Major Complications, Mortality, and Resource Utilization After
Open Abdominal Surgery
0.9% Saline Compared to Plasma-Lyte
Andrew D. Shaw, MB, FRCA, FCCM,∗ Sean M. Bagshaw, MD,† Stuart L. Goldstein, MD,‡ Lynette A. Scherer, MD,§
Michael Duan, MS, Carol R. Schermer, MD,¶ and John A. Kellum, MD#
Ann Surg 2012;255:821–829
Click this link to view the article: Saline versus plasmalyte
The purpose of this study was to evaluate adult patients undergoing major open abdominal surgery who received either 0.9% saline (30,994 patients) or a balanced crystalloid solution (926 patients).
The major findings of this study are:
- The in-hospital mortality was 5.6% in the saline group and 2.9% in the balanced group (P < 0.001).
- One or more major complications occurred in 33.7% of the saline group and 23% of the balanced group (P < 0.001).
- Treatment with balanced fluid was associated with fewer complications (odds ratio 0.79; 95% confidence interval 0.66–0.97).
- Postoperative infection (P = 0.006), renal failure requiring dialysis (P < 0.001), blood transfusion (P < 0.001), electrolyte disturbance (P = 0.046), acidosis investigation (P < 0.001), and intervention (P = 0.02) were all more frequent in patients receiving 0.9% saline.
The body defends its so-called milieu. Electrolytes are kept within a narrow range, as is the pH at 7.4. Temperature is also maintained at 37 degrees Celsius. Through evolution, this is the environment in which enzymes and metabolic processes work most efficiently. In fact, acidosis and hypothermia are two components of the triad of death (the third is coagulopathy).
During a trauma, we spend much of our time correcting hypothermia, hypovolemia, and coagulopathy, while the acidosis gets scant attention. This is probably because we believe that the acidosis is owing to hypoperfusion and once circulation is restored the body will correct the acidosis. Yet, isn’t it feasible that while we are fixing the hypovelemia, the acidosis will contribute to the coagulopathy by inhibiting the many enzymes of the clotting cascade?
More importantly the acidosis is iatrogenic in the majority of trauma. It is due to the administration of excessive amounts of normal saline (NS). Actually “normal saline” is anything but normal and one speaker at a recent anesthesiology meeting referred to it as “AB-normal saline.” NS contains an excess of sodium and chloride. As little as two liters of NS is enough to cause hyperchloremic acidosis. Many physicians view hyperchlormic acidosis as inconsequential. However in a trauma where the pH is 7.0, it is anything but inconsequential and more often than not it is the greatest cause of acidosis.
In my practice, I find that the base excess in a traumatized healthy individual is nearly always [-1 X (chloride excess + lactic acid)]. In many cases it is the chloride excess, not the lactic acid, that is the greatest contributor to the low pH (see blog on blood gas interpretation under categories, left side of screen). This acidosis owing to excess chloride is easily arrested by simply taking down all of the NS that is hanging and hanging Plama-Lyte in its place.
While the acidosis can be arrested in this way, the already present low pH will also need to be addressed and that is done by giving sodium bicarbonate or THAM.
A more appropriate solution to this problem would be to prevent developing the hyperchloremic acidosis at the outset by avoiding NS in the field, the emergency room, and operating room. Instead give Plasma-Lyte. Unlike Lactated Ringer’s solution, Plasma-Lyte contains no calcium and it is compatible with blood products.
Unfortunately, changing the trauma culture from NS to Plasma-Lyte will not be easy. But that is my “Personal Campaign Against Iatrogenic Acidosis.”
Stumbled onto this document from the New South Wales Institute of Trauma and Injury Management:
In Vietnam we treated hypovolemia with copious amounts of crystalloid. It appears that the lessons learned from Iraq and Afghanistan are that we should be treating blood loss with RBC:FFP:Platelets in a 1:1:1 ratio.
Section 5.2 of the above document give a good overview of “repleating intravascular volume.”
The current thinking, at least in New South Wales, is that (in the absence of TBI, aka traumatic brain injury) lower blood pressures should be tolerated and crystalloid/colloid minimized. This lessens dilution of coagulation factors and promotes clot formation. Resuscitation fluid should be RBC, FFP, and platelets. Preferably in a ration of 1:1:1.
Much of what we know about trauma surgery comes from the management of the severest trauma… that which occurs on the battlefield.
This link will bring you to the most current U.S. Army Institute of Surgical Research GUIDLINES for managing the trauma patient:
The information here is astounding. As civilians, we may be unable to duplicate the military’s trauma system, but there is nothing that should get in the way of us trying.
The “Lethal Triad” or the “Triad of Death” comprises:
The two guidelines, which most completely address these issues are:
The management of acidosis is not addressed per se. It appears that clinicians treat acidosis indirectly by control of bleeding and hypoperperfusion, expecting those measures to correct the acidosis. The article on Damage Control Resuscitation mentions the use of THAM to treat acidosis. Since all three conditions in the Lethal Triad contribute to bleeding, should not all be treated? Enzymes function best at physiological pH. So why should the non-treatment of acidosis be allowed to inhibit the enzymes that promote coagulation until coagulation and hypoperfusion are controlled by massive infusion of blood products? Would optimizing the milieu (pH) that enzymes work in permit the enzymes to work more efficiently and decrease the blood products required ?
I had a fantasy that with a large bore catheter and the Belmont Rapid Infuser, I would be able to transfuse blood products at a rate of 700 ml/minute, keeping the bleeding patient alive while the surgeons found and stopped the bleeding.
The reality is that although I was able to do this once or twice, the majority of my experiences with the Belmont Rapid Infuser has been that I spend too much time distracted by the Belmont’s alarms and not enough time taking care of the patient.
June 4, 2013:
Actually, there was a problem with the Rapid Infuser that has been rectified by the company.
The device now works as advertised and it is life saving.
The fantasy and reality are congruent.