Non-medical risk factors associated with postponing elective surgery: a prospective observational study.

BACKGROUND: Operation room (OR) planning is a complex process, especially in large hospitals with high rates of unplanned emergency procedures. Postponing elective surgery in order to provide capacity for emergency operations is inevitable at times. Elderly patients, residents of nursing homes, women, patients with low socioeconomic status and ethnic minorities are at risk for undertreatment in other contexts, as suggested by reports in the medical literature. We hypothesized that specific patient groups could be at higher risk for having their elective surgery rescheduled for non-medical reasons. METHODS: In this single center, prospective observational trial, we analysed 2519 patients undergoing elective surgery from October 2018 to May 2019. A 14-item questionnaire was handed out to illicit patient details. Additional characteristics were collected using electronic patient records. Information on the timely performance of the scheduled surgery was obtained using the OR's patient data management system. 6.45% of all planned procedures analysed were postponed. Association of specific variables with postponement rates were analysed using the Mann-Whitney U test and Fisher's exact test/χ2-test. RESULTS: Significantly higher rates of postponing elective surgery were found in elderly patients. No significant differences in postponing rates were found for the variables gender, nationality (Germany, EU, non-EU), native language, professional medical background and level of education. Significantly lower rescheduling rates were found in patients with ties to hospital staff and in patients with a private health insurer. CONCLUSIONS: Elderly patients, retirees and nursing home residents seem to be at higher risk for having their elective surgery rescheduled. However, owing to the study design, causality could not be proven. Our findings raise concern about possible undertreatment of these patient groups and provide data on short-term postponement of elective surgery. Trial registration DRKS00015836. Retrospectively registered.

Procedural times in early non-intubated VATS program - a propensity score analysis.

BACKGROUND: Non-intubated video-assisted thoracic surgery (NiVATS) has been introduced to surgical medicine in order to reduce the invasiveness of anesthetic procedures and avoid adverse effects of intubation and one-lung ventilation (OLV). The aim of this study is to determine the time effectiveness of a NiVATS program compared to conventional OLV. METHODS: This retrospective analysis included all patients in Leipzig University Hospital that needed minor VATS surgery between November 2016 and October 2019 constituting a NiVATS (n = 67) and an OLV (n = 36) group. Perioperative data was matched via propensity score analysis, identifying two comparable groups with 23 patients. Matched pairs were compared via t-Test. RESULTS: Patients in NiVATS and OLV group show no significant differences other than the type of surgical procedure performed. Wedge resection was performed significantly more often under NiVATS conditions than with OLV (p = 0,043). Recovery time was significantly reduced by 7 min (p = 0,000) in the NiVATS group. There was no significant difference in the time for induction of anesthesia, duration of surgical procedure or overall procedural time. CONCLUSIONS: Recovery time was significantly shorter in NiVATS, but this effect disappeared when extrapolated to total procedural time. Even during the implementation phase of NiVATS programs, no extension of procedural times occurs.

Increasing efficiency by optimizing table position for elective primary THA and TKA: a prospective monocentric pilot study.

INTRODUCTION: Hip and knee arthroplasties are very frequently performed surgeries with high quality standards and continuous optimization potential. Intraoperative processes can be standardized and simplified by optimization of table setups in the operating room to improve the quality and to increase efficiency. PATIENTS AND METHODS: The existing surgical setups for primary hip and knee arthroplasties in a university maximum care hospital with endoprosthesis center were simulated and analysed with a computer program and optimized setup suggestions were worked out, based on handover times, walking distance and ergonomic aspects determined in the program. In a prospective monocentric analysis, primary hip arthroplasties and knee arthroplasties were examined in currently used and in the new optimized setups (standard procedure according to in-house SOP, senior and main surgeons, no assistants). The surgeries were externally and independently supervised and analysed, whereby the time between incision and suture beginning, handovers per minute and handover times were documented, amongst other things. In addition, an evaluation sheet, which showed the satisfaction with the new setup, was filled by the surgical team. RESULTS: In the period from April 2016 to December 2018, 19 hip arthroplasties in currently used and 15 in the new optimized setup as well as 9 knee arthroplasties in currently used and 13 in the new setup were performed. Attention was paid to constant conditions in the compared groups and disruptive factors (assisted surgeries, complex surgeries, different cementings, etc.) were excluded. In the group of hip arthroplasties, the handover times were significantly different (old 1.82 +/- 1.43 s.; new 1.08 +/- 0.78 s.; p <0.001), as well as the handovers per minute (old 1.62 +/- 0.45 handovers/min.; new 2.10 +/- 0.32 handovers/min.; p = 0,001). The time between incision and suture beginning indicated no significant difference (old 53.89 +/- 18.92 min.; new 49.73 +/- 12.18 min; p = 0.466): During the knee arthroplasties, handovers per minute were significantly different (old 1.83 +/- 0.38 handovers/min.; new 2.40 +/- 0.35 handovers/min.; p = 0.002). The time between incision and suture beginning (old 71.11 +/- 20.72 min.; new 70.69 +/- 17.12 min.; p = 0.959) and the handover times (old 1.06 +/- 0.64 s.; new 0.91 +/- 0.59 s.; p = 0.152) indicated no significant difference. The evaluation of the questionnaires showed a significant difference (p < 0.001) in the group of hip arthroplasties in the category "visibility". For the knee arthroplasties, all items except "visibility" (p = 0.261) differed significantly. Overall, a high level of staff satisfaction with the new setup was achieved. CONCLUSIONS: In both groups, more handovers per minute could be achieved in the optimized setup and in the group of the hip arthroplasties, the handover times were significantly faster. The evaluation sheet showed a high satisfaction of the surgical staff with the new setup. No reduction of the time between incision and suture beginning could be determined. This can be attributed to a certain training effect, the adjustment to the setup modification and the low number of cases. The new setup offers a practical alternative for hip arthroplasties as well as for knee arthroplasties as it optimizes the events in the operating room in many ways. For example, there were more handovers per minute possible and passing of the surgical instruments free from interferences. Moreover, it increases the efficiency and achieves a high satisfaction of the staff.

Retraction Notice: Lack of Relationship Between Occupational Workload and Microscopic Alterations in Lumbar Intervertebral Disc Disease.

[This retracts the article on p. 242 in vol. 8.].

Lack of relationship between occupational workload and microscopic alterations in lumbar intervertebral disc disease.

OBJECTIVES: The study investigated the impact of occupational workloads on disc surgery specimens. We report the relationship between workload and histological features. METHODS: Specimens were collected prospectively from patients suffering from lumbar disc prolapse (n=90) or spinal osteochondrosis (n=19). Histomorphology and occupational workload data and histomorphological features were evaluated. Occupational data were collected in a structured, standardized patient interview assessing lifting and carrying loads. In this way the exposure was assessed for each test subject's entire working life up to surgery. RESULTS: There was no association between cumulative workload and histological patterns. In a subgroup of patients with a workload period of 12 months prior to surgery a relevant formation of chondrocyte clusters (p=0.055) was apparent. Chondrocyte cluster formation was found in 83% (n=74) of the prolapse patients and in 58% (n=11) of the osteochondrosis patients (p=0.02). Fibrocyte mediated scar formation was found in 55% of the prolapse patients and in 45% of the spinal stenosis patients. Chondrocyte clusters and their de novo collagen matrix did not integrate biomechanically sufficient with collagen fibers of the disc. Disintegration of clusters from disc matrix and formation of intra-discal sequesters were observed. CONCLUSION: Matrix degeneration was common but displayed no relationship to occupational workload or other histological features. Scar formation was observed in every second specimen. Regenerative chondrocyte cluster proliferation was a common feature in disc specimens and tended to be associated in patients with a workload one year before surgery.

Obesity in anesthesia and intensive care.

Obesity is a global epidemic increasingly affecting management of anesthesia as well as intensive care medicine. Possible improvements in therapy require consideration of the specific pathophysiology of the obese, their concomitant diseases, and the complications associated with morbid obesity. Systematic assessment of perioperative risk factors is essential for an appropriate management. Paradoxically, overweight and moderately obese patients undergoing surgery have a lower risk when compared to patients with normal weight. The highest mortality and morbidity rates in this setting are reported for underweight and morbidly obese patients. The better chance of survival when compared to normal-weight individuals in the perioperative setting has been described the obesity paradox. In particular, the commitment of all involved physicians to improve all aspects of care will reduce the perioperative risk in obese patients. Physiological and pharmacological characteristics of the obese should also be considered. Furthermore, adequate technical equipment and practical skills of all members of the anesthesia team significantly contribute to risk reduction and therapeutic success in obese patients.

Vertebral osteoporosis: perfused animal cadaver model for testing new vertebroplastic agents.

STUDY DESIGN: Experimental study. OBJECTIVE: It was aimed to establish a cadaver model to imitate osteoporotic perfused vertebral bone and to allow for transpedicular transfer of bone cement and various new materials into vertebrae. The model was perfused to simulate vertebroplasty in the presence of transvertebral blood flow. SUMMARY OF BACKGROUND DATA: The injection of bone cement into vertebrae bears the risk of irreversible discharge of material into the venous system of the spinal canal. The bovine cadaver model studied allows visual studies of material distribution in a vertebral bone, the potential spill-out of material, and quantification of washout and disintegration phenomena. METHODS: Thoracic and lumbar vertebrae from 1-year-old calves were cut transversally into 5 mm slices, macerated, and decalcified. The softened bone slices were compressed between 2 transparent plastic discs. A standard vertebroplasty cannula (outer diameter 3.5 mm, inner diameter 2.5 mm) was inserted into the vertebral body via the pedicle to transfer the different vertebroplasty materials. Arterial blood flow was simulated by means of liquid irrigation via 2 needles in the ventral part of the vertebral body slice. Metal powder was mixed with the solution to indicate the blood flow in the bone. The model was evaluated with the vertebroplasty cement polymethylmethacrylate. RESULTS: The model permitted visualization of the insertion and distribution of vertebroplasty materials. Liquid bone cement was effused into the spinal canal as in the clinical situation. Higher modulus cement acted in the same way as in clinical vertebroplasty. Rigid vertebroplasty agents led to trabecular fractures and stable mechanical interactions with the bone and eventually moved dorsal bone fragments into the spinal canal. Sedimentation of the metal powder indicated regions of perfusion. CONCLUSION: The model simulated the clinical behavior of liquid and higher modulus vertebroplasty agents in the presence of blood flow. It enabled safe ex vivo testing of the mechanical and physical properties of alternative vertebroplasty materials under flow conditions.

Clinical evaluation of a new multiparameter neuromonitoring device: measurement of brain tissue oxygen, brain temperature, and intracranial pressure.

OBJECTIVE: The study presented evaluated the first clinical use of a new multiparameter catheter measuring intracranial pressure (ICP), partial pressure of brain tissue oxygen (ptiO2), and brain temperature (TBr) (Neurovent PTO). To assess the validity of measured ptiO2 a second probe, which represents the current golden standard of ptiO2 measurement, was implanted (Licox system). METHODS: Thirty patients with indicated invasive measurement of ICP under intensive care unit conditions were included. Using a double lumen bolt, ptiO2 was measured simultaneously with Licox and Neurovent PTO. Ex vivo tests on both probes were conducted independently by the manufacturer of the Neurovent PTO (Raumedic AG, Germany). RESULTS: The average of individual mean ptiO2 measurements showed no relevant differences between the Licox (19.5+/-7.1) and Neurovent multiparameter probe (21.7+/-9.5). Twenty-eight Licox probes out of 30 showed proper functioning over the desired monitoring period. Raumedic multiparameter probes displayed a higher malfunction/handling error frequency (2 device errors, 11 handling errors). A comparison of the ptiO2 data between the Licox and Raumedic systems according to Bland and Altman was possible in 18 out of 30 patients and showed acceptable results (mean difference -1.24 mm Hg; limits of agreement: -25.1 to +22.6 mm Hg). A total of 95.2% of 96,083 recordings was within the calculated limits of agreement. Ex vivo tests of the probes after explantation revealed stable ICP and TBr function of the Raumedic probe. Precision of Zero ptiO2 did not differ between the probes, whereas precision of the 150 mm Hg ptiO2 was greater in the Raumedic probes. CONCLUSIONS: Combining 3 different neuromonitoring functions in 1 probe might ease monitoring by making a second (ptiO2) probe unnecessary. Interpretation of our data is limited by several factors: (1) monocentric study; (2) reduced mechanical probe stability, handling difficulties with the double lumen bolt; (3) design changes to improve mechanical stability will require further study; (4) conflict of interest with Raumedic because of its support for the study. The conclusion drawn from our study is that the new multiparameter probe evaluated does measure ICP, TBr, and ptiO2. But all the initial data given in this paper have to be interpreted cautiously. A new study will be necessary when the mechanical stability of the new probe has been improved.

[Principles and risks of electrosurgery]. / Elektrochirurgie--Grundlagen und Risiken.

Electrosurgical instruments are routinely used in many applications by the surgeon. In principle, high-frequency electrical currents are used by passing trough tissue for cutting and coagulation. The heat generated by the electrosurgical unit is proportional to the resistance and diameter of the tissue. There are two commonly used electrosurgical modalities: monopolar and bipolar. Since negative side-effects of electrosurgery are possible (e.g. burn, interaction with other electric devices) a proper knowledge of all staff involved in electrosurgery is warranted. In the context of a safe perioperative patient management the anesthesiologist should know basic principles of high-frequency surgery as well. This article describes the main aspects of electrosurgery for anesthesiologists.

Does brain temperature correlate with intracranial pressure?

OBJECTIVE: A positive correlation between brain temperature and intracranial pressure (ICP) has been proposed for patients under intensive care conditions. DESIGN AND METHODS: Data were recorded at 5-minute intervals in patients under ICP monitoring conditions. Brain temperature: combined ICP/temperature probe (Raumedic), core temperature: indwelling urinary catheter with temperature probe (Rüsch). The correlation between brain temperature and ICP was assessed by computing an estimated mean correlation coefficient (re) and by a time series analysis. PATIENTS: Forty consecutive neurosurgical patients receiving intensive care therapy for trauma, cerebrovascular malformation, and spontaneous hemorrhage were studied. A total of 48,892 measurements (9778 h) were analyzed. No additional interventions were performed. RESULTS: The median ICP was 14 mm Hg (range: -13 to 167). The brain temperature (median 38 degrees C; range 23.2 to 42.1) was 0.3 degrees C (range: -3.6 to 2.6) higher than the core temperature (median 37.7 degrees C; range 16.6 to 42.0), P<0.001. The mean Pearson correlation between ICP and brain temperature in all patients was re=0.13 (P<0.05); the time series analysis (assuming a possible lagged correlation between ICP and brain temperature) revealed a mean correlation of 0.05+/-0.25 (P<0.05). Both correlation coefficients indicate that any relationship between brain temperature and ICP accounts for less than 2% of the variability [coefficient of determination (r)<0.02]. CONCLUSIONS: These data do not support the notion of a clinically useful correlation between brain temperature and ICP.

Olive oil based nutrition in multiple trauma patients: a pilot study.

OBJECTIVE: A negative effect of hyperglycemia on clinical outcome has been proposed for patients treated under intensive care conditions. So far, however, the safety and effect of fat based nutrition regimen, especially of olive oil based emulsions, have not been systematically studied. DESIGN AND SETTING: Prospective, open-labeled, randomized, pilot study in a 14-bed surgical intensive care unit. PATIENTS AND INTERVENTIONS: Thirty-three consecutive, severe multiple trauma patients (injury severity score 31.6+/-11.5) were included; 18 (L group) received a parenteral lipid-based nutrition; 15 (G group) were given a standard parenteral glucose-based nutrition. MEASUREMENTS AND RESULTS: The energy expenditure (EE) showed no difference between groups and no significant difference between the energy intake/EE ratio. The daily mean energy intake was lower in the L group (17.9+/-6.3 kcal/kg) than in the G group (22.3+/-4.2 kcal/kg). Triglycerides and nitrogen balance showed no significant differences between groups. The L group had significantly lower blood glucose (L 7.4+/-1.6, G 8.7+/-1.6 mmol/l), carbon dioxide production, and minute volume and shorter duration of mechanical ventilation (L 13.0+/-8.9, G 20.4+/-7.0 days), and stay in the ICU (L 17.9+/-11.2, G 25.1+/-7.0 days). CONCLUSIONS: Our findings suggest a good tolerance, a decrease in blood glucose, clinically relevant shortening of ICU stay, and shorter time on mechanical ventilation for patients treated with olive oil based than with conventional glucose-heavy nutrition.