Course Case Studies

Moderate Sedation/Analgesia

Course #30464 - $90 -

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Learning Tools - Case Studies

CASE STUDIES

The radiology department occasionally performs moderate sedation on patients who exhibit a high level of anxiety prior to a procedure. On today's schedule, there are two patients requiring MRIs. Both patients will require moderate sedation to allow the radiologist and technician to obtain an accurate study.

A nurse from the emergency department is scheduled to administer the moderate sedation agents as no registered nurse is routinely staffed in radiology. Upon arrival, the nurse begins to prepare the radiology suite for the procedure and review the patients' histories and physicals.

PATIENT J

Patient J is a young girl, 2 years of age, with a history of hydrocephalus since birth. She has been brought to the hospital with complaints of continuous vomiting, lethargy, and inappropriate behavior for her age. The pediatric neurologist orders the MRI to evaluate the current status of her cerebral spinal fluid circulation.

The neurologist orders the procedure to be performed under moderate sedation, as Patient J is not cooperative and is easily agitated. The nurse reviews her history, which is otherwise unremarkable. She is not taking any current medications at home, either prescribed or over-the-counter. She had previously been on anticonvulsant medication, which was discontinued more than a week prior to the procedure.

Upon arrival of Patient J in the radiology suite, the nurse performs a presedation assessment. Her cardiac and respiratory systems are within normal limits for her age. However, neurologic assessment of Patient J is challenging due to her decreased mental status. The nurse notes that Patient J responds to her mother, who accompanies her to the department. Although Patient J has had previous MRIs, the nurse discusses the procedure with the mother and patient. She explains what will be happening and that she will be asked to lie still for a number of minutes. Additionally, the nurse explains the use of moderate sedation to the mother and patient, ensuring the mother that Patient J will be comfortable and everything will be done to try and reduce her fear of separation from her mother. When the mother asks to stay in the room with Patient J, the nurse explains that this is neither safe nor allowed.

Additional review of Patient J's chart shows that she was admitted yesterday afternoon and received antiemetics upon admission. Upon admission, her blood pressure was low for her age. Her admission vital signs were: blood pressure, 84/68 mm Hg; pulse, 104 bpm; respiratory rate, 30 breaths/minute; and temperature, 99.7°F. Currently, her blood pressure is 92/64 mm Hg; pulse, 100; and respiratory rate, 30 breaths/minute. She has an IV line infusing 5% dextrose in 0.25% normal saline at a rate of 45 cc/hr. Her admission weight was 25 pounds (approximately 11 kgs). Upon questioning, her mother states that she has lost some weight; her normal weight is about 28 pounds. She has not taken anything by mouth since admission.

After obtaining the presedation assessment, the nurse must prepare the room, equipment, and medications for Patient J. The nurse ensures that a crash cart is located in the radiology department and checks the defibrillator for proper functioning. The oxygen set-up in the scanner is checked, as is the suction. The pulse oximeter and noninvasive blood pressure monitor are warmed up to assure that they will be ready when the sedation is to begin. Furthermore, all equipment should be determined to be MR-compatible to prevent burns during the procedure.

The medication ordered for Patient J includes midazolam 0.02 mg/kg IV or a dose of 0.5 mg/kg orally. (As Patient J has a history of vomiting, the nurse chooses to administer the midazolam via the intravenous route to ensure proper drug dosing and reduce the risk of vomiting.) Also ordered is fentanyl 0.5 mcg/kg, to be given in the event that the midazolam is inadequate in achieving the appropriate level of sedation. The nurse first calculates the correct dose based upon Patient J's weight of 11 kgs. Thus, the dose of midazolam is 0.2 mg, and the dose of fentanyl is 5 mcg. These medications are drawn into syringes and labeled. Additionally, the nurse draws 0.5 mg of naloxone (based on a dose of 0.05 mg/kg); this syringe is also labeled and placed off to the side, where it is easily accessible in the event of oversedation or other complications.

Finally, Patient J is brought into the room with the scanner and hooked up to the oxygen, pulse oximeter, and noninvasive blood pressure monitor. A presedation set of vital signs are obtained, including oxygen saturation measurements before and after oxygen therapy is initiated. The patient's IV is checked for patency and another set of vital signs is obtained. At this point, the mother is asked to leave the room, and Patient J becomes quite agitated. The radiologist orders the nurse to begin administering the sedation medications immediately in order to relax Patient J and prevent any further agitation.

The nurse administers the 0.2 mg of midazolam and monitors Patient J's response to the medication. After one minute, her blood pressure is noted to fall to a systolic pressure of 84 mm Hg. Neurologically, she is less agitated and appears to be relaxing. When asked her name she answers appropriately, but also asks again for her mother. The blood pressure decline is of concern; in response to this, the nurse increases the IV rate to 50 cc/hr. Within five minutes, her blood pressure is back up to its presedation level.

The radiologist is ready to start the scan; however, Patient J continues to move on the scanner table. The radiologist requests the nurse to administer additional medication, and the nurse administers an additional 0.2 mg of midazolam. Within two minutes, Patient J is quiet and calm and the procedure is initiated.

During the procedure, the nurse must leave the room and monitor the patient from the outside viewing area. Patient J's vital signs are continually monitored via the blood pressure monitor cycles. The nurse also observes the pulse oximeter reading as part of the patient assessment. After 10 minutes, the nurse notes that Patient J's pulse oximeter reading has fallen to a level of 91%. The radiologist is informed, and the scan is momentarily terminated to allow the nurse to enter the room and evaluate the patient. The patient's respiratory rate is now 15 breaths/minute, and the pulse oximeter reading has fallen further to 90%. The nurse immediately places Patient J's head into the sniffing position to open her airway and increase the oxygen flow rate. The patient's pulse oximeter reading increases to only 91% with this maneuver, and the nurse decides to administer a reversal agent to prevent the respiratory insufficiency from progressing further.

It is at this point that the nurse realizes that naloxone has been drawn as an antagonist. As the patient has only thus far received midazolam, the naloxone will be ineffective at reversing a benzodiazepine, as it is a narcotic antagonist. Immediately, the nurse draws up a dose of 0.1 mg of flumazenil and administers this through the IV line. Within two minutes, Patient J is breathing at a rate of 25 breaths/minute, her pulse oximeter reading has increased to 94% saturation, and her other vital signs remain within normal limits. However, she is starting to move on the table and the scan cannot be completed until she is sedated adequately to prevent body movement.

Patient J is allowed to stabilize for another five minutes, at which time the radiologist requests further sedation so the scan can be completed. The remaining time to perform the scan is approximately 10 to 12 minutes. The nurse now chooses to administer 2.5 mcg of fentanyl to Patient J and to monitor the drug effects. Although a dose of 5 mcg was ordered, the nurse is concerned that the patient will develop a second episode of respiratory insufficiency. After three minutes, Patient J remains agitated and a second dose of 2.5 mcg of fentanyl is administered.

Throughout administration of the fentanyl, Patient J's vital signs and oxygen saturations remain within normal limits. After the second dose of fentanyl (for a total of 5 mcg), the procedure can continue and is able to be completed without further complication.

Upon completion, Patient J's mother is allowed to return to her daughter's bedside and the effects of the medication are allowed to wear off. No further reversal agents are administered. Based upon the length of action of the midazolam and fentanyl, it is expected that Patient J will remain sedated for another 20 to 30 minutes. During this recovery period, the nurse continues to assess the patient's vital signs and oxygen saturations, and all parameters remain within normal limits.

Due to the fact that Patient J is an inpatient, the recovery and discharge is different than for a patient who is being discharged to home. After 30 minutes, Patient J remains sleepy but opens her eyes and recognizes her mother. When asked her name she answers appropriately. At this point, the nurse finishes documenting the procedure and Patient J is returned to her bed on the pediatric unit.

Discussion

The nurse caring for Patient J performed quite well. The presedation assessment was very thorough; it was important to consider the fact that continuous vomiting can lead to protracted volume status in children, and this could impact her response to medications. The nurse recognized that the intravenous route of medication administration is far more appropriate in this patient than the oral route. Her history of a decreased level of consciousness could hinder oral administration. Additionally, with the patient's history of vomiting, oral drug administration could precipitate a further bout of vomiting.

Preparing the medications was critical to the success of this procedure. The biggest error was in not drawing up a dose of flumazenil. The nurse chose to prepare the naloxone, without considering that the fentanyl may not have been utilized at all. It would have been to everyone's benefit had both the naloxone and flumazenil been prepared initially. However, the outcome was good; this delay did not harm the patient in any manner.

When the radiologist asked to continue the procedure, the nurse administered a dose of fentanyl that was one-half of the ordered dose, most likely based on the fact that Patient J had experienced the previous episode of respiratory insufficiency. This choice was not inappropriate, but in review of the case, it was probably inadequate due to the length of time since the initial administration of the midazolam. Had the nurse recognized that the duration of the midazolam was reached, administering the full 5 mcg of fentanyl most likely would have been safe. However, in this instance, the nurse chose to act cautiously, and no one should find fault with this action.

Finally, the recovery of this patient was uneventful. The patient reached her presedation level of functioning. As she had an altered level of functioning to begin with, this was an appropriate way to evaluate her neurologic status. However, had the nurse not performed a good presedation assessment, recognition of the patient's return to her presedation level of functioning would have been challenging.

PATIENT D

The next patient scheduled for the MRI scanner is Patient D, a man 76 years of age, who fell at home yesterday and has a history of falling. There is point tenderness at the hip joint, and the patient is unable to ambulate. The orthopedic surgeon requests an MRI of the hip and pelvic area to determine what, if any, injury could be causing this pain and dysfunction.

Patient D states that he is very claustrophobic and initially refused the MRI because of the fear of the "tube." After discussion with the surgeon, with a guarantee that he would be sedated and comfortable, Patient D agreed to the scan.

Upon review of the patient's history, it is determined that he has a history of congestive heart failure, smokes two packs of cigarettes a day, and denies alcohol ingestion. The nurse performs a presedation assessment, obtaining baseline vital signs and auscultates the patient's heart and lungs. The patient is asked to open his mouth wide, and a Mallampati score of 2 is assigned to the patient. The patient is questioned about any dentures or partials, which he denies. An anesthesia history is obtained; the patient has had two previous surgeries under general anesthesia. He denies any complications with either procedure.

Due to the patient's history of congestive heart failure, the nurse reviews the chart for a current 12-lead electrocardiogram and finds that one was obtained yesterday on admission. Additionally, Patient D's admission laboratory values are reviewed. The only abnormality is a potassium level of 3.3 mEq. The nurse determines that the patient is a Class 3 on the ASA Risk Classification score. The nurse also reviews the patient's current medication use, which includes digoxin, furosemide, and naproxen for arthritic pain control.

Although the surgeon reviewed the moderate sedation procedure with the patient, the nurse conducts patient education as well. The nurse explains that the patient will be receiving medications to help him relax and decrease his fears about the scanner. Patient D responds, "Just knock me out. I don't want to remember or feel a thing!" The nurse then proceeds to offer further information; it is imperative that the patient recognize that he will not be asleep. The patient may be asked to respond to questions throughout the procedure to adequately assess the level of sedation. Additionally, the nurse explains that the medications can help alleviate some of the patient's pain, but there is discomfort that is experienced from lying on a hard table. The patient is assured that everything will be done to make the patient as comfortable as possible, but the procedure is not discomfort-free.

At this point, Patient D reconsiders his decision to have the procedure performed. When he agreed to the procedure it was his understanding that he would be asleep, similar to what occurs with general anesthesia. It is unfortunate that the surgeon allowed the patient to develop this misunderstanding; it not only delayed the start of the procedure but backfired in that the patient's level of anxiety was heightened. It took the nurse more than 20 minutes to educate the patient and receive his permission to continue with the scan.

In preparing the room for Patient D, the nurse has only recently finished sedating the first patient and knows the equipment was functional. She places the patient on the monitor, pulse oximeter, and oxygen by face mask. Presedation vital signs are obtained and compared to the vital signs obtained on the inpatient unit. An oxygen saturation of 91% is obtained prior to initiating oxygen therapy, as is expected. With oxygen, the saturation increases to only 93%. The existing IV line is checked for patency.

The medications ordered for Patient D include midazolam 2 mg IV, fentanyl 50 mcg IV, and methohexital 10 mg IV, as needed. The nurse draws the appropriate dosages into syringes and labels each. Learning from the first patient, the nurse draws both flumazenil (0.2 mg) and naloxone (1 mg) and labels these syringes as well.

The radiologist orders the sedation to be initiated, and the nurse administers 2 mg midazolam IV over one minute. The patient demonstrates a slight drop in blood pressure; however, it is within acceptable limits. The patient remains quite agitated, asking when the medication is going to work. At this point, the nurse administers 25 mcg fentanyl IV. Patient D's blood pressure starts to fall after the dose of fentanyl, and the IV rate is increased. The patient continues to complain of discomfort and fear. His heart rate increases to a rate of 90 bpm (from a normal of 62 bpm). The radiologist requests additional sedation medication in an attempt to achieve an appropriate level of sedation in this patient.

The nurse then administers an additional 2 mg IV of midazolam. Patient D appears to relax, and he is moved into the "tube." Immediately upon entering the tube, the patient becomes severely agitated, asking to get out, and calling out, "Somebody help me." It is obvious that the patient's level of sedation is inadequate at this point, and the patient is removed from the scanner. The nurse enters the room and notes that the patient is very confused; he is unable to answer appropriately to his name, he is calling for his wife (who had died three years before), and his blood pressure, pulse, and respiratory rate are all quite high.

The radiologist orders an additional 3 mg IV of midazolam, which the nurse administers. At this point, Patient D appears more relaxed; however, when the nurse approaches the patient to listen to his heart and lungs, the patient starts thrashing about on the table. Obviously, Patient D is at risk of further injury, especially at the injured hip joint. The radiologist orders an additional 3 mg IV midazolam. However, the nurse refuses to administer this dose based upon concern of oversedation, common to the elderly individual. The nurse expresses this concern, and the order is changed to fentanyl 50 mcg IV. The nurse agrees to administer the fentanyl, and upon administration, the patient experiences a short burst of ventricular tachycardia that spontaneously converts to the patient's normal rhythm.

At this point, the radiologist decides to cancel the procedure until such time that the patient can be appropriately sedated. It is obvious that the radiologist blames the nurse for the patient's deterioration.

Despite the apparent animosity, the nurse's responsibility is to stay with Patient D and provide for his safety. The patient's oxygen flow rate is increased, after which the patient becomes quite agitated and removes the oxygen mask. While the nurse is preparing an amiodarone bolus to prevent further episodes of ventricular tachycardia, the patient becomes agitated to the point of requiring restraints. The nurse looks for assistance from other staff members but has been left alone with Patient D.

At this point, the nurse remembers the naloxone and administers 1 mg IV, hoping to see a reduction in the patient's level of agitation. However, this is not accomplished. Subsequently, flumazenil (0.2 mg IV) is administered, and the patient begins to appear more relaxed, with improving vital signs.

After three minutes, the nurse administers a second dose of flumazenil, and Patient D is able to answer questions appropriately. Throughout this time period, the nurse continues to assess Patient D's vital signs, which are slowly returning to normal.

Once the patient reaches his presedation level of functioning, the nurse transfers the patient back to the inpatient unit. Upon moving the patient into his bed, he asks, "What did they find?" Patient D is unaware that the procedure had not been completed.

Discussion

A number of mistakes were made in preparing and sedating Patient D. However, the nurse did perform a good presedation assessment. All the appropriate information was obtained from the patient, and the patient was assessed fully. One omission was putting the information to use. Elderly patients with a history of cardiac disease, especially congestive heart failure, are at increased risk of poor circulation and low cardiac outputs. These patients need special care when administering sedating agents. Additionally, the patient was on digoxin with a low potassium level, increasing the risk of dysrhythmia development. Had the nurse considered the risks involved in this patient, the incidence of ventricular tachycardia may have been avoided by further stabilization measures prior to the start of the sedation.

It was an error on the surgeon's part to assure Patient D that he would be comfortable throughout the procedure. With this false assurance, the patient was at risk for agitation when his expectations were not met. As soon as Patient D entered the scanner, this anxiety level was enhanced. Thus, the medication effects were inadequate to meet the patient's needs.

In preparing the room for this second patient, the nurse assumed that the equipment was functioning properly because it had done so during the last case. This assumption can be deadly; the equipment should always be re-tested prior to the start of a subsequent procedure. In this case, there were no apparent equipment failures, but had this occurred, the outcome could have been disastrous.

The medications ordered for Patient D were probably not the best for an elderly patient with a history of congestive heart failure. Midazolam is known to precipitate an episode of paradoxical excitement in the elderly, which became quite apparent throughout this case study. Of all the narcotics, fentanyl has the least effect upon the cardiovascular system; however, patients with a history of cardiac disease are at risk of hemodynamic instability with any of the sedating drugs. Methohexital, a barbiturate, can precipitate a profound drop in the patient's blood pressure, and although the dosage ordered was quite low, this may have been a risk for Patient D had he received this medication.

Throughout the procedure, the sedating drug of choice was midazolam. The initial dose was tolerated by the patient; however, subsequent doses caused further patient compromise. After the second dose of midazolam, Patient D was moved into the scanner, and this is when he began to exhibit signs of paradoxical excitement and confusion. Rather than treating this with flumazenil, Patient D was administered an additional 3 mg of midazolam, which caused a further decline in his level of functioning and his vital signs.

The nurse was appropriate in refusing to administer the next 3 mg dose of midazolam. However, in its place, fentanyl was administered. Prior to administering the fentanyl, the patient should have been evaluated and the cause of his agitation further investigated.

This dose of fentanyl most likely precipitated a fall in the patient's blood pressure, leading to a decreased coronary artery blood flow and precipitating the run of ventricular tachycardia. Fortunately, the dysrhythmia was self-limiting and the patient did not experience further cardiac failure, including ventricular fibrillation or asystole.

It was at this point that the radiologist canceled the procedure and left the room. Patient D was definitely not stable at this point, and additional backup should have been called. Instead, the nurse continued to support the patient alone. Fortunately, the nurse was able to handle the developments as they arose; however, had the patient developed a second bout of ventricular tachycardia or other life-threatening complications, it would have been difficult to access additional backup support.

Eventually, the nurse remembered the antagonists that were available. The dose of naloxone was appropriate to reverse the effects of the fentanyl; however, Patient D's greatest problem was the agitation secondary to the midazolam. It may have been wiser to administer the flumazenil first, followed by the naloxone, if needed.

During this difficult period, the nurse and the radiologist's relationship deteriorated to the point of becoming ineffective. Early attempts at communication and a collegial discussion of why the patient was deteriorating may have reduced the number of complications experienced by Patient D. It is imperative that the nurse and physician in charge of the procedure communicate regarding patient condition and work together to achieve a successful outcome.

When Patient D returned to his inpatient unit, he did not remember that the MRI was not performed. This is a common occurrence after the administration of benzodiazepines. The antegrade amnesia prevents the patient from remembering details. In many cases, this is a desirable effect; in this case, it may only lead to further patient mistrust. He was told that he would not remember, but at the same time, the procedure was not accomplished.

This case study demonstrates a number of the risks involved in providing moderate sedation to the elderly. This patient population is at increased risk of complications. In addition, they exhibit varying responses to the "typical" sedating medications. Prior to initiating sedation in this population, it is wise to review the risks, consider the causes, and evaluate the potential effectiveness of interventions. Then, if the patient does develop untoward complications, the cause can be more easily identified and therapies instituted earlier.

  • Back to Course Home
  • Participation Instructions
    • Review the course material online or in print.
    • Complete the course evaluation.
    • Review your Transcript to view and print your Certificate of Completion. Your date of completion will be the date (Pacific Time) the course was electronically submitted for credit, with no exceptions. Partial credit is not available.