The influence of intraoperative hypotension and perioperative blood transfusion on disease-free survival in patients with complete resection of colorectal liver metastases.

An increased interest in surgical treatment of liver metastases from colorectal origin has evolved recently. However not all patients benefit from this approach, with early recurrence and death still being encountered. To evaluate clinical as well as perioperative factors that might significantly affect the outcome of patients with completely resected colorectal liver metastases, we examined 116 patients who underwent resection between September 1987 and August 1989. Median follow-up time was 13.2 months (0.6 to 31.4 months). The overall survival rate was 91% at 1 year and 75% at 2 years. Median survival was not reached. Median disease-free survival time was 11.5 months, with 49.4% and 21.2% of the patients being free of disease at 1 and 2 years, respectively. By univariate analysis, site of primary colorectal cancer, preoperative carcinoembryonic antigen (CEA) level, size of metastases, number of metastases, length of operation time, percentage mean arterial pressure, number of hypotensive episodes, duration of hypotensive episodes, and whole blood transfusion significantly affected recurrence rate following resection. However only site of primary tumor, CEA, number of metastases, and number of hypotensive episodes remained significant in the multivariate analysis. The most significant single factor that affected recurrence rate was the number of hypotensive episodes during the operative procedure. It is concluded that hypotensive episodes, even when well controlled, should be avoided during operation to maximize the chances of cure and prolong disease-free survival of patients with colorectal liver metastases.     

Infection after farm machine-related injuries in children and adolescents

Infection played an important role in prolonging hospitalization and increasing morbidity in 68 children injured in farm settings. Predominantly gram-negative enteric organisms, group D streptococci, and anaerobic organisms were isolated in cultures of specimens obtained from wounds. Infection was more often associated with severe injuries of the large bones of the extremities than in amputation injuries of the digits and crush or roll-over injuries when the skin barrier was intact. The occurrence of infection in farm injuries was associated with prolonged hospitalization for parenteral antibiotic therapy, multiple surgical débridements with a need for general anesthesia, and permanent disability (decreased range of motion and loss of limbs and digits). Early aggressive surgical débridement and antimicrobial therapy guided by isolation and sensitivity testing of the major organisms are required because of polymicrobial invasion of vascularly compromised tissue.     

Iron status of children with short stature during accelerated growth due to growth hormone treatment

We determined the influence of human growth hormone (hGH) treatment on blood soluble transferrin receptor (sTfR) in 35 children with short stature. Whereas the serum concentration of ferritin decreased from 29.6 μg/1 to 19.7 μg/l, and that of transferrin increased from 2.9g/1 to 3.2g/1 during 6 months ( p < 0.001), only a minimum rise in the sTfR concentration was observed (7.12 ± 0.20mg/1 vs 7.51 ± 0.19mg/l, p = 0.025). The prevalence of anaemia or microcytosis did not increase. Most of the changes in serum ferritin and transferrin concentrations occurred during the first week. The study demonstrates that rapid body growth per se does not affect the sTfR concentration, but it may affect the serum transferrin and ferritin concentrations. Alternatively, GH may have a specific effect on serum ferritin and transferrin concentrations.     

Andrology: Pentoxifylline-supplemented cryoprotectant improves human sperm motility after cryopreservation

In this study, human spermatozoa obtained from donors (n = 15)with normal semen characteristics were cryopreserved in humansperm preservation medium, supplemented with the phosphodiesteraseinhibitor pentoxifylline at concentrations of 0, 1, 3 and 10mM. The effect of pentoxifylline on cryopreserved spermatozoawas determined by monitoring changes in sperm motility and acrosomemorphology by labelling the spermatozoa with fluorescein-conjugatedconcanavalin A lectin. Cryoprotectant supplemented with 1 mMpentoxifylline was found to improve post-thaw progressive motilityfrom 15.3 ± 2.4 (control) to 23.1 ± 3.8% (P <0.01), and total motility from 27.4 ± 3.3 (control) to38.2 ± 3.9% (P < 0.05) without reducing the percentageof spermatozoa with normal acrosomal regions, and so appearsuseful for cryopreservation purposes. The beneficial effectsof 1 mM pentoxifylline on sperm motility were shown to be maintainedpost-thaw over a 6 h time course. Cryoprotectant supplementedwith 3 mM pentoxifylline was found to improve only post-thawprogressive motility, from 15.3 ± 2.4 (control) to 20.7± 3.0% (P < 0.05). However, cryopreservation in thepresence of 10 mM pentoxifylline was found to have a significantly(P < 0.01) detrimental effect on acrosome morphology post-thaw,reducing it from 29.0 ± 2.0 (control) to 21.0 ±2.4% without affecting sperm motility. This suggests that assessmentof the acrosomal region may indicate subtle deleterious effectsof cryoprotectant supplements that cannot be determined frompost-thaw motility assessments alone. These findings differfrom previous studies in that a lower concentration of pentoxifylline(1 mM) was found to be optimal for cryopreservation purposes.     

Lack of Effect of Intrathecally Administered N-methyl-D-aspartate Receptor Antagonists in a Rat Model for Postoperative Pain

Background: Evidence from experiments by others indicates an important role for excitatory amino acids activating spinal n-methyl-d-aspartate (NMDA) receptors in models of persistent pain. The purpose of this study was to examine the effect of intrathecal (+)-5-methyl-10,11-dihydro-5H-dibenzo(a,d)cyclohepten-5,10-imine (MK-801), a noncompetitive NMDA receptor antagonist, 2-amino-5-phosphonovaleric acid (AP5), a competitive NMDA receptor antagonist, and N-G-nitro-L-arginine methyl ester (L-Name), a nitric oxide synthase inhibitor, on pain behaviors in a rat model of postoperative pain.

Methods: Rats with intrathecal catheters were anesthetized and underwent a plantar incision. Withdrawal threshold to punctate stimulation applied adjacent to the wound, response frequency to application of a nonpunctate stimulus applied directly to the wound, and nonevoked pain behaviors were measured before and after intrathecal administration of MK-801 or AP5. The effect of intrathecal L-Name on mechanical hyperalgesia was also examined.

Results: Mechanical hyperalgesia increased and was persistent after plantar incision and was not decreased by intrathecal administration of 4, 14, or 40 nmol MK-801 or 10 nmol AP5. Only the greatest dose of AP5, 30 nmol, caused a small decrease in punctate and nonpunctate hyperalgesia. Intrathecal L-Name had no effect. Neither intrathecal MK-801 nor intrathecal AP5 affected nonevoked pain behaviors. The greatest doses caused motor deficits.     

Computer-assisted and frameless stereotaxy: the initial Australian experience.

The trends towards minimally invasive surgery coupled with the increasing use of computer software and hardware have led to an increasing use of stereotactic neurosurgery as a part of mainstream neurosurgery. Computer-assisted and frameless stereotactic systems allow the performance of stereotactic procedures without the need for the mechanical linkage to a stereotactic frame. St Vincent's Hospital, Sydney, has used the Radionics Operating Arm System since March 1994 in 106 cases for stereotactic biopsy, localization of superficial lesions and volumetric resection of tumours. The Operating Arm System uses mechanical digitizers and has the advantages of being able to be used for both framed-based and frameless stereotactic procedures, simplicity of use, and the arm as a 'mouse' software program allowing the surgeon control of the computer program within the sterile operative field.