[Measuring core body temperature--a methodological challenge?].
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Body Temperature↗
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Results for “Monitoring, Intraoperative”
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[Temperature measurement in the ear canal: comparison of an infrared thermometer with conventional temperature probes and evaluation of clinical factors on infrared measurement].
PURPOSE: We compared the readings of the GENIUS 3000A FirstTemp infrared thermometer with a conventional temperature probe (MON-A-THERM tympanic) placed in contact with the tympanic membrane. We also systematically evaluated user-dependent factors influencing the infrared readings. METHODS: In 100 postoperative patients we investigated the repeatability of the infrared measurements and the agreement with tympanic thermocouple probes in the contralateral ear regarding the degree of auditory canal contamination. In 20 volunteers we evaluated the influence of three factors: interval between consecutive measurements, dwell time in the auditory canal before reading the temperature, and positioning of the grip. Finally, we compared the infrared readings in the same ear of 20 different users who were not familiar with this new method. RESULTS: Comparison with the tympanic contact probes revealed a mean difference of -0.67 degree C (+/-0.65 degree C 2 SD). The infrared thermometer significantly underestimated the temperature of the thermocouple probes. Repeatability was +/-0.3 degree C. The presence of cerumen in the auditory canal had no influence on the infrared readings. Shortening of the interval between two consecutive readings (30 and 60 s.) led to increasing differences between the two measurements with the second reading decreasing. After positioning the infrared thermometer in the auditory canal 5 seconds before taking temperatures, the recorded temperatures were significantly lower compared to the immediate temperature recordings. Rotation of the device out of the telephone handle position led to an increasing lack of agreement between infrared thermometry and thermistor probes. In 20 inexperienced operators agreement with the thermocouple probe was -0.80 degree C (+/-0.60 degree C 2 SD) and repeatability was +/-0.6 degree C. CONCLUSION: Although easy to use, infrared thermometry requires careful handling and experienced users. To get optimal recordings, the time between consecutive measurements should not be less than 90 seconds. Recordings should be taken immediately after positioning the device in the auditory canal. Best results are obtained when the grip of the device follows the ramus mandibulae like a telephone handle. The lower readings of the infrared thermometer compared to tympanic contact-probes indicate that the obtained readings represent the temperature of the auditory canal rather than of the tympanic membrane itself.
Ear Canal↗
[The role of mixed venous oxygen saturation in perioperative monitoring and therapy. A critical stock taking].
Since mixed venous oxygen saturation (SvO2) depends on O2-supply and O2-consumption, its measurement is said to indicate tissue O2-balance and to be suitable for ensuring tissue oxygenation in critically ill patients. Blood for SvO2 determinations should be drawn exclusively from the pulmonary artery, because mixing of systemic venous blood is incomplete in the right atrium and ventricle. SvO2 can be determined in vitro and in vivo. Current in vivo techniques determine oxygen saturation from the relation between light emitted into the blood stream and that reflected from blood cells, the use of 3 instead of 2 wavelengths greatly improving the accuracy of the method. For reasonable interpretation of SvO2 it is necessary to consider the concentration of haemoglobin and its derivatives, shifts of the O2-dissociation curve, intracardiac left-to-right shunts, and systemic arteriovenous shunts. Disturbances of macrocirculation (e.g. vascular surgery) and microcirculation (e.g. sepsis) also impair the diagnostic value of SvO2 determinations. The critical value of SvO2 appears to depend on the prevailing disease. Patients with chronically impaired O2 transport appear to tolerate very low SvO2 values better than acutely ill patients, presumably due to adaptive changes in the former group. Central venous oxygen saturation may indicate directional changes of the SvO2, but does not estimate the real SvO2-value. The hypothesis that continuous SvO2 measurements improve prognosis or lower treatment costs has not yet been confirmed. Measurements of mixed venous oxygen saturation may improve monitoring and treatment of critically ill patients in selected cases; however, these measurements are not suitable to indicate reliably the status of tissue oxygenation under all conditions.
Humans↗
Iatrogenic impairment of hearing during surgery for acoustic neuroma.
Isolated or combined labyrinthine, neural, and vascular damage account for failure to preserve hearing during removal of acoustic neuromas. However, the specific mechanisms of auditory impairment remain unclear unless surgical maneuvers can be related to peri- and postoperative hearing on the basis of intraoperative monitoring of auditory function.Among the different auditory monitoring techniques, recording of cochlear nerve action potentials (CNAPs) from the intracranial portion of the nerve has proven particularly useful for identifying the mechanisms of iatrogenic auditory injury.The present investigation analyzes intra- and postoperative auditory impairment in relation to surgical steps in a group of 38 subjects with acoustic neuroma (size ranging from 5 to 24 mm) undergoing removal via a retrosigmoid approach.Coagulation close to the cochlear nerve, drilling of the internal auditory canal, and removal of the intrameatal portion of the acoustic neuroma have prove to be the most critical surgical steps in hearing preservation.Changes were correlated with intra- and extrameatal tumor size, the relationship between the internal auditory canal and vestibule, and internal auditory canal enlargement, anatomic involvement of the cochlear nerve, preoperative auditory level, and ABR and ENG test findings.Changes in CNAP morphology and latency are detailed, and mechanisms of injury are analyzed and discussed as a function of these variables.
Journal Article↗
[Endoscopic transthoracic sympathectomy in a paraneoplastic Raynaud's syndrome].
Six months after nephrectomy for renal-cell carcinoma and during treatment with interferon-alpha and vinblastin, a 70-year-old patient developed necrotizing Raynaud's phenomenon in both hands (at first: pain, livid skin and hyperhidrosis; later: painful acral ulcers; finally: trophic changes plus almost complete impairment of mobility and fine movements in both hands). These changes persisted even after the end of chemotherapy and despite several months on aspirin, naftidrofuryl, nitrates and glucocorticoids, so that the patient's general health was seriously affected. Because repeated sympathetic blocks were efficacious for brief periods, bilateral transthoracic endoscopic sympathectomy (TES) was performed. The patient became free of pain at once, the acral ulcers healed within a few weeks and he could again use his hands. Until his death from advanced metastases 10 months later the Raynaud's phenomenon did not recur. This case suggests that sympathetic vasoconstriction is apparently involved in the maintenance and progression of malignant neoplasm-associated Raynaud's phenomenon. TES is recommended as a reasonable palliative measure in patients with limited life expectancy, as long as preceding sympathetic blockage has indicated likely success and the procedure is performed under intraoperative monitoring of acral and facial skin temperature.
Aged↗
Minimally invasive aortic valve replacement: echocardiographic and clinical results.
BACKGROUND: Port access has been described for mitral and bypass surgery. The purpose of this study was to review the clinical and echocardiographic outcomes of aortic valve replacement by use of port access. METHODS: Between 1996 and 1999, 153 port-access aortic valve replacements were performed at our institution. The mean age was 63 years (range 16-91 years); 58% were male. The New York Heart Association mean class was III; 18% were in class IV. Thirteen percent had diabetes, 42% hypertension, 7% prior transient ischemic episode or stroke, 7% lung disease, 3% renal failure, and 13% previous surgery. Echocardiograms were obtained after valve replacement in 125 patients (96 intraoperative transesophageal and 97 transthoracic echoes). RESULTS: Median length of stay was 8 days. There were no intraoperative deaths; 10 patients (6.5%) died in the postoperative period. Stroke occurred in 4 (2.6%), sepsis in 5 (3.3%), renal failure in 5 (3.3%), pneumonia in 3 (2%), and wound infection in 1 (0.7%). Tissue prosthesis was present in 83 and a mechanical prosthesis in 42. No or trace regurgitation was seen on 94 of 96 (98%) postbypass intraoperative echocardiograms and mild on 2. On follow-up echocardiograms, moderate regurgitation was seen in 4 of 97 (4.1%), mild-to-moderate in 2 (2.1%), mild in 18 (18.6%), and no or trace in 71 (73.2%). Of those who had aortic regurgitation on intraoperative or follow-up echocardiograms, it was paravalvular in 8. CONCLUSIONS: Minimally invasive aortic valve replacement with a port-access approach is feasible, even in high-risk patients. Small incisions, a low infection rate, and a short length of stay are attainable. However, the complications associated with traditional aortic valve replacement still occur. Echocardiography is valuable both for intraoperative monitoring and follow-up of this new procedure.
Adolescent↗
Management of pararenal aneurysms of the abdominal aorta.
The operative treatment of 77 patients with atherosclerotic aneurysms of the pararenal aorta (54 juxtarenal and 23 suprarenal) is analyzed. Repair of these complex lesions is formidable because of difficult exposure, renal ischemia and myocardial strain as a result of proximal aortic occlusion, and associated renal atherosclerosis with secondary renal functional impairment. Nineteen (25%) patients were normotensive with normal renal function. Sixteen patients (21%) had hypertension alone and 42 (54%) were hypertensive with abnormal renal function. There were multiple renal arteries in 22% of patients. Aortic reconstruction involved infrarenal graft in 27 patients (35%), infrarenal graft plus pararenal aortic endarterectomy (TEA) in 26 (34%), and infra- and pararenal aortic graft in 24 (31%). Twenty-two patients (30%) had normal renal arteries and therefore no renal reconstruction. Of the 55 patients who required combined aortic and renal artery repair, 24 required renal artery repair because of involvement of the renal arteries by the aneurysm and 31 because of atherosclerotic renal artery disease. TEA was the most common technique of renal artery repair (54 of 93 arteries, 58%), followed by reimplantation (18 arteries) and prosthetic graft (13). The perioperative mortality rate was 1.3%. The perioperative morbidity rate was 28% and consisted principally of renal insufficiency (23%). This was usually transient (44%) and (89%) mild. Renal morbidity was adversely affected by renal ischemia status, severity of renal artery disease and extent of renal revascularization. Following reconstruction, hypertension was cured or improved in 77% of patients and abnormal renal function was cured or improved in 46% and stabilized in an additional 39% of patients. These results show that combined aortic aneurysm repair and renal artery reconstruction can be performed with minimal mortality and an acceptable morbidity. Aggressive intraoperative monitoring is necessary to minimize myocardial complications. Careful attention must be paid to the technical details of the reconstruction, especially in minimizing renal ischemia, to reduce the subsequent incidence of renal function deterioration.
Aged↗
Silent myocardial ischemia monitoring predicts late as well as perioperative cardiac events in patients undergoing vascular surgery.
In a previous study we have shown that perioperative monitoring for silent myocardial ischemia can noninvasively identify those patients undergoing peripheral vascular surgery who are at significantly increased risk for perioperative myocardial infarction. In the present study a group of 385 patients undergoing peripheral vascular surgery was studied long-term as well as short-term to determine whether perioperative monitoring for silent ischemia can identify those patients who are at significantly increased risk of late cardiac death or late cardiac complications as well as those patients at increased risk of perioperative myocardial infarction. All patients were monitored before, during, and after operation and were divided into two groups on the basis of results of monitoring: patients whose total duration of silent ischemia as a percentage of the total duration of perioperative monitoring was 1% or greater (group I, n = 120) and those for whom this value was less than 1% (group II, n = 265). Among patients in group I 13.3% (16 of 120) suffered a perioperative myocardial infarction in contrast to only 1.1% (3 of 265) patients in group II (p less than 0.001). Multivariate logistic regression analysis of preoperative and perioperative characteristics showed that the presence of a total perioperative percent time ischemic 1% or greater and age were the only significant predictors of perioperative myocardial infarction.(ABSTRACT TRUNCATED AT 250 WORDS)
Aged↗
Peripheral arterial embolization: Doppler ultrasound scan diagnosis.
Use of intraoperative monitoring with transcranial Doppler scanning during carotid endarterectomy has enabled identification of embolus signals in the ultrasound spectrum. Extension of this technique to preoperative screening has enabled identification of actively embolizing lesions and correlation with neurologic deficits. We report embolus signals in the peripheral circulation before operation, which aided diagnosis and decision to operate. The patient had been transferred from another institution after multiple revascularization procedures, including posterior tibial artery thrombectomy. Angiography performed on arrival at our institution confirmed an open bypass graft, although a small indentation was noted at the site of the previous posterior tibial artery thrombectomy. Runoff was intact to the plantar arch where there was attenuation of that vessel and occlusion of most digital branches. Duplex monitoring revealed no embolic signals in the graft or in the posterior tibial artery proximal to the previous arteriotomy. Distal to this site, embolic signals were detected. At the time of operation, a large platelet thrombus was identified at the site of the previous arteriotomy, and platelet thrombus was obtained from the plantar artery. It is concluded that doppler ultrasound scanning enables detection of peripheral embolization and the identification and location of lesions with such embolic activity. Diagnostic accuracy may be improved when there is clinical suspicion of embolization, enabling better patient selection for surgical procedures. This report provides the first clinicopathologic characterization of the emboli detected.
Amputation, Surgical↗
An endoscopic pedicle probe: preliminary development.
Insertion of pedicle screws in the thoracolumbar spine can be challenging. Incorrect placement can lead to a failure of fusion or to significant neurologic morbidity. Recently, techniques utilizing intraoperative monitoring and stereotaxis have been developed to achieve proper screw placement. While these techniques may be accurate, they are expensive and may require additional operating room personnel. We have developed an endoscopic pedicle probe for placement of pedicle screws that may overcome some of these limitations. A small 1.2 mm endoscope was adapted to fit within a hollow pedicle probe. Irrigation was provided via a separate channel within the endoscope. Images from the probe were displayed both on a monitor screen and on a heads up display. The endoscopic probe was used to probe 36 sawbone and 22 cadaver thoracolumbar pedicles. After cannulation each specimen was examined to assess nonvisualized pedicle perforation. In sawbones, perforation was visualized endoscopically in 3 pedicles (8%) with no further perforations found on later direct examination. In cadavers the cortical cancellous interface was adequately visualized and no perforations occurred. These preliminary results suggest that the endoscopic probe may have utility in the placement of thoracolumbar pedicle screws.
Bone Screws↗
Bilateral infraorbital nerve block is superior to peri-incisional infiltration for analgesia after repair of cleft lip.
Cleft lip repair is a common operation in infants and requires that the child is pain-free during the postoperative period so that handling does not affect the integrity of the delicate surgical site. This study was designed to compare the efficacy and duration of effect of 0.125% bupivacaine given preoperatively as a bilateral infraorbital nerve block with peri-incisional infiltration of the same local anaesthetic for postoperative analgesia in cleft lip repair. It was a randomised, double blind, prospective study in 30 children aged 4-20 months (ASA grade 1). After a standard induction, group A (n = 15) were given a bilateral infraorbital nerve block with 0.125% bupivacaine and group B (n = 15) had peri-incisional infiltration with the same solution. No additional systemic analgesics were given before or during the operation. Intraoperative monitoring comprised measurement of heart rate and blood pressure and post-operatively pain relief was recorded using a behavioural pain relief score. The heart rate, respiratory rate, and blood pressure were also monitored at 0, 1, 2, 4, 8, and 24 hours after tracheal extubation. The results showed that group A had significantly better pain relief (higher scores) than group B for eight hours postoperatively (p < 0.05). The analgesic requirement in group B became significant at two hours postoperatively, while group A had significant analgesic requirements only after eight hours. The significant rise in heart rate and blood pressure that accompanied tracheal intubation in both groups suggested that while both methods of analgesia may be adequate to prevent responses to skin incision, they do not substitute for adequate systemic analgesia during the operation. We conclude that infraorbital nerve block with 0.125% bupivacaine provides better and more prolonged analgesia than peri-incisional infiltration in cleft lip repair.
Analgesia↗
A virtual instrument (VI) for haemodynamic management in ICU and during surgery.
Systolic pressure variations (SPV) during mechanical ventilation and its single components, related to short apnea, reflect changes of the volemic condition of the patient. To introduce their determination during clinical monitoring for different fluid states and for different tidal volumes, they must be computed on-line without introducing interference with standard activities. A system computing on-line systolic pressure variation during mechanical ventilation, connected to standard monitoring devices, has been proposed. It is based on a notebook PC implemented with graphical software comprising a user panel in the form of a virtual instrument and is able to acquire, process and present signals from different instruments utilized in ICU and during surgery. It can be used as a base to assess the ability of computed parameters helpful in clinical decision. The use of a notebook PC and open software allows operators, even if non-expert in computer science, to test and implement this, as well as other innovative tools in clinical practice.
Blood Pressure Determination↗
Captopril improves oxygen and glucose extraction in pig hearts during reperfusion after cold cardioplegic storage.
The purpose of this study was to evaluate the haemodynamic and metabolic effects of captopril during reperfusion of pig hearts following 360 min global hypothermic cardioplegia and storage (HCS). The hearts were perfused with one litre of cold crystalloid cardioplegia (Bretschneider solution no. 3), excised and stored in saline at 4 degrees C for 360 min. The hearts were then reperfused with blood in a modified Langendorff model for 60 min. Left ventricular function, myocardial blood flow, and arteriovenous differences in oxygen, glucose and lactate were monitored intraoperatively and during reperfusion. Two groups of hearts were studied. Group I (captopril treated, n = 9): the pigs were pre-medicated with increasing oral doses of captopril for 3 weeks (12.5 mg-150 mg daily) and an intravenous dose (25 mg) upon arrival at the laboratory. Captopril was added to the cardioplegia (1000 microg/l) and to the reperfusion media (1000 microg/l). Group II (controls, n = 8): the pigs were given no premedication, captopril-free cardioplegia and the hearts were reperfused with captopril-free blood. Captopril increased myocardial oxygen and glucose extraction during reperfusion (p < 0.05 for both) while lactate remained unchanged after 360 min HCS. Treatments with captopril increased developed left ventricular pressure (DLVP) and relaxation (-dP/dtmax) during reperfusion (p < 0.05 for both), while contractility (+dP/dtmax) was unchanged. Heart rate was reduced in captopril-treated hearts (p < 0.05) while myocardial blood flow (MBF) was similar in the two groups. Captopril administration prior to and during HCS and postcardioplegic reperfusion improves oxygen and glucose extraction in large spontaneously beating porcine hearts during reperfusion. The underlying mechanisms seem to involve metabolic modulation, since myocardial uptake of oxygen and glucose was increased in the absence of changes in myocardial blood flow.
Angiotensin-Converting Enzyme Inhibitors↗
Single-center comparison of purely laparoscopic, hand-assisted laparoscopic, and open radical nephrectomy in patients at high anesthetic risk.
BACKGROUND AND PURPOSE: The laparoscopic approach for management of high-risk patients with renal-cell carcinoma (RCC) may reduce perioperative and postoperative morbidity. The aim of this study was to compare the outcome of purely laparoscopic radical nephrectomy (LRN), hand-assisted laparoscopic radical nephrectomy (HALRN), and open radical nephrectomy (ORN) for renal tumors in a population of patients at high risk for perioperative complications. PATIENTS AND METHODS: All patients undergoing radical nephrectomy for presumed RCC between August 1999 and August 2001 at Vanderbilt University Medical Center and having an American Society of Anesthesiologists (ASA) score of >/=3 were reviewed. Patients with known metastasis, local invasion, caval thrombi, or additional simultaneous surgical procedures were excluded from analysis. Thirteen patients underwent LRN, eight patients underwent HALRN, and 26 underwent ORN. The patient demographics were similar in the three groups. The groups were compared with regard to intraoperative and postoperative parameters. Statistical analysis was done using chi-square testing for categorical variables and analysis of variance (ANOVA) for continuous variables. Differences in outcomes were examined using ANOVA and Dunnett's T for pairwise comparisons. RESULTS: The ASA 4 patients had significantly longer hospital stays and total hospital costs than the ASA 3 patients. The mean operative time in the ASA 3 patients was similar in the three groups: 2.8 hours, 2.8 hours, and 2.5 hours for the LRN, HALRN, and ORN patients, respectively. Both the LRN patients (22.9 mg of morphine sulfate equivalent) and the HALRN patients (42.1 mg) required less pain medication than the open surgery patients (97.7 mg). When the total hospital costs were compared, LRN was less costly than HALRN ($6089 v $7678; P = 0.57) and open surgery ($6089 v $7694; P = 0.04). The complication rate in the LRN, HALRN, and ORN group was 0%, 25%, and 27%, respectively, although the differences were not statistically different (P = 0.12). CONCLUSIONS: Both LRN and HALRN can be performed safely in patients with significant comorbid conditions. Careful preoperative preparation, intraoperative monitoring, and awareness of laparoscopy-induced oliguria can preclude inadvertent overhydration, hemodilution, and congestive heart failure. Both LRN and HALRN result in less pain medication requirement and faster return to oral intake than ORN, and LRN results in fewer perioperative complications than HALRN or ORN in patients at high perioperative risk. The LRN technique has a 21% lower total cost than both HALRN and ORN.
Adult↗
Craniofacial hyperhidrosis treated with video endoscopic sympathectomy.
Craniofacial hyperhidrosis as well as palmar hyperhidrosis is an abnormal state of local excessive sweating of unclear etiology. The hyperhidrosis may be isolated in the craniofacial region or associated with palmar hyperhidrosis. The patient's face is so wet with sweat that their daily activities are often seriously disturbed. To the best of our knowledge, there has been no satisfactory medical therapy, nor any effective surgical treatment reported in the literature. In 1991, we started to treat a patient with such distress using endoscopic ablation of the sympathetic T2 segment, because we mastered the technique after treating a large series of palmar hyperhidrosis patients. Furthermore, we were impressed by concomitant reduction of craniofacial sweating after T2-3 sympathectomy resulting from the relatively different domination of sympathetic supply between the eye and face. It appears possible to relieve excessive sweating of the head and face, without producing ptosis or miosis by ablation of the T2 segment. During the past 2 years, 7 patients with severe craniofacial hyperhidrosis have been successfully treated with the method and all obtained a satisfactory result. No complete Horner's syndrome has been produced except in one patient, who showed a mild and transient left eye ptosis, in whom coagulation of the sympathetic trunk higher than the T2 segment was performed. Intraoperative monitoring of forehead skin perfusion and observation of the change of pupillary size is emphasized during the lesion making. The longest postoperative follow-up was 2 years, with a mean follow-up of 12.4 months.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
The use of two continuous glucose sensors during and after surgery.
BACKGROUND: Maintaining plasma glucose between 80 and 120 mg/dL is beneficial for patients admitted to a surgical intensive care unit, but requires frequent glucose monitoring to ensure adequacy of treatment and detection of hypoglycemia. We examined whether continuous glucose sensing is feasible and reliable during and after major surgical procedures using two commercially available sensors. METHODS: Eight patients undergoing abdominal surgery were studied. A CGMS device (Medtronic MiniMed, Northridge, CA) and a GlucoDay device (A. Menarini Diagnostics, Florence, Italy) were placed in the shoulder region, and a second GlucoDay device was placed in the upper leg. Blood glucose was measured every 15 min for a total duration of 12 h. RESULTS: Technical failure of the CGMS was observed peroperatively more frequently than postoperatively (66% of all time points vs. 18%, P < 0.001). Technical failure of the GlucoDay device occurred most frequently in the GlucoDay placed in the upper leg (64% vs. 17%, P < 0.001). Accuracy of all three sensors was comparable peroperatively (74%, 76%, and 63% of values in Zone A of the Clarke error grid for the CGMS, GlucoDay shoulder, and GlucoDay upper leg, respectively, P = 0.2). Postoperatively, better accuracy was observed in both sensors placed in the shoulder compared with the GlucoDay placed in the upper leg (73%, 69%, and 51% of values in Zone A for the CGMS, GlucoDay shoulder, and GlucoDay upper leg, respectively, P < 0.001). CONCLUSIONS: Technical performance and accuracy of continuous glucose sensors need improvement before continuous glucose sensors can be used to monitor strict glycemic control during and after surgery.
Adult↗
Untoward cardiac changes during CO2 insufflation in laparoscopic cholecystectomies in low-risk patients.
In the past decade, laparoscopic cholecystectomy has become the gold standard treatment for gallbladder disease. A debate has arisen about using CO2 to distend the abdomen because of negative effects on venous return to the heart and declining cardiac output. Some authors have supported the use of pulmonary artery catheters for intraoperative monitoring while others have recommended gasless techniques to avoid these negative effects for high-risk patients. In this study, four cases of bradycardia and/or asystole during CO2 pneumoinsufflation at the beginning of planned, elective laparoscopic cholecystectomies are described. These patients were ASA category II, without history of cardiac disease. To determine the frequency and any underlying common denominators, we analyzed these laparoscopic cholecystectomies. Each patient experienced bradycardia shortly after the start of the laparoscopic cholecystectomy. None had known cardiac disease or symptoms. Two were on antihypertensive medications, and one had experienced an episode of unexplained bradycardia 6 years earlier. These cases occurred during 725 laparoscopic cholecystectomies (0.6% approximately). Using the senior author's conversion rate of 10% to open cholecystectomies, the entire group would be approximately 800, and the risk of bradycardia upon induction of CO2 is 4 per 800, or 0.5%. Although cardiovascular changes were noted during laparoscopic gynecologic surgery approximately 20 years ago, only in the last few years have cardiovascular changes been reported during laparoscopic cholecystectomies. This study reviews four cases of bradycardia during CO2 insufflation in patients that were considered to be low-risk. Surgeons should be prepared to encounter such cardiovascular changes even with low-risk patients.
Adult↗
Continuous intravascular blood gas monitoring: development, current techniques, and clinical use of a commercial device.
This review focuses on the development, current techniques, and clinical use of continuous intravascular blood gas monitoring (CIBM) devices in anaesthesia and intensive care. The operating principles, range of application, performance, limitations, costs, and impact on patient treatment and outcome, are discussed. Studies of early and currently available CIBM devices were analysed. At present, the Paratrend 7+ (PT7+) for adults and Neotrend (NT) for newborns are the only commercially available CIBM systems. The PT7+ contains three optical sensors to measure PO(2), PCO(2) and pH, as well as a thermocouple to measure temperature. The NT is a modification of the PT7+ to continuously monitor PO(2), PCO(2), pH and temperature in newborns. Under laboratory conditions, good performance over a wide range of blood gas values was observed with the Paratrend 7 (PT7. Performance in the clinical setting was not as satisfactory, especially for PO(2) values. However, the performance and accuracy of CIBM devices appear to be sufficient for clinical use and they are being used clinically in selected patient groups. Several factors affecting the performance of CIBM are considered.
Adult↗