (OASAS) licenses the largest system of methadone maintenance clinics nationwide. In 1996, a survey was undertaken to evaluate the functioning of patients continuously active in treatment for ten or more years. Information was obtained on a 10% random sample from the OASAS client data system and the records of the clinics. Data were collected concerning methadone dose, illicit drug and problematic alcohol use, employment, criminal activity, health, living situations, and the primary type of payment for treatment. A contrast group was constructed of discharged patients who had no more than 5 years of continuous treatment. The long-term active patients in the study sample showed superior outcomes on all variables, although some of the differences were small. However, the arrest rate for the discharged contrast group was 20 times as large as the arrest rate for the active study sample. These results are consistent with nationwide evaluations of methadone maintenance treatment. Factors that negatively impacted on the adjustments of the active patients were heavy use of crack/cocaine and disabilities. The long-term active patients in this sample belong to distinct subgroups with different levels of functioning, achievement, and ongoing health and social needs that must be investigated and addressed.

Introduction of proton pump inhibitors--consequences for surgical treatment of peptic ulcer.

BACKGROUND/AIMS: This retrospective study analyzes the influence of different factors on morbidity and mortality after surgical treatment of peptic ulcer. METHODOLOGY: At the Municipal Hospital of Offenbach, Germany, from 1985-1996, 485 patients underwent surgery. RESULTS: Of the 485 patients, 70.7% (343) were diagnosed to have duodenal ulcer and 29.2% (142) had suffered from gastric ulcer. During this period, 79.2% (384) of the operations were performed under emergency conditions because of acute complications (56% of these with perforation, 20% with penetration, 24% with ulcer bleeding), whereas the rest was done electively. Two hundred and ninety-one (60%) patients were male, the average age was 59 years and 71.7% (348) of the patients had certain concomitant diseases. We observed complications in 48% of the cases with a total postoperative mortality of 21%. CONCLUSIONS: Between 1985 and 1996 the total number of ulcer surgeries performed at the Municipal Hospital Offenbach per year has stayed almost constant. However, a definite increase of acute operations in addition to a decrease of elective interventions was noticed. The dissatisfying results of surgical treatment of peptic ulcer after the introduction of proton pump inhibitors seems to be the consequence of the negative selection of patients mentioned above. A connection could be proved between the age and condition of the patient, the type of the surgical intervention (acute or elective) and the morbidity and mortality after the surgery.

Colorectales Carcinom--Behandlungsalternative durch intraoperative Radiotherapie mittels Afterloading-flab-Technik?

Intraoperative radiotherapy (IORT) is a new concept in the treatment of recurrent and primary advanced colorectal tumors. Between October 1994 and December 1997 27 patients (primary tumor: 8, first recurrent tumor: 12, second recurrent tumor: 7) received IORT (32 applications). Chemotherapy and percutaneous radiotherapy had already been given to all patients with advanced and recurrent colorectal tumors. The intraoperative irradiation was performed through HDR iridium afterloading. A flexible flab--individually adapted to the "tumor bed"--was used as applicator. The contact dose ranged from 10 to 15 Gy. The mean operation time (rectum resection: 5, rectum amputation: 14, debulking: 8) increased by 30 min on average. Eight patients had postoperative complications: perianal wound infections (3), sacrovesical fistulas (3), leakage of anastomosis (1) and neural ureter dysfunction (1). To date--on average 17.1 months (range: 3-33) after operation--13 patients are free of tumor recurrence or show stable disease. Ten patients--all of them had macroscopic residual tumor--have local tumor progression combined with good quality of life. Only 4 patients died (acute kidney failure, stroke, marasmus, systemic progression). The afterloading flab technique represents a technically simple, minimally harmful procedure in the therapy of colorectal tumor. Even when IORT with electrons is not feasible or the patients have already been irradiated, a higher radiation dose is possible. Given the demonstrated rate of local tumor recurrence, the afterloading flab technique seems to be a valuable treatment alternative to extended, high-risk resections. Long-term follow-ups will be necessary.

Noninvasive physiologic monitoring of high-risk surgical patients.

OBJECTIVES: To study the feasibility of multicomponent noninvasive monitoring, consisting of a new bioimpedance method for estimating cardiac output together with routine pulse oximetry and transcutaneous oximetry, and to compare physiologic data obtained noninvasively with hemodynamic and oxygen transport data obtained by standard invasive pulmonary artery thermodilution catheter to evaluate circulatory function in high-risk surgical patients. DESIGN: Prospective descriptive analysis of the time course of physiologic patterns in surgical patients. SETTING: University-run county hospital. PATIENTS: Seventy-one consecutively monitored, high-risk critically ill surgical patients in their perioperative period. OUTCOME MEASURES: Simultaneous measurements by invasive and noninvasive methods to describe and compare the temporal physiologic patterns of survivors and nonsurvivors. RESULTS: The new impedance cardiac output estimations closely approximated those of the thermodilution method (r = 0.82, P < .001). Episodes of hypotension, tachycardia, low cardiac index, arterial hemoglobin desaturation, low transcutaneous oximetry, reduced oxygen delivery, and low oxygen consumption occurred with both groups but were more pronounced in the nonsurvivors than in the survivors. Noninvasive monitoring provided information similar to that of the thermodilution method. Both approaches indicated low flow and poor tissue perfusion (oxygenation) that was worse in the nonsurvivors. CONCLUSIONS: The multicomponent noninvasive monitoring provides continuous online, real-time displays of physiologic data that allow immediate recognition of circulatory dysfunction as well as the means to titrate therapy to appropriate predetermined therapeutic goals. The noninvasive systems are easy to apply, safe, inexpensive, reasonably accurate, and cost-effective.

Temporal patterns of radiographic infiltration in severely traumatized patients with and without adult respiratory distress syndrome.

We prospectively evaluated the patterns of pulmonary structural and functional changes in 100 consecutive surgical intensive care unit trauma patients who had (1) emergent major surgery, (2) a pelvic fracture, or (3) two or more major long bone fractures. For each patient, arterial blood gas measurements (ABGs), central venous pressure (CVP), pulmonary capillary occlusion pressure (PAOP), thoracic compliance, arterial oxygen tension/fraction of inspired oxygen (PAO2/FIO2), pulmonary venous admixture (Qs/Qt), and portable chest roentgenograms were sequentially tracked. The senior staff radiologist interpreted all chest roentgenograms. Pulmonary infiltration was quantitated in each of six fields using a scale ranging from 0 to 4, with 0 being no infiltration and 4 being the maximum. Adult respiratory distress syndrome (ARDS) was defined as follows: Qs/Qt > or = 20%, PAO2/FIO2 < 250 or both; dependence on mechanical ventilation for life support for > or = 24 hours; PAOP or CVP or both < 20 mm Hg; and thoracic compliance < 50 mL/cm H2O. Time zero (T0) the time of onset of ARDS, was defined as the time these criteria were met. Eighty-three of 100 study group patients had penetrating injuries, and 17 were admitted with blunt trauma. Fifty-one of 100 patients developed ARDS: 36 of 51 died. Only 4 of 49 (8%) patients without ARDS died. The injured lungs of patients with and without ARDS had similar amounts of infiltration over most measured time intervals. The noninjured lungs of the ARDS patients, however, had significantly greater infiltration than those without ARDS at T0 and over subsequent time intervals.(ABSTRACT TRUNCATED AT 250 WORDS)

Temporal patterns of blood volume, hemodynamics, and oxygen transport in pathogenesis and therapy of postoperative adult respiratory distress syndrome.

Time relationships of physiologic patterns that are relevant to the pathogenesis of adult respiratory distress syndrome (ARDS) have not been well studied. The purpose of this review is to summarize the temporal relationship of blood volume, hemodynamics, and oxygen transport patterns occurring in postoperative patients before and after ARDS in order to develop a more complete mechanistic evaluation of its pathophysiology and to propose more rational therapeutic strategies. The data indicate that hypovolemia, reduced or uneven blood flow, inadequate delivery of oxygen, and insufficient consumption of oxygen precede the appearance of ARDS and are the primary precipitating physiologic events. This is contrary to conventional thinking which emphasizes capillary leak and fluid overload as the primary problems. The conventional approach also ignores events antecedent to ARDS that produce hypoxia of the lung tissue, result in pulmonary vasoconstriction, and increased pulmonary venous admixture (shunt). Therapy to prevent or rapidly treat these antecedent events has been shown to prevent or attenuate postoperative and posttraumatic ARDS. Various mediators such as interleukin (IL)-1, IL-6, and IL-8 and tumor necrosis factor as measured by plasma concentrations do not precede diagnostic criteria of ARDS, but may accelerate and augment the disorder as it is occurring.

Hemodynamic and oxygen transport responses in survivors and nonsurvivors of high-risk surgery.

OBJECTIVES: To describe temporal hemodynamic and oxygen transport patterns in a large series of high-risk surgical patients in order to document physiologic patterns, to develop therapeutic goals for a wide range of surgical conditions, and to propose a mechanistic model for acute postoperative circulatory failure. DESIGN: Prospective, longitudinal study. Patients identified as high risk were studied prospectively. The data were analyzed immediately after they were acquired, again on formal rounds twice daily, and at a formal data review after completion of monitoring. SETTING: A university-run county hospital. PATIENTS: The patient series consisted of 708 consecutively monitored high-risk surgical patients. INTERVENTIONS: Hemodynamic and oxygen transport values and their responses to surgical trauma are known to vary widely with age and prior medical conditions; they may be used to predict outcome with a high degree of accuracy. Temporal hemodynamic and oxygen transport patterns in a large series of high-risk surgical operations were treated by one group, using a well-developed protocol. MEASUREMENTS AND MAIN RESULTS: Hemodynamic and oxygen transport monitored variables were analyzed before, during, and at frequent intervals after surgical operations. We stratified the temporal patterns of survivors and nonsurvivors in each of the following groups: a) patients without evidence of cardiovascular disease whose preoperative baseline cardiac index values were normal; and b) patients with high or low preoperative baseline cardiac index values due to the presence of preoperatively identified medical conditions that affect the circulatory status. In addition, we stratified patients in various age ranges who were without known cardiovascular diseases. The present study analyzed over 20,000 data sets with up to 32 variables in each data set or > 500,000 values. The major findings were intraoperatively reduced circulatory functions, principally cardiac index values, oxygen delivery (DO2), and oxygen consumption (VO2). These reductions in circulatory functions intraoperatively were followed, in the early postoperative period, by increases in these variables. The postoperative increases in cardiac index, DO2, and VO2 values were greater in survivors than in nonsurvivors; these findings were more apparent when the postoperative patterns of each strata were related to their own preoperative control values. CONCLUSIONS: The data indicate that there are increased metabolic requirements after surgical trauma and that the changes in cardiac index and DO2 represent compensatory increases in circulatory functions stimulated by increased metabolic needs. However, these metabolic needs change with age, gender, severity of illness, type of operation, associated medical conditions, duration of shock, complications, organ failure, and outcome.

Hemodynamic and oxygen transport patterns for outcome prediction, therapeutic goals, and clinical algorithms to improve outcome. Feasibility of artificial intelligence to customize algorithms.

A generalized decision tree or clinical algorithm for treatment of high-risk elective surgical patients was developed from a physiologic model based on empirical data. First, a large data bank was used to do the following: (1) describe temporal hemodynamic and oxygen transport patterns that interrelate cardiac, pulmonary, and tissue perfusion functions in survivors and nonsurvivors; (2) define optimal therapeutic goals based on the supranormal oxygen transport values of high-risk postoperative survivors; (3) compare the relative effectiveness of alternative therapies in a wide variety of clinical and physiologic conditions; and (4) to develop criteria for titration of therapy to the endpoints of the supranormal optimal goals using cardiac index (CI), oxygen delivery (DO2), and oxygen consumption (VO2) as proxy outcome measures. Second, a general purpose algorithm was generated from these data and tested in preoperatively randomized clinical trials of high-risk surgical patients. Improved outcome was demonstrated with this generalized algorithm. The concept that the supranormal values represent compensations that have survival value has been corroborated by several other groups. We now propose a unique approach to refine the generalized algorithm to develop customized algorithms and individualized decision analysis for each patient's unique problems. The present article describes a preliminary evaluation of the feasibility of artificial intelligence techniques to accomplish individualized algorithms that may further improve patient care and outcome.

Prospective trial of supranormal values as goals of resuscitation in severe trauma.

We prospectively tested the effect of the early postinjury attainment of supranormal values of cardiac index (> or = 4.52 L/min per square meter), oxygen delivery (> or = 670 mL/min per square meter), and oxygen consumption (> or = 166 mL/min per square meter) on outcome in traumatized patients with an estimated blood loss of 2000 mL or more. The goals in control patients were to attain normal values for all hemodynamic measurements. During the 6-month period, 33 protocol patients and 34 control patients with similar vital signs, estimated blood losses, and severity of injuries were enrolled in the study. Eight (24%) protocol patients died, while 15 (44%) control patients died. The protocol patients had fewer mean (+/- SEM) organ failures per patient (0.76 +/- 1.21 vs 1.59 +/- 1.60), shorter stays in the intensive care unit (5 +/- 3 vs 12 +/- 12), and fewer mean days requiring ventilation (4 +/- 3 vs 11 +/- 10) than did the control patients (P < .05 for each). We conclude that attaining supranormal circulatory values improves survival and decreases morbidity in the severely traumatized patient.

Role of oxygen debt in the development of organ failure sepsis, and death in high-risk surgical patients.

In a series of 253 high-risk surgical patients, we measured the oxygen consumption (VO2) at frequent intervals before, during, and immediately after surgical operations and calculated the rate of VO2 deficit from the measured VO2 minus the VO2 need estimated from the patient's own resting preoperative control values corrected for both temperature and anesthesia. The calculated oxygen deficit was related to multiple organ failure, complications, and outcome. The 64 patients who died all had organ failure; their cumulative VO2 deficit averaged 33.2 +/- 4.0 L/m2 (+/- SEM) at its maximum, which occurred 17.8 +/- 2.2 h after surgery. In the 31 survivors with organ failure, the cumulative VO2 deficit averaged 21.6 +/- 3.7 L/m2 at its maximum, which occurred 10.1 +/- 2.7 h after surgery (p less than 0.05). In the 158 survivors without organ failure or major complications, the maximum cumulative VO2 deficit averaged 9.2 +/- 1.3 L/m2 at 4.1 +/- 0.6 h after surgery (p less than 0.05). In a prospective randomized clinical trial, a protocol group maintained at supranormal hemodynamic and oxygen transport values had significantly reduced oxygen debt (7.6 +/- 3.4 L/m2 vs 17.3 +/- 6.8 L/m2; p less than 0.05), fewer organ failures, and lower mortality (4 percent vs 33 percent; p less than 0.05) compared with a control group maintained at normal hemodynamic values. The data demonstrate a strong relationship between the magnitude and duration of the VO2 deficit in the intraoperative and early postoperative period and the subsequent appearance of organ failure and death. The latter may be reduced when oxygen debts were prevented or minimized by augmenting naturally occurring compensations that increased oxygen delivery.

The relationship between ARDS, pulmonary infiltration, fluid balance, and hemodynamics in critically ill surgical patients.

Hypervolemia from fluid overload with resultant pulmonary edema is thought to be a frequent cause of Adult Respiratory Distress Syndrome (ARDS). However, ARDS may also occur as a result of the hypovolemic shock of surgery or trauma. To develop an appropriate rationale for fluid therapy in high-risk surgical patients, the relationship between fluid balance, hemodynamics, the onset of ARDS by physiologic criteria (shunt greater than or equal to 20%, and/or PaO2/FiO2 ratio less than 250) and the onset of pulmonary infiltration (PI) associated with ARDS were examined. Fifty patients were prospectively followed from admission throughout their hospitalizations; 38 (76%) had trauma and 12 (24%) were postoperative. Cardiac index, central venous pressure (CVP), wedge pressure (WP), and shunt (Qsp) were measured. All chest x rays were read by one staff radiologist who was blinded to the patients' identities. PI was graded from "0" to "4" (0 = no PI, 4 = maximum PI). The first x ray reading of "2" or greater was used as the time of onset of PI. ARDS by physiologic criteria occurred in 29 of 50 (58%) patients; 27 of these 29 (94%) also developed +2 or greater PI. The mean onset times of ARDS and of +2 PI were 40 +/- 41 hours and 40 +/- 38 hours, respectively. The ARDS patients had a significantly smaller net positive fluid balance than the non-ARDS patients over the first 40 hours after admission (+6,831 ml +/- 4,909 ml vs 12,440 ml +/- 7,817 ml, (P less than 0.01)).(ABSTRACT TRUNCATED AT 250 WORDS)

The efficacy of central venous and pulmonary artery catheters and therapy based upon them in reducing mortality and morbidity.

The purpose of this study was to (1) evaluate the relative cost effectiveness of the central venous pressure and flow-directed pulmonary artery catheters used to maintain normal hemodynamic values as therapeutic goals in the control groups vs supranormal values empirically observed in critically ill postoperative survivors in the protocol groups, and (2) to evaluate tissue perfusion and oxygenation in relationship to organ failure and mortality. In two prospective clinical trials there were no significant differences in outcome between the central venous pressure and pulmonary artery control groups that used normal values as therapeutic goals. However, there were marked and significant reductions in morbidity and mortality of the protocol groups using the supranormal cardiac index, oxygen delivery, and oxygen consumption values as goals. The cumulative oxygen debt was less and organ failures were fewer and less severe in the protocol groups than in the control groups.

Measurement of tissue perfusion by oxygen transport patterns in experimental shock and in high-risk surgical patients.

Survivors of high-risk general (noncardiac) surgery were observed to have cardiac index (CI) values averaging 4.5 l/min.m2, oxygen delivery (DO2) of greater than 600 ml/min.m2, and oxygen consumption (VO2) of 170 ml/min.m2. In contrast, these values were relatively normal in patients who subsequently died. A very early predictive index based on these observations was found to predict outcome in 94% of high-risk patients. The hypotheses that increased DO2 and VO2 in the survivors represent compensatory physiologic responses and that these values were appropriate therapeutic goals were tested in prospective randomized clinical trials and found to reduce mortality and morbidity significantly. The optimal goals were more easily attained with colloids, red cells, dobutamine, and vasodilators, according to their capacity to improve tissue perfusion, as reflected by increased flow and oxygen transport. The extremely complex interactions between DO2 and VO2 are reviewed.

Therapy of shock based on pathophysiology, monitoring, and outcome prediction.

High-risk patients who survived general (noncardiac) surgery were observed to have cardiac index (CI) values averaging 4.5 L/min.m2, oxygen delivery (DO2) greater than 600 ml/min.m2, and oxygen consumption (VO2) 170 ml/min.m2 during the first 2 or three days postoperatively. Patients who subsequently died maintained relatively normal CI, DO2, and VO2 values in this period. Values of other variables in survivors and nonsurvivors were not appreciably different. An index based on these observations correctly predicted outcome in 94% in a subsequent prospective study. Two hypotheses: a) that increased flow and oxygen transport represent compensatory physiologic responses to an earlier tissue oxygen debt, and b) that these survivors' values were appropriate therapeutic goals, were tested in prospective randomized clinical trials. The protocol group attained those therapeutic goals. This resulted in significantly reduced mortality and morbidity. Optimal goals were more easily attained with colloids, red cells, and an inotropic agent, dobutamine. Dobutamine was used because, in a prospective crossover clinical trial with dopamine at various doses, dobutamine produced greater increases in flow and flow-related variables. More importantly, it improved tissue perfusion as reflected by greater increases in VO2 and greater reductions in pulmonary and systemic vascular resistance.

Testicular oximetry: a new method for the assessment of tissue perfusion and viability following torsion and detorsion.

This study evaluated the use of a polarographic surface PO2 electrode to assess testicular perfusion and viability following torsion and detorsion. Adult male Sprague-Dawley rats were divided into groups and subjected to unilateral testicular torsion and detorsion of varying degrees and durations. Rats subjected to sham torsion or 720 degrees torsion did not show significant decreases in testicular PO2 after 15 minutes, whereas those subjected to 1,080 degrees torsion or spermatic cord ligation uniformly decreased their testicular PO2 to 0 mm Hg within 10 minutes. Testicular PO2 values were similar in rats subjected to 60 minutes of 720 degrees torsion followed by detorsion and those undergoing 15 minutes of 1,080 degrees torsion and detorsion. Rats subjected to breathing 100% oxygen uniformly increased their testicular PO2 to an average of more than twice room-air values. However, rats subjected to 1,080 degrees torsion for 6 hours followed by detorsion did not increase their testicular PO2 when subjected to breathing 100% oxygen, whereas those subjected to 720 degrees torsion for 6 hours followed by detorsion did increase their testicular PO2 when subjected to breathing 100% oxygen. The latter rats did not show microscopic changes associated with acute testicular infarction, whereas the former did.(ABSTRACT TRUNCATED AT 250 WORDS)

Prediction of below-knee amputation wound healing using noninvasive laser Doppler velocimetry.

Preoperative laser Doppler velocimetry (LDV) measurements of calf and brachial skin perfusion were performed in 29 patients prior to undergoing below-knee amputation; dual calf measurements on the anterior and posterior skin flaps were routinely obtained. Patients' ages ranged from 24 to 83 years; 16 had diabetes, 13 were smokers, 6 had hypertension, and 2 had known coronary artery disease. Anterior and posterior calf LDV values greater than or equal to 20 mV were associated with successful below-knee amputation wound healing in 25 of 26 patients; all 3 patients with either anterior or posterior calf LDV values less than 20 mV had below-knee amputations that failed to heal. Calculation of calf-brachial LDV indexes did not increase predictive accuracy compared to calf LDV measurements alone, although patients with wounds that failed to heal tended to have lower calf-brachial indexes. Preoperative noninvasive LDV may be used to aid in predicting the likelihood of successful healing after below-knee amputation.

Comparison of hemodynamic and oxygen transport effects of dopamine and dobutamine in critically ill surgical patients.

Hemodynamic and oxygen transport effects of dopamine and dobutamine were studied in a series of 25 critically ill postoperative general surgical patients by a prospective, randomized crossover design after maximal response to fluids had been obtained. Dopamine increased MAP, HR, CI, PvO2, DO2, and Qsp while decreasing PaO2. Dobutamine increased HR, CI, SI, stroke work, DO2, VO2, and Qsp while decreasing PAWP and SVRI and PVRI. In general, the effects of the two drugs were greater in patients in the first 72 hours after surgery. The effects of dobutamine on flow and oxygen transport were greater than those of dopamine, especially in the early postoperative period. The effects were smaller and not significant in patients more than three days after surgery, as well as in those with sepsis, respiratory failure, renal failure, age over 65 years, and hyperdynamic states, in part because of the small number of patients in each group. These data are consistent with the hypothesis that the beta 2-adrenergic action of dobutamine vasodilates the previously constricted peripheral circulation, enhances tissue perfusion by improving micro-circulatory flow distribution, and improves DO2 and VO2.

Multisensor transcutaneous oximetric mapping to predict below-knee amputation wound healing: use of a critical Po2.

Preoperative transcutaneous oxygen tension (tcPo2) measurements of calf and brachial skin were performed on 40 patients before they underwent below-knee amputation (BKA); dual calf measurements on the anterior and posterior skin were obtained. Both anterior and posterior calf tcPo2 values were significantly lower in patients with unsuccessful wound healing after BKA compared to those with successful healing (p less than 0.01). Successful wound healing occurred in 50% (6/12) of patients with calf tcPo2 values less than 20 torr and in 96% (27/28) of patients with calf tcPo2 values greater than 20 torr. Calculation of a critical Po2 index (defined as the lesser of the anterior and posterior calf/brachial tcPo2 ratios) resulted in improved predictive accuracy; 100% (6/6) of patients with a critical Po2 index of 0.20 or less had unsuccessful wound healing after BKA, whereas 97% (33/34) of patients with a critical Po2 index greater than 0.20 had successful healing. The use of a critical Po2 index greater than 0.20 as predictive of successful healing after BKA was associated with a sensitivity, specificity, and overall accuracy of 100%, 86%, and 98%, respectively, compared to 82%, 86%, and 83%, respectively, by use of absolute calf tcPo2 values. In conclusion, multisensor transcutaneous oximetric mapping is an accurate method for predicting wound healing success after BKA. Measurement of both anterior and posterior calf tcPo2 should be performed; calf tcPo2 values less than 20 torr may indicate local ischemia, but ischemia should be confirmed by comparison of calf tcPo2 with brachial tcPo2 before the patient is denied BKA.(ABSTRACT TRUNCATED AT 250 WORDS)