Sources of error when tracking irrigation fluids during hysteroscopic procedures

Intraoperative Irrigation: Fluid Administration and Management Amidst Conflicting Evidence

Surgeons use irrigation during open cavity procedures to improve their view of the patient's anatomy and to reduce the patient's risk of infection. However, there are no standard guidelines that recommend a specific type of fluid, additive, or volume of irrigation to use during open procedures. Intraoperative hypothermia can occur if irrigation fluids have not been warmed or have cooled before use, causing adverse patient outcomes. In addition, failing to manage (eg, measure and document) fluid volume accurately may affect clinical decision making and cause other complications. Perioperative personnel should evaluate new technologies that may improve the efficiency and accuracy of irrigation temperature and volume measurements. More research is needed to develop standardized practice guidelines for intraoperative irrigation and fluid management.

Complications of Hysteroscopic and Uterine Resectoscopic Surgery

Adverse events associated with hysteroscopic procedures are generally rare, but, with increasing operative complexity, it is now apparent that they are experienced more often. There exists a spectrum of complications that relate to generic components of procedures, such as patient positioning, anesthesia, and analgesia, to a number that are specific to intraluminal endoscopic surgery that largely comprise perforation and injuries to surrounding structures and blood vessels. Whereas a number of endoscopic procedures require the use of distending media, the response of premenopausal women to excessive absorption of nonionic fluids used for hysteroscopy is somewhat unique, and deserves special attention on the part the surgeon. There is also an increasing awareness of uncommon but problematic sequelae related to the use of monopolar radiofrequency uterine resectoscopes that involve thermal injury to the vulva and vagina. Furthermore, the uterus that has previously undergone hysteroscopic surgery may behave in unusual ways, at least in premenopausal women who experience menstruation or who become pregnant. Fortunately, better understanding of the mechanisms involved in these adverse events, as well as the use or development of a number of innovative devices, have collectively provided the opportunity to perform hysteroscopic and resectoscopic surgery in a manner that minimizes risk to the patient.

Rapid correction of severe hyponatremia after hysteroscopic surgery – a case report

BACKGROUND

One of the most feared complications during hysteroscopic surgery is haemodilution by absorption of distension media. One facet of haemodilution, i.e. hyponatremia, can lead to respiratory distress, pulmonary oedema, as well as cardiovascular collapse.

CASE PRESENTATION

Here we report the swift recovery of a 45 year, female, Caucasian patient with acute hyponatremia (74 mEq/L) and pulmonary oedema by the employment of rapid correctional strategies.

CONCLUSION

The absorption of irrigation fluids, as presented in this case, is an inevitable side effect of hysteroscopic surgery. Utmost caution should, therefore, be mandatory to reduce and actively monitor fluid intake. If these measures fail, as in the case presented here, it is essential to rapidly eliminate any free water and to normalize the sodium levels. Anecdotal reports of pontine myelinolysis are not in line with literature concerning acute hyponatremia and should, therefore, not obstruct determined action against it.

Implementing AORN recommended practices for MIS: Part II

This article focuses on the equipment and workplace safety aspects of the revised AORN "Recommended practices for minimally invasive surgery." A multidisciplinary team that includes the perioperative nurse should be established to discuss aspects of the development and design of new construction or renovation (eg, room access, ergonomics, low-lighting, OR integration, hybrid OR considerations, design development). Equipment safety considerations during minimally invasive surgical procedures include using active electrode monitoring; verifying the properties of distention media; using smoke evacuation systems; reducing equipment, electrical, thermal, and fire hazards; performing routine safety checks on insufflation accessories; and minimizing the risk of ergonomic injuries to staff members. Additional considerations include using video recording devices, nonmagnetic equipment during magnetic resonance imaging, and fluid containment methods for fluid management.

Glucose as a marker of fluid absorption in bipolar transurethral surgery

BACKGROUND

Historically, a reduced serum sodium concentration has been used to diagnose absorption of electrolyte-free irrigating fluid during transurethral resection of the prostate (TURP). In bipolar TURP, the irrigating solution contains electrolytes, thus invalidating the serum sodium method. In this study, we investigated whether glucose can be used to diagnose the absorption of irrigating fluid during TURP procedures.

METHODS

The serum glucose and sodium concentrations were measured in 250 patients undergoing monopolar TURP using either 1.5% glycine or 5% glucose for urinary bladder irrigation. The glucose kinetics was analyzed in 10 volunteers receiving a 30-min infusion of 20 mL/kg of acetated Ringer's solution with 1% glucose. These data were then used in computer simulations of different absorption patterns that were summarized in a nomogram for the relationship between the glucose level and administered fluid volume.

RESULTS

There was a statistically significant inverse linear relationship between the decrease in serum sodium and the increase in glucose levels after absorption of 5% glucose during TURP (r(2) = 0.80). The glucose concentration increased, from 4.6 (sd 0.4) to 8.3 (0.9) mmol/L, during the experimental infusions. Regardless of the absorption pattern, all simulations indicated that the uptake of 1 L of fluid containing 1% glucose corresponded to an increase in the glucose level of 3.7 (sd 1.6) mmol/L at the end of surgery, whereas 2 L yielded an increase of 6.9 (1.7) mmol/L.

CONCLUSIONS

In bipolar TURP, the addition of glucose to a concentration of 1% in the electrolyte-containing irrigation fluid can be used as a tracer of absorption that is comparable with measuring serum sodium after monopolar TURP.

Monitoring of fluid absorption with nitrous oxide during transurethral resection of the prostate

BACKGROUND

The fluid absorption that occurs during transurethral resection of the prostate (TURP) can be indicated and quantified by the ethanol method. Recently, nitrous oxide (N(2)O) was tested in animals and volunteers and seemed to be more accurate and safe. The present study compared these two methods in surgical patients.

METHODS

Eighty-six TURPs were performed at two hospitals using an irrigating fluid that contained 3% mannitol, 1% ethanol and 0.004% N(2)O (40 ml/l). The ethanol concentration was measured by end-expiratory tests every 10 min. The N(2)O concentration was measured by a flared nasal cannula every second. Fluid absorption was calculated based on a regression equation (ethanol method) from the area under the curve based on the samples where CO(2) >median (N(2)O method).

RESULTS

Thirteen patients (15%) absorbed >300 ml of fluid as indicated by the ethanol method. The median volume was 707 ml (range 367-1422). Ethanol yielded higher figures for fluid absorption up to 700-800 ml, whereafter the N(2)O method indicated that the absorption was larger. Over the entire range, the mean difference between the two methods at the end of any 10-min period of TURP was only +45 ml, although the 95% limits of agreement were quite separated (-479 to +569 ml).

CONCLUSIONS

The N(2)O method does not require forced breath sampling and was successfully apply clinically. However, there was a dose-dependent difference in result between the ethanol and N(2)O methods, which markedly separated the limits of agreement for a wider range of fluid absorption events.

Nitrous oxide for monitoring fluid absorption in volunteers †

BACKGROUND

We studied whether nitrous oxide (N(2)O) added to a fluid allows the infused volume to be quantified by measuring N(2)O in the expired air during normal breathing. If so, N(2)O might serve as a tracer of fluid absorption during endoscopic surgery.

METHODS

Twelve male volunteers received continuous and intermittent i.v. infusions (5-45 min) of fluid containing 40 ml litre(-1) of N(2)O. Breath N(2)O and CO(2) concentrations were measured every second via a flared nasal cannula, a standard nasal cannula, or a Hudson mask.

RESULTS

An expression for the amount of infused fluid was obtained by calculating the area under the N(2)O concentration-time curve for samples representative for exhalation (CO(2)>median) and then dividing this area by the median CO(2) for the remaining samples. The N(2)O method then estimated fluid volumes of between 50 and 1400 ml within a 95% prediction interval of +/-200 ml. There were differences of up to 14% in results between the airway devices tested, but the volunteers preferred the flared nasal cannula. N(2)O showed a distinctly higher 3 min variability during intermittent infusion, which could indicate whether fluid absorption is directly intravascular or extravascular. No adverse effects were seen.

CONCLUSIONS

N(2)O method does not require forced end-expiratory breath sampling but still predicts an administered fluid volume with high precision. N(2)O variability can probably be used to distinguish immediately between intravascular and perivesical fluid absorption during surgery.

Long-term follow-up of endometrial ablation by modified loop resection

STUDY OBJECTIVE

To describe endometrial ablation by rollerbar-loop-rollerbar (RLR) technique and determine the procedure's long-term results.

DESIGN

Prospective observational study (Canadian Task Force classification II-2).

SETTING

Private gynecology practice.

PATIENTS

One hundred seventeen women with menorrhagia not related to malignancy who were not interested in future fertility.

INTERVENTION

After performing rollerbar ablation through a short large Graves speculum, loop resection was carried out down to and throughout superficial myometrium. Rollerbar redesiccation of the cornua and supracervical areas of the uterus completed the procedure.

MEASUREMENTS AND MAIN RESULTS

Patients were contacted by telephone or mail 4 to 5 years after RLR and asked to complete a questionnaire to assess their bleeding status, level of satisfaction with the procedure, and whether or not they had undergone hysterectomy. Of 109 patients responding, 60 (55%) were amenorrheic or menopausal with no bleeding, 21 (19%) had spotting, and 17 (16%) had undergone hysterectomy. Eighty-four (79%) were very satisfied.

CONCLUSION

RLR endometrial ablation was associated with a high rate of amenorrhea and substantial long-term patient satisfaction, but the rate of postablation hysterectomy remained significant.