The clinical stakes are considerable. Thermal ablation, whether by radiofrequency or microwave energy, destroys tumor tissue by heating it through an applicator placed percutaneously into the lesion. Precise placement of that applicator is vital to achieve sufficient ablation margins around the tumor and to avoid injuring healthy structures nearby. Ventilation-induced organ movement complicates this task in several ways: for stereotactic puncture techniques, control of respiratory motion strongly influences accuracy, and for software that confirms ablation completeness by fusing pre- and post-ablation images, respiratory movement can render co-registration between image sets genuinely challenging. When the target shifts several millimeters with each breath, even sophisticated navigation systems struggle to guarantee that the entire tumor and a safety halo around it have been treated.

Historically, the preferred technique for stabilizing the liver has been one-lung ventilation, in which a double-lumen tube allows the right lung to be deliberately deflated while the left lung is ventilated. With the right lung collapsed, the liver loses much of the mechanical push from the diaphragm on that side, and the acoustic window for tumors near the top of the liver also improves. But this strategy is far from benign. It is profoundly non-physiological: the ventilated lung may suffer injury from high end-inspiratory volumes, oxidative stress, and increased perfusion, while the deflated lung is exposed to atelectasis-related ischemia-reperfusion injury and re-expansion damage when it is finally reinflated. The larger dimensions of the double-lumen tube increase the risk of laryngeal injury, and patient factors such as cardiopulmonary comorbidity, obesity, and advanced age can reduce tolerance of one-lung ventilation altogether, sometimes forcing the team to abandon the technique mid-procedure because of hypoxia or hemodynamic instability.

An increasingly popular alternative is high-frequency jet ventilation, or HFJV, which delivers very small pulses of gas at extremely high rates, in this study at the manufacturer’s default setting of 600 breaths per minute. Because each pulse is tiny, the diaphragm barely moves, and the liver stays nearly still. HFJV has been shown in previous work to provide minimal ventilation-induced liver movement and is now widely used for image-guided ablation. It is not, however, a universal solution. It requires specialized equipment and expertise that are not available everywhere, it can cause carbon dioxide retention during prolonged procedures, and it carries a risk of barotrauma if air cannot escape adequately. Patients with chronic obstructive pulmonary disease, obesity, or recent pneumothorax may be unsuitable candidates. One refinement, so-called double-jet ventilation, adds a normal-frequency jet component to improve carbon dioxide removal, but the researchers suspected this might come at the cost of increased liver movement.

To settle these questions, the Norwegian team conducted a single-center, non-randomized observational crossover study as a predefined substudy of the New Comet trial, a randomized controlled trial comparing surgical resection with thermal ablation of colorectal cancer liver metastases. Twenty patients scheduled for ablation between November 2022 and April 2024 each received all five ventilation modes in a predefined sequence, meaning every patient served as their own control. The modes were standard ventilation at 6 milliliters per kilogram of ideal body weight; a gentler low-tidal-volume, high-frequency strategy at 4 milliliters per kilogram delivered through a conventional endotracheal tube and ventilator; one-lung ventilation with right lung deflation; and high-frequency jet ventilation with and without the additional normal-frequency jet component. Anesthesia was maintained with target-controlled propofol and remifentanil infusions, with depth of anesthesia monitored by bispectral index, and rocuronium was given to facilitate intubation. The team aimed to keep arterial carbon dioxide below 8 kilopascals and oxygen saturation above 90 percent, with an adverse incident protocol ready if those targets were missed.

Measuring liver motion required careful technique. An experienced radiologist used ultrasound to record the cranio-caudal displacement of the inferior liver margin in both lobes: the left lobe was imaged in a sagittal plane in the epigastrium, while the right lobe was imaged through a parasagittal subcostal window as close as possible to the anterior axillary line. For each ventilation mode, the distance between the most cranial and most caudal positions of the inferior margin was measured across at least two respiratory cycles, with the transducer held in the same position throughout. The order of ventilation modes was not disclosed to the radiologist, although complete blinding proved impossible because jet ventilation produces characteristic noise and torso movement. In total, 200 measurements were collected, ten per patient, and the reliability of the method was verified by having two additional blinded radiologists independently analyze recorded ultrasound videos, with interobserver agreement assessed using intraclass correlation coefficients and Bland-Altman analysis against a predefined clinically acceptable variability of 2 millimeters or less.

The numbers were striking. Standard ventilation produced the greatest movement, with the left inferior liver margin traveling 5.8 millimeters and the right margin 7.3 millimeters during a respiratory cycle. The gentle low-tidal-volume, high-frequency strategy cut this to 4.0 millimeters on the left and 4.6 millimeters on the right, a meaningful reduction achieved with equipment available in any operating room. High-frequency jet ventilation was the clear winner, holding movement to just 1.2 millimeters on the left and a remarkable 0.5 millimeters on the right. Right-sided one-lung ventilation performed nearly as well for the right lobe, limiting movement of the right margin to 1.6 millimeters, though it offered far less benefit on the left, where the persistently ventilated left lung kept pushing the liver. Double-jet ventilation fell between HFJV and the conventional modes, confirming that adding the normal-frequency jet component to improve carbon dioxide removal does indeed increase liver movement on both sides.

Statistical analysis using linear mixed-effects models with a random intercept for each subject confirmed that these differences were robust. After log transformation of the movement data and Bonferroni correction for multiple testing, standard ventilation produced significantly greater movement than each of the other four methods on both sides, with all comparisons reaching significance except one-lung ventilation versus double-jet ventilation on the left side. Applying the predefined 2-millimeter clinical tolerance, only one-lung ventilation remained within that threshold of HFJV on the right side, while both double-jet ventilation and one-lung ventilation fell within tolerance on the left. Notably, gender, body mass index, and ideal body weight showed no statistically significant association with liver movement, and there was even a tendency toward less movement in the higher BMI group. Interobserver reliability was good, with 93.3 percent of paired video measurements within the 2-millimeter tolerance, and no intraoperative complications were registered during the study.

The authors are candid about the limitations. The sample of twenty patients was small, though the crossover design increased precision by allowing within-patient comparisons. The ventilation modes were applied in a fixed order, so order and carry-over effects cannot be excluded despite a standardized one-minute stabilization period, and neuromuscular blockade was not standardized, meaning residual rocuronium effect may have influenced diaphragmatic tone in later modes. The measurements were taken under short, controlled conditions rather than during prolonged ablation with a single strategy, and jet ventilation was delivered through the tracheal lumen of a double-lumen tube rather than a standard endotracheal tube, which the team chose deliberately to avoid the laryngeal risk of additional tube changes. Jet ventilation settings also vary across the literature, with many centers using lower frequencies of around 200 to 250 breaths per minute to limit hypercarbia over long procedures, potentially at the cost of more movement.

Even so, the practical message is clear and likely to influence practice well beyond Oslo. No single ventilation mode is universally optimal, and the choice should be individualized according to tumor location, patient comorbidities, and local expertise. High-frequency jet ventilation remains the preferred option when available and feasible, with one-lung ventilation as a strong alternative for selected right-sided tumors, particularly those in the hepatic dome where the deflated lung also improves the ultrasound window. For patients in whom advanced techniques are too risky or simply unavailable, gentle ventilation combined with timed breath holds offers a pragmatic middle path that meaningfully reduces motion compared with standard ventilation. The authors suggest that future research should explore whether more aggressive gentle ventilation strategies can further reduce movement safely over longer periods, and whether simple decision tools can be developed to guide ventilation strategy by incorporating tumor location, comorbidity, and the availability of advanced equipment. In a field where millimeters determine margins, knowing exactly what each breath costs is a powerful new piece of information.

Subject of Research: The effect of ventilation methods on liver movement during general anesthesia for thermal ablation of liver tumors

Article Title: The effect of ventilation methods on liver movement during general anesthesia for thermal ablation of liver tumors

Article References: Lappen, K. R., Hansen, I. S., Björk, I., Østergaard, D., Halvorsen, P. S., Orrem, H. L., Fretland, Å. A., Syversveen, T., & Espinoza, A. (2026). The effect of ventilation methods on liver movement during general anesthesia for thermal ablation of liver tumors. CVIR Oncology, 2(1), Article 32. https://doi.org/10.1007/s44343-026-00065-z

Image Credits: AI Generated

DOI: 10.1007/s44343-026-00065-z

Keywords: thermal ablation, liver tumors, high-frequency jet ventilation, one-lung ventilation, gentle ventilation, liver movement, anesthesia, interventional radiology, colorectal liver metastases, ultrasound measurement, ventilation strategies, Oslo University Hospital

The study, led by Dr Sofie Ragnhild Aminoff of Oslo University Hospital together with international collaborators, surveyed 267 women of reproductive age with bipolar disorder. The questionnaire was distributed through the Norwegian Bipolar Association and professional networks over a ten-week period in spring 2025. Of the respondents, 166 women, or 62 percent of the sample, reported regular menstruation, while 101 women, or 38 percent, reported irregular cycles. Participants were asked about premenstrual symptoms experienced every or almost every premenstrual phase during the previous year, covering irritability, anger, relationship difficulties, physical symptoms, and significant distress or interference with work, daily activities or relationships.

The results showed a clear pattern. Women with regular menstrual cycles were more likely than those with irregular cycles to report this full cluster of severe premenstrual symptoms recurring month after month. In other words, the very group whose cycles followed the most regular rhythm reported the heaviest symptomatic burden in the days before menstruation. This was, the researchers acknowledge, an unexpected result, and one that raises questions about how hormonal stability and hormonal sensitivity interact in women living with a severe mental illness.

The survey also uncovered a second, closely related pattern involving contraception. Ninety-three percent of the women in the sample had tried hormonal contraceptives at some point, reflecting how ubiquitous these medications are in reproductive-age populations. Yet the women with regular menstruation were less likely to be current users of hormonal contraceptives than those with irregular cycles. A larger proportion of the regular-cycle group had stopped taking hormonal contraception because of side effects, and these women also expressed greater reluctance to use hormonal methods in general. Taken together, the data suggest that women with bipolar disorder who experience regular cycles may be a subgroup with particular sensitivity to hormonal medication.

Dr Aminoff described the contraceptive findings as raising important questions about whether some women with bipolar disorder may be especially sensitive to hormonal contraceptives, while others might potentially benefit from them. That distinction matters clinically. Hormonal contraceptives are among the most widely prescribed medications in the world, and for women with a mood disorder the risk-benefit calculation is far from trivial. Hormonal fluctuations are known to influence mood states, and a medication that stabilises the cycle for one patient might destabilise mood in another. The current findings hint that menstrual cycle regularity itself could serve as a marker helping clinicians identify which women fall into which group, although the researchers emphasise that much more work is needed before such guidance can be formalised.

Bipolar disorder is a serious mental health condition characterised by episodes of depression alternating with episodes of elevated or irritable mood, interspersed with periods of few or no symptoms. A majority of women with bipolar disorder experience some form of premenstrual disturbance, whether as standalone premenstrual symptoms or as premenstrual exacerbations of the underlying bipolar illness, in which depressive, manic or psychotic symptoms intensify in the days before menstruation. Despite how common these experiences are, reproductive mental health in women with severe mental illness remains an under-studied area, and the new survey adds to a small but growing body of evidence that the intersection of gynaecology and psychiatry deserves far more systematic attention.

The clinical stakes are considerable. Dr Aminoff noted that she has met many women with bipolar disorder who described changes in mood, psychotic symptoms or suicidal thoughts that varied with their menstrual cycle, experiences that can have a real impact on daily life. Clinicians, she said, currently have very limited guidance on how best to help. Her central message is that premenstrual symptoms in women with bipolar disorder need to be taken seriously, and that more research and clearer clinical guidelines are needed so that women and the health care system can make better-informed decisions about treatment, contraception and mood-stabilising medication. She argued that assessment of premenstrual symptom burden, alongside tailored advice on hormonal contraception and mood-stabilising medication, should be standard care, but that in practice it frequently is not.

The gap between what patients report and what the health system delivers emerged as a recurring theme. Many women with bipolar disorder report that their premenstrual symptoms are not taken seriously, and few experience receiving the treatment they need, according to the research team. This pattern of dismissal is not unique to bipolar disorder; it reflects a broader documented tendency for women’s reproductive and mental health complaints to be minimised in clinical settings. For women with severe mental illness, however, the consequences of inaction can be severe, given that premenstrual worsening can include suicidal ideation and relapse of psychotic symptoms, not merely discomfort or irritability.

Independent experts welcomed the study while stressing its preliminary nature. Professor Louise Howard, Professor Emerita in Women’s Mental Health at King’s College London, who was not involved in the work, said it was valuable to see preliminary research into the reproductive health of women with bipolar disorder being presented at the conference, adding that this has been an under-studied area for too long and that the relevance of menstrual cycle regularity to symptoms and to potential interventions such as hormonal contraception is poorly understood and deserves further investigation. Dr Clare Dolman, Co-chair of the Bipolar Commission and Ambassador for Bipolar UK, also independent of the study, said she agreed with the take-home message that premenstrual symptoms in women with bipolar disorder need to be taken more seriously. She pointed out that such symptoms can exacerbate bipolar illness, and that sensitivity to hormonal change can be a marker for potentially dangerous relapse at other times of hormonal upheaval, including pregnancy, childbirth and perimenopause. Women’s mental health generally, she argued, has been ignored for too long.

The authors are careful to frame the findings appropriately. The work is preliminary, based on an online survey rather than clinical assessment, and has not yet been submitted to a peer-reviewed journal. Self-reported cycle regularity and symptom severity can be influenced by recall and selection bias, and the sample was recruited through patient organisations, which may over-represent women with particularly troublesome symptoms. Even so, the study’s size for this field, its focus on a neglected population, and the consistency of its two main signals, greater premenstrual burden and greater contraceptive side-effect burden among women with regular cycles, give it a significance that extends beyond the conference hall. Dr Aminoff’s concluding call is for closer collaboration between psychiatry and gynaecology, and for research that looks not only at mental health symptoms but also at hormonal contraception and reproductive health. If subsequent controlled studies confirm these patterns, menstrual cycle regularity could become a simple, low-cost clinical marker, helping clinicians tailor contraception and mood-stabilising treatment for hundreds of thousands of women across Europe who currently navigate this intersection of hormones and mental illness with almost no formal guidance.

Subject of Research: Premenstrual symptoms and hormonal contraceptive use in women with bipolar disorder in relation to menstrual cycle regularity

Article Title: Regular periods, but worse symptoms: Women with bipolar disorder losing out on gynaecological care

Article References: Regular periods, but worse symptoms: Women with bipolar disorder losing out on gynaecological care. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: bipolar disorder, premenstrual symptoms, menstrual cycle, hormonal contraceptives, women's mental health, gynaecology, psychiatry, reproductive health, ECNP Congress, mood-stabilising medication, premenstrual exacerbation, Oslo University Hospital

The research team, led by Trine Sand Kaastad and Trond-Eirik Strand, set out to quantify a figure that has proven notoriously difficult to pin down. Existing literature places the proportion of preventable in-hospital deaths anywhere between 0.5 and 8.4 percent, a range so wide that it offers hospitals and health authorities little practical guidance. That uncertainty stems largely from the method at the heart of the study: retrospective case record review, or RCRR, in which trained reviewers comb through patient charts after death to determine whether harm from care, rather than the underlying disease, contributed to the outcome. The technique is considered the gold standard for assessing preventable deaths, but it has a well-documented weakness, namely that different reviewers looking at the same record can reach strikingly different conclusions.

To confront that problem, the researchers adopted a design that few studies of this kind have attempted. All 1,081 in-hospital deaths recorded at Oslo University Hospital in 2014 were reviewed by a single physician using a standardized Mortality Analysis form derived from the Institute for Healthcare Improvement’s method of reviewing 50 consecutive deaths. The same reviewer worked through the entire cohort over a period of eight years, an unusually long review window that would later prove scientifically revealing. In addition, a random subset of 20 percent of the cases was independently assessed by a patient safety specialist, allowing the team to measure how consistently two trained professionals judged the same material.

The headline result is sobering but bounded. Of the 1,078 deaths that could be formally reviewed, 32, or three percent, were judged to have had a probability of 50 percent or more of being prevented. In 19 of those cases, an adverse event was considered the direct cause of death, and such events clustered most frequently during or after surgical treatment. Perhaps just as telling is what happened after those deaths were identified: only 12 of the 32 preventable deaths, or 37.5 percent, had ever been reported through the hospital’s own incident reporting system. That gap suggests that formal reporting channels, whatever their administrative value, capture only a fraction of the lethal harm that retrospective review can uncover.

The dual-reviewer exercise exposed the method’s central vulnerability in quantitative terms. In the randomly selected subset assessed by both reviewers, one found 12 preventable deaths, a rate of six percent, while the other found 11, or 5.5 percent. Although those raw numbers appear reassuringly close, the overall interrater agreement was only fair, with a Kappa statistic of 0.4. Kappa corrects for chance agreement, and a value in that range means the two reviewers concurred far less often than the raw counts imply. In practical terms, a case one expert deemed preventable the other frequently did not, a discrepancy that reflects genuine ambiguity in judging counterfactuals: would this patient have survived with different care, or was death imminent regardless?

The most striking finding, however, emerged from the passage of time. Because the same physician reviewed the entire 2014 cohort across four consecutive review periods spanning eight years, the researchers could track whether the reviewer’s own judgments drifted. They did, and dramatically so. The proportion of deaths deemed preventable fell from 5.5 percent in the first review period to 1.0 percent in the last, a statistically significant decline with a p-value below 0.001. Nothing about the care provided in 2014 changed during those eight years; what changed was the person reading the charts. The authors interpret this as evidence that prolonged review work may alter a reviewer’s threshold for what counts as preventable, whether through growing caution, deepening familiarity with the hospital’s routines, or simple fatigue.

That drift has consequences well beyond academic debate. Hospitals and national health authorities increasingly rely on measures such as the Hospital Standardized Mortality Ratio and tools like the Global Trigger Tool to benchmark safety performance, and RCRR-based preventable death estimates feed into programs such as the UK’s Learning from Deaths initiative. If the proportion of deaths judged preventable depends heavily on who reviews the records and when, then comparisons between hospitals, or even within a single hospital over time, may reflect reviewer characteristics more than genuine differences in care quality. The Norwegian team states this conclusion plainly: using RCRR to benchmark preventable deaths may capture reviewer differences more than hospital differences.

The study’s methodology deserves attention for how it balanced rigor with feasibility. The Mortality Analysis form standardized what information the reviewer extracted and how preventability was scored, anchoring judgments to the convention that a death counts as preventable only when the probability reaches at least 50 percent. Reviewing every death rather than a sample eliminated sampling error, and the eight-year single-reviewer design, initially a practical necessity, became an accidental experiment on intra-rater reliability. The project was conducted as a quality assurance initiative under Norwegian law, approved by the hospital’s data protection officer, with data made non-identifiable before analysis and handled in accordance with GDPR and the Declaration of Helsinki.

Placed against the international literature, the three percent figure sits comfortably within the published range. Previous retrospective review studies, from the landmark Harvard Medical Practice Study onward, have produced estimates spanning half a percent to more than eight percent, shaped by differences in case mix, review instruments, reviewer training, and preventability thresholds. The Oslo findings align with the middle of that distribution, which the authors take as evidence that a standardized form can produce results consistent with comparable institutions. Yet the fair interrater agreement and the dramatic intra-rater drift temper any temptation to treat the number as a precise measurement of hospital safety.

For clinicians and policymakers, the study offers a dual message. First, preventable deaths remain a real and measurable problem: three percent of deaths at one of Europe’s largest hospitals, many linked to surgical care, and most never captured by routine incident reporting. Second, the instruments used to count those deaths are less stable than the patient safety movement has often assumed. The authors suggest that RCRR may be better suited to identifying individual cases for learning and improvement than to producing benchmarking statistics that rank institutions. As hospitals worldwide invest in mortality review programs, the Oslo experience stands as a caution: before comparing preventable death rates between hospitals, the field must first solve the harder problem of whether two reviewers, or even one reviewer over time, can agree on what preventable means.

Subject of Research: Preventable in-hospital deaths due to adverse events assessed by retrospective case record review

Article Title: Preventable in-hospital deaths due to adverse events: a retrospective case record review study

Article References: Kaastad, T. S., Tveiten, H., Riiser, T. J., Bukholm, G., & Strand, T.-E. (2026). Preventable in-hospital deaths due to adverse events: a retrospective case record review study. BMC Health Services Research. https://doi.org/10.1186/s12913-026-15787-2

Image Credits: AI Generated

DOI: 10.1186/s12913-026-15787-2

Keywords: patient safety, preventable death, in-hospital mortality, retrospective case record review, adverse events, hospital benchmarking, interrater reliability, mortality review, Oslo University Hospital, health services research, incident reporting, quality of care