A pilot study investigating the effects of remote ischemic preconditioning in high-risk cardiac surgery using a randomised controlled double-blind protocol.

The efficacy of remote ischemic preconditioning (RIPC) in high-risk cardiac surgery is uncertain. In this study, 96 adults undergoing high-risk cardiac surgery were randomised to RIPC (3 cycles of 5 min of upper-limb ischemia induced by inflating a blood pressure cuff to 200 mmHg with 5 min of reperfusion) or control. Main endpoints were plasma high-sensitivity troponin T (hsTNT) levels at 6 and 12 h, worst post-operative acute kidney injury (AKI) based on RIFLE criteria, and noradrenaline duration. hsTNT levels were log-normally distributed and higher with RIPC than control at 6-h post cross-clamp removal [810 ng/ml (IQR 527-1,724) vs. 634 ng/ml (429-1,012); ratio of means 1.41 (99.17% CI 0.92-2.17); P=0.04] and 12 h [742 ng/ml (IQR 427-1,700) vs. 514 ng/ml (IQR 356-833); ratio of means 1.56 (99.17% CI 0.97-2.53); P=0.01]. After adjustment for baseline confounders, the ratio of means of hsTNT at 6 h was 1.23 (99.17% CI 0.88-1.72; P=0.10) and at 12 h was 1.30 (99.17% CI 0.92-1.84; P=0.05). In the RIPC group, 35/48 (72.9%) had no AKI, 5/48 (10.4%) had AKI risk, and 8/48 (16.7%) had either renal injury or failure compared to the control group where 34/48 (70.8%) had no AKI, 7/48 (14.6%) had AKI risk, and 7/48 (14.6%) had renal injury or failure (Chi-squared 0.41; two degrees of freedom; P = 0.82). RIPC increased post-operative duration of noradrenaline support [21 h (IQR 7-45) vs. 9 h (IQR 3-19); ratio of means 1.70 (99.17% CI 0.86-3.34); P=0.04]. RIPC does not reduce hsTNT, AKI, or ICU-support requirements in high-risk cardiac surgery.

A multidisciplinary perioperative medicine clinic to improve high-risk patient outcomes: A service evaluation audit.

Various perioperative interventions have been demonstrated to improve outcomes for high-risk patients undergoing surgery. This audit assessed the impact of introducing a multidisciplinary perioperative medicine clinic on postoperative outcomes and resource usage amongst high-risk patients.Between January 2019 and March 2020, our institution piloted a Comprehensive High-Risk Surgical Patient Clinic. Surgical patients were eligible for referral when exhibiting criteria known to increase perioperative risk. The patient's decision whether to proceed with surgery was recorded; for those proceeding with surgery, perioperative outcomes and bed occupancy were recorded and compared against a similar surgical population identified as high-risk at our institution in 2017.Of 23 Comprehensive High-Risk Surgical Patient Clinic referrals, 11 did not proceed with the original planned surgery. Comprehensive High-Risk Surgical patients undergoing original planned surgery, as compared to high-risk patients from 2017, experienced reduced unplanned intensive care unit admission (8% versus 19%, respectively), 30-day mortality (0% versus 13%) and 30-day re-admission to hospital (0% versus 20%); had shorter postoperative lengths of stay (median (range) 8 (7-14) days versus 10.5 (5-28)) and spent more days alive outside of hospital at 30 days (median (range) 18 (0-25) versus 21 (16-23)). Cumulatively, the Comprehensive High-Risk Surgical patient cohort compared to the 2017 cohort (both n=23) occupied fewer postoperative intensive care (total 13 versus 24) and hospital bed-days (total 106 versus 212).The results of our Comprehensive High-Risk Surgical Patient pilot project audit suggest improved individual outcomes for high-risk patients proceeding with surgery. In addition, the results support potential resource savings through more appropriate patient selection.

Amniotic fluid embolism after intrauterine fetal demise.

We present a case of the successful treatment of severe amniotic fluid embolism in a 41-year-old woman undergoing emergency caesarean section at 36 weeks of gestation for placental abruption and intrauterine fetal demise. The treatment included prolonged cardiopulmonary resuscitation, emergency hysterectomy, re-operation with intra-abdominal packing and intra-aortic balloon pump insertion. The patient made a remarkable recovery and to date has minimal residual morbidity. Amniotic fluid embolism syndrome (AFES) is a rare and often fatal obstetric condition that remains one of the main causes of maternal mortality in developed countries. The incidence varies from 2 to 6 per 100,000 and suggested mortality rates exceed 60%.1-2 The classic triad of sudden hypoxia, hypotension and coagulopathy with acute onset during labour or immediately after delivery forms the hallmark of the AFES diagnosis, however AFES is primarily a clinical diagnosis of exclusion. We present a case of successful maternal outcome following severe amniotic fluid embolism after placental abruption and intrauterine fetal demise.

Tricuspid valve avulsion after blunt chest trauma.

Blunt cardiac trauma causing tricuspid regurgitation is rare and is most often associated with traffic accidents. Falling from a height can also cause such injuries, resulting in hemodynamic compromise and arrhythmias. The signs of traumatic tricuspid regurgitation can appear early or be delayed, depending upon the severity of injury. We present the case of a 68-year-old woman who fell from a height onto rocks during a hike. She sustained blunt cardiac injury with complete tricuspid valve avulsion, and underwent successful repair. In addition, we review the relevant medical literature.

The use of high-fidelity human patient simulation and the introduction of new anesthesia delivery systems.

New anesthesia delivery systems are becoming increasingly complex. Although equipment is involved in a large proportion of intraoperative anesthesia problems (most also involving human error), the current methods of introducing new equipment into clinical practice have not been well studied. We designed a randomized, controlled, prospective study to investigate an alternative method of introducing new anesthesia equipment. Fifteen anesthesiology trainees were randomized to either the standard introduction to a Drager Fabius GS anesthesia delivery machine plus simulated clinical use of the new machine in a high-fidelity human patient simulator (HPS) (Group 1) or to the standard introduction alone (Group 2). We used a questionnaire to seek their opinion on the new equipment, and responses showed that both groups were comparable in their reported confidence to use the new equipment safely. All trainees were then tested in two simulated anesthetic crises with the new machine. Performance was analyzed in terms of time to resolve the emergency, by using analysis of videos by an independent rater. Group 1 resolved both crises significantly faster. HPS allowed us to detect design features that were common sources of error.