Massive saline absorption during holmium laser excision of prostate manifesting with parotid area sign

Sheetal Y Chiplonkar; Pratibha V Toal; Adit J Palsania

doi:10.4103/2349-0977.201003

CASE IN POINT - CLINICS IN ANESTHESIOLOGY

Year : 2016 | Volume : 3 | Issue : 3 | Page : 168-170

Massive saline absorption during holmium laser excision of prostate manifesting with parotid area sign

Sheetal Y Chiplonkar, Pratibha V Toal, Adit J Palsania
Department of Anaesthesia, Bhabha Atomic Research Centre Hospital, Mumbai, Maharashtra, India

Date of Web Publication

27-Feb-2017

Correspondence Address:
Dr. Sheetal Y Chiplonkar
Department of Anaesthesia, Bhabha Atomic Research Centre Hospital, Anushakti Nagar, Mumbai, Maharashtra
India

Source of Support: None, Conflict of Interest: None

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DOI: 10.4103/2349-0977.201003

Abstract

While conducting a Holmium Laser Excision of Prostate (HoLEP), it is a standard practice to use normal saline as an irrigation solution. Usually, the amount of saline absorbed systemically during HoLEP ranges between 200 and 900 mL. However, rarely this amount can become excessive and lead to toxicity. Currently, two methods are used to measure the quantity of normal saline absorbed during a HoLEP – a volumetric fluid balance method and ethanol tagging of saline. These methods, however, have certain limitations. They can possibly be supplemented by a third method – a real time “parotid area sign.” This case report highlights the significance of this clinical sign in a 67-year-old male, who while undergoing HoLEP, developed frank signs of toxicity due to massive saline absorption.

Keywords: Atrial fibrillation, excessive saline absorption, HoLEP, parotid area sign

How to cite this article:
Chiplonkar SY, Toal PV, Palsania AJ. Massive saline absorption during holmium laser excision of prostate manifesting with parotid area sign. Astrocyte 2016;3:168-70

How to cite this URL:
Chiplonkar SY, Toal PV, Palsania AJ. Massive saline absorption during holmium laser excision of prostate manifesting with parotid area sign. Astrocyte [serial online] 2016 [cited 2023 May 28];3:168-70. Available from: http://www.astrocyte.in/text.asp?2016/3/3/168/201003

Introduction

During Holmium Laser Excision of Prostate (HoLEP), it is a standard practice to use normal saline for irrigation. Because Holmium laser acts like an endoscopic scalpel which cuts and coagulates simultaneously, it reduces the absorption of saline, making it a method of choice for larger prostates requiring prolonged excision times. Hence, the amount of saline absorbed during HoLEP usually does not exceed 1 L.^[1] The risk of massive saline absorption that exists with a bipolar resection of prostate is thus rarely observed during HoLEP.^[2],[3]

Very occasionally, however, the quantity of saline absorption can increase manifold. This risk is greater if a capsular perforation occurs and produces open venous sinuses. The standard risk of capsular perforation is approximately 10%. However, a number of factors can add to the risk. An immediate and early recognition of this excessive saline absorption is critical from the standpoint of clinical management, if the patient has to be pulled out of this dire situation.

This case in point developed frank signs of excessive saline absorption 1 hour into a HoLEP procedure.

Case Report

A 67-year-old male, weighing 50 kg, and fitting into the American Society of Anesthesiologists physical status category 1 was planned for an elective HoLEP for a benign enlargement of the prostate. Preoperatively, his hemoglobin was 11.7 g/dL, hematocrit 35.6%, total leucocyte count 5980/µL, platelet count 302,000/µL, and serum electrolytes Na ⁺ 136 mmol/L, K ⁺ 4.4 mmol/L, and Cl ⁻ 99mmol/L. He had a normal coagulation profile and a normal electrocardiogram (EKG). His baseline hemodynamic parameters were stable, his noninvasive blood pressure (NIBP) was 142/85 mmHg, and he had a heart rate of 82/min.

At the time of surgery, he received a subarachnoid block under aseptic conditions with 12.5 mg of bupivacaine and 90 µg buprenorphine. Intravenous dexmedetomedine was commenced at 0.2 µg/kg ^/ h for conscious sedation. After ensuring T8 block level, the HoLEP procedure was begun in the lithotomy position. Normal saline at a height of 60 cm was used as the irrigation fluid. The laser settings were 2 J with a frequency of 15 Hz. The lateral lobe of the prostate was resected and retrieved by morcellation. At approximately 1 hour into the procedure, the patient complained of chest discomfort. He was conscious, following commands, his NIBP was 100/70 mmHg, SpO₂ was99%, and his pulse rate was irregular and varying between 80–90/min. The cardioscope showed an irregular rhythm with changing R-R duration and intermittently absent P waves. His dexmedetomedine infusion was stopped, and the patient was given 100% oxygen via a Hudson mask. At this time, his chest auscultatory findings were unremarkable. He had, however, developed a bilateral prominent, turgid swelling in the parotid area. The philtrum–mastoid prominence distance measured 22 cm bilaterally [Figure 1]. A quick assessment revealed an inflow of 53 L of saline against 42 L of outflow. On the basis of these twin findings, empirically, a diagnosis of excessive saline absorption was made. The patient was given frusemide 20 mg intravenously and the surgeon was asked to expedite the procedure. Five minutes later, his NIBP was 80/50 mmHg. He was administered ephedrine 12 mg intravenously to treat the hypotension. His arterial blood gas analysis showed the signs of a metabolic acidosis: pH 7.24, PCO₂ 34.9 mmHg, pO₂ 368 mmHg, SpO₂ 98.8%, and bicarbonates 15.4mmol/L. He was receiving oxygen6 Lvia a mask. His hemoglobin was 7.4 g/dL, hematocrit 21.7%, Na ⁺ 140 mmol/L, K ⁺ 3.4 mmol/L, and Cl ⁻ 118 mmol/L.

Figure 1: Widening of the philtrum–mastoid prominence distance denoting the parotid area sign.

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Although there was no unusual bleeding, to achieve a complete hemostasis of the prostatic fossa, the surgeon switched to a unipolar cautery and used additional 6 L of irrigation with 1.5% glycine to complete the surgery. While the total inflow was 59 L (53 + 6), the total outflow was measured to be 48 L with a deficit of approximately 11 L. The cardioscope, at this time, showed an irregular heart rate with absent P waves. His NIBP was 84/52 mmHg. In view of the persistent hypotension, intravenous noradrenaline was started at 0.1 mg/kg/h and the internal jugular vein was cannulated. The patient was shifted to the recovery. The 12 lead EKG confirmed atrial fibrillation. The two-dimensional echocardiogram showed a collapsed inferior vena cava with normal left ventricular contractility and ejection fraction. Hence, a diagnosis of noncardiogenic hypotension was made and the patient was given a maintenance infusion of intravenous Gelofusine followed by Ringer's lactate. His NIBP became stable at 106/80 mmHg. About 4 hours following the inotropic support, his ECG reverted to a sinus rhythm and noradrenaline was tapered off. His total urine output was approximately 6 L excluding the bladder irrigation fluid volume. Twelve hours later, the patient was stable, with a normal hemogram, electrolytes, and coagulation profile.

Discussion

Normal saline is used for irrigation during HoLEP because of its isoosmolarity. The amount of saline absorbed systemically usually falls between 200 and 900 mL. This quantity can, however, increase if a capsular perforation occurs and produces open venous sinuses. The standard risk of capsular perforation is approximately 10%. A number of factors, however, can add to the risk, among them being the adeptness of the surgeon in performing the procedure, the weight of the resected prostatic tissue, the preoperative weight of the prostate, the total duration of irrigation, and the total amount of fluid used for irrigation.^[1]

Currently, two methods are in vogue for measuring the quantity of the irrigation fluid absorbed during a HoLEP – volumetric fluid balance method and ethanol tagging of saline.^[4] Although considered fairly reliable, both the methods have limitations. While in the volumetric fluid balance method, extraneous losses can be missed due to spillage; the method of ethanol tagging is not commonly available at all centers. In this setting, the early signs of fluid overload, for example, hypertension and tachycardia must be quickly recognized. However, that is not always simple because such signs stand easily masked by the regional anesthesia and/or sedation.

A real time “parotid area sign” described previously,^[5] can possibly fill in this void. It has been known to supplement the volumetric method for detecting the absorption of 1.5% glycine (which is hypoosmolar) employed during resectoscopic surgeries. Though the precise cause of parotid swelling due to glycine absorption is still not known, animal experiments carried out on the mice submandibular glands suggest that a hypotonic environment stimulates an increases in the glandular secretion.^[6] Based on this finding, it may be surmised that a mildly hypotonic environment created by glycine absorption could well produce increased secretion in the parotid glands, and the same may be accountable for the parotid area sign.

In the present case, the philtrum–mastoid distance was 22 cm, and the parotid area appeared distinctly swollen when the patient complained of breathlessness. The swelling regressed to 17 cm subsequent to induction of diuretic therapy in the recovery room. The 5 cm engorgement of the parotid area following massive saline absorption and its regression post diuretic therapy suggests either a fluid transfer from the intravascular space to interstitial space or a mild hypoosmolar environment created by massive saline absorption triggering excessive salivary secretion.

The patient also had a dilutional hyperchloremic acidosis and anemia,^[7] which corrected itself post diuresis. The intraoperative hypotension following frusemide therapy suggests hypovolemia despite massive absorption. It is known that crystalloid infusions spread differently in body cavities after 30 min, and 60% go in to the interstitium.^[8] Therefore, when intravascular fluid is excreted following diuresis, the altered elasticity of the interstitial fibres gives rise to a paradoxical situation with peripheral edema occurring side by side with hypovolemia. The two-dimensional echo of the patient done in the recovery room showed a collapsed inferior vena cava indicative of hypovolemia despite massive saline absorption. The patient also developed atrial dysrhythmia possibly due to the atrial stretch subsequent to excessive saline absorption.^[9]

Conclusion

The parotid area sign, previously reported with excessive glycine absorption, can be a useful clinical sign for monitoring the quantity of normal saline absorbed during a low risk procedure such as HoLEP. An obvious bilateral widening of philtrum–mastoid distance due to a distinctly swollen parotid during the course of a procedure can warn the anesthesiologist that the patient may be developing signs of toxicity due to excessive saline absorption.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

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