Age
Systolic blood pressure [mmHg]
Diastolic blood pressure [mmHg]
Heart rate [min−1]
Newborns
65–80
40–50
130 ± 20
1 month
85
60
120 ± 20
1 year
95
65
120 ± 20
2 years
95
65
110 ± 20
4 years
95
65
100 ± 20
6 years
100
60
100 ± 20
Tachypnea can be a sign of compensation for early shock. The assumption that a satisfactory blood pressure alone equals cardiovascular stability can be a fatal assumption in children, and this delays the diagnosis of pediatric shock. Due to increases of systemic vascular resistance (SVR) and heart rate, blood loss can be well compensated for a long time in pediatric patients. Then, hemodynamic decompensation occurs suddenly. Small children can maintain their cardiac output almost completely from an increase in heart rate, because stroke volume and contractility are limited due to the small amount of contracting components. Blood pressure may be sustained in children until hypovolemia is extremely severe.
>> Dr. Maverick looked for a vein. Apart from the bruises from the many missed attempts that morning, there were no veins to be found. Kevin’s heart rate increased to 180 beats/min, the saturation hovered at about 90 %, and the blood pressure was down to 72/45 mmHg. Kevin was uneasy, fearful, and pale. Tech Bruce held an oxygen mask over Kevin’s face, and he seemed to calm down a bit.
7.1.4 What Is the Cause of the Uneasiness? How Much Blood Do You Think He Has Lost?
The patient’s uneasiness can be a result of beginning cerebral hypoxia, caused by hypotension and anemia. The increase of the inspiratory oxygen concentration via the face mask increased the dissolved oxygen (see Sect. 4.1.6) and might have improved cerebral hypoxia. Of course, pain, fear, or the taste of blood could also be a cause of the uneasiness.
Children of Kevin’s age have a blood volume of 80 ml/kg body weight. Therefore, the total blood volume is 1,600 ml. A blood pressure decrease of >25 % with symptoms of shock indicates a blood loss of >20 % of the blood volume. Therefore, the blood loss is >300 ml.
>> Dr. Maverick was totally stressed out. He could only find one vein on the back of Kevin’s foot, but he didn’t trust himself to puncture the last possible option. Where was his attending? Why didn’t someone come? Why couldn’t he just have one functioning IV?
At that moment he heard the voice of the attending anesthesiologist, Dr. Emery, as he conversed with the ENT surgeon and approached the OR. Dr. Emery recognized the severity of the situation at first glance. “Why didn’t you call me sooner? I had no idea the child was in critical condition!” Dr. Emery was quite upset and cried out, “He doesn’t even have decent venous access!” Sheepishly, Dr. Maverick showed his attending the last vein. Dr. Emery complained about the many ruined veins which had been blown that morning. He was given his requested IV catheter, but even his attempt to puncture the vein on the back of the foot failed. The next blood pressure reading was 60/30 mmHg; the heart rate remained at 180 beats/min. They needed venous access stat.
7.1.5 What Options Do You Have for IV Access?
Obviously, Kevin now has a life-threatening hypovolemia, and immediate volume replacement is necessary. Since peripheral access is no longer possible, there are two possibilities:
Insert a central venous catheter.
Obtain intraosseous access.
Placement of a central venous catheter in a child is not easy, is especially challenging for the inexperienced, and is a time-consuming process. Intraosseous access is the best option in this case.
7.1.5.1 Intraosseous Access
All necessary infusions, medications, and blood products can be administered via an intraosseous line.
The rate of flow is equivalent to that of intravenous access.
It is even possible to draw a blood sample.
In the current guidelines of the Pediatric Advanced Life Support, intraosseous line placement is indicated after cardiac arrest if venous access is not immediately obtained [1, 4].
A recent article promoted the use of intraosseous access in the event of difficult IV access in pediatric anesthesia [9]. Following these guidelines, three indications for use are outlined (Table 7.2).
Definition | Signs | |
---|---|---|
Emergent indications | Early or primary | Respiratory or circulatory arrest |
Critical hemodynamic instability | ||
Shock | ||
Severe hypovolemia | ||
Urgent indications | Without delay, following unsuccessful venous puncture attempts | Urgent anesthesia induction in a non-fasting child |
Urgent anesthesia induction in a hemodynamically unstable child or a child with severe cardiovascular insufficiency | ||
Semi-elective indications | After unsuccessful venous puncture attempts and after careful use–risk consideration | After anesthesia induction with face mask (if access is necessary) |
Required intravenous induction (e.g., disposition to malignant hyperthermia) |
Intraosseous puncture locations include the proximal tibia, a few centimeters distal to the tuberosity, the proximal femur, the humerus, the tibia’s medial malleolus, or the anterior superior iliac spine on the iliac crest of the pelvis, with lower extremity locations most popular in children. The puncture location must be spaced safely away from the epiphyseal plate, and the direction of puncture must also point away from the growth plate.
Various systems are available, which are more or less equivalent [3]. In pediatric anesthesia, manual insertion systems are usually used. Apart from the manual insertion systems, there are intraosseous needles (Cook/Jamshidi), mechanical devices which use a spring-loaded gun (F.A.S.T. 1/B.I.G.), and a drill device (EZ-IO).
>> The attending anesthesiologist, Dr. Emery, requested an intraosseous needle and promptly placed it right into the proximal tibia. Kevin briefly moaned. Dr. Maverick was so relieved to see blood flow in the needle. “I didn’t even know that we had such a thing in the OR,” thought Dr. Maverick. Attending anesthesiologist, Dr. Emery, took a sample of blood and gave it to Dr. Maverick, ordering a hematocrit. Then he started a crystalloid infusion on the needle and began the anesthesia induction.
7.1.6 How Would You Induce Anesthesia?
Kevin has swallowed a lot of blood. Therefore, to prevent aspiration, rapid sequence induction with cricoid pressure and insertion of an endotracheal tube is indicated. Apart from that, Magill pliers and large lumen OP suction should be prepared in order to remove coagulated and fresh blood that may block the view of the larynx. Propofol/barbiturates and opioids can cause severe hypotension in this hypovolemic child; therefore, ketamine or etomidate should be given for induction.