Randomized prospective comparison of forced air warming using hospital blankets versus commercial blankets in surgical patients

BACKGROUND: The purpose of this study was to evaluate the efficacy of an experimental approach to forced air warming using hospital blankets or a Bair Hugger warming unit (Augustine Medical Inc., Eden Prairie, MN) to create a tent of warm air. METHODS: Adult patients undergoing major surgery were studied. Patients were randomized to receive forced air warming using either a commercial Bair Hugger blanket (control group, n = 44; set point, 43 degrees C) or standard hospital blankets (experimental group, n = 39; set point, 38 degrees C). Distal esophageal temperatures were monitored. Patients were contacted the following day regarding any problems with the assigned warming technique. RESULTS: Surface area covered was 36 +/- 12% (mean +/- SD) in the experimental group and 40 +/- 10% in the control group. Final temperatures at the end of surgery were similar between groups: experimental, 36.2 +/- 0.6 degrees C; control, 36.4 +/- 0.7 degrees C. A similar number of patients had esophageal temperature less than 36 degrees C at the end of surgery in both groups (experimental, 12 of 39 [31%]; control, 12 of 44 [27%]). The majority of patients were satisfied with their anesthetic and warming technique: experimental, 38 of 39 patients; control, 44 of 44 patients. There were no thermal injuries. CONCLUSIONS: Standard hospital blankets heated to 38 degrees C forced air were equally as effective as commercial blankets heated with forced air at 43 degrees C. However, based on concerns expressed by the manufacturer, this experimental technique should not be used until further safety evaluation has been undertaken.     

Reflective Blankets Are as Effective as Forced Air Warmers in Maintaining Patient Normothermia During Hip and Knee Arthroplasty Surgery

Background

The use of forced air warming devices in the operating room has been shown to cause disruption of laminar airflow and a potential for increase in surgical site contamination. In contrast, conductive warming devices such as reflective blankets do not disrupt airflow and therefore have no potential for this increase in surgical site infection. However, some studies have shown them to be inferior to forced air warming devices in maintaining normothermia. We tested the hypothesis that the use of reflective blankets is as effective as forced air warming devices in maintaining intraoperative normothermia after adequate prewarming.

Comparison of forced-air warming systems with lower body blankets using a copper manikin of the human body

Background: Forced‐air warming has gained high acceptance as a measure for the prevention of intraoperative hypothermia. However, data on heat transfer with lower body blankets are not yet available. This study was conducted to determine the heat transfer efficacy of six complete lower body warming systems. Methods: Heat transfer of forced‐air warmers can be described as follows: Q˙=h·ΔT·A ([1]) where Q˙ = heat transfer [W], h = heat exchange coefficient [W m^?2 °C^?1], ΔT = temperature gradient between blanket and surface [°C], A = covered area [m²]. We tested the following forced‐air warmers in a previously validated copper manikin of the human body: ( 1 ) Bair Hugger^® and lower body blanket (Augustine Medical Inc., Eden Prairie, MN); ( 2 ) Thermacare^® and lower body blanket (Gaymar Industries, Orchard Park, NY); ( 3 ) WarmAir^® and lower body blanket (Cincinnati Sub‐Zero Products, Cincinnati, OH); ( 4 ) Warm‐Gard^® and lower body blanket (Luis Gibeck AB, Upplands Väsby, Sweden); ( 5 ) Warm‐Gard^® and reusable lower body blanket (Luis Gibeck AB); and ( 6 ) WarmTouch^® and lower body blanket (Mallinckrodt Medical Inc., St. Luis, MO). Heat flux and surface temperature were measured with 16 calibrated heat flux transducers. Blanket temperature was measured using 16 thermocouples. ΔT was varied between ?10 and +10 °C and h was determined by a linear regression analysis as the slope of ΔT vs. heat flux. Mean ΔT was determined for surface temperatures between 36 and 38 °C, because similar mean skin temperatures have been found in volunteers. The area covered by the blankets was estimated to be 0.54 m². Results: Heat transfer from the blanket to the manikin was different for surface temperatures between 36 °C and 38 °C. At a surface temperature of 36 °C the heat transfer was higher (between 13.4 W to 18.3 W) than at surface temperatures of 38 °C (8–11.5 W). The highest heat transfer was delivered by the Thermacare^® system (8.3–18.3 W), the lowest heat transfer was delivered by the Warm‐Gard^® system with the single use blanket (8–13.4 W). The heat exchange coefficient varied between 12.5 W m^?2°C^?1 and 30.8 W m^?2°C^?1, mean ΔT varied between 1.04 °C and 2.48 °C for surface temperatures of 36 °C and between 0.50 °C and 1.63 °C for surface temperatures of 38 °C. Conclusion: No relevant differences in heat transfer of lower body blankets were found between the different forced‐air warming systems tested. Heat transfer was lower than heat transfer by upper body blankets tested in a previous study. However, forced‐air warming systems with lower body blankets are still more effective than forced‐air warming systems with upper body blankets in the prevention of perioperative hypothermia, because they cover a larger area of the body surface.     

Comparison of forced-air warming systems with upper body blankets using a copper manikin of the human body

Background: Forced‐air warming with upper body blankets has gained high acceptance as a measure for the prevention of intraoperative hypothermia. However, data on heat transfer with upper body blankets are not yet available. This study was conducted to determine the heat transfer efficacy of eight complete upper body warming systems and to gain more insight into the principles of forced‐air warming. Methods: Heat transfer of forced‐air warmers can be described as follows: Q˙=h · ΔT · A, where Q˙= heat flux [W], h=heat exchange coefficient [W m^?2 °C^?1], ΔT=temperature gradient between the blanket and surface [°C], and A=covered area [m²]. We tested eight different forced‐air warming systems: (1) Bair Hugger^® and upper body blanket (Augustine Medical Inc. Eden Prairie, MN); (2) Thermacare^® and upper body blanket (Gaymar Industries, Orchard Park, NY); (3) Thermacare^® (Gaymar Industries) with reusable Optisan^® upper body blanket (Willy Rüsch AG, Kernen, Germany); (4) WarmAir^® and upper body blanket (Cincinnati Sub‐Zero Products, Cincinnati, OH); (5) Warm‐Gard^® and single use upper body blanket (Luis Gibeck AB, Upplands Väsby, Sweden); (6) Warm‐Gard^® and reusable upper body blanket (Luis Gibeck AB); (7) WarmTouch^® and CareDrape^® upper body blanket (Mallinckrodt Medical Inc., St. Luis, MO); and (8) WarmTouch^® and reusable MultiCover? upper body blanket (Mallinckrodt Medical Inc.) on a previously validated copper manikin of the human body. Heat flux and surface temperature were measured with 11 calibrated heat flux transducers. Blanket temperature was measured using 11 thermocouples. The temperature gradient between the blanket and surface (ΔT) was varied between ?8 and +8°C, and h was determined by linear regression analysis as the slope of ΔT vs. heat flux. Mean ΔT was determined for surface temperatures between 36 and 38°C, as similar mean skin surface temperatures have been found in volunteers. The covered area was estimated to be 0.35 m². Results: Total heat flow from the blanket to the manikin was different for surface temperatures between 36 and 38°C. At a surface temperature of 36°C the heat flows were higher (4–26.6 W) than at surface temperatures of 38°C (2.6–18.1 W). The highest total heat flow was delivered by the WarmTouch? system with the CareDrape? upper body blanket (18.1–26.6 W). The lowest total heat flow was delivered by the Warm‐Gard^® system with the single use upper body blanket (2.6–4 W). The heat exchange coefficient varied between 15.1 and 36.2 W m^?2 °C^?1, and mean ΔT varied between 0.5 and 3.3°C. Conclusion: We found total heat flows of 2.6–26.6 W by forced‐air warming systems with upper body blankets. However, the changes in heat balance by forced‐air warming systems with upper body blankets are larger, as these systems are not only transferring heat to the body but are also reducing heat losses from the covered area to zero. Converting heat losses of approximately 37.8 W to heat gain, results in a 40.4–64.4 W change in heat balance. The differences between the systems result from different heat exchange coefficients and different mean temperature gradients. However, the combination of a high heat exchange coefficient with a high mean temperature gradient is rare. This fact offers some possibility to improve these systems.     

Therapeutische Hypothermie bei Neugeborenen

Background

Mild systemic hypothermia improves the outcome of hypoxic-ischemic encephalopathy in neonates. We summarize our experiences over a period of 3 years with hypothermia as a standard procedure.

Patients and methods

Out of 56 asphyxiated newborn infants (gestational age >35 weeks) 33, who were admitted within 6 h, showed clinical and EEG signs of encephalopathy and had no contraindications, were included in a protocol to be cooled to 33–34°C for 72 h using a cooling blanket.

Results

29 neonates were continuously cooled while in 4 cases the therapy was prematurely discontinued. Adverse events, in particular cardiorespiratory and renal function disorders as well as coagulation problems, could not be linked to hypothermia and were manageable.

Conclusions

Therapeutic hypothermia seems to be a feasible method for neuroprotection in neonatal hypoxic-ischemic encephalopathy.     

Heat conservationvs convective warming in adults undergoing elective surgery

Purpose

To determine the relative efficacy of heat conservation and convective warming in maintaining penoperative normothermia. (central temperature ≥36°C).

Methods

Thirty-seven patients undergoing elective gynaecological, orthopaedic, or general surgery scheduled to last two hours were prospectjvely studied. Patients were randomized to one of two groups. Group I patients received heat conservation with reflective blankets (Thermadrape?, Vital Signs, Inc., Totowa, NJ) applied preoperatively and warmed iv fluids (Hotline? SIMS Level I Technologies, Inc, Rockland, MA). Group 2 patients received convective warming (BairHugger, Augustine Medical, Inc., Eden Prairie, MN) after induction of anaesthesia andiv fluids at room temperature. All patients received general anaesthesia with isoflurane. Tympanic membrane and forearm-fingertip skin temperature gradients were measured penoperatively at 15 min intervals.

Results

Central temperature decreased after induction to a minimum level of 35.9 ± 0.1°C in group I and 36.0 ± 0.1°C in group 2 and then increased towards pre-induction values in group 2, and were higher (P < 0.05) than in group 1: 95% group 2 patients had central temperature ≥ 36.0°C at the end of surgery (vs 69% of group l.P < 0.05). During the first 30 mm in PACU, central temperatures were higher in group 1 than in group 2 (36.8 ± 0.1°C vs 36.2 ± 0.2°C. P< 0.05). After 60 mm, central temperatures were similar (36.8°C). The incidence of shivering and degree of penpheral cutaneous vasoconstnction were also similar.

Conclusion

Patients receiving convective warming were more likely to leave the operating room normothermic. and had higher central temperatures dunng the first 30 mm in the recovery room. The intergroup temperature differences were small, and by 60 min, had disappeared.     

What Is the Risk of Clinical Anastomotic Leak in the Diverted Colorectal Anastomosis?

Objective

The objective of this study was to identify clinical leak in diverted colorectal anastomoses.

Design

Cohort analysis.

Setting

The study was conducted in a subspecialty practice at a tertiary care facility.

Patients

Consecutive subjects undergoing colorectal anastomosis and proximal fecal diversion between July 16, 2007 and June, 31 2012.

Interventions

No intervention was applied.

Main Outcome Measures

Clinical anastomotic leak.

Results

Two hundred forty-five patients underwent a colorectal anastomosis with proximal fecal diversion. A total of 34 (14 %) clinical leaks were identified at a median of 43 days. Clinical leaks were identified in 13 (5 %) patients within 30 days of surgery (early leaks) and in 21 (9 %) patients after 30 days of surgery (late leaks). Age, sex, use of neoadjuvant chemoradiotherapy, and method of anastomotic construction were similar in patients with clinical leaks as compared to those with no evidence of leak. However, clinical leaks were more likely to develop in patients with a diagnosis of inflammatory bowel disease or other diagnoses, i.e., radiation enteritis, ischemia, and injury/enterotomy. Patients with clinical leak were not more likely to have air leaks on intraoperative air leak testing.

Conclusions

In diverted anastomoses, most leaks become clinically apparent beyond 30 days. The standard practice of censoring outcomes that occur beyond postoperative day 30 will fail to identify a substantial fraction of leaks in diverted colorectal anastomoses.     

Prävention intraoperativer Hypothermie bei Kindern

Children are very sensible to the occurrence of intraoperative hypothermia (HT) (core temperature ≤36.0?ºC) during general anaesthesia because their regulation capacity is less effective than in adults and due to a large skin-surface area compared with their body mass. We compared the efficacy of different heating devices to prevent HT in children during surgery. Methods: With approval of the local ethics committee 50 children between one and seven years, scheduled for peripheral surgery lasting at least 2 hours were included in this studie. Anaesthesia was standardized in all patients. Patients were randomly divided into 5 groups. In group 1, in addition to the usual cotton blankets, room temperature was elevated to 27–28?ºC. In group 2, room temperature was maintained at 27–28?ºC, and the patients were additionally wrapped into an aluminum blanket. In group 3, elevated room temperature was combined with a convective heating blanket. Patients in group 4 were warmed with an aluminum blanket, while the room temperature was maintained at 22?ºC. In group 5, room temperature was maintained at 22?°C and patients were warmed with a convective heating device (Tab.?1). Room and core body temperature (tympanon membran) were continuously measured. ANOVA and Fisher’s exact Test (significance level: p<0.05) were performed for the statistical analysis of the results. Results: The demographic data of all 5 groups, the infused fluid volume and the anaesthetic technique were similar. There were no significant differences concerning age, hight and weight of the pediatric patients (Tab.?2). The core temperature decreased by ?1.7?ºC in group 1. In group 4 core temperature decreased by ?1.6?°C. Using a convective warming system in normal am-bient temperature (group 5) core temperature increased by 0.2?ºC and was as effective in the prevention of HT as group 2. A significant increase in core temperture occurred in group 3 +0.7?°C (Tab.?3 and Fig.?1). Discussion: OR temperature seems to be a critical factor influencing heat loss. Increasing OR temperature and covering with cotton sheets was not effective in preventing the heat loss. Increasing room temperature in combination with aluminum sheets is one alternative to prevent HT. Our study shows that the use of a convective warming device prevents HT during a 2-hour surgery in young children even at a OR temperature of about 22?°C. In conclusion, in pediatric patients the use of a convective heating system proved to be an effective alternative to room heating.     

Self-warming blanket versus forced-air warming blanket during total knee arthroplasty under spinal anaesthesia: A randomised non-inferiority trial

Background

Arthroplasty patients are at high risk of hypothermia. Pre-warming with forced air has been shown to reduce the incidence of intraoperative hypothermia. There is, however, a lack of evidence that pre-warming with a self-warming (SW) blanket can reduce the incidence of perioperative hypothermia. This study aims to evaluate the effectiveness of an SW blanket and a forced-air warming (FAW) blanket peri-operatively. We hypothesised that the SW blanket is inferior to the FAW blanket.

Methods

In total, 150 patients scheduled for primary unilateral total knee arthroplasty under spinal anaesthesia were randomised to this prospective study. Patients were pre-warmed with SW blanket (SW group) or upper-body FAW blanket (FAW group) set to 38°C for 30 min before spinal anaesthesia induction. Active warming was continued with the allocated blanket in the operating room. If core temperature fell below 36°C, all patients were warmed using the FAW blanket set to 43°C. Core and skin temperatures were measured continuously. The primary outcome was core temperature on admission to the recovery room.

Results

Both methods increased mean body temperature during pre-warming. However, intraoperative hypothermia occurred in 61% of patients in the SW group and in 49% in the FAW group. The FAW method set to 43°C could rewarm hypothermic patients. Core temperature did not differ between groups on admission to the recovery room, p = .366 (CI: −0.18–0.06).

Conclusions

Statistically, the SW blanket was non-inferior to the FAW method. Yet, hypothermia was more frequent in the SW group, requiring rescue warming as we strictly held to the NICE guideline.

Trial Registration

Clinicaltrials.gov identifier: NCT03408197.     

Arthroskopische Arthrolyse des Hüftgelenks

Objective

Increase of range of motion and pain reduction for pain limited movement of the hip joint by arthroscopic arthrolysis of the peripheral compartment.

Indications

Painful primary or secondary restriction of movement of the hip joint with adhesive capsulitis and after previous surgery or additional arthroscopically treatable intra-articular changes.

Contraindications

Extensive periarticular ossification, severe arthrofibrosis and advanced arthritis of the hip.

Surgical technique

Arthroscopy of the peripheral compartment of the hip, initially using a lateral portal for the arthroscope and an anterolateral portal for instruments. After expansion of the portal entry site with a shaver and/or HF applicator and removal of scar tissue between the capsule and femoral neck, the capsule is reduced from anterolateral to anteromedial. After exchange of arthroscope and working portal, the lateral and dorsolateral arthrolysis is done.

Postoperative management

Administration of nonsteroidal anti-inflammatory drugs for prophylaxis of heterotopic ossifications. Thrombosis prophylaxis with heparin. Mobilization with full weight bearing. Intensive physiotherapeutic exercises for at least for 6 weeks and if needed for 12 postoperative weeks.

Results

After arthroscopic (n=38) or open (n=11) hip surgeries, 49 revision hip arthroscopies were performed from January 2009 to August 2013. Arthrolysis in the described technique was performed if adhesions were present. In 19 of these cases, a limitation of at least 30?% for one direction of movement was present pre-operatively. The following average values were obtained for the range of motion (preoperative/postoperative/increase): flexion 94°/128°/34 °, abduction 18°/40°/22°, internal rotation of 8°/20°/12°, external rotation 18°/38°/20°.     

Modifiable factors delaying early discharge following primary joint arthroplasty

Aims

Recent NHS reforms have incentivised reduction in length of stay, with the UK department of health expecting health trusts to reduce bed days and ultimately reduce overall costs. The aim of this study was to identify avoidable causes for protracted hospital admission following total hip arthroplasty (THA) or total knee arthroplasty (TKA) within a fast-track unit.

Methods

During a 6-month period, 535 consecutive patients underwent primary THA or TKA under the care of a single surgeon. All patients with a post-operative stay of greater than 72 h were identified, and reasons for delayed discharge were determined.

Results

The majority of arthroplasty patients were discharged within 3 days post-operatively. Twenty-one per cent of THA patients and 25 % of TKA patients remained as inpatients for greater than 72 h. For the THA population, this equates to 43 % of bed days used by 21 % of patients, and for the TKA population, 44 % of bed days were used by 25 % of patients. The major factor within both groups for delayed discharge was attributed to inadequate social support.

Conclusions

Delayed discharge can never be totally prevented. This unit aims to develop improvement in social work provision, with a greater focus on pre-admission discharge planning to reduce the number of delayed discharges and ultimately reduce the cost burden of joint replacement surgery. It is not conducive with the ethos of fast-track arthroplasty to only identify social circumstances upon admission.     

A clinical prediction model for prolonged air leak after pulmonary resection

Objective

Prolonged air leak increases costs and worsens outcomes after pulmonary resection. We aimed to develop a clinical prediction tool for prolonged air leak using pretreatment and intraoperative variables.

Endovaskuläre Kühlung oder Oberflächenkühlung?

Introduction

Time course, time necessary to achieve the target temperature and stable maintenance, as well as a controlled rewarming period are important factors influencing the outcome of patients after successful cardiopulmonary resuscitation.

Methods

After successful cardiopulmonary resuscitation a total of 49 patients were cooled via an endovascular or external cooling device to a target temperature of 33°C. Relevant cooling parameters, such as time between admission and initiation of cooling, achievement of target temperature and stable maintenance of cooling therapy, were compared between both groups.

Results

In the endovascular cooling group the target temperature was reached significantly faster (154±97 min vs. 268±95 min, p=0.0002) and showed stable and controlled maintenance of cooling therapy (deviation from target temperature: 0.189±0.23°C vs 0.596±0.61°C, p=0.00006). The rewarming phase was better controlled and length of ICU stay was shorter in the group with endovascular cooling (8.8±3 vs. 12.9±6 days).

Conclusion

Endovascular cooling offers the possibility to reach the target temperature significantly faster and a stable maintenance of therapeutic hypothermia. It is capable of a more controlled rewarming period and shortens the length of ICU stay.     

Determinants of evolution of endplate and disc degeneration in the lumbar spine: a multifactorial perspective

Purpose

Evolution and progression of disc and endplate bone marrow degeneration of the lumbar spine are thought to be multifactorial, yet, their influence and interactions are not understood. The aim of this study was to find association of potential predictors of evolution of degeneration of the lumbar spine.

Methods

Patients (n = 90) who underwent two lumbar magnetic resonance imaging (MRI) exams with an interval of at least 4 years and without any spinal surgery were included into the longitudinal cohort study with nested case–control analysis. Disc degeneration (DD) was scored according to the Pfirrmann classification and endplate bone marrow changes (EC) according to Modic in 450 levels on both MRIs. Potential variables for degeneration such as age, gender, BMI, scoliosis and sagittal parameters were compared between patients with and without evolution or progression of degenerative changes in their lumbar spine. A multivariate analysis aimed to identify the most important variables for progression of disc and endplate degeneration, respectively.

Results

While neither age, gender, BMI, sacral slope or the presence of scoliosis could be identified as progression factor for DD, a higher lordosis was observed in subjects with no progression (49° ± 11° vs 43° ± 12°; p = 0.017). Progression or evolution of EC was only associated with a slightly higher degree of scoliosis (10° ± 10° vs 6° ± 9°; p = 0.04) and not to any of the other variables.

Conclusion

While a coronal deformity of the lumbar spine seems associated with evolution or progression of EC, a higher lumbar lordosis is protective for radiographic progression of DD. This implies that scoliotic deformity and lesser lumbar lordosis are associated with higher overall degeneration of the lumbar spine.     

Anterior 90° Partial vs Nissen Fundoplication—5?Year Follow-Up of a Single-Centre Randomised Trial

Introduction

Nissen fundoplication can be followed by side effects, and this has driven modifications, including partial fundoplications. We previously reported early outcomes from a randomised trial of Nissen vs anterior 90° partial fundoplication. This paper reports 5-year follow-up outcomes to determine whether anterior 90° fundoplication achieves a satisfactory longer-term outcome.

Methods

From February 1999 to August 2003, 79 patients were randomised to Nissen vs anterior 90° fundoplication. Patients were followed yearly using a standardized clinical questionnaire which included symptom scores to assess heartburn, dysphagia, other post-fundoplication side effects and overall satisfaction with the outcome. Five-year clinical outcomes were analysed.

Results

Seventy-four patients were available for follow-up at 5?years. There were no significant differences for heartburn or satisfaction, although more patients used antisecretory medication after anterior 90° fundoplication (29.7 vs 8.1?%). Dysphagia was greater after Nissen fundoplication when measured by an analogue score for solid food and a composite dysphagia score. Symptoms of bloating were more common following Nissen fundoplication (80.0 vs 32.4?%), and less patients could eat a normal diet (78.4 vs 94.6?%). Re-operation was undertaken in four patients after Nissen fundoplication (dysphagia, three; hiatus hernia, one) vs three after anterior 90° fundoplication (recurrent reflux, three).

Conclusions

At 5?years, anterior 90° partial fundoplication was associated with less side effects, offset by greater use of antisecretory medication. Reflux symptoms and overall satisfaction were similar to Nissen fundoplication. Laparoscopic anterior 90° partial fundoplication is an effective treatment for gastro-esophageal reflux.     

Predicting proximal femur rotation by morphological analyses using translucent 3-dimensional computed tomography

Background

Predicting rotation of proximal femur in femur fracture surgeries is important to prevent malrotation.

Objective

We aimed to prevent malrotation by developing a simple guideline that enables the prediction of proximal femur rotation using translucent 3-dimensional computed tomography (3D CT).

Design

Retrospective.

Setting

One tertiary general hospital in the Republic of Korea.

Patients

Thirty-six subjects who underwent CT angiographies for vascular evaluation.

Intervention

Translucent 3D CT images were created from the CT data.

Main outcome measure

Morphologic ratios of the great trochanter (GT) and lesser trochanter (LT) with the hip center as a basic point were measured at neutral position and at 5°, 10°, 15°, 20°, 25°, and 30° of internal rotation (IR) and external rotation (ER). The rotation angles at which the GT ratio becomes 0.5 and 0.33 and the rotation angles at which the LT ratio becomes 0.0 and 1.0 were determined to serve as guide angles.

Results

Both the proportion of GT and LT compared with proximal femur with hip center as a reference (GT and LT ratio) gradually increased in the shift from IR to ER. At a neutral position, the GT and LT ratios were approximately 0.4 and 0.5, respectively. At 10°?C15° of ER, the approximate GT and LT ratios were 0.5 and 1.0, respectively. At 30° of ER, the GT ratio exceeded 0.6, and the LT ratio exceeded 1.0. Between 10° and 15° of IR, the GT ratio decreased to approximately 0.33 and the LT ratio decreased to 0.0, which indicated that the LT was invisible.

Conclusions

We suggested practical values which might be useful as a reference in the operating room practically and hope that our findings would be helpful to prevent malrotation while performing proximal femur or femur shaft surgeries.     

Operative field temperature during transnasal endoscopic cranial base procedures

Background

Data regarding the safety of endoscopic skull base exploration are very scarce. With this method, fragile vital structures (cranial nerves, the optic complex, brainstem, hypothalamus or cerebral ventricles) are exposed to direct illumination within a closed space. Also, high-speed drills, cauterization and ultrasonic aspiration deliver a significant load of thermal energy. The aim of this study was to record the temperature close to the structures of the skull base and in the intradural space during the procedures performed using extended endoscopic transnasal approaches.

Methods

The temperature of the skull base was continuously recorded during six transnasal endoscopic procedures. Implantable copper-constantan thermocouples were inserted: one into the esophagus and another through the nostril to reach the operative field at the skull base.

Results

At the beginning of the procedure, the temperature of the operative field was on average 36.8 °C?±?0.80 °C, i.e. only 1 °C higher than the esophageal temperature. Then it grew continuously during the whole procedure, to eventually reach a level of 42–43 °C at the final stage, whereas the esophageal temperature remained stable. Occasionally, the temperature increased up to 45 °C during cauterization and ultrasonic aspiration, and even up to 62 °C during high-speed drilling.

Conclusion

Endoscopic skull base surgery is associated with an incessant increase of the temperature of the intraoperative field. The temperature can peak suddenly to levels which can potentially harm neural structures and influence the rate of postoperative complications.     

Venous air embolism (VAE) associated with stereotactic biopsies

Background

Venous air embolism (VAE) is a serious potential complication of neurosurgical procedures. Stereotactic biopsies can also cause VAE; therefore, we evaluated VAE patients to call attention to the risk of VAE associated with stereotactic biopsies.

Methods

In this report, symptomatic VAE was defined as paroxysmal coughing with associated symptoms. Air in the dural sinus, cortical vein and/or pterygoid plexus on postoperative computed tomography (CT) scans was considered to be a radiographic VAE.

Results

Three patients developed symptomatic VAE following 36 stereotactic biopsies, and the incidence of symptomatic VAE was 8.3 % (3/36). There were five patients with evidence of radiographic VAE on postoperative CT scans, with an incidence of 13.8 % (5/36). A high angle of the head seemed to be associated with VAE, allowing air to flow into the central venous system.

Conclusions

The present report emphasizes that VAE should be recognized as an important adverse effect of stereotactic biopsies because VAE occasionally requires additional treatment and/or termination of surgery. Surgeons must be aware of the possibility of VAE, especially when it is necessary to position the patient’s head at a high angle.     

Effect of warm intravenous and irrigating fluids on body temperature during transurethral resection of the prostate gland

Background

Transurethral resection of the prostate gland with irrigation fluid at room temperature leads to perioperative hypothermia which could give rise to adverse cardiovascular events in the perioperative period. The use of isothermic irrigation fluid reduces but does not eliminate this risk. Routine use of warm intravenous fluids along with isothermic irrigation had not been documented. This study set out to investigate the effect of the use of warm intravenous fluid together with isothermic irrigation fluid on the body temperature in patients undergoing transurethral resection of the prostate gland.

Methods

One hundred and twenty consented patients with obstructing benign prostatic hyperplasia were randomly assigned to one of 3 groups. Group 1 received irrigation and intravenous fluids at room temperature, group 2 received warmed irrigation fluid at 38°C along with intravenous fluid at room temperature while group 3 patients received warmed irrigation fluid and warmed intravenous fluids at 38°C. Their perioperative body temperature changes were monitored, analyzed and compared.

Results

The mean decrease in body temperature at the end of the procedure was significantly greater in group 1 (0.98 ± 0.56°C) than in group 2 (0.42 ± .21°C) (p < 0.001). Significantly more patients in group 1 also experienced shivering. However, in group 3, there was no significant change in the mean body temperature (p > 0.05) and none of them felt cold or shivered.

Conclusion

It is concluded that the use of isothermic irrigation fluid together with warm intravenous fluids during TURP prevents the occurrence of perioperative hypothermia.

Trial registration number

CCT-NAPN-15944