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Chapter 4

Battle Casualties in Korea: Studies of the Surgical Research Team Volume III

Evaluation of the Use of a Standard Tilt Test*

Lieutenant Colonel Curtis P. Artz, MC, USA

Not infrequently a patient is admitted to the hospital with an appreciable blood loss and still he appears to be in good condition.

Such a patient has been able to compensate for his blood-volume deficiency by vasoconstriction. From the usual clinical signs, he appears to be able to withstand operation; however, when his compensatory ability is abolished by anesthesia, he may have a blood-volume deficiency of 1,000 cc. or more and his blood pressure may fall. When further blood loss occurs during operation, the resulting oligemia may be severe.

In the management of large numbers of casualties in the 46th Surgical Hospital (Mobile Army) in Korea, it was frequently observed that movement of the patient to x-ray abolished compensatory mechanisms. Because of this, it was believed that some type of standard postural change might be of value in determining the circulatory status of an injured patient.

It was the purpose of this study to evaluate the use of a standard tilting procedure in order to estimate blood-volume deficiency and adequacy of preparation for operation.


A simple tilt table was devised (Fig.1). The table was made of wood having a platform of convenient size to hold a litter. The platform was suspended with the fulcrum in the center. This type of table enabled a litter patient to be placed on the platform so that his head could be raised or lowered. The degree of tilt could be adjusted as desired.

All patients studied were young, healthy males who had been injured in combat. When a patient's vital signs were approximately normal, he was tilted for varying periods of time with his body elevated to a 30-degree angle, head up. If his blood pressure fell and his condition deteriorated on tilting, it was believed that appreciable blood-volume deficiency was present. All patients were tilted at this same angle, head up. Patients who were put on the tilt table were

 * Previously published in Surgical Forum, Proceedings of the Fortieth Clinical Congress of the American College of Surgeons, p. 803. W.B. Saunders Company, Philadelphia, 1955.


examined carefully to make sure that hemorrhage had ceased and that physiologic derangements other than blood-volume deficiency had been corrected. The duration of the tilt and the degree of deterioration of the patient's condition were correlated with the amount of blood required to stabilize the patient.

FIGURE 1. A tilt table of wood made by carpenters in Korea. The platform is on a fulcrum. The patient on the litter is placed on the platform.


Several patients admitted to the preoperative section of the forward surgical hospital were placed on the tilt table and their response to tilting was observed. All patients who showed definite deterioration, when placed in the tilt position for several minutes, remained relatively stable when tilted after adequate transfusion.

The tilting of a patient aided the surgeon considerably in determining the need for blood.

Seven patients were selected for specific study. All patients showed a significant fall in blood pressure after the initial tilt, but no significant deterioration was observed following adequate transfusion. None of the patients who withstood tilting for 10 minutes or more experienced hypotension at the time of anesthesia. The following brief summaries illustrate salient points.

PATIENT 1 (Fig. 2). An American soldier was admitted with a blood pressure of 120/80, pulse  78. following small penetrating wounds of the upper quadrant of the abdomen and buttocks. His condition appeared excellent. When tilted


FIGURE 2.  Chart of Patient 1.  This patient's blood pressure was normal, but his condition
deteriorated when he was tilted.  Later, after infusion of 1,000 normal cc. of blood, he withstood
tilting well.

FIGURE 3.   Chart of Patient 2.   Response to tilting during resuscitation was in direct relation to
the amount of blood given.


for 7 minutes, he became nauseated and pale; and sweat broke out on his forehead. His blood pressure fell to 78/60. Following administration of 1,000 cc. of blood, his blood pressure remained stable after tilting. He experienced no difficulty during splenectomy and débridement.

PATIENT 2 (Fig.3). An American soldier received perforations of the colon, pancreas, kidney, and spleen from small arms fire. He was admitted with a blood pressure of 120/60, pulse 84; but when tilted, his blood pressure fell to 70/30 within 3 minutes. After administering each 500 cc. of blood, the tilt test was performed. At each tilt, blood pressure fell until he had received 1,250 cc. of blood, at which time there was no particular deterioration in his condition. He withstood the extended operative procedure well, in spite of a tremendous blood loss. In the first 24 hours after injury, the total amount of blood received was 14 pints. He experienced no difficulty until 7 days postoperatively, when he developed a severe pancreatitis and peritonitis and died. During his pre-operative resuscitation, this patient was tilted at various intervals; and, in each instance, his response appeared to give a good indication as to the status of his circulation.

PATIENT 3. A Korean soldier was admitted to the hospital with a blood pressure of 120/80, pulse 84, following a penetrating wound of the left side of the chest. He appeared to be in excellent condition. When he was tilted for 5 minutes, his blood pressure fell and cold perspiration broke out on his face. Following infusion of 1,000 cc. of blood, his blood pressure remained stable at 124/76 during a 13-minute tilt. He had no difficulty during the closure of the sucking wound of the chest.

PATIENT 4. A Korean soldier was admitted with a blood pressure of 120/68, pulse 88, a few hours after receiving a perforating wound of the upper abdomen. After tilting, his blood pressure fell to 88/57, pulse 120. His blood pressure rose to 120/60 when lowered to a horizontal position. After infusion of 1,000 cc. of blood, he was tilted again. Following a 15-minute tilt, there was no change in his blood pressure. At operation there were perforations of the liver, duodenum, and transverse colon. He withstood the operative procedure well.

PATIENT 5. An American soldier was admitted with a blood pressure of 110/60 following a grenade  wound of the right thigh. After a 5-minute tilt, his blood pressure fell to 80/50, pulse 86. He was pale; and he complained of being sleepy and thirsty. He was shifted to a level position and given 1,000 cc. of blood rapidly. His blood pressure rose to 120/80; and he was tilted for 15 minutes. Blood pressure remained stable. After receiving 75 mg. of demerol intravenously, he was tilted again for 10 minutes. On tilting, no change in vital signs was observed. He withstood a rather extensive débridement of the multiple grenade wounds of the thigh without difficulty.

PATIENT 6. A Korean soldier was admitted with a blood pressure of 70/40, pulse 100, following a land-mine wound of the right lower leg and a penetrating wound of the left upper quadrant of the abdomen from which 24 inches of small bowel protruded. He was pale; and there was a clinical impression of severe oligemia. He received 1,000 cc. of blood during the next hour, and his blood pressure rose to 92/30. On tilting, his blood pressure fell precipitously and his pulse became irregular. He then received a second liter of blood and his blood pressure rose to 124/90, pulse 112. After a 14-minute tilt, no change occurred in blood pressure or pulse. Following an additional infusion of 500 cc. of blood, a prolonged operative procedure was carried out without difficulty. His good response to anesthesia and the operative procedure indicated that he was well resuscitated.

PATIENT 7. A Korean soldier was admitted to the hospital 3 hours after receiving mortar-fragment wounds of the abdomen, shoulder, an open, com-


minuted fracture of the right femur and below-knee traumatic amputation of the right leg. He had an unobtainable blood pressure. Three intravenous infusions and one intra-arterial transfusion were started. After infusing 9 pints of blood, his blood pressure rose to 128/90. It was difficult to determine whether or not this patient had received sufficient blood to withstand operation. He was tilted for 10 minutes; and there was no change in blood pressure or pulse rate. He was given 3,000 cc. of blood and 1,000 cc. of dextran during the prolonged operative procedure. He experienced no difficulty during operation and recovered.

This very severely wounded patient required a vast quantity of blood for resuscitation. The use of the tilt test was of value in determining when adequate blood replacement had been carried out.


Observations in this study show that a patient whose blood pressure was within normal limits, but who apparently had lost a fair amount of blood, would have a fall in blood pressure upon tilting his body to a 30-degree angle, head up. Immediately following adequate blood replacement, however, he was able to tolerate the same change in body position without fall in blood pressure.

It is generally believed that., following blood loss, compensation by vasoconstriction is mediated through the sympathetic nervous system. When the body of a hypovolemic patient is tilted, decreased blood to the brain makes for cerebral anoxia. With the loss of central nervous system control, sympathetic activity disappears and the compensatory mechanism is abolished.

Determination of blood volume before operation would be ideal if time, equipment, and space would permit. In most hospitals, this is not only impracticable but almost impossible as a routine procedure. On the other hand, the tilt test is a simple procedure. It can be utilized rapidly, without discomfort to the patient and without critical equipment. Although no blood-volume determinations were performed in correlation with responses to the tilt test, there was clinical evidence during the operative and postoperative period of the patient's stable response to a l0-minute tilting. This proved to be a good indication of adequate replacement.

These observations are in agreement with those of Green and Metheny, who studied estimation of acute blood loss by the tilt test. They felt that in the absence of a syncopal reaction, an increase in cardiac rate less than 25 beats per minute on tilting indicated either a negligible or a compensated acute blood loss. Transfusion was not required unless an increase in cardiac rate of 30 beats or more per minute was observed on tilting. This suggested a blood-volume deficiency of from 9 to 14 cc. per kilogram of the patient's body weight and a probable transfusion requirement of 1,000 cc. of blood. These investigators felt that the occurrence of a syncopal reaction to tilting


suggested a probable blood-volume deficiency of 1,500 cc. of blood.

Duncan, Sarnoff, and Rhode studied the effect of postural change in 30 patients with varying degrees of injury. They noticed that less severely injured patients who were placed in a head-up position experienced a state of collapse. They believed that this was due to vasodilation and pooling of blood in dependent areas and resultant cerebral anemia.2

One of the most perplexing problems in patients who have experienced varying degrees of blood loss is the determination of adequacy of replacement. From the size and character of a wound, experienced surgeons can estimate the approximate amount of blood required before surgery can be attempted. Great difficulty is encountered, however, in determining the adequacy of resuscitation in the very severely wounded patient. Without adequate knowledge of the amount of blood lost, it is difficult to determine the state of resuscitation after a patient has received 6 or 7 pints of blood. Tilting the body of a patient at a 30-degree angle, with head up, seems to be a test of additional value in determining the adequacy of the circulation.


Several wounded patients whose circulatory status was difficult to determine by clinical observation were placed on a tilt table and their bodies were titled to a 30-degree angle, head up. If the blood pressure fell and the patient showed other signs of deterioration, it was believed that further transfusions were required prior to operation. When the patient's condition remained stable during a 10-minute tilt, it was believed that adequate replacement therapy had been carried out. Although the experience with the tilt table has not been extensive enough to formulate definite policies concerning its routine use, careful studies in several patients suggested that the response to tilting offers additional criteria for determining the status of the circulation and adequacy of replacement therapy.


1. Green, D. M., and Metheny, D.: The Estimation of Acute Blood Loss by the Tilt Test. Surg., Gynec. & Obst. 84: 1045,  l947.
2. Duncan, G. W.; Sarnoff, S. J., and Rhode, C. M.: Studies on the Effects of Posture in Shock and Injury. Ann. Surg. 120: 24, 1944.