RESUMEN
OBJECTIVE(S): The monopolar "Bovie" is used in virtually every laparoscopic operation. The active electrode and its cord emit radiofrequency energy that couples (or transfers) to nearby conductive material without direct contact. This phenomenon is increased when the active electrode cord is oriented parallel to another wire/cord. The parallel orientation of the "Bovie" and laparoscopic camera cords cause transfer of energy to the camera cord resulting in cutaneous burns at the camera trocar incision. We hypothesized that separating the active electrode/camera cords would reduce thermal injury occurring at the camera trocar incision in comparison to parallel oriented active electrode/camera cords. METHODS: In this prospective, blinded, randomized controlled trial, patients undergoing standardized laparoscopic cholecystectomy were randomized to separated active electrode/camera cords or parallel oriented active electrode/camera cords. The primary outcome variable was thermal injury determined by histology from skin biopsied at the camera trocar incision. RESULTS: Eighty-four patients participated. Baseline demographics were similar in the groups for age, sex, preoperative diagnosis, operative time, and blood loss. Thermal injury at the camera trocar incision was lower in the separated versus parallel group (31% vs 57%; P = 0.027). CONCLUSIONS: Separation of the laparoscopic camera cord from the active electrode cord decreases thermal injury from antenna coupling at the camera trocar incision in comparison to the parallel orientation of these cords. Therefore, parallel orientation of these cords (an arrangement promoted by integrated operating rooms) should be abandoned. The findings of this study should influence the operating room setup for all laparoscopic cases.
Asunto(s)
Quemaduras/prevención & control , Colecistectomía Laparoscópica/instrumentación , Electrocoagulación/instrumentación , Piel/patología , Adulto , Quemaduras/etiología , Quemaduras/patología , Colecistectomía Laparoscópica/efectos adversos , Electrocoagulación/efectos adversos , Electrodos/efectos adversos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Método Simple Ciego , Instrumentos Quirúrgicos/efectos adversosRESUMEN
OBJECTIVES: To determine whether the postoperative administration of tryptophan would be beneficial for elderly adults undergoing surgery who are at risk of developing postoperative delirium. DESIGN: Randomized, double-blind, placebo-controlled trial. SETTING: Denver Veterans Affairs Medical Center. PARTICIPANTS: Individuals aged 60 and older undergoing major elective operations requiring a postoperative intensive care unit (ICU) admission (n = 325). INTERVENTION: L-tryptophan, 1 g orally three times a day or placebo was started after surgery and continued for up to 3 days postoperatively. MEASUREMENTS: Delirium and its motor subtypes were measured using the Confusion Assessment Method-Intensive Care Unit (CAM-ICU) and the Richmond Agitation and Sedation Scale. The primary outcome for between-group comparison was the incidence of excitatory (mixed and hyperactive) postoperative delirium. The secondary outcomes for comparison were the incidence and duration of overall postoperative delirium. RESULTS: The overall incidence of postoperative delirium was 39% (95% confidence interval = 34-44%) (n = 116). Seventeen percent of participants in the tryptophan group and 9% in the placebo group had excitatory delirium (P = .18), and the duration of excitatory delirium was 3.3 ± 1.7 days for tryptophan and 3.1 ± 1.9 days for placebo (P = .74). Forty percent of participants in the tryptophan group and 37% in the placebo group had overall delirium (P = .60), and the duration of overall delirium was 2.9 ± 1.8 days for tryptophan and 2.4 ± 1.6 days for placebo (P = .17). CONCLUSION: Postoperative tryptophan supplementation in older adults undergoing major elective operations requiring postoperative ICU admission did not reduce the incidence or duration of postoperative excitatory delirium or overall delirium.
Asunto(s)
Antidepresivos de Segunda Generación/uso terapéutico , Delirio/prevención & control , Complicaciones Posoperatorias/prevención & control , Triptófano/uso terapéutico , Anciano , Delirio/sangre , Delirio/diagnóstico , Método Doble Ciego , Procedimientos Quirúrgicos Electivos , Femenino , Humanos , Unidades de Cuidados Intensivos , Masculino , Melatonina/sangre , Persona de Mediana Edad , Cuidados Posoperatorios , Serotonina/sangre , Triptófano/sangreRESUMEN
IMPORTANCE: More than one-third of all US inpatient operations are performed on patients aged 65 years and older. Existing preoperative risk assessment strategies are not adequate to meet the needs of the aging population. OBJECTIVES: To evaluate the relationship of a history of falls (a geriatric syndrome) to postoperative outcomes in older adults undergoing major elective operations. DESIGN, SETTING, AND PARTICIPANTS: This prospective, cohort study was conducted at a referral medical center. Persons aged 65 years and older undergoing elective colorectal and cardiac operations were enrolled. The predictor variable was having fallen in the 6 months prior to the operation. MAIN OUTCOMES AND MEASURES: Postoperative outcomes measured included 30-day complications, the need for discharge institutionalization, and 30-day readmission. RESULTS: There were 235 subjects with a mean (SD) age of 74 (6) years. Preoperative falls occurred in 33%. One or more postoperative complications occurred more frequently in the group with prior falls compared with the nonfallers following both colorectal (59% vs 25%; P = .004) and cardiac (39% vs 15%; P = .002) operations. These findings were independent of advancing chronologic age. The need for discharge to an institutional care facility occurred more frequently in the group that had fallen in comparison with the nonfallers in both the colorectal (52% vs 6%; P < .001) and cardiac (62% vs 32%; P = .001) groups. Similarly, 30-day readmission was higher in the group with prior falls following both colorectal (P = .04) and cardiac (P = .02) operations. CONCLUSIONS AND RELEVANCE: A history of 1 or more falls in the 6 months prior to an operation forecasts increased postoperative complications, the need for discharge institutionalization, and 30-day readmission across surgical specialties. Using a history of prior falls in preoperative risk assessment for an older adult represents a shift from current preoperative assessment strategies.
Asunto(s)
Accidentes por Caídas/estadística & datos numéricos , Procedimientos Quirúrgicos Electivos/efectos adversos , Procedimientos Quirúrgicos Electivos/mortalidad , Evaluación Geriátrica/métodos , Complicaciones Posoperatorias/mortalidad , Centros Médicos Académicos , Anciano , Anciano de 80 o más Años , Procedimientos Quirúrgicos Cardíacos/efectos adversos , Procedimientos Quirúrgicos Cardíacos/métodos , Estudios de Cohortes , Cirugía Colorrectal/efectos adversos , Cirugía Colorrectal/métodos , Procedimientos Quirúrgicos Electivos/métodos , Femenino , Mortalidad Hospitalaria , Humanos , Masculino , Anamnesis/métodos , Complicaciones Posoperatorias/fisiopatología , Valor Predictivo de las Pruebas , Cuidados Preoperatorios/métodos , Pronóstico , Estudios Prospectivos , Tasa de Supervivencia , Resultado del TratamientoRESUMEN
OBJECTIVE: The purpose of this study was to determine the relationship between the Timed Up and Go test and postoperative morbidity and 1-year mortality, and to compare the Timed Up and Go to the standard-of-care surgical risk calculators for prediction of postoperative complications. METHODS: In this prospective cohort study, patients 65 years and older undergoing elective colorectal and cardiac operations with a minimum of 1-year follow-up were included. The Timed Up and Go test was performed preoperatively. This timed test starts with the subject standing from a chair, walking 10 feet, returning to the chair, and ends after the subject sits. Timed Up and Go results were grouped as fast ≤ 10 seconds, intermediate = 11-14 seconds, and slow ≥ 15 seconds. Receiver operating characteristic curves were used to compare the 3 Timed Up and Go groups to current standard-of-care surgical risk calculators at forecasting postoperative complications. RESULTS: This study included 272 subjects (mean age of 74 ± 6 years). Slower Timed Up and Go was associated with increased postoperative complications after colorectal (fast 13%, intermediate 29%, and slow 77%; P < 0.001) and cardiac (fast 11%, intermediate 26%, and slow 52%; P < 0.001) operations. Slower Timed Up and Go was associated with increased 1-year mortality following both colorectal (fast 3%, intermediate 10%, and slow 31%; P = 0.006) and cardiac (fast 2%, intermediate 3%, and slow 12%; P = 0.039) operations. Receiver operating characteristic area under curve of the Timed Up and Go and the risk calculators for the colorectal group was 0.775 (95% CI: 0.670-0.880) and 0.554 (95% CI: 0.499-0.609), and for the cardiac group was 0.684 (95% CI: 0.603-0.766) and 0.552 (95% CI: 0.477-0.626). CONCLUSIONS: Slower Timed Up and Go forecasted increased postoperative complications and 1-year mortality across surgical specialties. Regardless of operation performed, the Timed Up and Go compared favorably to the more complex risk calculators at forecasting postoperative complications.
Asunto(s)
Procedimientos Quirúrgicos Cardíacos/mortalidad , Técnicas de Apoyo para la Decisión , Procedimientos Quirúrgicos del Sistema Digestivo/mortalidad , Procedimientos Quirúrgicos Electivos/mortalidad , Complicaciones Posoperatorias/diagnóstico , Cuidados Preoperatorios , Caminata/fisiología , Anciano , Anciano de 80 o más Años , Femenino , Estudios de Seguimiento , Humanos , Estimación de Kaplan-Meier , Masculino , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Pronóstico , Estudios Prospectivos , Curva ROC , Medición de Riesgo , Factores de RiesgoRESUMEN
BACKGROUND: Our purpose was to determine the relationship between preoperative frailty and the occurrence of postoperative complications after colorectal and cardiac operations. METHODS: Patients 65 years or older undergoing elective colorectal or cardiac surgery were enrolled. Seven baseline frailty traits were measured preoperatively: Katz score less than or equal to 5, Timed Up and Go test greater than or equal to 15 seconds, Charlson Index greater than or equal to 3, anemia less than 35%, Mini-Cog score less than or equal to 3, albumin less than 3.4 g/dL, and 1 or more falls within 6 months. Patients were categorized by the number of positive traits as follows: nonfrail: 0 to 1 traits, prefrail: 2 to 3 traits, and frail: 4 or more traits. RESULTS: Two hundred one subjects (age 74 ± 6 years) were studied. Preoperative frailty was associated with increased postoperative complications after colorectal (nonfrail: 21%, prefrail: 40%, frail: 58%; P = .016) and cardiac operations (nonfrail: 17%, prefrail: 28%, frail: 56%; P < .001). This finding in both groups was independent of advancing age. Frail individuals in both groups had longer hospital stays and higher 30-day readmission rates. Receiver operating characteristic curves examining frailty's ability to forecast complications were colorectal (.702, P = .004) and cardiac (.711, P < .001). CONCLUSIONS: A simple preoperative frailty score defines older adults at higher risk for postoperative complications across surgical specialties.
Asunto(s)
Procedimientos Quirúrgicos Cardiovasculares , Procedimientos Quirúrgicos del Sistema Digestivo , Anciano Frágil , Evaluación Geriátrica , Complicaciones Posoperatorias , Medición de Riesgo , Anciano , Colon/cirugía , Femenino , Humanos , Tiempo de Internación/estadística & datos numéricos , Modelos Logísticos , Masculino , Readmisión del Paciente/estadística & datos numéricos , Estudios Prospectivos , Curva ROC , Recto/cirugíaRESUMEN
BACKGROUND: The purpose of this study was to compare histologic evidence of thermal injury at the epigastric and umbilical incisions after elective laparoscopic cholecystectomy performed using the monopolar "Bovie" instrument set on the higher voltage coag mode versus the lower voltage blend mode. We hypothesized that the higher voltage coag mode would create more unintended thermal tissue injury at the epigastric trocar's incision. METHODS: A prospective blinded randomized controlled trial of patients undergoing elective laparoscopic cholecystectomy was performed. Patients were randomized to have their operation performed with the monopolar instrument set at 30 W on either the coag mode or the blend mode. Immediately at the end of the operation, a biopsy sample of skin was obtained from the lower edge of the epigastric incision (through which the monopolar instrument was inserted) and the umbilical incision (through which the camera/telescope was inserted). The outcomes measured were histologic evidence of thermal injury at the epigastric and umbilical incisions (determined by a blinded pathologist). RESULTS: Forty patients were randomized (20 per group). Baseline demographics in the two groups were similar for age, gender, body mass index, preoperative diagnosis, operative time, and blood loss. Unintentional thermal injury was found at 20 % of epigastric incisions and 35 % of umbilical incisions in the total group. The incidence of thermal injury was higher after operations using the coag mode compared to the blend mode at both the epigastric (35 vs. 5 %; p = 0.044) and umbilical (55 vs. 15 %; p = 0.019) trocar incisions. CONCLUSIONS: Radiofrequency energy from the monopolar Bovie instrument causes unintentional thermal injury to skin adjacent to the epigastric and umbilical trocar incisions. The incidence of thermal injury was reduced by using the lower voltage blend mode compared to the coag mode at both the epigastric and umbilical trocar incisions. REGISTRATION NUMBER: NCT016648060 ( www.clinicaltrials.gov ).
Asunto(s)
Quemaduras por Electricidad/etiología , Quemaduras por Electricidad/prevención & control , Colecistectomía Laparoscópica/efectos adversos , Colecistectomía Laparoscópica/instrumentación , Electrocirugia/efectos adversos , Adulto , Quemaduras por Electricidad/patología , Procedimientos Quirúrgicos Electivos/efectos adversos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Tempo Operativo , Estudios Prospectivos , Instrumentos Quirúrgicos , Ombligo/cirugíaRESUMEN
OBJECTIVES: (1) To determine if antenna coupling occurs in common operating room scenarios. (2) To define modifiable clinical variables that reduce the magnitude of antenna coupling. BACKGROUND: Mechanisms of electrosurgical burns where monitoring devices contact the surgical patient are unclear. Antenna coupling occurs when the "bovie" active electrode (electrically active transmitting antenna) emits energy, which is captured by a nonelectrically active wire (electrically inactive receiving antenna) in close proximity without direct contact. METHODS: Monopolar radiofrequency energy was delivered to a laparoscopic instrument (electrically active transmitting antenna), whereas other nonelectrically active wires (electrically inactive receiving antenna) including electrocardiogram (EKG) lead, nonactive "bovie" pencil, and nerve electrode monitor were placed in proximity. Temperature changes of tissue placed adjacent to the electrically inactive receiving antennae were measured. RESULTS: Nonelectrically active wires (receiving antenna) increase tissue temperature when lying parallel to the active electrode cord: EKG pad 2.4°C ± 1.2°C (P = 0.002), "bovie" pencil tip 90°C ± 9°C (P < 0.001), and nerve electrode monitor 106°C ± 12°C (P < 0.001). Factors that reduced the heat generated by antenna coupling included the following: increasing angulation between transmitting and receiving antennae (parallel = 90°C ± 9°C; 45° angle = 53°C ± 10°C; perpendicular = 35°C ± 11°C; P < .001), increasing separation distance between parallel transmitting and receiving antenna (<1 cm = 90°C ± 9°C; 15 cm = 44°C ± 18°C; 30 cm = 39°C ± 2°C; P < .001); and decreasing generator power setting (15 W = 59°C ± 11°C; 30 W = 90°C ± 9°C; 45 W = 98°C ± 8°C; P < .001). CONCLUSIONS: Antenna coupling occurs in common operating room scenarios. Simple, practical measures by the surgeon, such as orienting the receiving antenna at a greater angle and with greater separation to the active electrode cord, or lowering the generator power setting reduce antenna coupling.
Asunto(s)
Quemaduras por Electricidad/etiología , Electrocirugia/efectos adversos , Laparoscopía/efectos adversos , Temperatura Corporal , Quemaduras por Electricidad/prevención & control , Electrodos , Humanos , Complicaciones Intraoperatorias , QuirófanosRESUMEN
BACKGROUND: Preoperative risk stratification is commonly performed by assessing end-organ function (such as cardiac and pulmonary) to define postoperative risk. Little is known about impaired preoperative cognition and outcomes. The purpose of this study was to evaluate the impact of baseline impaired cognition on postoperative outcomes in geriatric surgery patients. STUDY DESIGN: Subjects 65 years and older undergoing a planned elective operation requiring postoperative ICU admission were recruited prospectively. Preoperative baseline cognition was assessed using the validated Mini-Cog test. Impaired cognition was defined as a Mini-Cog score of ≤ 3. Delirium was assessed using the Confusion Assessment Method-ICU by a trained research team. Adverse outcomes were defined using the Veterans Affairs Surgical Quality Improvement Program definitions. RESULTS: One hundred and eighty-six subjects were included, with a mean age of 73 ± 6 years. Eighty-two subjects (44%) had baseline impaired cognition. The impaired cognition group had the following unadjusted outcomes: increased incidence of 1 or more postoperative complications (41% vs 24%; p = 0.011), higher incidence of delirium (78% vs 37%; p < 0.001), longer hospital stays (15 ± 14 vs 9 ± 9 days; p = 0.001), higher rate of discharge institutionalization (42% vs 18%; p = 0.001), and higher 6-month mortality (13% vs 5%; p = 0.040). Adjusting for potential confounders determined by univariate analysis, logistic regression found impaired cognition was still associated with the occurrence of 1 or more postoperative complications (odds ratio = 2.401; 95% CI, 1.185-4.865; p = 0.015). Kaplan-Meier survival analysis revealed higher mortality in the impaired cognition group (log-rank p = 0.008). CONCLUSIONS: Baseline cognitive impairment in older adults undergoing major elective operations is related to adverse postoperative outcomes including increased complications, length of stay, and long-term mortality. Improved understanding of baseline cognition and surgical outcomes can aid surgical decision making in older adults.
Asunto(s)
Trastornos del Conocimiento/complicaciones , Complicaciones Posoperatorias/etiología , Anciano , Procedimientos Quirúrgicos Electivos , Femenino , Humanos , Incidencia , Masculino , Complicaciones Posoperatorias/epidemiología , Estudios ProspectivosRESUMEN
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.
Asunto(s)
Ablación por Catéter/instrumentación , Laparoscopios , Fenómenos Electromagnéticos , CalorRESUMEN
BACKGROUND: This study aimed to quantify the clinical parameters of mono- and bipolar instruments that inhibit pacemaker function. The specific aims were to quantify pacer inhibition resulting from the monopolar instrument by altering the generator power setting, the generator mode, the distance between the active electrode and the pacemaker, and the location of the dispersive electrode. METHODS: A transvenous ventricular lead pacemaker overdrive paced the native heart rate of an anesthetized pig. The primary outcome variable was pacer inhibition quantified as the number of beats dropped by the pacemaker during 5 s of monopolar active electrode activation. RESULTS: Lowering the generator power setting from 60 to 30 W decreased the number of dropped paced events (2.3 ± 1.2 vs 1.6 ± 0.8 beats; p = 0.045). At 30 W of power, use of the cut mode decreased the number of dropped paced beats compared with the coagulation mode (0.6 ± 0.5 vs 1.6 ± 0.8; p = 0.015). At 30 W coagulation, firing the active electrode at different distances from the pacemaker generator (3.75, 7.5, 15, and 30 cm) did not change the number of dropped paced beats (p = 0.314, analysis of variance [ANOVA]). The dispersive electrode was placed in four locations (right/left gluteus, right/left shoulder). More paced beats were dropped when the current vector traveled through the pacemaker/leads than when it did not (1.5 ± 1.0 vs 0.2 ± 0.4; p < 0.001). CONCLUSIONS: Clinical parameters that reduce the inhibition of a pacemaker by monopolar instruments include lowering the generator power setting, using cut (vs coagulation) mode, and locating the dispersive electrode so the current vector does not traverse the pacemaker generator or leads.