Keryn Davidson on aneurysms, vasospasm, clipping, and the art of watching the patient

In this NeuroResus episode, Oli Flower speaks with Keryn Davidson, vascular neurosurgeon at Royal North Shore Hospital, about aneurysmal subarachnoid haemorrhage, open cerebrovascular surgery, ICU-neurosurgery collaboration, and why the bedside exam still matters in an era obsessed with scans, monitors, and numbers. Keryn trained across Queensland and New South Wales before completing fellowship training at Royal North Shore with a focus on open cerebrovascular surgery. She is the first female neurosurgeon in the department's history, a fellowship examiner with the Royal Australasian College of Surgeons, and will be contributing to ISAH2026 in Sydney. The big theme: look at the patient, not just the numbers A recurring message throughout the conversation was deceptively simple: focus on the patient. In subarachnoid haemorrhage, teams can become fixated on ICP, arterial pressure, imaging, protocols, and monitors. Those things matter, obviously, because medicine has apparently decided numbers are comforting. But Keryn's strongest point was that subtle clinical change often comes first. The early warning sign may not be a dramatic drop in GCS or a dense focal deficit. It may be that the patient is "a bit off": mildly agitated, picky, confused, or subtly different in personality. Experienced nurses often detect this before the scan or angiogram confirms the problem. That has huge implications for DCI research, bedside care, and escalation culture. If our endpoints only capture obvious deterioration, we may be missing the earlier, more clinically meaningful phase of delayed cerebral ischaemia. The first hours: resuscitate before you prognosticate Keryn emphasised that early SAH management is not a recipe. The first questions are patient-centred: How old is the patient? How did they present? Are they intubated? Do they have hydrocephalus? Do they need an EVD? Do they need urgent clot evacuation? The concept of the resuscitated WFNS grade came up as particularly important. A poor-grade patient with hydrocephalus may look very different after CSF diversion. Prognosis should not be locked in before the brain has been given a chance to declare itself properly. What ICU does well Keryn highlighted the value of experienced ICU care in the first 24 hours: smooth resuscitation, avoiding prolonged hypotension or hypertension, preparing the patient for aneurysm treatment, and managing the shared territory of EVDs, physiology, and neurological observation. Her one gentle jab at ICU culture: asking too early how long a "not-too-sick" SAH patient will need ICU. Understandable, given bed pressure. Still, probably not the opening philosophical question while the aneurysm is still unsecured. Humanity survives another process failure. EVDs: the Goldilocks problem EVD management was framed as simple in principle but high stakes in practice. Too little drainage risks ongoing ventricular distension and impaired recovery. Too much drainage risks subdural collections and altered CSF dynamics. The target is "Goldilocks drainage": not blocked, not over-draining, not leaking, and not quietly ignored for four hours because the patient "seemed okay." The practical message: if an EVD is not draining when it should be, escalate early. Vasospasm: not over-obsessed, still unsolved Asked whether the field is too obsessed with vasospasm, Keryn's answer was clear: no. Her view is that vasospasm and DCI remain the part of SAH care we have not solved. At Royal North Shore, the unit has traditionally used DSA around day 5–7 to detect and treat vasospasm before it becomes clinically obvious. Keryn acknowledged that this approach is not universal and not backed by perfect evidence, but the rationale is pragmatic: DCI is multifactorial, but vasospasm is one potentially modifiable contributor. CT perfusion and TCDs were discussed as evolving or limited tools. CT perfusion has promise, but interpretation and actionability remain issues. TCDs can be useful in experienced hands, but interobserver variability and inadequate bone windows limit reliability. The holy grail remains a non-invasive test that reliably tells us who needs intervention, where the problem is, and when DSA is unnecessary. Apparently medicine has not yet delivered this obvious convenience. Rude. Sleep deprivation: are we helping or harming? The episode also explored the tension between intensive neuro-observation and sleep deprivation. Everyone wants to detect deterioration early. Nobody wants to turn the ICU into a neurological interrogation chamber. The practical compromise: cluster care where possible, combine observations with medications and other tasks, and protect blocks of real sleep when safe. This is especially relevant during the vasospasm window, when every tiny change can matter but exhaustion can also mimic or worsen clinical concern. Clip versus coil: rivalry is the wrong frame Keryn loves clipping aneurysms, but she was clear that the correct treatment is the one that best serves the patient. The clip-versus-coil debate is often misunderstood as rivalry, when in good units it should be a collegial decision. Some aneurysms still strongly favour open surgery, especially ruptured aneurysms with large haematoma, mass effect, blown pupil, or situations where surgery is needed anyway to decompress the brain. Conversely, some aneurysms are better treated endovascularly, especially when the anatomy makes open surgery high risk. A major nuance is the need for dual antiplatelet therapy after stent-assisted treatments, especially in patients with EVDs who may later need shunts. This is where SAH care becomes "boutique" medicine: aneurysm anatomy, CSF circulation, bleeding risk, and recovery trajectory all collide. Open vascular neurosurgery is not dead Although aneurysm clipping volumes are declining globally, Keryn argued that open cerebrovascular skills remain essential. The cases that still need clipping are often the difficult ones: complex aneurysms, mass effect, clot evacuation, and lesions not easily managed endovascularly. That creates a training challenge. If fewer cases are clipped, how do trainees develop the skill set needed for the hardest cases? Keryn's answer is deliberate training, courses, exposure, mentorship, and keeping open vascular surgery visible as a living craft rather than a museum exhibit with better lighting. What makes a great vascular neurosurgeon? Keryn's answer was not just technical. A great vascular neurosurgeon needs to be bold, brave, resilient, and comfortable being uncomfortable. But they also need humility: knowing limits, asking for help, and staying patient-centred. One of the most powerful parts of the conversation was her reflection on bad outcomes. You can do a technically perfect operation and still have a devastating result. The answer is not to become reckless or avoidant, but to reflect honestly, look after yourself, and keep learning without letting one case distort all future judgement. Women in neurosurgery Keryn spoke about training in a male-dominated specialty, the importance of visible role models, and the need to call out casual bias. Her advice to female trainees was direct: if you have the passion, pursue it. Neurosurgery is hard, but it should not be considered off-limits because of gender or outdated expectations about what a surgeon looks like. The unexpected bit: neurosurgery for dogs In the episode's most unusual detour, Keryn described how she became involved in complex veterinary neurosurgical cases, including a transpalatal approach to a pituitary tumour in a golden retriever. Yes, really. The story was funny, strange, and unexpectedly moving. It also reinforced a serious point: anatomy, preparation, humility, and adaptability matter across species. Dogs, Keryn observed, often recover with a kind of uncomplicated determination. They do not overthink illness. Humans, naturally, have turned suffering into a full-time interpretive project. Fast takeaways The most underrated bedside sign in SAH may be subtle confusion or personality change. Arterial blood pressure is important, but probably overcomplicated. A resuscitated neurological grade matters more than the first impression. EVDs need active attention: under-drainage and over-drainage both matter. Vasospasm remains central because it is one modifiable part of DCI. DSA-first vasospasm surveillance is not universal, but has a clear physiological rationale in experienced centres. Clip versus coil should be a patient-centred decision, not a turf war. Open vascular skills remain vital, especially for complex aneurysms. Bad outcomes require reflection, not denial or career-long overcorrection. The future is likely to involve better imaging, modelling, AI-supported prediction, and more precise vasospasm therapy. Why this matters for ISAH2026 This conversation captures exactly the kind of discussion ISAH2026 is designed to host: practical, multidisciplinary, honest, and focused on the unresolved questions in subarachnoid haemorrhage care. SAH management sits at the intersection of neurosurgery, interventional neuroradiology, neurocritical care, nursing, anaesthesia, imaging, rehabilitation, and long-term outcomes. The episode shows why the field needs more than protocols. It needs shared language, bedside wisdom, better evidence, and the humility to admit where current practice is still based on physiology, experience, and informed uncertainty. That is the space ISAH2026 aims to create: where consensus, controversies, and future trials are shaped.