Effects of platelet transfusion on post cardiopulmonary bypass bleeding.

A common complication of cardiopulmonary bypass (CPB) surgery is post-operative bleeding that may result in re-exploration. Bleeding is often due to the coagulopathy that follows the procedure, rather than the surgical technique. Etiology of this coagulopathy has been attributed to platelet dysfunction. We reviewed the medical records of 592 patients who had undergone CPB surgery between 1992 and 1994. Bleeding times (both pre and post operative) in treated (those who received platelets) and untreated patients were recorded where available. Both groups showed a rise in bleeding time (295 sec versus 192 sec, respectively, p<0.001). However, the treated group had a greater increase in the bleeding time compared to the un-treated (p<0.05). The result was the same when we compared 2 subgroups with similar pre-operative bleeding times. When the treated group was subdivided into those who received >10 units of platelets and those who received <10 units, there was no significant difference in the increase in their bleeding times (p>0.1). Administration of platelets did not improve bleeding time abnormalities induced by CPB. Both treated and untreated groups had a significant rise in their bleeding times, irrespective of the amount of platelets administered. The mean rise in the bleeding time in patients who bled significantly to require surgical re-exploration (but did not receive platelets) was not significantly different from those who received platelets. These observations suggest that the administration of platelets has no clinical benefit in improving bleeding time following CPB.

Preinsertion local anesthesia at the trocar site improves perioperative pain and decreases costs of laparoscopic cholecystectomy.

BACKGROUND: Local anesthesia at the trocar site in laparoscopic cholecystectomy is expected to decrease postoperative pain and hence expedite recovery. The aims of this prospective randomized study were to investigate the effect of local anesthesia and to discover whether it is cost effective. METHODS: For this study, 100 patients undergoing laparoscopic cholecystectomy were randomized into two groups. The 43 study patients were injected with 0.5% bupivacaine hydrochloride at the trocar site before the trocars were inserted. They then were compared with 41 control patients who received no local anesthesia. The remaining 16 patients were excluded from the study. The postoperative pain was evaluated at the standard four trocar sites at 4 h and 24 h after surgery on a scale 1 (the mildest pain the patient had ever experienced) to 10 (the most severe pain the patient had ever experienced). Postoperative pain medications and their cost were evaluated. RESULTS: There was no difference between the two groups with regard to gender, age, weight, operative time, estimated operative blood loss, and bile culture. The patients who received bupivacaine at the trocar site clinically had less pain (p < 0.001 for all four sites) both at 4 and 24 h after surgery. The treatment group patients used less mepiridine and promethzine than the control group (p = 0.001 and 0.002, respectively) postoperatively. Overall, the patients who had local anesthesia used less postoperative pain and antiemetic medication than the control patients (p = 0.02). This afforded a significant decrease in the costs and charges of these medications (p = 0.004 and 0.005, respectively). Three patients in the study group were discharged from the hospital the day of surgery. CONCLUSION: Preinsertion of local anesthesia at the trocar site in laparoscopic cholecystectomy significantly reduces postoperative pain and decreases medication usage costs.

Scanning electron microscopic changes in the morphology of rabbit pulmonary tissue biopsied following ischemia and reperfusion: a window of opportunity?

Reperfusion is known to cause tissue damage in ischemic pulmonary tissue. We investigated the time frame of this occurrence by examining electron microscopic changes in lung tissue. Isolated, perfused, and ventilated rabbit lungs (and heart) were placed en bloc in a 37 degrees C chamber and perfused through the pulmonary artery at 15 mm Hg pressure with oxygenated Krebs-Henseleit buffer, pH 7.4, 70 ml min(-1), for 20 min and the pulmonary pump and ventilator were stopped. The resultant ischemic state was maintained for 2 h, and reperfusion resumed with the same buffer. The lungs of four groups of rabbits (n = 5 per group) were each subjected to 30 min, 1, 2, and 4 h of reperfusion respectively. Upon completion, lungs were biopsied for scanning electron microscopy. Ischemic damage including the loss of lung architecture, and edema were seen. Reperfusion restored some of the tissue anatomy and the return to normalcy increased up to 1 h of reperfusion after which the damage increased with time. Results suggest that damage due to ischemia alone may be reversible. Initial recovery is due to the re-establishment of circulation. However, with time, the damage seen may be due to free radicals and with 4 h of reperfusion, cell death may have occurred.

Cancer chemopreventive mechanisms of tea against heterocyclic amine mutagens from cooked meat.

Cooking meat and fish under normal conditions produces heterocyclic amine mutagens, several of which have been shown to induce colon tumors in experimental animals. In our search for natural dietary components that might protect against these mutagens, it was found that green tea and black tea inhibit the formation of heterocyclic amine-induced colonic aberrant crypt foci (ACF) in the rat. Since ACF are considered to be putative preneoplastic lesions, we examined the inhibitory mechanisms of tea against the heterocyclic amines. In the initial studies using the Salmonella mutagenicity assay, green tea and black tea inhibited according to the concentration of tea leaves during brewing and the time of brewing; a 2-3-min brew of 5% green tea (w/v) was sufficient for >90% antimutagenic activity. N-hydroxylated heterocyclic amines, which are direct-acting mutagens in Salmonella, were inhibited by complete tea beverage and by individual components of tea, such as epigallocatechin-3-gallate (EGCG). Inhibition did not involve enhanced mutagen degradation, and EGCG and other catechins complexed only weakly with the mutagens, suggesting electrophile scavenging as an alternative mechanism. Enzymes that contribute to the metabolic activation of heterocyclic amines, namely microsomal NADPH-cytochrome P450 reductase and N, O-acetyltransferase, were inhibited by tea in vitro. Studies in vivo established that tea also induces cytochromes P450 and Phase II enzymes in a manner consistent with the rapid metabolism and excretion of heterocyclic amines. Collectively, the results indicate that tea possesses anticarcinogenic activity in the colon, and this most likely involves multiple inhibitory mechanisms.

Endoscopic technique for harvesting the intercostal nerve as a nerve graft: a feasibility preliminary study in cadavers.

Endoscopic surgical procedures in plastic surgery have been applied in numerous aesthetic and reconstructive surgical techniques. The use of the endoscopic video-assisted technique in peripheral nerve surgery is one of the most recent advances in reconstructive surgery. In this preliminary report, the seventh intercostal nerve, in fresh human cadavers, was harvested with the aid of endoscopy through a single 2-cm transverse incision. The anatomy of the intercostal nerve and the endoscopic surgical technique are described in this report. Multiple intercostal nerve grafts of adequate size, number, and length could be harvested, with less donor site morbidity, and used for future reconstruction of the injured peripheral nerve. The advantages of using an endoscopic technique to harvest the intercostal nerve include a magnified, clear, and illuminated visualization; a better remote access incision site; and an atraumatic technique, which may be proven particularly applicable in clinical procedures in patients who are prone to hypertrophic scars such as in women and children.

Relationship of mortality to increasing oxygen delivery in patients > or = 50 years of age: a prospective, randomized trial.

OBJECTIVE: To investigate the relationship of mortality to early resuscitation using two levels of oxygen delivery (DO2) in critically ill surgical patients > or =50 yrs of age who were stratified into groups: age < or =75 yrs (age 50 to 75 yrs group); and age >75 yrs (age >75 yrs group). DESIGN: A prospective, randomized trial, continued from a previous project. SETTING: Surgical intensive care unit, university affiliated. PATIENTS: Consecutive patients, >50 yrs of age, unable to generate a DO2 of > or =600 mL/min/m2 with fluid resuscitation alone, with a diagnosis of systemic inflammatory response syndrome, sepsis, severe sepsis, septic shock, and/or acute respiratory distress syndrome. INTERVENTIONS: During the first 24 hrs of resuscitation, patients were randomized to receive fluids, blood transfusions, and vasoactive agents in order to achieve DO2 treatment goals of > or =600 mL/ min/m2 in the protocol group and 450 to 550 mL/min/m2 in the control group. MEASUREMENTS AND MAIN RESULTS: One hundred five patients completed the study. In patients aged 50 to 75 yrs, the mortality rate was 21% (9/43) in the protocol group and 52% (12/23) in the control group (p=.01, 95% confidence interval of -58% to -4%). In patients >75 yrs of age, the mortality rate was 57% (12/21) in the protocol group and 61% (11/18) in the control group. Oxygen extraction ratios (O2ER) and oxygen consumption values were significantly (p=.02) lower in the age >75 yrs group compared with the age 50 to 75 yrs group. CONCLUSIONS: Patients 50 to 75 yrs of age receiving a DO2 of > or =600 mL/min/m2 demonstrated a statistically significant (p=.01) improved survival rate over patients in the control group. Patients >75 yrs of age demonstrated no benefit from attempts to increase DO2 to >600 mL/min/m2, and they may have been overtreated as reflected by the lower O2ER values in this age group. Treating to an O2ER that reflects a balance between oxygen consumption and DO2 may be an alternative goal that allows individual titration.

High-volume vs standard fluid therapy in a septic pig model. Impact on pulmonary function.

OBJECTIVE: To compare pulmonary function and peripheral organ blood flow in septic pigs receiving high-volume fluid resuscitation or standard-volume fluid resuscitation with similar goals in oxygen delivery. DESIGN: A prospective study comparing 2 groups of septic pigs. SETTING: A university animal research laboratory. SUBJECTS: Eleven septic pigs. INTERVENTIONS: Basal oxygen delivery was increased from 450 to 550 mL/min to at least 600 mL/min by the sixth hour and maintained for 24 hours. From a baseline pulmonary artery occlusion pressure (PAOP) measurement of approximately 6 mm Hg, the high-volume group (n = 5) was treated until a PAOP measurement of 12 mm Hg was reached and the standard-volume group (n = 6) was treated until a PAOP measurement of 8 mm Hg was reached. Blood transfusions and inotropic agents were added as necessary to reach the oxygen delivery goal. RESULTS: The high-volume group had a significantly greater positive fluid balance, greater weight gain, and a higher PAOP but similar intrapulmonary shunt and extravascular lung water as compared with the standard-volume group. CONCLUSION: Resuscitation with large volumes of fluid in early sepsis with a physiological goal of a higher PAOP to augment oxygen delivery did not cause increased pulmonary edema and oxygenation deficit compared with maintenance of lower cardiac filling pressures.

Inhibitory activity of green and black tea in a free radical-generating system using 2-amino-3-methylimidazo[4,5-f]quinoline as substrate.

Green tea and black tea inhibit colon carcinogenesis in rats exposed to the cooked meat mutagen 2-amino-3-methylimidazo[4,5-f]quinoline (IQ). In the present investigation, green tea, black tea and (-)-epigallocatechin gallate (EGCG) were shown to block the production of oxygen free radicals derived from IQ in the presence of NADPH-cytochrome P450 reductase. In kinetic studies using IQ as the substrate and DMPO as a free radical spin trap, EGCG increased the K(m) of the reaction without altering Vmax, suggesting competitive enzyme inhibition (Ki = 9.96 microM). This was confirmed in spectrophotometric studies using cytochrome c as the substrate, in which EGCG acted as a competitive inhibitor of NADPH-cytochrome P450 reductase (Ki = 9.7 microM). These results suggest that the inhibitory activities of green tea and black tea in electron spin resonance assays using IQ as the substrate for the reductase are related to an indirect effect on the enzyme rather than via direct scavenging of the free radicals. The possible implications of these findings are discussed in the context of pathways involved in the activation and detoxification of IQ in the colon.

Eosinophilia as a marker of adrenal insufficiency in the surgical intensive care unit.

BACKGROUND: Because hemodynamic instability may have several causes in critically ill patients, adrenal insufficiency may not be readily diagnosed. Eosinophilia has been described in patients with chronic adrenal insufficiency but not in critically ill patients. The goal of this study was to determine whether eosinophilia could serve as a marker of adrenal insufficiency in critically ill patients. STUDY DESIGN: During a 1-year period, all surgical patients admitted to the surgical intensive care unit with an eosinophil count greater than 3 percent were prospectively studied. To diagnose adrenal insufficiency, the synthetic corticotropin (cosyntropin) stimulation test was used. RESULTS: Eosinophilia was diagnosed in 31 patients, 7 (23 percent) of whom had adrenal insufficiency. The mean time interval to diagnosis was 13.7 days (range, 4 to 39 days). In 82 percent of the patients treated with hydrocortisone, a response was evidenced within 24 hours of treatment by a decrease in the required inotropic support by more than 50 percent, an increase in the mean arterial blood pressure of more than 25 percent, or both. CONCLUSIONS: New-onset eosinophilia may be a useful marker for adrenal insufficiency. Prompt testing and diagnosis may avoid the occurrence of a treatable, life-threatening condition.

Direct laparoscopic entry using a sharp and dull trocar technique.

For direct laparoscopic entry using a sharp and dull trocar technique, the sharp trocar is inserted with a twisting motion under constant pressure, then replaced with a dull trocar when a slight loss of resistance is felt. A slow, gradual entry into the peritoneal cavity is accomplished by twisting the dull trocar under constant pressure. Previous major abdominal or pelvic surgery is not a contraindication to this procedure, and use of these trocars, which can be resterilized for every use, may reduce surgical costs by decreasing the need for disposable trocars. This technique has been used in 1655 patients without complication or failure.

Efficacy of subcutaneous silver-impregnated cuffs in preventing central venous catheter infections.

STUDY OBJECTIVES: To determine the efficacy of an attachable subcutaneous silver-impregnated cuff in preventing local central venous catheter (CVC)-related infection and catheter-related sepsis in critically ill surgical patients. DESIGN: A prospective analysis of the use of an attachable subcutaneous silver-impregnated cuff compared with a control group in two consecutive time periods. SETTING: Two surgical ICUs at the Queen's Medical Center at the University of Hawaii Surgical Residency Program, Honolulu. PATIENTS: All surgical ICU patients requiring insertion of central catheters. INTERVENTIONS: None. MEASUREMENT AND MAIN RESULT: Two hundred thirty-five CVCs in 154 patients were prospectively evaluated. Silver-impregnated cuffs were used in the first 100 catheters, but none were used in the remaining 135 catheters. The incidence of catheter-related infection in both groups was 15% and 20%, respectively, not statistically significant. Catheter-related sepsis was 3% in both groups. CONCLUSIONS: The use of an attachable subcutaneous silver-impregnated cuff failed to decrease the incidence of CVC-related infection and sepsis.

Hemolytic anemia secondary to a porcine mitral prosthetic valve leaflet dissection.

This is a case of a dissecting cusp of a mitral porcine xenograft causing severe hemolytic anemia in the absence of valvular dysfunction and regurgitation. Six months after valve replacement, the patient had no evidence of hemolytic anemia. A cuspal dissection between the atrial and ventricular membranes was found on histologic evaluation.

Atrial myxomas: experiences with 35 patients in Hawaii.

BACKGROUND: Thirty-five patients with an intracardiac myxoma underwent excision of the tumor in Hawaii between 1974 and 1993. PATIENTS AND METHODS: There were 28 female and 7 male patients in the group. Their ages ranged from 11 to 79 years (mean 48) with the majority (71%) between 30 and 60 years old. The patients' medical records were reviewed and special attention was paid to clinical presentation, methods of diagnosis, operative findings, and postoperative course. RESULTS: No ethnic predisposition was found. Forty-six percent of the presenting symptoms were cardiac (congestive heart failure 26%, palpitations 14%, and syncope 6%) while arterial embolization accounted for 11%. Diagnosis was made by angiography, echocardiography, or gated cardiac blood pool imaging. All were reliable, but two-dimensional (2-D) echocardiography was used most often, with no false-positive or false-negative results. There were 32 left atrial, 2 right atrial, and 1 biatrial myxomas. Limited septectomy was performed in most cases, but 9 patients (26%) required Dacron patch repair of the atrial septum. There was 1 death from a cerebrovascular accident the day after the removal of a left-sided atrial myxoma. Other patients had few minor postoperative complications. One patient presented with a recurrence 8 years after resection at another institution; no further recurrences were found. CONCLUSIONS: We conclude that due to the non-specific presentation of atrial myxoma, a high index of suspicion is needed. The diagnostic method of choice is 2-D echocardiography. Limited septectomy is a safe procedure, but close follow-up for at least 10 years may be needed to rule out recurrence.

Frequency of mortality and myocardial infarction during maximizing oxygen delivery: a prospective, randomized trial.

OBJECTIVES: To determine the frequency of myocardial infarction and mortality during treatment that increased oxygen delivery (DO2) to > or = 600 mL/min/m2. To define the characteristics of patients achieving a high DO2 without inotropes in order to guide future studies. DESIGN: A prospective, randomized, controlled trial. SETTING: Two surgical intensive care units at The Queen's Medical Center in the University of Hawaii Surgical Residency Program. PATIENTS: Eighty-nine surgical patients (> or = 18 yrs of age), who were admitted to a surgical intensive care unit and who required pulmonary artery catheter monitoring, were selected for the study. Diagnoses included sepsis, septic shock, adult respiratory distress syndrome, or hypovolemic shock. Patients facing imminent death were excluded from the study. INTERVENTIONS: The treatment group received fluid boluses, blood products, and inotropes, as needed, to achieve a DO2 of > or = 600 mL/min/m2 in the first 24 hrs. Using the same interventions, we treated the control group to reach a DO2 of 450 to 550 mL/min/m2. MEASUREMENTS AND MAIN RESULTS: Hemodynamic measurements were obtained every 4 hrs until the pulmonary artery catheter was removed. DO2 and oxygen consumption were calculated by standard formulas. Serial creatine kinase myocardial fraction and electrocardiograms were documented for the first 48 hrs after study entry and for any new onset of arrhythmia or increasing hemodynamic instability. The patients who generated a high DO2 (> or = 600 mL/min/m2) with only preload treatment were reflective of patients with better cardiac reserve and low mortality rates. These patients, from both treatment and control groups, were excluded in the final analysis. The treatment group who received inotropes to achieve the high DO2 had a 14% mortality rate. Those patients who failed to achieve the high DO2 had a 67% mortality rate, and the control group who achieved a normal DO2 had a 62% mortality rate (p = .005). The frequency of myocardial infarction after study entry was 5.6% (five of 89 patients). This rate was not higher among the groups who received inotropes. Logistic regression analysis showed that age of > or = 50 yrs could be used to classify patients as not self-generating, with an 83% chance of being correct. CONCLUSIONS: The group that required catecholamines to achieve a DO2 of > or = 600 mL/min/m2 had a lower mortality rate, with no increase in the frequency of myocardial infarction. Future prospective, controlled trials examining select groups of patients (age > or = 50 yrs) may demonstrate a difference between control and treatment groups by eliminating the majority of patients who generate the high DO2 with only preload augmentation.

War injuries during the Gulf War: experience of a teaching hospital in Kuwait.

The war injuries of 361 patients admitted to Mubarak Al-Kabeer Teaching Hospital, during the Gulf War are reported. More abdominal and chest injuries were seen in this series in comparison with other conflicts owing to the short evacuation time. Of the injuries, 54% were caused by gunshots, 34% were fragment injuries and 5.5% were glass and stab injuries. Civilians accounted for 50% of the injured. Wound infection rate was 7%, average hospital stay was 8.8 days and hospital mortality was 5.5%. We advocate radical wound excision, exploration of penetrating wounds of neck and abdomen, and mainly conservative management of chest injuries that do not involve the mediastinum.

Early morbidity and mortality of non-therapeutic operations for penetrating trauma.

A retrospective study was performed in order to evaluate early morbidity and mortality associated with non-therapeutic operations for penetrating trauma. Over a 3-year period, 1,062 operations were performed on 1,015 patients for penetrating injury: abdomen 860, chest 103, neck 40, and extremities 58. A total of 230 (21.7%) of these operations were non-therapeutic. The incidence of significant complications directly related to the anesthesia or operation in this group of patients was 8.2 per cent. One patient with an additional major thoracic injury died secondary to complications related to a non-therapeutic abdominal operation (0.4%). The average hospital stay for uncomplicated non-therapeutic operations was 5.1 days, and for patients with complications 11.9 days. We conclude that non-therapeutic operations for penetrating trauma are associated with significant morbidity and mortality that must be considered when designing management schemes for penetrating injury.

Acute compartment syndrome of both lower legs caused by ruptured tibial artery aneurysm in a patient with polyarteritis nodosa: a case report and review of literature.

A unique case of acute compartment syndrome of both lower legs caused by a ruptured tibial artery in a patient with polyarteritis nodosa is reported. No similar cases have been reported in the literature. A review of the literature on ruptured aneurysms in patients with polyarteritis nodosa is discussed.