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PubMed1989

Platelet aggregation and erythrocyte deformability in surgical patients under total parenteral nutrition.

Platelet aggregation (PA) and erythrocyte deformability (ED) were studied in twenty patients undergoing TPN for major abdominal surgery. PA was studied by the method of Born. ED was evaluated using standard filters (Uni Pore) and recording the filterability time (FT). All the patients had normal basal values of both parameters. In those receiving TPN slight increases of PA and FT were noticed after the first post-operative day (ADP 1 muM = 31.29 + 6.4%, EPI 5 muM = 24.08 + 8.2%, COLL 0.5 mug/ml = 27.94 + 6.5%, FT = 35.5 + 3.5''). This trend was more pronounced on post-operative day 4, and was statistically significant on days 7, 14, and 19 (ADP = 49.76 + 8.8, EPI = 57.2 + 11%) (p 0.05), (COLL = 73.2 + 8.6%) (P 0.01), (FT = 65.5 + 10.5'') (p 0.05). Some days after stopping TPN, these values slowly returned towards normal. These changes were not observed in a control group of ten patients, not undergoing TPN. From our data the following conclusions can be drawn: 1) PA is progressively enhanced in surgical patients undergoing TPN and slowly returns to normal several days after oral feeding resumption. 2) There is a significant linear relationship between PA and FT in the post-operative phase.

Journal Article↗
PubMed1978

Prevention of postoperative endophthalmitis.

Prevention of postoperative endophthalmitis (POE) requires (1) environmental control, (2) tissue control, and (3) anticipation of eyes at special risk of infection. Environmental control entails an adequate supply of finely filtered air and absolute sterility of solutions, medications, and objects and materials used during surgery. Tissue control involves degerming the skin of the operative field, inhibition of the flora of the lid margins by an antibiotic ointment use preoperatively, and pretreatment of the conjunctival tear film by soluble antibiotics possessing activity against Proteus and Pseudomonas as well as gram-positive species. Eyes at special risk of infection include those of diabetics, chronic alcoholics, and individuals who have been maintained for long periods of time on systemic or topical corticosteroids. Patients who have had multiple eye operations, recurrent uveitis, and who are scheduled for surgery on the second eye during a single hospital admission should receive special consideration preoperatively.

Anti-Bacterial Agents↗
PubMed2005

Comparison of conventional extracorporeal circulation and minimal extracorporeal circulation with respect to microbubbles and microembolic signals.

The intention of minimal extracorporeal circulation (MECC) is to reduce priming volume and minimize contact of blood with polymers and air in a closed system. In contrast to conventional extracorporeal circulation (ECC), a venous reservoir is missing. Thus, air trapping is limited and avoidance of bubble embolism is a major concern. This study investigates microbubbles (MBB) number and size in the venous and arterial lines of ECC and MECC compared to the number of microembolic signals (MES) in the right and left middle cerebral artery (MCA). Twenty patients undergoing coronary surgery were operated either with conventional ECC (cardiotomy reservoir, Rotaflow pump, Quadrox oxygenator, Quart filter) or MECC (Quart filter, Rotaflow pump, Quadrox oxygenator). Number and size of MBB were monitored in the venous and arterial lines with an ultrasound Doppler system. MES in right and left MCAs were measured by transcranial Doppler (TCD) monitoring. Patients undergoing MECC had additional sealing of the venous cannula by a ligature at the site of its insertion into the right atrium. There were no significant differences between groups with respect to age, X-clamping, bypass time and number of distal anastomoses. The number of MES and MBB in the arterial line was comparable between the groups. On the venous side, MECC-perfusion shows a significantly lower number of MBB. This could be explained with the additional sealing of the venous cannula. Furthermore, our data indicate that the MBB-volume reaching the pump will also appear in the arterial outflow and into the patient's MCA. For this reason, the avoidance of air contamination is a major concern for surgeons, anaesthesiologists and perfusionists.

Aged↗
PubMed1990

Liquefaction of human vitreous in model aphakic eyes by 300-nm UV photolysis: monitoring liquefaction by fluorescence.

After the lens is removed in cataract surgery, the vitreous presumably receives all of the ambient 300-nm light that has filtered through the cornea. Using this model for aphakic eyes, we progressively irradiated intact vitreous samples of a 49-year-old human with 300-nm light and monitored changes in absorption, fluorescence, and circular dichroism (CD) properties. CD and fluorescence measurements of unirradiated vitreous samples showed a) a strong tryptophan fluorescence band of non-collagenous protein at 336 nm and a very weak band around 430 nm due to N-formylkynurenine (N-FK), a photoproduct of tryptophan, and b) a strong, negative CD band below 250 nm representing a composite spectrum of hyaluronic acid, collagen, and non-collagenous protein. Upon irradiation, the tryptophan emission band at 336 nm progressively decreased with time and the band maximum was concomitantly red-shifted; the N-FK fluorescence band at 430 nm, on the other hand, continually increased with the time of irradiation. A significant increase in the fluidity (liquefaction) of the vitreous gel also was noted upon irradiation, a change that was monitored successfully by measuring the progressive decrease in the polarization value of tryptophan fluorescence. The extent of liquefaction, measured spectroscopically, was found to be 40% upon irradiation for 10 hr. In addition, CD measurements indicated a partial loss in the secondary structure of the non-collagenous protein.

Aphakia, Postcataract↗
PubMed2003

Sudden complete obstruction of breathing circuit during postural change upon completion of thoracic spinal surgery in a pediatric patient.

Positioning patients during the perioperative period is a common event to anesthesiologists. A variety of complications may arise during this cumbrous moment. We describe a rare circumstance that we came across immediately after changing the posture of a pediatric patient at the end of thoracic spinal surgery. A total occlusion of the combined heat-moisture exchanger (HME) and bacterial/viral filter was responsible for breathing circuit obstruction. The use of the combined HME and bacterial/viral filter is not entirely riskless during general anesthesia.

Anesthesia↗
PubMed2005

Disposable surgical face masks: a systematic review.

UNLABELLED: Surgical face masks were originally developed to contain and filter droplets of microorganisms expelled from the mouth and nasopharynx of healthcare workers during surgery, thereby providing protection for the patient. However, there are several ways in which surgical face masks could potentially contribute to contamination of the surgical wound. Surgical face masks have recently been advocated as a protective barrier between the surgical team and the patient, but the role of the surgical face mask as an effective measure in preventing surgical wound infections is questionable. The aim of the systematic review is to identify and review all randomised controlled trials evaluating disposable surgical face masks worn by the surgical team during clean surgery to prevent postoperative surgical wound infection. All relevant publications about disposable surgical face masks were sought through the Specialised Trials Register of the Cochrane Wounds Group (March 2001). Manufacturers and distributors of disposable surgical masks as well as professional organisations including the National Association of Theatre Nurses and the Association of Operating Room Nurses were contacted for details of unpublished and ongoing studies. Randomised controlled trials (RCTs) and quasi-randomised controlled trials comparing the use of disposable surgical masks with the use of no mask were included. MAIN RESULTS: Two randomised controlled trials were included involving a total of 1453 patients. In a small trial there was a trend towards masks being associated with fewer infections, whereas in a large trial there was no difference in infection rates between the masked and unmasked group. Neither trial accounted for cluster randomisation in the analysis. REVIEWERS' CONCLUSIONS: From the limited results it is unclear whether wearing surgical face masks results in any harm or benefit to the patient undergoing clean surgery.

Antisepsis↗
PubMed1990

Internal sclerostomy with argon contact laser--animal experiment using 5-fluorouracil.

A full-thickness sclerostomy was carried out with an ab interno approach, using an argon endolaser, in 9 eyes of 7 rhesus monkeys. After the injection of sodium hyaluronate into the subconjunctival space and the anterior chamber, a 300 micron fiber optic probe coupled with a water-cooled argon laser was inserted into the anterior chamber through the corneal incision made by a 23-gauge needle and positioned on the trabecular meshwork opposite to the corneal incision. A patent sclerostomy was obtained in all 9 eyes by 1 to 3 laser pulses with an energy of 4 W and a pulse duration of 0.5 seconds. After the surgery, 0.1 ml of 5-fluorouracil was injected subconjunctivally every day for one week. Intraocular pressure (IOP) was determined by pneumatic tonometer for one month at appropriate intervals. Mean preoperative IOP was 22 mmHg in both operated and nonoperated eyes. After one month IOP was 4.6 +/- 0.4 mmHg lower in the operated eyes than in the nonoperated eyes. Histologic study revealed that the sclerostomies from the anterior chamber opening to the subconjunctival space with the diameter of 200-300 microns still remained patent one month after surgery. Ab interno sclerostomy with an argon endolaser would be useful as a new filtering procedure which can easily be performed with minimum conjunctival damage.

Animals↗
PubMed1987

Long-term results of modified trabeculectomy with supramid implant for neovascular glaucoma.

Sixteen patients with neovascular glaucoma and residual visual function underwent modified trabeculectomy, including insertion of a Supramid sheet under the scleral flap. After 1 to 8.5 years of follow-up the intraocular pressure was substantially reduced in 12 patients and was maintained at 22 mm Hg or less in 10. Four patients were able to discontinue their medical therapy, and in 10 others it was considerably reduced. Functional filtering blebs were obtained in 12 patients. Visual acuity was about the same after surgery as before surgery in 8 of the 12; among the 4 others, visual loss was attributed to progressive cataracts in 2 and to macular degeneration in 2.

Glaucoma↗
PubMed1981

Lack of correlation between activated clotting time and plasma heparin during cardiopulmonary bypass.

The activated clotting time (ACT) with a Hemochron system for determining heparin requirements during cardiopulmonary bypass surgery, (CPB) accompanied by hemodilution and hypothermia was evaluated using plasma heparin levels as a standard. In 28 patients who were administered a standard heparin regimen (300 units/kg prebypass, 8000 units in the pump prime and 100 units/kg hourly during CPB) mean prebypass plasma heparin was 4 units/ml, and ACT was 493 seconds. During CPB mean plasma heparin decreased significantly (p < 0.001) to 3.1 units/ml, whereas mean ACT increased significantly (p < 0.001) to 674 seconds. The mean protamine requirement predicted from ACT was significantly higher (43%) than predicted from plasma heparin levels or actual protamine administered. The ACT neither accurately reflected plasma heparin during CPB nor predicted protamine requirements. The fixed-dose regimen employed, however, prevented both intraoperative thrombosis, assessed clinically in all patients, and clotting on six arterial line filters, as determined by scanning EM, despite wide variations in ACT and plasma heparin levels during surgery.

Adult↗
PubMed2006

Lightless cataract surgery using a near-infrared operating microscope.

PURPOSE: To describe the near-infrared (NIR) operating microscopy (NIOM) system using the NIR wavelength as the illumination source and to evaluate the feasibility of this system for lightless cataract surgery. SETTING: HenAm Kim Eye Center, Haenam-Gun, South Korea. METHODS: In this noncomparative interventional case series, cataract surgery was performed in 4 patients with bilateral cataract using the NIOM system in 1 eye and conventional microscopy in the fellow eye. The primary components of the system include an optical filter, a stereoscopic camera, head-mounted displays, and a recording system. This system uses invisible NIR (wavelength 850 to 1300 nm) illumination to facilitate cataract surgery without light. The differences between the NIOM system and conventional microscopy during cataract surgery were evaluated. RESULTS: The NIOM system provided excellent 3-dimensional viewing in real time. The image resolution was sufficient while performing all steps of cataract surgery. Immediately postoperatively and at 10 and 30 minutes and 1 hour, the visual acuity was better in the 4 eyes in which the NIOM system was used than in the 4 eyes in which conventional microscopy was used. However, using the NIOM system required good surgical skill. CONCLUSIONS: Lightless cataract surgery using the NIOM system seems useful for obtaining good visual acuity immediately postoperatively. The system may also reduce the incidence of light-induced retinal toxicity and the need for mydriatic administration and be a good educational tool.

Aged↗
PubMed2006

A simple venous thromboembolism prophylaxis protocol for patients undergoing bariatric surgery.

OBJECTIVE: Pulmonary embolism is a leading cause of death for bariatric patients. Numerous regimens have been proposed, but a comprehensive, simple approach is lacking. This study provides a simple, easily implemented prophylaxis regimen. RESEARCH METHODS AND PROCEDURES: One hundred fifty bariatric surgery patients were evaluated. Patients considered at high risk for venous thromboembolism had heart failure, a BMI of >/=50 kg/m(2), or a history of venous thromboembolism or pelvic surgery. Preoperatively and postoperatively, all patients received subcutaneous enoxaparin or unfractionated heparin. High-risk patients received either preoperatively inserted inferior vena cava filters or continuous heparin infusions intraoperatively. All high-risk patients were anticoagulated with warfarin (Coumadin; Bristol Myers-Squibb, Princeton, NJ) for at least 3 months postoperatively. Initially, some patients experienced significant hemorrhage; to prevent this, sutures were oversewn into staple lines. RESULTS: No patient experienced venous thromboembolism; a binomial test showed that the regimen reduced the risk of this complication to less than 2% (p < 0.05). Hemorrhage sufficient to require transfusion occurred in 4 of the first 20 patients; of the remaining 130 patients, into whose staple lines sutures were oversewn, none required transfusion (p < 0.05). DISCUSSION: Patients should be divided into those who are at high risk and those who are at low risk for venous thromboembolism. All patients should receive pre- and postoperative anticoagulation. High-risk patients should also receive either an inferior vena cava filter or intraoperative heparin infusions, as well as at least 3 months of Coumadin therapy. Oversewing of staple lines may reduce the risk of hemorrhage.

Anticoagulants↗
PubMed1989

Are routine inferior vena cavograms necessary before Greenfield filter placement?

In August 1983 we began routinely studying the inferior vena cava (IVC) before placement of a Greenfield filter. We have performed 83 caval interruptions since that time, but six patients were excluded from this study because an IVC clip had been placed in three patients during other abdominal surgery, and the medical records of three others could not be retrieved. Of the remaining 77 patients, 65 (84%) had IVC venograms taken before placement of their filter. We personally reviewed 63 of these cavograms but had to accept the radiologist's reports for two studies that could not be retrieved. Ten (15%) cavograms showed abnormalities that significantly affected the placement of the filter. The most frequent abnormality was intracaval clot extending above the L3-4 interspace. Other important abnormalities were severe narrowing of the diaphragmatic IVC (two patients) and a tortuous IVC in a patient with severe scliosis. Seven (11%) additional cavograms showed unilateral iliac thrombus that would have influenced the surgical approach had a femoral approach been required. Formal preoperative cavography expedited filter placement and reduced operating time by obviating the need for intraoperative angiograms. Because 26% of the cavograms showed clinically important information, we recommend that routine IVC angiograms be taken before filter placement.

Evaluation Studies as Topic↗
PubMedDate not supplied

Considerations of glaucoma in patients undergoing corneal refractive surgery.

Glaucoma patients present a unique set of challenges to physicians performing corneal refractive surgery. Corneal thickness, which is modified during corneal refractive surgery, plays an important role in monitoring glaucoma patients because of its effect on the measured intraocular pressure. Patients undergo a transient but significant rise in intraocular pressure during the laser-assisted in situ keratomileusis (LASIK) procedure with risk of further optic nerve damage or retinal vein occlusion. Glaucoma patients with filtering blebs are also at risk of damage to the bleb by the suction ring. Steroids, typically used after refractive surgery, can increase intraocular pressure in steroid responders, which is more prevalent among glaucoma patients. Flap interface fluid after LASIK, causing an artificially low pressure reading and masking an elevated pressure has been reported. The refractive surgeon's awareness of these potential complications and challenges will better prepare them for proper management of glaucoma patients who request corneal refractive surgery.

Cornea↗
PubMed1999

Signal-averaged P-wave duration does not predict atrial fibrillation after thoracic surgery.

BACKGROUND: Atrial fibrillation (AF) is the most common dysrhythmia seen early after major thoracic surgery but occurs infrequently after minor thoracic or other operations. A prolonged signal-averaged P-wave duration (SAPWD) has been shown to be an independent predictor of AF after cardiac surgery. The authors sought to determine whether a prolonged SAPWD alone or in combination with clinical or echocardiographic correlates predicts AF after elective noncardiac thoracic surgery. METHODS: Of the 250 patients enrolled, 228 were included in the final analysis. Preoperative SAPWD was obtained in 155 patients who had major thoracic surgery and in 73 patients undergoing minor thoracic or other operations who served as comparison control subjects. The SAPWD was recorded from three orthogonal leads using a sinus P-wave template. The filtered vector composite was used to measure total P-wave duration. Clinical, surgical, and echocardiographic parameters were collected and patients followed for 30 days after surgery for the development of symptomatic AF. RESULTS: Symptomatic AF developed in 18 of 155 (12%) patients undergoing major thoracic surgery and in 1 of 73 (1%) patients having minor thoracic or abdominal surgery, most commonly 2 or 3 days after surgery. In comparison with similar patients undergoing major thoracic surgery without AF, those who developed AF were older (66+/-8 vs. 62+/-10 yr; P = 0.04) but did not differ in SAPWD (145+/-17 vs. 147+/-16, ms) in standard electrocardiographic P-wave duration (105+/-7 vs. 107+/-10 mns), incidence of left-ventricular hypertrophy on 12-lead electrocardiography, male sex, history of hypertension, diabetes, or coronary heart disease. Thoracic-surgery patients at risk for postoperative AF did not differ from all other patients at low risk for AF in clinical or SAPWD parameters. CONCLUSIONS: Under the conditions of this study, SAPWD did not differentiate patients who did or did not develop AF after noncardiac thoracic surgery, and therefore its measurement cannot be recommended for the routine evaluation of these patients. Older age continues to be a risk factor for AF after thoracic surgery.

Adult↗
PubMed2004

Functional and anatomic results of macular hole surgery complicated by massive indocyanine green subretinal migration.

PURPOSE: To report the functional and anatomic results of macular hole (MH) surgery complicated by massive subretinal migration of indocyanine green (ICG) dye. DESIGN: Interventional case report. METHODS: We performed standard pars plana vitrectomy surgery for a stage 3, senile idiopathic MH. After posterior vitreous detachment and vitreous removal, we instilled 2 ml of ICG (0.5%, 270 mOsm); the surgery was complicated by diffuse subretinal migration of the ICG dye but peeling of the internal limiting membrane (ILM) was performed (despite the obvious difficulties from the low contrast between the green-stained ILM overlying a green-stained subretinal space) and the rest of the procedure was completed with a final injection of 16% C3F8. RESULTS: Post-surgical optical coherence tomography confirmed the anatomic closure of the MH. Digital photography with the excitation and barrier filters for ICG showed a striking autofluorescence along the inferior vascular arcade, which remained intense 7 months after surgery. Despite the massive subretinal migration of ICG, visual acuity (VA) improved to 20/30. CONCLUSIONS: This is the first report of VA recovery despite massive subretinal migration of ICG dye during MH surgery. Subretinal migration of ICG dye may be a potential complication during MH surgery; this should alert the surgeon to limit its use, despite the possible absence of clinically apparent toxic effects.

Coloring Agents↗
PubMed1999

Timing of sentinel lymph node mapping after lymphoscintigraphy.

BACKGROUND: Sentinel lymph node (SLN) mapping is an effective technique for staging patients with melanoma. In an attempt to avoid reinjection of radiolabeled colloid and facilitate SLN mapping at the time of surgery, we examined whether residual radioactivity from preoperative lymphoscintigraphy could be used to accurately identify SLNs during surgery 18 to 24 hours later. METHODS: Forty-six patients with newly diagnosed melanoma underwent injection of 0.22-micron filtered technetium 99m-labeled sulfur colloid followed by lymphoscintigraphy. Patients returned the next day for SLN biopsy with Isosulfan blue dye and the hand-held gamma-probe to identify SLNs. Thirty of 46 patients underwent repeat imaging before operation. No patient had reinjection of radiocolloid. RESULTS: Ninety-five SLNs were identified on initial lymphoscintigraphy, and repeat imaging on the day of surgery confirmed all SLNs previously identified. A total of 122 SLNs (2.65 per patient) were resected from 58 basins. Eighty-four (69%) of 122 SLNs stained blue, and 118 (97%) of 122 SLNs had in vivo gamma-counts greater than 4 times background. Microscopic metastases were present in 13 (10.7%) of 122 SLNs in 12 (26.1%) of 46 patients. There have been no recurrences over a mean follow-up time of 320 days. CONCLUSIONS: Intraoperative gamma-probe detection combined with blue dye injection is highly effective in identifying SLNs 18 to 24 hours after injection of 0.22-micron filtered 99mTc-sulfur colloid. Reinjection of radiocolloid is not required. This technique avoids radiopharmaceutical administration in the operating room, minimizes radiation exposure, and increases scheduling flexibility.

Adult↗
PubMed2002

Inferior vena caval filters following deep vein thrombosis in patients with ruptured intracranial aneurysm.

Anticoagulant therapy is highly effective and prevents death in more than 95% of patients who have suffered pulmonary embolism following deep vein thrombosis. Inferior vena caval filters provide an alternative to full anticoagulation in those patients at highest risk of catastrophic haemorrhagic complications. We report on two patients who developed deep vein thrombosis following ruptured unsecured intracranial aneurysms. Inferior vena caval filters were inserted prior to aneurysm clipping, as a prophylactic measure to prevent pulmonary embolism while awaiting surgery. The patients did not receive anticoagulant therapy following successful clipping of the aneurysm. Both patients had clinical resolution of the lower limb swelling and no radiological evidence of propagation of the thrombus. During 18 months of follow-up there were no complications and no evidence of post-thrombotic syndrome.

Aneurysm, Ruptured↗
PubMed2003

Hygiene and room climate in the operating room.

The ventilation system is not the most important source to cause surgical site infections via the air. More important is the skin of both staff and patients. The literature did not reveal any reduction of the risk of surgical site infections resulting from the employment of ultra-clean air-systems during surgical procedures, the one exception being high risk operations such as orthopaedic implant surgery. Both ultra-clean air and antimicrobial prophylaxis can reduce the incidence of surgical site infections. If HEPA filters are used, they are only necessary directly in the operating rooms. Other rooms such as the washroom, the anaesthesia preparation room or corridors which are connected to the OR do not have to be treated with HEPA filters. If a laminar air-flow system is installed, there are some factors which have to be considered. The number of operating lamps and the heads of the operating team affect the function of the air ceiling as they form thermic and air-flow resistance and create turbulences. Also, forced air-warming systems, which are used to maintain normal body temperatures for patients during surgery, disturb the ultra-clean field through the air emitted from the blankets used. Moreover, any medical equipment which is cooled by integrated cooling blowers can influence an ultra-clean air system. Existing ventilation systems are not able to create good room conditions for all persons inside the OR. Therefore new ways have to be found to create a room climate taking into account the level of activity.

Journal Article↗