More Salt, Less Fluid Cuts Complications in Whipple Surgery

Upping the saline and cutting the fluid volume has a pronounced effect on the rate of complications after pancreatic surgery, new research shows.

Investigators found that using a hypertonic saline intravenous drip and moderately restricting the total volume of fluid resulted in a trend toward a 21% reduction in the rate of complications and a significant 26% reduction in the total number of complications in patients undergoing Whipple surgery for pancreatic cancer.

The study was published in the Annals of Surgery.

"This was a fairly straightforward and simple alteration in the management of patients that resulted in a somewhat dramatic reduction in complications," said first investigator Harish Lavu, MD, associate professor of surgery at Thomas Jefferson University in Philadelphia.

"It has implications for our understanding of how much intravenous fluid patients actually need," he explained. "It may be that we've been giving patients too much fluid all along."

He pointed out that a concentrated hypertonic saline solution was used, so patients received less total fluid. "When the patients recovered, they didn't have to excrete as much fluid and there was less opportunity for fluid to build up in the lungs and tissue or put a strain on the heart."

The team wanted to moderately restrict fluid, and tried not to be too aggressive in doing so, Dr. Lavu told Medscape Medical News.

"If we limit it too much, that could put a strain on the kidneys and circulatory system, which can also lead to complications," he explained. "We wanted to find that perfect pivot point, where we are giving the patient just enough fluid and trying to get the risk of complications as low as possible. We think we've come close to that with this regimen."

"Based on these findings, using hypertonic saline is now our standard of care for this surgery," Dr. Lavu said.

Useful for Other Procedures

Historically, pancreaticoduodenectomy has been associated with one of the highest complication rates of the major surgical procedures, the investigators note. Even though in recent decades there has been a dramatic decline in the length of postoperative hospital stay (from 3 weeks to 1 week) and in perioperative mortality (from more than 20% to 2% to 4%), morbidity rates have continued to remain high, in the range of 40% to 60%This surgery is long, taking about 5 to 8 hours to perform. "During the course of surgery, we would see some of the fluid building up in the abdominal cavity and tissue edema in the intestines," Dr. Lavu said. "We don't see much of that anymore. The patients seem to be a little bit more active, there is clearly less tissue edema, and the complication rates were reduced by about 25%."

These results can be extrapolated to other types of surgery, and could be particularly useful in longer complicated surgeries where patients receive liters of fluids and the complication rates are high. Hypertonic saline "is useful in thoracic surgery, where fluid can rapidly build up in the lungs and cause problems," he explained, and has been shown to be effective in trauma surgery.The amount of fluid required to achieve optimal tissue perfusion varies by procedure. With the Whipple procedure, the intraoperative stress response can be profound, with a resultant systemic capillary leak more pronounced than in most other forms of abdominal surgery. It has been suggested that 3% hypertonic saline can maximize intravascular volume by making optimal use of the patients' own total body water, and pulling interstitial "third space" fluid back into the circulation, the investigators point out.

Restrictive fluid management strategies have been studied previously. Recent studies in the fields of anesthesia, liver surgery, and colorectal surgery have lent support to goal-directed and restrictive fluid management strategies. In the postoperative setting, improvements include an earlier return of bowel function, fewer blood transfusions, and reduced rates of cardiopulmonary, wound, and anastomotic complications.

Study Details

In their randomized single-center prospective trial, Dr. Lavu and colleagues evaluated 259 patients who underwent pancreaticoduodenectomy.

They were randomized to 1 of 2 groups: Lactated Ringers solution 15 mL/kg per hour intraoperatively and 2 mL/kg per hour postoperatively until the next morning; or Lactated Ringers solution 9 mL/kg per hour plus hypertonic saline 1 mL/kg per hour intraoperatively and hypertonic saline 1 mL/kg per hour postoperatively until the next morning.

The trial was powered to detect a 33% reduction in the overall rate of complications.

The primary end point was the percent of patients who experienced at least 1 complication after the procedure. These included pancreatic fistula, delayed gastric emptying, intra-abdominal abscess, cardiac complications, respiratory complications, and deep vein thrombosis.

Secondary end points included the total number of complications, estimated intraoperative blood loss, the number of fluid boluses required, length of postoperative hospital stay, readmission rate, and perioperative mortality.

The demographic and clinical variables were similar in the 2 groups, except preoperative weight was higher in the hypertonic saline group than in the Ringers group (78 vs 72 kg).

The majority of patients in the hypertonic saline and Ringers groups underwent pylorus preservation (75% vs 80%), and periampullary malignancy was the most common reason for surgery (69% vs 73%).

Table. Outcomes

Outcome	Hypertonic Saline Group	Lactated Ringers Group	P Value
Procedure length (min)	414	386	.12
Estimated intraoperative blood loss (mL)	350	400	.99
Fluid required
Intraoperative (mL/kg per h)	11.0	14.7	<.001
Total hospital admission (mL/kg)	278	315	.017

Fluid output, which consisted mainly of urine, was significantly lower in the hypertonic saline group than in the Ringers group (1.8 vs 2.5 mL/kg per hour; P = .008), but there were no significant postoperative differences.

Lower Complication Rate

The overall rate of complications was lower in the hypertonic saline group than in the Ringers group (43% vs 54%; relative risk, 0.79; P = .073). After adjustment for age and weight, the relative risk for complications in the hypertonic saline group was 0.75 (P = .023).

The total number of complications was significantly lower in the hypertonic saline group than in the Ringers group (93 vs 123; incidence rate ratio [IRR], 0.74; P = .027). After adjustment for age and weight, the IRR for the total number of complications was 0.69 (P = .0068).