Pterygium

Ultrasonic scalpel use versus electrocoagutation in thyroidectomy

Surgery March 2005

The thyroid is a small, soft, butterfly-shaped gland located just below the larynx. The gland uses iodine to produce thyroid hormone, which has a key role in regulating metabolism and calcium levels. Thyroidectomy, one of the most frequently performed procedures in endocrine surgery, is the surgical removal of all or part of the thyroid gland. The procedure requires meticulous dissection and exhaustive hemostasis to prevent damage to adjacent structures.

Suture ligatures and electrocoagulation are the two most common techniques for hemostasis. The use of electrocoagulation has the potential risk of injuring the surrounding structures from lateral dispersion of heat. In 1990, the ultrasonic scalpel was introduced. This instrument uses ultrasonic energy and mechanical vibrations at 55.5 kHz to cut and coagulate simultaneously and has the theoretical advantage of producing less thermal damage to surrounding tissue. The objective of this prospective, randomized, single-blinded study was to evaluate the potential advantages of using the ultrasonic scalpel versus electrocoagulation during thyroidectomies. (1)

Between July 2001 and July 2002, 60 patients undergoing thyroidectomy at a hospital in Mexico were randomly assigned to one of two groups. All patients received endotracheal general anesthesia, and a single surgeon performed all the procedures. In study group procedures (n = 30), dissection and vascular control of the gland, as well as division of superior, middle, and inferior vessels, were performed using the ultrasonic scalpel. In control group procedures (n = 30), electrocoagulation was used to transect small vessels, and knot tying was employed for the superior thyroid vessels, the thyroid vein, and some inferior arterial branches.

Outcome measures assessed included operative time; blood loss; postoperative drainage; number of ligatures and clips used; postoperative pain at the surgical site; and procedure complications, such as recurrent laryngeal nerve palsy and hypoparathyroidism. Pain was assessed using a numeric, visual pain rating scale where zero indicated no pain and 10 indicated the worst imaginable pain. Common statistical techniques were used to analyze differences between the two groups.

Findings. The mean operative time was significantly lower (P = .005) in ultrasonic scalpel procedures (96 [+ or -] 23 minutes versus 121 [+ or -] 34 minutes). The median number of ligatures used during the procedure was significantly lower (P < .001) for ultrasonic scalpel procedures than for electrocoagulation procedures (1, range 0 to 7 versus 17, range 6 to 28).

There was no significant difference in intraoperative bleeding, postoperative bleeding, and reports of postoperative pain between the groups. Three patients (ie, two in the ultrasonic scalpel group and one in the electrocoagulation group) had transient recurrent laryngeal nerve palsy that resolved spontaneously within 30 days. Nine patients in the electrocoagulation group and three patients in the ultrasonic scalpel group developed clinical hypocalcemia, manifested by numbness in the lips and hands. There were no mortalities.

Clinical implications. The results of this study revealed that the main advantage of using ultrasonic coagulation is the reduction in operative time; however, the authors note that controlled studies with larger numbers of patients may be needed to determine conclusively if using the ultrasonic scalpel is safer than using the standard technique. Perioperative managers should consider conducting studies on cost-effectiveness to evaluate whether the operative time savings can translate into surgical cost savings.

Using fibrin glue to attach conjunctival autografts

Ophthalmology April 2005

A pterygium is a pinkish, triangular-shaped growth of scar tissue and blood vessels on the sun-exposed surface of the eye that develops in response to ultraviolet damage from the environment. Although the growths are benign, they can cause decreased vision, pain, irritation, redness, and scarring. In addition, they are cosmetically unacceptable to many patients.

The main challenge of pterygium excision procedures is preventing recurrence. Conjunctival autografting after pterygium excision is associated with lower recurrence rates. The current method of attaching conjunctival autografts is by suturing; however, suturing requires a high degree of surgical skill and prolonged operating time. It also is associated with postoperative discomfort and the potential for suture-related complications, including buttonholes, suture abscess, granuloma formation, tissue necrosis, and giant papillary conjunctivitis. Tissue adhesives, including fibrin glue, are alternative means for attaching conjunctival grafts. The objective of this prospective, randomized study was to compare the safety and efficacy of fibrin glue to nylon sutures for attaching conjunctival autografts during pterygium excision procedures. (2)

Twenty-two patients undergoing excision of primary pterygium from June to August 2001 at a university hospital in the Philippines were prospectively enrolled in the study. In the control group (n = 11 eyes) the graft was placed onto the bare sclera, and its four corners were anchored to the episclera with 10-0 nylon sutures. The sutures were removed one month postoperatively. In the study group (n = 11 eyes), a drop of fibrin glue was placed on the bare sclera, and the graft was immediately transferred to the site. In both groups, tobramycin-dexamethasone ointment was placed in all the eyes, and a pressure patch was applied for 24 hours. Operating times were measured starting from the placement of the lid retractors to their removal at the end of the procedure.

Patients were assessed on the first day after surgery and then at weeks one, two, four, and eight for visual acuity, autograft integrity, and complications. Graft success was defined as an intact graft by the fourth week after surgery. Graft failure was defined as absence of the graft by the fourth week after surgery, and recurrence was defined as any growth of conjunctiva into the cornea. Subjective symptoms of pain, foreign body sensation, tearing, and discomfort were evaluated on the first postoperative day and at weeks one, two, and four using a five-point scale where zero equaled no pain and four equaled severe pain that interfered with usual activity or sleep. Analysis of covariance and the Friedman test for K-related samples were used to analyze the differences between the two groups.

Findings. Of the 22 patients, 13 (59%) were male and nine (41%) were female with a mean age of 54 [+ or -] 20 years (range 23 to 67 years). The mean operating time was significantly shorter when fibrin glue was used compared to sutures (P < .001). The mean surgical duration was 67 [+ or -] 3.6 minutes for patients in the suture group and 27.8 [+ or -] 1 minute for patients in the fibrin glue group. All the grafts were attached successfully and were intact at the end of the follow-up period. There were no cases of pterygium recurrence at the end of the follow-up period.

Subjective symptoms of pain, foreign body sensation, tearing, and discomfort were fewer and disappeared more rapidly for patients in the fibrin glue group compared to patients in the suture group. Additionally, the intensity of these symptoms was significantly lower for patients in the fibrin glue group (P < .001) on all follow-up days.

Clinical implications. This study revealed that the use of fibrin glue is an effective and safe method for attaching conjunctival autografts during pterygium surgery. It can significantly shorten operating time and result in fewer postoperative symptoms and less discomfort. The authors point out that long-term studies are needed to determine whether the rate of pterygium recurrence is affected by the use of fibrin glue instead of suture material. Perioperative nurses should be prepared to assist in conducting these studies.

Preventing glove perforation and contamination

The Journal of Bone and Joint Surgery April 2005

Total hip arthroplasty is a common surgical procedure performed to alleviate pain and debilitation caused by osteoarthritis, rheumatoid arthritis, fractures, dislocations, congenital deformities, and other hip-related problems. Preventing contamination is a principal focus during hip arthroplasty because infection can have devastating consequences for patients and perioperative personnel. A high incidence of glove perforation that can result in contamination is known to occur during orthopedic surgical procedures because of the need to manipulate bone or bone fragments; consequently, double gloving during these procedures is widespread. The purposes of this randomized, controlled study were to

* investigate the incidence of glove perforation and contamination,

* determine whether changing gloves at specified intervals can reduce incidences of perforation and contamination, and

* identify strains of contaminating bacteria during primary total hip arthroplasty. (3)

Fifty patients undergoing primary cemented total hip replacement at a university hospital in England were randomly assigned to one of two groups. All members of the surgical team wore double gloves for all procedures. In study group procedures (n = 25), the outer gloves were changed after draping, at 20-minute intervals, and immediately before cement was used. In control group procedures (n = 25), outer gloves were changed per current practice (ie, after draping and before cementing of the components). Additionally, for all procedures, gloves were changed whenever a visible puncture was detected.

The outer gloves of surgeons, first assistants, and the scrub persons were studied for contamination. An impression of each gloved finger was made on sterile blood agar culture material before each set of gloves was removed. The number of colonies, density of growth, and strain of bacteria were noted for each culture. Contamination was classified as

* no contamination (ie, no growth);

* low contamination (ie, between one and five colonies); and

* heavy contamination (ie, more than five colonies).

Glove perforation was determined using a water test. Common statistical procedures, including chi-square and Fisher's exact tests, were used to analyze differences between the groups.

Findings. There was no difference in operating times between the two groups. The median operating time for study group procedures was 70 minutes (95% confidence interval [CI] 60 to 80 minutes). The median operating time for control group procedures also was 70 minutes (95% CI 65 to 90 minutes).

During study group procedures, the surgical team changed gloves more frequently (median time 16 minutes, 95% CI 15 to 20 minutes) than during control group procedures (median time 23 minutes, 95% CI 21.5 to 25 minutes). The proportion of perforated gloves was significantly lower for study group procedures compared to control group procedures for both surgeons and scrub persons (P = .04 and P = .01, respectively).

Glove contamination was significantly lower for study group procedures compared to control group procedures (4.8% versus 13.9%). All members of the surgical team remained free of contamination in 56% of the study group procedures compared to 42% of the control group procedures (P = .02). One hundred six bacterial isolates were found. The majority (69%) were coagulase-negative staphylococci.

Clinical implications. This study revealed that changing gloves at regular intervals is an effective way to decrease the incidence of glove perforation and bacterial contamination during total hip arthroplasty. Perioperative nurses and managers should understand that contamination not only increases the risk for transmission of infection to patients but also increases the risk for the transmission of bloodborne infection to perioperative personnel. Consequently, they should consider implementing policies and procedures that require a change of gloves at regular intervals during total hip arthroplasty procedures.

Preoperative hemoglobin level as an indicator of blood toss

Joint Disease and Related Surgery 2005

Over time, hip arthroplasty procedures have become a safer, more reliable method of treating severe arthritis pain; however, the procedure is associated with significant blood loss. The objective of this multicenter prospective study was to determine the amount of blood loss in total hip arthroplasty by using blood hemoglobin levels during the preoperative assessment as an indicator for predicting blood loss for a particular patient. (4)

Between February 2000 and August 2003, 723 patients undergoing primary total hip arthroplasty at three different hospitals received a cemented Charnley prosthesis with the use of a modified Harding approach under normotensive general anesthesia. Patients were excluded from the study if they had any blood disorder; had a past history of transfusion; were using anticoagulation medications; or had ischemic heart disease, rheumatoid arthritis, psoriatic arthritis, or Paget's disease.

All patients were assessed preoperatively and met criteria that included having a hemoglobin level of at least 12 g/dL, not having received a preoperative transfusion, and not having donated blood for autologous transfusion. The patients did not receive blood transfusions or any blood products during or after the procedure. The hemoglobin count was repeated 24 to 48 hours postoperatively. All patients had the same fluid regimen during the immediate postoperative period and a rehabilitation protocol that included full weight-bearing ambulation on the first postoperative day. Common statistical techniques were used to analyze the data.

Findings. Of the 723 patients, 416 (57.5%) were female and 307 (42.5%) were male. The mean age was 68 years (range 69 to 79 years). Preoperative blood hemoglobin levels ranged from 12 g/dL to 15.3 g/dL (mean 12.8 g/dL). The mean difference between the preoperative and postoperative hemoglobin within the first 48 hours from the beginning of the procedure, defined as the estimated blood loss, was 4.2 g/dL.

Clinical implications. In this study, the amount of blood loss associated with total hip arthroplasty was 4.2 g/dL. The authors noted that these findings can be used as a simple and useful guide during the preoperative assessment and can help surgeons and perioperative nurses anticipate the amount of possible intraoperative blood loss without the use of complicated calculations and costly procedures.

NOTES

(1.) C Cordon et al, "A randomized, prospective, parallel group study comparing Harmonic Scalpel to electrocautery in thyroidectomy," Surgery 137 (March 2005) 337-341.

(2.) H S Uy et al, "Comparison of fibrin glue and sutures for attaching conjunctival autografts after pterygium excision, Ophthalmology 112 (April 2005) 667-671.

(3.) M Al-Mayiah et al, "Glove perforation and contamination in primary total hip arthroplasty," The Journal of Bone and Joint Surgery, British volume 87 (April 2005) 556-559.

(4.) N R Chenthil Kumar et al, "The value of preoperative haemoglobin level as an indicator of blood loss in total hip arthroplasty: Results of a multicentre pilot and prospective study," Joint Diseases and Related Surgery 16 no 1 (2005) 12-15. Also available at http://www.arthroplasty-arthroscopic surgery.org/aas/2005/pdfsno1/vol/16n o1-3.pdf (accessed 20 May 2005).

This information is intended for general use only. The clinical implications are specific to the abstracted article only. Individuals intending to put these findings into practice are strongly encouraged to review the original article to determine its applicability to their setting.

GEORGE ALLEN

RN, PHD, CNOR, CIC

DIRECTOR OF INFECTION CONTROL

DOWNSTATE MEDICAL CENTER

BROOKLYN, NY

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