CSA News

APSF Anesthesia Monitoring Statement Enhances Patient Safety

Apr 26, 2022
The Anesthesia Patient Safety Foundation (APSF) has issued four recommendations for patient monitoring during anesthesia that further bolster patient safety and help prevent postoperative complications
The Anesthesia Patient Safety Foundation (APSF) has issued four recommendations for patient monitoring during anesthesia that further bolster patient safety and help prevent postoperative complications. 

“Currently, there is a wide variation in practice for neuromonitoring in patients under general anesthesia, either intravenously or inhalationally,” said Tong Joo (T.J.) Gan, MD, MBA, a member of the APSF Committee on Technology, which authored the recommendations, and a professor and the chair of anesthesiology at the Renaissance School of Medicine at Stony Brook University, in Stony Brook, N.Y. “We also do not have specific guidelines for airway pressure monitoring and for monitoring of neuromuscular blockade.”

The first recommendation by the APSF committee is that for awareness prevention with inhaled anesthesia, the agent’s end-expired concentration is to be measured and, if available, a low-concentration alarm activated. Also, in cases where 0.7 minimum alveolar concentration cannot be maintained with a neuromuscular blocking agent, an EEG-based monitor of anesthetic depth should be used, along with an alarm for inadequate anesthetic depth.

The second recommendation, for awareness prevention with IV anesthesia, is similar to that for inhaled anesthesia.

The third recommendation covers postoperative residual muscle weakness, for which a neuromuscular block train-of-four (TOF) monitor is to be applied whenever a neuromuscular blocking agent is usedThe fourth recommendation addresses airway pressure monitoring. When ventilation is controlled by a mechanical ventilator, a device capable of measuring airway pressure should be in continuous use, plus an audible signal when the alarm threshold is exceeded.

Recommendations Not Surprising

“In general, the recommendations should not come as a surprise to clinicians,” said Gan, who is a member of the Anesthesiology News editorial advisory board. “However, some anesthesiologists do not perform these recommendations routinely—specifically, monitoring of neuromuscular residual muscle weakness. In fact, many clinicians do not even use quantitative twitch monitoring.”

Gan noted that every patient responds differently to a neuromuscular blocking agent. “Some patients may need more and some may need less,” he said. “But there is no effective way to assess how much each patient needs other than to monitor the neuromuscular function by a quantitative twitch monitorBy not monitoring the neuromuscular blocking agent, “you may inadvertently give too much or too little,” Gan said. “We also believe that quantitative monitoring is preferable to qualitative monitoring.”

An insufficient amount of a neuromuscular blocking drug may cause the patient to move, which could jeopardize the surgery, whereas too much at the end of the case might cause the patient to stop breathing, resulting in a prolonged stay in the OR. “If not reversed adequately after surgery, the patient may require reintubation,” Gan said.

For awareness prevention, a bispectral index monitor is also not universally employed, according to Gan, particularly for total IV anesthesia.

Overall, clinicians need to be more vigilant in monitoring a patient’s stage in the OR, according to Gan, whether for neuromuscular blockade or depth of anesthesia. “Unfortunately, most anesthesiologists do not set an alarm for detecting the lower concentration of inhalation anesthetic,” he said.

The monitoring recommendations were based on the APSF’s review of existing recommendations from several professional societies around the world.

“We were motivated to foster a consistent global approach to monitoring and patient safety,” said Jeffrey Feldman, MD, the chair of the APSF Committee on Technology and a member of the APSF board of directors. “However, monitors do not keep patients safe in and of themselves; they only provide information to help the anesthesia professional make good decisions. A skilled anesthesia professional trained to use monitoring devices effectively is the most important component of safe anesthesia care.”

The primary clinical implication of the statement is the emphasis on patient monitoring to evaluate not only physiologic stability but drug effect as well, according to Feldman. “This is not a new concept, but not necessarily part of the monitoring recommendations from all professional societies,” he said.

In the case of muscle relaxants, clinical effect is evaluated by various types of nerve stimulators that assess the motor response to stimulation; yet, TOF monitoring is not consistently recommended or used, said Feldman, a professor of clinical anesthesiology at the Perelman School of Medicine at the University of Pennsylvania, in Philadelphia.

“While any type of neuromuscular blockade monitoring is better than none, more advanced technologies provide a quantitative measurement of the force of contraction, allowing for a more refined assessment to better guide dosing and reversal of muscle relaxants,” he said.