Intraoperative Local Insufflation of Warmed Humidified CO2 Increases Open Wound and Core Temperatures: A Randomized Clinical Trial

Background

The open surgical wound is exposed to cold dry ambient air, resulting in substantial heat loss through radiation, evaporation, and convection. At the same time, anesthesia decreases the patient’s core temperature. Despite preventive measures, mild intraoperative hypothermia has been associated with postoperative morbidity. We hypothesized that local insufflation of warmed humidified carbon dioxide (CO₂) would maintain wound and core temperature.

Methods

Eighty patients undergoing open colon surgery were randomized to standard warming measures, or to additional local wound insufflation of warmed (30?°C) humidified (93?% rH) CO₂ via a gas diffuser. Surface temperature of the open abdominal wound was measured with a heat-sensitive infrared camera, and core temperature was measured with an ear thermometer.

Results

Mean operative time was 219?±?104 and 205?±?85?min in the CO₂ group and the control group, respectively (p?=?0.550). Clinical variables did not differ significantly between the groups. The median wound area and wound edge temperatures were 1.2?°C (p?<?0.001) and 1.0?°C (p?=?0.002) higher in the CO₂ group, respectively, than in the control group. The mean core temperature after intubation was the same (35.9?°C) in both groups, but at end of surgery core temperature in the two groups differed, with a mean of 36.2?±?0.5?°C in the CO₂ group and a mean of 35.8?±?0.5?°C in the control group (p?=?0.003).

Conclusions

Insufflation of warmed, humidified CO₂ in an open surgical wound cavity prevents intraoperative decrease in surgical wound temperature as well as core temperature.     

Präoperative Vorwärmung in der klinischen Routine

Background

Despite the broad application of intraoperative warming new studies still show a high incidence of perioperative hypothermia. Therefore a prewarming program in the preoperative holding area was started.

Methods

The efficacy of the prewarming program was assessed with an accompanying quality assurance check sheet over a period of 3 months.

Results

During the 3 month test period 127 patients were included. The median length from arrival in the holding area to beginning prewarming was 6 min and the average duration of prewarming was 46±38 min. During prewarming the core temperature rose by 0.3±0.4°C to 37.1±0.5°C and decreased to 36.3±0.5°C after induction of anesthesia. At the end of the operation the core temperature was 36.4±0.5°C and 14% of the patients were hypothermic.

Conclusion

These data allow 2 conclusions: 1. Prewarming in the holding area is possible with a sufficient duration. 2. Prewarming is highly efficient even when performed over a relatively short duration.     

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.     

What influence does intermittent pneumatic compression of the lower limbs intraoperatively have on core hypothermia?

Background

Intermittent pneumatic compression (IPC) devices have been widely used for thrombosis prophylaxis in laparoscopic colorectal surgery. However, periodic compression using an IPC device may inject augmented boluses of cool blood from the lower limbs into the central circulation repetitively, thereby causing a reduction in core temperature. The authors therefore conducted a prospective, randomized, double-blind, controlled study to compare the effects of intraoperative IPC on core temperature in patients undergoing laparoscopic colorectal surgery.

Methods

For this study, 56 patients ages 18–60 years and scheduled to undergo laparoscopic resection for colorectal cancer under general anesthesia were randomly assigned to receive either no IPC (control group) or calf-thigh-length IPC in both legs using the SCD Express (IPC group). Anesthetic, thermal, and pneumoperitoneum management were standardized. Esophageal temperature, as an indicator of core temperature, was measured at 15-min intervals for 2 h after induction of anesthesia.

Results

A total of 47 subjects (23 control and 24 IPC subjects) were included in the analysis. The core temperature drop in the IPC group was significantly greater than in the control group, starting from 45 min after induction of anesthesia (P < 0.05). As a result, the total temperature drop during the 2-h study period was significantly greater in the IPC group (1.2 ± 0.3 °C) than in the control group (0.9 ± 0.3 °C) (P = 0.004).

Conclusions

Because intraoperative application of IPC carries an increased risk of a core temperature drop, appropriate temperature monitoring and active thermal management are required for surgical patients receiving IPC.     

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.     

Randomized non-inferiority trial of the vitalHEAT™ Temperature Management System vs the Bair Hugger® warmer during total knee arthroplasty

Purpose

Intraoperative and postoperative hypothermia occur commonly; mild hypothermia (34–36°C) is associated with adverse events. The use of perioperative warming devices has become routine, but currently available active warming devices may be limited in certain circumstances. The vitalHEAT? Temperature Management System provides conductive warming (circulating warm water) around a single extremity together with a vacuum that is applied to the limb. In this randomized trial, we tested the hypothesis that the vitalHEAT? system is non-inferior to the Bair Hugger^® during unilateral total knee arthroplasty.

Methods

Physical status I–III patients who were ≥18 yr-old were eligible to participate. The patients were randomly assigned to the vitalHEAT? system (n = 30) or to Bair Hugger^® (n = 25) warming. Intraoperative and first recovery room temperatures were recorded in both groups.

Results

The baseline characteristics of the groups were similar. In terms of the primary outcome measure, i.e., sublingual temperature measured within 10 min of recovery room arrival, the vitalHEAT? system did not meet the criterion for non-inferiority. Specifically, the confidence interval for the difference between means included the non-inferiority margin (?0.5°C). In terms of the secondary measures, i.e., intraoperative esophageal temperatures, the vitalHEAT? system also underperformed compared with the Bair Hugger^®.

Conclusions

The vitalHEAT? system may have advantages over convective warming systems because it requires a much smaller body surface area; however, in this study of warming during total knee arthroplasty, it underperformed when compared with the Bair Hugger^®, especially around and after the time of tourniquet release. Clinical trial registration number: NCT00711867.     

Clonidine decreases vasoconstriction and shivering thresholds, without affecting the sweating threshold

Purpose

This study was conducted to test the hypothesis that clonidine produces a dose-dependent increase in the sweating threshold and dose-dependent decreases in vasoconstriction and shivering thresholds.

Methods

Six healthy subjects (two female) were studied on four days after taking clonidine in oral doses of either 0 (control). 3. 6 or 9 μg · kg. The order followed a balanced design in a double-blind fashion. Oesophageal temperature and mean skin temperature (from 12 sites) were measured. Subjects were seated in 37°C water which was gradually warmed until sweating occurred (sweat rate increased above 50 g · m 2 · h^?1). The water was then cooled gradually until thresholds for vasoconstnction (onset of sustained decrease in fingertip blood flow) and shivering (sustained elevation m metabolism) were determined. Thresholds were then referred to as the core temperature, adjusted to a designated mean skin temperature of 33°C.

Results

High dose clonidine similarly decreased the adjusted core temperature thresholds for vasoconstriction by 1. 16 ± 0.30°C and for shivenng by 1.63 ± 0.23°C (P< 0.01). The dose response effects were linear for both cold responses with vasoconstriction and shivenng thresholds decreasing by 0.13 ± 0.05 and 0.19 ± 0.09°C · μg^?1 respectively (P < 0.0001). The sweating threshold was unaffected by clonidine, however the interthreshold range between sweating and vasoconstnction thresholds increased from control (0.19 ± 0.48°C) to high dose donidine (1.31 ±0.54°C).

Conclusion

The decreases in core temperature thresholds for cold responses and increased interthreshold range are consistent with the effects of several anaesthetic agents and opioids and is indicative of central thermoregulatory inhibition.     

Lidocaine prolongs the safe duration of circulatory arrest during deep hypothermia in dogs

Purpose

To test the hypothesis that lidocaine prolongs the safe period of circulatory arrest during deep hypothermia.

Methods

Sixteen dogs were subjected to cooling, first surface cooling to 30°C and then core cooling to 20°C rectal temperature). The circulation was then stopped for 90 min. In the lidocaine group, 4 mg·kg^?1 lidocaine was injected into the oxygenator two minutes before circulatory arrest and 2 mg·kg^?1 at the beginning of reperfusion and rewarming. The control group received equivalent volumes of normal saline. Post-operatively, using a neurological deficit scoring system (maximum deficit score — 100; minimum — zero indicating that no scored deficit could be detected). Neurological function was evaluated hourly for six hours and then daily for one week. the pharmacokinetic parameters were calculated using one compartment model.

Results

On the seventh day, the neurological deficit score and overall performance were better in the lidocaine (0.83 ± 2.04) than in the control group (8.33 ± 4.08P < 0.05). During the experiment, the base excess values were also better in the lidocaine than in the control group (at 30 min reperfusion: ?4.24 ± 1.30vs ?8.20 ± 2.82P < 0.01, at 60 min reperfusion was ?3.34 ± 1.87vs ?7.52 ± 2.40 (P < 0.01). On the eighth day the extent of pathological changes were milder in the lidocaine group than that in the control group. The elimination half life of lidocaine was 40.44 ± 7.99 during hypothermia and 2.01 ± 4.56 during rewarming.

Conclusions

In dogs lidocaine prolongs the safe duration of circulatory arrest during hypothermia.     

Local warming at injection site helps alleviate pain after rocuronium administration

Purpose

Various strategies have been proposed to reduce discomfort of pain after rocuronium injection. These studies have shown pretreatment of drugs such as fentanyl and lidocaine to be effective. In a prospective randomized study, we evaluated whether pretreatment with local warming at injection site using an air-warming device could effectively alleviate pain induced by rocuronium.

Methods

Ninety patients undergoing spinal surgeries were randomly divided into two groups: group C (control) and group T (treatment). Patients in group T were subjected to warming at 40°C for 1 min prior to injecting 1 ml (10 mg) of rocuronium at the site of venous access. Patients were then assessed for any discomfort and to quantify their discomfort on a 5-point scale.

Results

Age, sex, and weight were comparable between the two groups. Pain on rocuronium administration was reported by 88.9% patient in group C versus 66.7% in group T (p < 0.05). Severe pain was significantly less in group T (35.6% vs. 8.9%).

Conclusion

Application of warmth over the vascular access prior to rocuronium administration effectively reduces injection-related pain.     

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     

Effect of preoperative warming on intraoperative hypothermia: a randomized-controlled trial

Purpose

The purpose of this study was to evaluate the effects of preoperative forced-air warming on intraoperative hypothermia.

Methods

In this randomized-controlled trial, adult patients scheduled for elective, non-cardiac surgery under general anesthesia were stratified by scheduled surgical duration (< 2.5 hr or ≥ 2.5 hr) and then randomized to a pre-warming group using a BairPaws? forced-air warming system for at least 30 min preoperatively or to a control group with warmed blankets on request. All patients were warmed intraoperatively via convective forced-air warming blankets. Perioperative temperature was measured using the SpotOn? temperature system consisting of a single-use disposable sensor applied to the participant’s forehead. The primary outcome was the magnitude of intraoperative hypothermia calculated as the area under the time-temperature curve for core temperatures < 36°C between induction of general anesthesia and leaving the operating room. Secondary outcomes included surgical site infections, packed red blood cell requirements, and 24 hr postoperative opioid consumption.

Results

Two hundred participants were analyzed (101 control; 99 pre-warmed). Pre-warmed participants had a lower median [interquartile range] magnitude of hypothermia than controls (0.00 [0.00-0.12] °C·hr^?1 vs 0.05 [0.00-0.36] °C·hr^?1, respectively; median difference, ?0.01°C·hr^?1; 95% confidence interval, ?0.04 to 0.00°C·hr^?1; P = 0.005). There were no between-group differences in the secondary outcomes.

Conclusion

A minimum of 30 min of preoperative forced-air convective warming decreased the overall intraoperative hypothermic exposure. While redistribution hypothermia still occurs despite pre- and intraoperative forced-air warming, their combined application results in greater preservation of intraoperative normothermia compared with intraoperative forced-air warming alone.

Trial registration

www.clinicaltrials.gov (NCT02177903). Registered 25 June 2014.

     

Preventive effects of conservative treatment with short-term teriparatide on the progression of vertebral body collapse after osteoporotic vertebral compression fracture

Summary

The progression of fractured vertebral collapse is not rare after a conservative treatment of vertebral compression fracture (VCF). Teriparatide has been shown to directly stimulate bone formation and improve bone density, but there is a lack of evidence regarding its use in fracture management. Conservative treatment with short-term teriparatide is effective for decreasing the progression of fractured vertebral body collapse.

Introduction

Few studies have reported on the prevention of collapsed vertebral body progression after osteoporotic VCF. Teriparatide rapidly enhances bone formation and increases bone strength. This study evaluated preventive effects of short-term teriparatide on the progression of vertebral body collapse after osteoporotic VCF.

Methods

Radiographs of 68 women with single-level osteoporotic VCF at thoracolumbar junction (T11–L2) were reviewed. Among them, 32 patients were treated conservatively with teriparatide (minimum 3 months) (group I), and 36 were treated with antiresorptive (group II). We measured kyphosis and wedge angle of the fractured vertebral body, and ratios of anterior, middle, and posterior heights of the collapsed body to posterior height of a normal upper vertebra were determined. The degree of collapse progression was compared between two groups.

Results

The progression of fractured vertebral body collapse was shown in both groups, but the degree of progression was significantly lower in group I than in group II. At the last follow-up, mean increments of kyphosis and wedge angle were significantly lower in group I (4.0°?±?4.2° and 3.6°?±?3.6°) than in group II (6.8°?±?4.1° and 5.8°?±?3.5°) (p?=?0.032 and p?=?0.037). Decrement percentages of anterior and middle border height were significantly lower in group I (9.6?±?10.3 and 7.4?±?7.5 %) than in group II (18.1?±?9.7 and 13.8?±?12.2 %) (p?=?0.001 and p?=?0.025), but not in posterior height (p?=?0.086).

Conclusions

In female patients with single-level osteoporotic VCF at the thoracolumbar junction, short-term teriparatide treatment did not prevent but did decrease the progression of fractured vertebral body collapse.     

Oesophageal, rectal, axillary, tympanic and pulmonary artery temperatures during cardiac surgery

Purpose

The gradient between temperatures measured at different body sites is not constant; one factor which will change this gradient is rapid changes in body temperature. Measurement of this gradient was done in patients undergoing rapid changes in body temperature to establish the best site to measure temperature and to compare two brands of commercial tympanic thermometers.

Method

A total of 228 sets of temperatures were measured from probes in the oesophagus, rectum, and axilla and from two brands of tympanic thermometer and compared with pulmonary artery (PA) temperature in 18 adults during cardiac surgery.

Results

Measurements from the oesophageal site was closest to PA readings (mean difference 0.0 ± 0.5°C) compared with IVAC tympanic thermometer (mean difference ?0.3 ± 0.5°C), Genius tympanic thermometer (mean difference ?0.4 ± 0.5°C), axillary (mean difference 0.2 ± 1.0dgC) and rectal (mean difference ?0.4 ± 1,0°C) readings. When data during cooling were analysed separately, all sites had similar gradients from PA except for rectal, which was larger. On rewarming, oesophageal readings were closest to PA readings; tympanic readings were closer to PA than were rectal or axillary readings. Readings from the two brands of tympanic thermometer were equivalent.

Conclusion

Oesophageal temperature is more accurate and will reflect rapid changes in body temperature better than tympanic, axillary, or rectal temperature. When oesophageal temperature cannot be measured, tympanic temperature done by a trained operator should become the reading of choice.     

Heat loss during carbon dioxide insufflation: comparison of a nebulization based humidification device with a humidification and heating system

Introduction

This study compared the heat loss observed with the use of MR860 AEA Humidifier? system (Fisher & Paykel Healthcare, New Zealand), which humidifies and heats the insufflated CO₂, and the use of the AeronebPro? device (Aerogen, Ireland), which humidifies but does not heat the insufflated CO₂.

Methods

With institutional approval, 16 experiments were conducted in 4 pigs. Each animal, acting as its own control, was studied at 8-day intervals in randomized sequence with the following four conditions: (1) control (C) no pneumoperitoneum; (2) standard (S) insufflation with nonhumidified, nonheated CO₂; (3) Aeroneb? (A): insufflation with humidified, nonheated CO₂; and (4) MR860 AEA humidifier? (MR): insufflation with humidified and heated CO₂.

Results

The measured heat loss after 720L CO₂ insufflation during the 4?h was 1.03?±?0.75?°C (mean?±?SEM) in group C; 3.63?±?0.31?°C in group S; 3.03?±?0.39?°C in group A; and 1.98?±?0.09?°C in group MR. The ANOVA showed a significant difference with time (p?=?0.0001) and with the insufflation technique (p?=?0.024). Heat loss in group C was less than in group S after 60?min (p?=?0.03), less than in group A after 70?min (p?=?0.03), and less than in group MR after 150?min (p?=?0.03). The heat loss in group MR was less than in group S after 50?min (p?=?0.04) and less than in group A after 70?min (p?=?0.02). After 160?min, the heat loss in group S was greater than in group A (p?=?0.03).

Discussion

As far as heat loss is concerned, for laparoscopic procedures of less than 60?min, there is no benefit of using any humidification with or without heating. However, for procedures greater than 60?min, use of heating along with humidification, is superior.     

Radiofrequency energy antenna coupling to common laparoscopic instruments: practical implications

Background

Electromagnetic coupling can occur between the monopolar “Bovie” instrument and other laparoscopic instruments without direct contact by a phenomenon termed antenna coupling. The purpose of this study was to determine if, and to what extent, radiofrequency energy couples to other common laparoscopic instruments and to describe practical steps that can minimize the magnitude of antenna coupling.

Methods

In a laparoscopic simulator, monopolar radiofrequency energy was delivered to an L-hook. The tips of standard, nonelectrical laparoscopic instruments (either an unlit 10?mm telescope or a 5?mm grasper) were placed adjacent to bovine liver tissue and were never in contact with the active electrode. Thermal imaging quantified the change in tissue temperature nearest the tip of the telescope or grasper at the end of a 5?s activation of the active electrode.

Results

A 5?s activation (30 watts, coagulation mode, 4?cm separation between instruments) increased tissue temperature compared with baseline adjacent to the grasper tip (2.2?±?2.2?°C; p?=?0.013) and telescope tip (38.2?±?8.0?°C; p?<?0.001). The laparoscopic telescope tip increased tissue temperature more than the laparoscopic grasper tip (p?<?0.001). Lowering the generator power from 30 to 15 Watts decreased the heat generated at the telescope tip (38.2?±?8.0 vs. 13.5?±?7.5?°C; p?<?0.001). Complete separation of the camera/light cords and the active electrode cord decreased the heat generated near the telescope tip compared with parallel bundling of the cords (38.2?±?8.0 vs. 15.7?±?11.6?°C; p?<?0.001).

Conclusions

Commonly used laparoscopic instruments couple monopolar radiofrequency energy without direct contact with the active electrode, a phenomenon that results in heat transfer from a nonelectrically active instrument tip to adjacent tissue. Practical steps to minimize heat transfer resulting from antenna coupling include reducing the monopolar generator power setting and avoiding of parallel bundling of the telescope and active electrode cords.     

Efficacy of Forced-Air Warming to Prevent Perioperative Hypothermia in Morbidly-Obese Versus Non-obese Patients

Background

Hypothermia is associated with an increased postoperative morbidity and mortality. Forced-air warming systems are the most effective methods for its prevention. When using a mattress, a reduction in the area of diffusion of warm air by crushing due to excess weight cannot be ruled out.

Methods

We designed a prospective study to compare the efficacy of a forced-air warming mattress (Bair Hugger® 585) to prevent hypothermia (core temperature (CT°) <?36 °C) in morbidly obese (group MO, body mass index (BMI) ≥?40 kg/m²) and non-obese patients (group NO, BMI <?30 kg/m²).

Results

Twenty-six patients were included in group MO (84% bariatric surgery, 96% laparoscopic procedures) and 32 in group NO (37.5% cholecystectomy, 62.5% laparoscopic procedures). The incidence of hypothermia was not different between the two groups 1 h after induction (H1) and at extubation: 22 vs 19% (not significant (NS)) and 23 vs 19% (NS) for the group MO versus group NO. At H1, the mean CT° was not different: 36.3?±?0.4 °C vs 36.4?±?0.5 °C (NS), group MO versus group NO. No patient presented severe hypothermia (CT° <?34.9 °C). Dysfunction of the forced-air warming mattress was observed for eight patients (31%) in group MO but for none in group NO.

Conclusion

The forced-air warming mattress is effective in preventing hypothermia in MO patients. However, excess weight is associated with frequent dysfunction of the system, which does not make it a practical system in a context of MO.

     

Thermal spread and heat absorbance differences between open and laparoscopic surgeries during energized dissections by electrosurgical instruments

Background

The reported literature suggests a higher incidence of collateral damage during energized dissections in laparoscopic surgery than in open surgery, probably because the ambient environment of the two approaches causes different heat absorbance and thermal spread during energized dissection.

Methods

The experimental design involved randomized allocation of the surgical approach (4 open and 4 laparoscopic procedures) for eight adult pigs. A bipolar electrosurgery system (LigaSure) was used to perform 40 standardized regional dissections and procedures (5 per animal in randomized order). During these procedures, both white light and infrared thermographic imaging (3–5 μm) were recorded, and biopsy specimens were procured for histology.

Results

The core body temperatures were significantly different between the two approaches. The laparoscopic group had a smaller temperature drop (3.08 ± 0.98°C vs 1.9 ± 0.72°C; p = 0.03). Differences also were observed in the thermal spread between the laparoscopic and open groups during portal vein dissection with the Advance (1.7 ± 0.2 mm vs 2.3 ± 1.7 mm; p = 0.07). Both thermography and histology confirmed the safety of the LigaSure system in limiting thermal spread and necrosis at the fusion line. Significant degradation of the instruments began after 10 activations. The deterioration was faster and more extensive in laparoscopic surgery.

Conclusions

Heat absorbance and thermal spread during bipolar electrosurgery are significantly different between open and laparoscopic surgery. Device performance degradation with repeat activations is more marked in laparoscopic surgery.     

Total cervical disc replacement with the Discocerv® (Cervidisc Evolution) cervical prosthesis: early results of a second generation

Purpose

The purpose of the present study is to evaluate the early clinical and radiographic outcome in patients operated with Discocerv^® Cervidisc Evolution semi-constrained cervical mobile prosthesis (Discocerv^®), made of ceramic materials (Zirconia & Alumina).

Study design

This is a monocentric prospective noncomparative study.

Patient sample

Seventeen consecutive patients (8 men/9 women) were enrolled in the study so far. Mean age was 46.1 ± 7.9 years (33–62).

Methods

Patients in this series underwent one or two level total cervical disc replacement (TCDR) with Discocerv for disc herniation (n = 13), stenosis (n = 2) or discopathy (n = 1). Mean follow up was 4.8 ± 1.8 months (0–7.2).

Outcome measures

Clinical evaluation criteria included: VAS 1–100 mm self-reported cervical and radicular pain, neck disability index (NDI), symptoms evolution (ODOM score), work status, patient satisfaction index (PSI), mobility preservation. Prior to surgery VAS self-reported cervical and radicular pain were 62 mm (4–95) and 67 mm (2–96) respectively. NDI was 25/50 (9/50–37/50). Out of the active population (88%) 66% of patients were in sick leave for cervical symptoms. Radiographic criteria such as intervertebral mobility of the operated level were also assessed.

Results

Sixteen patients had a one level total cervical disc replacement (C3C4 n = 1, C4C5 n = 3, C5C6 n = 9, C6C7 n = 3. One patient had C5C6 and C6C7 total cervical disc replacement. Surgery duration was 67.1 ± 20.2 min (35–120). Hospital stay was 3.6 ± 1.5 days (2–7). No pre-operative or post-operative complications were reported in this series, except for excessive bleeding in one patient without any further consequences. About 47% of active patients resumed their previous work within the first 3 months after surgery. The ODOM score showed 100% excellent and good results. Three months post-operatively, mean VAS self-reported cervical and radicular pain decreased to 13 mm (0–60) and 5 mm (0–20) respectively and NDI decreased to 11/50 (0–24). All patients were satisfied with the results so far. Quantitative radiographic analysis showed satisfactory restoration of cervical mobility at the operated levels, with mean intervertebral mobility of 4.9° ± 5.6° (0 to 19.0°) in flexion-extension and 8.4° ± 4.1° (2.7°–16.9°) in lateral bending.

Conclusion

Early results with Discocerv^® Cervidisc Evolution cervical prosthesis are encouraging. However, further follow-up on a larger group is necessary to confirm these findings.     

Measurement of the Q-tip angle before and after tension-free vaginal tape-obturator (TVT-O): preoperative urethral mobility may predict surgical outcome

Introduction and hypothesis

The purpose of this study was to compare the results of the Q-tip test before and after the tension-free vaginal tape-obturator (TVT-O) in women with stress urinary incontinence (SUI) to determine the value of the Q-tip test in predicting the outcome of transobturator tape (TOT).

Methods

Between June 2008 and June 2009, 59 women with SUI who underwent the TVT-O procedure and were followed up for at least 6 months were analyzed. Urethral hypermobility was defined as a maximal straining angle greater than 30° as measured by the Q-tip test. Parameters of evaluation included a comprehensive medical history, physical examination, Q-tip test, stress test, and urodynamic study, which included determination of the Valsalva leak point pressure. Cure was defined as no leakage of urine postoperatively either subjectively or objectively, whereas failure was defined as the objective loss of urine during the stress test.

Results

The patients were divided into two groups according to their preoperative Q-tip angle: <30° (group 1, n?=?21) and ≥30° (group 2, n?=?38). The Q-tip angle decreased significantly in both groups: from 25.9?±?5.98° preoperatively to 18.4?±?7.23° postoperatively in group 1 (p?=?0.04) and from 36.6?±?6.75° preoperatively to 24.1?±?5.48° postoperatively in group 2 (p?=?0.03). The difference was obviously pronounced in group 2. The incontinence cure rate was significantly higher in group 2 (97.4 %) than in group 1 (85.7 %; p?=?0.04).

Conclusions

Our results suggest that mobility of the proximal urethra is associated with a high rate of success of the TVT-O procedure.     

The role of surgical timing in the treatment of thoracic and lumbar spinal tuberculosis

Purpose

To determine the outcome and safety of surgical treatment of thoracic and lumbar spinal tuberculosis in patients without obvious clinical and laboratory improvement after preoperative short-time chemotherapy.

Methods

Data of 86 patients with single-level thoracic and lumbar tuberculosis, treated by one-stage posterior instrumentation combined with anterior radical debridement and fusion, were studied retrospectively. Patients were divided into two groups based on the results of erythrocyte sedimentation rate (ESR) after preoperative 2-week chemotherapy. Surgical outcome and prognosis were compared between the two groups.

Results

After antituberculous chemotherapy for 2 weeks, the ESR did not decrease or even increase in 57 patients (group A), but decreased in 29 patients (group B). However, the ESR decreased gradually after surgery and returned to a normal level at the final follow-up in both groups. Between group A and B, no significant difference was observed in pain improvement (6.3 ± 1.4, 6.4 ± 1.4, respectively, P = 0.805). The corrected angle was 12.4° ± 5.9°, 13.8° ± 6.4°, respectively, for group A and group B (P = 0.305).

Conclusions

It is safe and effective to carry out the surgery just after a short-time antituberculous chemotherapy. And it is the postoperative drugs, not the preoperative drugs, that play an important role in reinforcing the surgical outcome.