A nerve block may involve a small needle and a carefully chosen injection, but its final safety decision is larger than either. The patient may be correctly identified, the consent signed, the intended side marked, and the ultrasound machine ready. Yet one question remains until the procedure begins: Did the people about to perform the block actually stop and agree that this is the correct patient, side, and procedure?
In regional anesthesia, a nerve block numbs part of the body to provide anesthesia or pain relief. Ultrasound helps clinicians see structures beneath the skin and guide the needle. It does not tell us which operation was planned, whether the site matches the consent, or whether a change in position has left an earlier check out of date. A technically accurate injection can still be the wrong procedure.
The distinction between preparing for a block and stopping just before it deserves attention. A checklist completed in advance is useful. It can bring together the patient’s identity, consent, medication risks, equipment, monitoring, and plans for complications. But the final pause answers a narrower question, at a more vulnerable moment: Are we all agreed on what is about to happen, here and now?
This is not a newly invented safety concept. In 2022, the Royal College of Anaesthetists described the U.K. “Prep, Stop, Block” protocol, developed with regional anesthesia safety groups. The central instruction is specific: Complete the preparation, then conduct a two-person stop immediately before needle insertion. A pause that occurs before repositioning the patient, before equipment is prepared, or while other tasks continue may no longer serve its intended purpose.
Real physician voices, twice a week
Free, and one click to unsubscribe.
A 2026 study provides a reminder of why details of implementation matter. Researchers examined reports submitted to the Australian and New Zealand webAIRS anesthesia incident system. Among the selected incidents, they identified 38 wrong-sided nerve blocks and 5 near misses. Failure to confirm the intended side was a frequent contributing factor. These were incident reports, not a count of all blocks performed; they cannot establish how often such errors occur in routine practice. Nor can they establish that one particular style of timeout would have prevented every event.
The human challenge begins after the checklist looks complete. The patient has been positioned. The skin may be prepared. The needle and ultrasound probe are within reach. Everyone expects the next action to be the block. Stopping at that moment requires more than recalling a memorized phrase. It asks the clinician performing the procedure and another participating team member to direct their attention to the same decision and check it against the available record and site marking.
A question or discrepancy should change what happens next. If the mark is not visible, the consent does not match the plan, or the intended block is unclear, the injection should not proceed until the uncertainty is resolved. This is different from a pause in which one person speaks, another continues setting up, and the record simply acquires a completed box.
In a 2025 discussion, the American Society of Regional Anesthesia and Pain Medicine (ASRA) distinguished the broad preparatory checklist from the final regional-anesthesia timeout. It emphasized active participation, confirmation of patient and site, and repeating the check when circumstances require it. The practical lesson is not to turn every last-minute pause into a lengthy repetition of the entire preprocedure assessment. It is to protect the decision that cannot safely be reversed once the needle has been used.
The patient may contribute to verification when alert and able to do so. That can be helpful, but it cannot be the foundation of the system. Some patients receive sedation, some have communication difficulties, and some blocks are performed under general anesthesia. The team remains responsible for verifying the intended procedure even when the patient cannot answer.
There is evidence that structured preparation may help. In a retrospective before-and-after study published in 2019, 4 wrong-site blocks occurred among 10,123 procedures before a regional-anesthesia checklist was introduced, and none among 35,890 afterward. The association is encouraging. It does not prove that the checklist alone caused the difference, and the study did not isolate the effect of a final two-person pause. That limitation matters because documentation, timing, and genuine participation are related but separate questions.
A fair objection is that clinical teams already complete multiple checks, and another interruption can feel burdensome when schedules are tight. A badly designed timeout can become background noise. But the answer is not to perform the same words faster or to add another signature. It is to place one brief, deliberate check where it can still prevent the wrong action. If the patient is repositioned or the block plan changes, the relevance of the earlier verification should be reconsidered.
The pause also depends on whether a colleague is genuinely able to speak. When a second person notices a mismatch, questioning the plan should be treated as part of the task, not as a challenge to the operator’s competence. That is a professional expectation, rather than an outcome demonstrated by the two studies cited here. It requires teams to take the final check seriously even when the clinical circumstances seem routine.
For patients, the point is reassuring rather than alarming: A careful team may take a few seconds to confirm information that has already been checked. For clinicians, the more demanding question is whether the check changed anyone’s attention. I would rather see a brief pause in which two people actually verify the decision than a perfectly documented pause that nobody truly participated in.
Before the needle enters the patient, the team should be able to say what will be done, where, and why. The value of the last pause lies in that shared understanding, not in the box that says it happened.
Girishkumar Modi is a senior specialist anesthesiologist at Sheikh Tahnoon Bin Mohammed Medical City and Tawam Hospital (SEHA) in the United Arab Emirates. His clinical practice includes regional anesthesia, trauma and orthopedic anesthesia, neuroanesthesia and spine anesthesia, obstetric anesthesia, pediatric anesthesia, perioperative medicine, and the management of complex surgical patients. He serves as faculty in an anesthesiology residency program accredited by the Accreditation Council for Graduate Medical Education International, where he contributes to resident teaching, clinical supervision, assessment, and mentorship. He also contributes to trauma-service development and multidisciplinary perioperative care.
His academic interests include perioperative physiology and pharmacology, regional anesthesia, total intravenous anesthesia, acute pain management, point-of-care coagulation and hemostasis, medical education, health care economics, and perioperative patient safety. He is active in clinical research, medical writing, and peer review, with publications spanning anesthesiology, pharmacology, perioperative medicine, regional anesthesia, point-of-care coagulation and rotational thromboelastometry, and medical education. His work has appeared in the Mathews Journal of Anesthesia, the Journal of Anesthesia & Pain Medicine, and Anaesthesia, with abstracts presented at the Association of Anaesthetists Winter Scientific Meeting in London and the Integrated Anesthesia and Comprehensive Care Conference in Abu Dhabi.
He also writes commentary on clinical judgment, artificial intelligence, and patient readiness for surgery, including rapid responses in The BMJ such as “Medicine is not a 64-square board: Human oversight requires independent judgment” and “AI systems need a tested exit plan.”
