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Biomedical subjects

D S Beebe

Publications and source records attributed to D S Beebe.

30 records · Page 2Linked to original sources
PubMed1993

High levels of carbon monoxide are produced by electro-cautery of tissue during laparoscopic cholecystectomy.

Pyrolysis of tissue in a hypoxic environment can produce carbon monoxide. The atmosphere of the peritoneal cavity is rendered hypoxic during laparoscopic cholecystectomy by insufflation with 100% carbon dioxide. To determine whether carbon monoxide is produced by electrocautery of tissue during laparoscopic cholecystectomy, nine patients undergoing this procedure had the insufflation gas after use of electrocautery analyzed for carbon monoxide. Blood was analyzed for carboxyhemoglobin in these same patients to determine whether carbon monoxide was being absorbed in dangerous amounts. Carbon monoxide was present in the peritoneal cavity 5 min after use of electrocautery was initiated at a median concentration of 345 ppm (range 25-1600 ppm), and at the end of surgery at a concentration of 475 ppm (range 100-1900 ppm). This was well in excess of the 35 ppm upper limit for a 1-h exposure set by the Environmental Protection Agency. The carboxyhemoglobin concentrations (mean +/- SD) were the same at the beginning (1.3% +/- 0.7%), end (1.2% +/- 0.7%), and the day after surgery (1.1% +/- 0.6%). Although there was no evidence of significant absorption of carbon monoxide in these patients, care should be taken to scavenge the gases produced by cautery of tissues to avoid operating room contamination during laparoscopic surgery.

Adolescent↗
PubMed1993

Evidence of venous stasis after abdominal insufflation for laparoscopic cholecystectomy.

Intraoperative venous stasis may increase the risk for perioperative deep vein thrombosis and pulmonary embolism. To determine if abdominal insufflation during laparoscopic cholecystectomy causes venous stasis, eight patients undergoing this procedure had their left common femoral veins examined by a duplex scanner before and after abdominal insufflation; the veins then were examined again before and after deflation. The right femoral veins were catheterized to measure femoral venous pressures. Abdominal insufflation to 14 millimeters of mercury pressure increased femoral venous pressures (10.2 +/- 4.1 millimeters of mercury to 18.2 +/- 5.1 millimeters of mercury; p < 0.001) and slowed peak blood velocities (24.9 +/- 8.5 centimeters per second to 18.5 +/- 4.5 centimeters per second; p < 0.05) without changing the cross-sectional areas (1.1 +/- 0.4 centimeter squared to 1.2 +/- 1.5 centimeter squared; p = NS) of the common femoral veins. Insufflation also reduced or eliminated pulsatility in the common femoral veins in 75 percent of the patients, indicating that insufflation was causing partial proximal venous obstruction. After 80 +/- 21 minutes of surgery, these changes remained significant. Deflation of the abdomen restored normal venous pulsatility in all patients, reduced femoral venous pressures (18.5 +/- 5.2 millimeters of mercury to 12.2 +/- 9.8 millimeters of mercury; p < 0.001), increased the peak blood velocities (14.2 +/- 6.8 centimeters per second to 28.1 +/- 16 centimeters per second; p < 0.05) and decreased the cross-sectional areas (1.4 +/- 0.6 centimeters squared to 0.9 +/- 0.4 centimeters squared; p < 0.05) of the common femoral veins, indicating venous decompression had occurred. The results suggest abdominal insufflation causes venous stasis during laparoscopic cholecystectomies. Measures shown to reduce intraoperative venous stasis, such as pneumatic compressive stockings, may benefit patients undergoing these procedures.

Adult↗
PubMed1992

Effectiveness of preoperative sedation with rectal midazolam, ketamine, or their combination in young children.

To determine which of three types of rectal sedation was most effective preoperatively in facilitating parental separation and intravenous cannulation in young children, 100 children 3.0 +/- 1.7 (mean +/- SD) yr of age were randomly assigned to four equal groups. One group (M-K-A) received rectal midazolam (0.5 mg/kg), ketamine (3 mg/kg), and atropine (0.02 mg/kg). The other sedation groups received the same doses of midazolam and atropine (M-A) or ketamine and atropine (K-A) alone, and the control group (A) received only rectal atropine. Most children in either the M-K-A (100%) or M-A (92%) groups separated easily from their parents without struggling or crying, significantly more than in the K-A (60%) or A (64%) groups. However, more children in the M-K-A group (44%) were asleep during separation than in the M-A group (8%; P < 0.05). Only 20% of the children in the M-A or M-K-A groups cried during intravenous catheter placement, significantly less than in the K-A (56%) or A (92%) groups. Intravenous catheter placement was also successful significantly more often in the M-A (80%) and M-K-A (84%) groups than in the K-A (48%) or A (40%) groups. Complications were similar among the groups, but there was evidence that midazolam prolonged recovery time in some patients. Rectal midazolam with or without ketamine is a useful technique when intravenous catheter placement before induction of anesthesia is desired.

Administration, Rectal↗
PubMed1992

Complications and mortality of the in-situ saphenous vein bypass for lower extremity ischemia.

We retrospectively reviewed the records of 88 patients who underwent a total of 95 in-situ bypass operations. Seventy-eight percent were diabetics, 56% hypertensives, 23% had a history of a myocardial infarction, 18% a previous stroke or transient ischemic attack, and 19% a renal transplant. Eighty-eight percent had general anesthesia. Eighty-four percent of the operations extended distal to the popliteal trifurcation, with an average operating time of 5.12 +/- 1.25 hours and blood loss of 354 +/- 239 ml. The overall mortality was 4.2%, with two deaths due to wound sepsis and two deaths due to congestive heart failure. The perioperative myocardial infarction rate was 6.3%. The average age of the patients who died was significantly greater than the age of those who survived (78.2 +/- 17.7 years vs. 59.9 +/- 14.8 years, p less than 0.05). The Goldman risk index was not helpful in predicting cardiac complications. The results show that patients undergoing in-situ bypass operations are at high risk for cardiovascular complications. Aggressive perioperative evaluation and management similar to that shown to reduce such complications in abdominal aortic aneurysm surgery should be helpful.

Adult↗
PubMed1991

Is dantrolene safe to administer in sepsis? The effect of dantrolene after endotoxin administration in dogs and rats.

Hyperthermia from septic shock may be indistinguishable from malignant hyperthermia. Dantrolene may be given in septicemia if the diagnosis is unclear. To determine if dantrolene is safe to use in sepsis, two studies were performed. In study 1, 18 anesthetized dogs in which profound septic shock was induced with 5 mg/kg of intravenous Escherichia coli endotoxin were randomized to receive (30 min later) intravenous injections of 10 mg/kg of dantrolene solution, the diluent of dantrolene, or maintenance intravenous fluids alone. The use of dantrolene solution and the diluent of dantrolene resulted in similar but transient statistically significant increases in the cardiac filling pressures and cardiac outputs and decreases in the vascular resistances compared with the control dogs. In a second study, 185 rats were randomized into five equal groups. Groups 1, 2, and 3 received 15 mg/kg of intraperitoneal Escherichia coli endotoxin followed 30 min later by 10 mg/kg of dantrolene solution, the diluent of dantrolene, or normal saline. Groups 4 and 5 received normal saline followed by dantrolene or normal saline. The survival of groups 1, 2, and 3 was less at 24 h (P less than 0.0001) than that of either control group, but was not significantly different from one another. The results suggest dantrolene can be administered safely under clinical conditions where the cause of hyperthermia and shock cannot clearly be ascribed to malignant hyperthermia or septicemia.

Analysis of Variance↗
PubMed1991

Anesthetic management of infants receiving an adult kidney transplant.

Renal transplantation in infants has been associated with a high incidence of acute tubular necrosis and of renal artery thrombosis. Since 1978, 24 infants who received an adult kidney transplant at the University of Minnesota have had aggressive administration of intravenous colloids to increase the central venous pressure to 16-20 mm Hg before renal reperfusion. Acute tubular necrosis developed in only two infants, and there were no cases of renal artery thrombosis. Chest radiographic evidence of pulmonary edema was present in the recovery room in seven patients (29%) and within the first four postoperative days in five patients (21%). Yet, only two infants (8.3%) required postoperative mechanical ventilation beyond 24 h to manage fluid overload. With aggressive intravenous colloid administration, infants in renal failure can receive an adult kidney transplant with a low incidence of active tubular necrosis or renal artery thrombosis, but pulmonary edema may develop requiring ventilatory support.

Acid-Base Equilibrium↗
PubMed1989

Prostatic carcinosarcomas. Clinical, histologic, and immunohistochemical data on two cases, with a review of the literature.

Carcinosarcomas of the prostate gland are exceedingly rare, and previous reports exist on only seven of these neoplasms. The authors studied two such tumors, which occurred in 63- and 69-year-old patients. One of them had osseous metastases develop, which were treated unsuccessfully by irradiation and diethylstilbestrol therapy. The other patient is free of disease 15 months after radical prostatectomy. Both tumors contained an intimate mixture of carcinoma and sarcoma; patient 1 displayed foci of chondrosarcoma, osteosarcoma, and leiomyosarcoma, whereas patient 2 exhibited areas of chondrosarcoma, osteosarcoma, rhabdomyosarcoma, and angiosarcoma. The phenotypic nature of these tissues was confirmed by immunohistochemical studies, showing reactivity for vimentin, S-100 protein, desmin, actin, myoglobin, or Ulex europaeus I agglutinin. Conversely, the sarcomatous components lacked prostate-specific antigen, epithelial membrane antigen, and cytokeratin, whereas carcinomatous elements expressed these three markers. The authors' data support the existence of true carcinosarcomas of the prostate, that is, malignant neoplasms with conjoint epithelial and mesenchymal differentiation. The question of whether prostatic carcinosarcoma is an entity that is totally distinct from sarcomatoid or metaplastic carcinoma remains problematic.

Actins↗
PubMed1987

Extreme dyspnea from unilateral pulmonary venous obstruction. Demonstration of a vagal mechanism and relief by right vagotomy.

A 43-yr-old woman developed severe exertional dyspnea after an unsuccessful attempt to correct a total right anomalous pulmonary venous connection. A clotted anastomosis resulted in unilateral pulmonary venous obstruction. Investigation excluded airway disease, left ventricular failure, and severe pulmonary hypertension as the cause of dyspnea. Exercise studies demonstrated a markedly abnormal ventilatory pattern consistent with excess vagal stimuli to the respiratory center. Temporary and then permanent vagal interruption markedly altered the respiratory pattern and improved her functional status from New York Heart Association Class III to Class I, confirming that vagal afferents were the cause of the dyspnea.

Adult↗
PubMed1984

Management of pancreatic pseudocysts.

Fifty-five patients with pancreatic pseudocysts were evaluated over a ten year period and most of these cysts were diagnosed over the last five years with the aid of CT scans, ultrasound and ERCP. Among 39 patients who underwent surgical treatment, ultrasound was correct in 17 of 20 (10 per cent) and falsely positive in one patient out of 20 patients (5 per cent). The CT scan was correct in 12 of 13 patients (92 per cent) and falsely positive in one patient out of 13 patients (8 per cent). ERCP was correct in ten of 12 patients (83 per cent) with one false-negative (8 per cent) and one indeterminate (8 per cent) result. The mortality for 39 surgical patients was 21 per cent and most deaths were because of sepsis. Among 15 patients who did not undergo operative treatment, five had pseudocysts greater than 4 centimeters in diameter and only one patient had clinical regression of the pseudocyst. Ten of the 15 patients had pseudocysts less than 4 centimeters and nine of these patients had clinical regression of the pseudocysts. The results of the data suggest that pseudocysts 4 centimeter in size or smaller may be safely observed by serial CT examination or ultrasound.

Adult↗
PubMedDate not supplied

Carbon dioxide embolism during laparoscopy: effect of insufflation pressure in pigs.

Carbon dioxide embolism is a rare but potentially devastating complication of laparoscopy. To determine the effects of insufflation pressure on the mortality from carbon dioxide embolism, six swine had intravascular insufflation with carbon dioxide for 30 seconds using a Karl Storz insufflator at a flow rate of 35 mL/kg/min. The initial insufflation pressure was 15 mm Hg. Following recovery from the first embolism, intravascular insufflation using a pressure of 20 mm Hg at the same flow rate was performed in the surviving animals. Significantly less carbon dioxide (8.3 +/- 2.7 versus 16.7 +/- 3.9 mL/kg; p < 0.02) was insufflated intravascularly at 15 mm Hg than at 20 mm Hg pressure. All of the pigs insufflated at 15 mm Hg pressure with a flow rate of 35 mL/kg/min survived. In contrast, 4 of the 5 pigs insufflated at 20 mm Hg pressure died. The surviving pig died when insufflated with 25 mm Hg pressure following an embolism of 15.7 mL/kg. Intravascular injection was often associated with an initial rise in end-tidal carbon dioxide tension, followed by a rapid fall in all cases where the embolism proved fatal. Insufflation should be begun with a low pressure and a slow flow rate to limit the volume of gas embolized in the event of inadvertent venous cannulation. Insufflation should immediately be stopped if a sudden change in end-tidal carbon dioxide tension occurs.

Animals↗