Nileshkumar Patel

Simulated clinical evaluation of conventional and newer fluid-warming devices

The purpose of the study was to evaluate the ability of five commercially available devices utilizing a variety of heat exchange technologies to deliver normothermic (37 degrees C) fluids.Conditions of slow (6.5 mL/min), moderate (13-25 mL/min), and rapid (gravity and pressure driven flows, roller clamp wide open) infusion were simulated. Fluid temperatures were measured using rapid response thermistors after the fluid exited the heat exchanger (T outlet) and before delivery to the patient intravenously (IV) (T distal). Devices tested were the FW537, H1000, Hotline Trademark, BairHugger Registered Trademark, and Flotem IIe. Fluids tested were crystalloid at room temperature and red cells diluted with saline (11-19 degrees C). At slow and moderate flows, T distal of crystalloid was between 35.3 and 37.9 degrees C for Hotline Trademark at 42 degrees C, 33.8 and 37.7 degrees C for H1000 at 42 degrees C, 29.4 and 34.2 degrees C for BairHugger Registered Trademark, 26.1 and 31.5 for Flotem IIe, and 23.8 and 32.1 for FW537 at 42 degrees C. With gravity and pressure driven flows, T distal of crystalloid were 39.0 and 38.9 for H1000 at 42 degrees C, 38.7 and 38.4 degrees C for FW537 at 42 degrees C, 34.7 and 28.9 degrees C for Hotline Trademark at 42 degrees C, 29.2 and 24.2 degrees C for BairHugger Registered Trademark, and 29.7 and 24.2 degrees C for Flotem. In conclusion, only the H1000 at 42 degrees C was effective at delivering normothermic fluids at all clinically relevant flow rates. The Hotline Trademark at 42 degrees C was effective at slow and moderate flow, whereas the FW537 was effective only at rapid flow. (Anesth Analg 1996;82:517-24)

Comparison of esophageal, tympanic, and forehead skin temperatures in adult patients

STUDY OBJECTIVE To compare esophageal, tympanic membrane, and forehead skin temperatures in patients undergoing elective surgeries. DESIGN Prospective clinical study. SETTING Operating room and postanesthesia care unit of a tertiary care teaching hospital. PATIENTS 40 adult ASA status I, II and III patients requiring anesthesia and surgery. INTERVENTION Application of crystalline thermometry strips to the forehead of patients. MEASUREMENTS AND MAIN RESULTS Concurrent forehead skin, tympanic membrane, and lower esophageal temperatures were measured and compared. The overall bias between esophageal and skin temperatures was 0.3 degrees C, between tympanic membrane and skin was 0.5 degrees C, and between esophageal and tympanic membrane was -0.1 degrees C The limits of agreement (precision) between esophageal and skin temperatures were: -1.64 degrees C to +2.32 degrees C, between esophageal and tympanic membrane were: -1.02 degrees C to +0.74, and between tympanic membrane and skin were: -1.48 degrees C to +2.52 degrees C. There was no significant relation between the change in skin temperature and change in esophageal temperature, whereas there was a weak linear relation between change in skin temperature and change in tympanic membrane temperature (y = -0.03 + 0.09, r = 0.12). CONCLUSION There was a lack of precision between the clinically accepted measurements (lower esophageal and tympanic membranes and the skin temperature measurement. The data suggest that forehead skin temperature is not interchangeable with standard core temperature measurements, and that sole reliance on the forehead skin measurement in the perioperative setting could adversely affect patient care.

Comparison of fluid warmer performance during simulated clinical conditions

The study evaluated the warming ability and flow rates associated with four fluid warming devices during pressure driven infusion and during wide open gravity driven roller clamp infusion. Warmers tested were the Astotherm, Flotem IIe, Level 1 System 250 and a modified cardioplegia heat exchanger. Fluids tested were crystalloid, red cells diluted with 200 ml, 0.9% saline, and undiluted red cells. The volume of fluid and outlet temperatures (point where iv tubing would be attached to the patient) were measured for each fluid and compared among warmers for each flow rate condition. For pressure driven infusion of red cells and crystalloid, the System 250, and modified heat exchanger delivered warmer fluids (33-35° C) at higher flow rates (160–740 ml · min− 1) than the Astotherm and Flotem (23–31° C, 44–268 ml · min− 1, P< 0.05). For gravity driven infusion, the System 250 delivered the warmest fluids (33–36° C, P < 0.05) compared with the modified heat exchanger (29–35°C), Astotherm (26–32°C) and Flotem (26–27° C). In conclusion, the modified heat exchanger and System 250 were moderately effective (outlet temperture >32°C) in warming crystalloid and red cells at pressure driven flow rates. Only the System 250 warmed red cells >35° C at gravity driven flow rates. The Flotem and Astotherm were not effective in warming rapidly infused solutions. None of the warmers tested was able to deliver fluids at normothermia (>36.5° C).RésuméCe travail évalue la capacité de réchauffement et les débits produits par quatre appareils de réchauffement destinés à la perfusion sous pression et à la perfusion par gravité. Les réchauffeurs sont l’Astotherm, le Flotem IIe, le Level 1 System 250 et une échangeur de chaleur de cardioplégie modifié. Les liquides étudiés sont les cristalloïdes, des hématies rouges dilués avec 200 ml, du physiologique 0,9% et des hématies non diluées. Le volume de liquide et la température à la sortie (au point d’attache de la tubulure au patient) sont mesurés pour chacun des liquides et comparés entre les réchauffeurs pour chacun des débits obtenus. Pour la perfusion sous pression des hématies et des cristalloïdes, le System 250 et l’échangeur de chaleur modifié fournissent des liquides plus chauds 03–35° C) à plus haut dédits (160–740 ml · min− 1, P < 0,05) que l’Asthotem et le Flotem (23–31°C, 44–268 ml · min− 1, P < 0,05). Pour les perfusions sous gravité, le System 250 fournit les liquides les plus chauds 33–36° C, P< 0,05) comparativement à l’échangeur modifié (29–35° C), l’Astotherm (26–32°C) et le Flotem (26–27°C). En conclusion, l’échangeur de chaleur modifié et le System 250 sont moyennement efficace (température à la sortie >32° C) pour réchauffer les cristalloïdes et les hématies à des débits contrôlés par la pression. Seul le System 250 réchauffe les hématies à plus de 35°C à des débits contrôlés par la gravité. Le Flotem et l’Astotherm sont inefficaces pour réchauffer des solutions perfusées rapidement. Aucun des réchauffeurs essayés ne fournit de liquides normothermiques (>36,5°C).

Taping methods and tape types for securing oral endotracheal tubes.

PurposeTo evaluate tapes and taping methods with respect to the minimum force required to dislodge endo tracheal tubes (ETTs).MethodsA simulated face model consisting of a section of PVC pipe was used. The ETT was attached to a piezo-electric force transducer and pullout force was manually applied in a vertical, right or left direction. Five tape types were tested: Curity. Leukosilk, Hy.tape. Leukopore, and Transpore. Seven taping methods were used to secure the ETT The methods differed with respect to tape width and whether the tape was split along its longitudinal axis. Each taping condition was replicated 20 times (7 methods x 3 tapes x 3 directions) for a total of 2100 pullout tests.ResultsMinimum forces to dislodge ETTs were higher (P < 0.05) with Cunty tape (mean ± SD: 135 ± 75 N) than with the other tapes (Leukosilk: 93 ± 51 N, Hy.tape: 78 ± 34 N, Leukopore: 47 ± 32, and Transpore: 37 ± 23 N). The most secure taping method was achieved by taping the ETT, using 2.5 cm wide Cunty tape, in a circumferential fashion to both the upper and lower borders of the simulated mouth opening, and reinforcing these tapes with two strips applied longitudinally across the borders of the mouth opening (method 7). Taping methods which involved splitting the tape along its longitudinal axis resulted in lower minimal pullout forces when-ever the pullout force was directed towards the side of attachment (P < 0.05vs right and vertical direction).ConclusionThere are differences in ETT pullout forces and mechanisms of dislodgement depending on taping method and tape type.RésuméObjectifÉvaluer les rubans adhésifs et leurs modes d’ancrage par rapport à la force minimale requise pour déloger un tube endotrachéal (TET).MéthodesUn modèle de face simulé constitué d’une section de tube en CPV a été utilisé. Le TET était relié à un transducteur de force piézo-électrique et on appliquait sur le tube une traction verticale, vers la droite ou vers la gauche. Cinq marques de ruban adhésif ont été testées: Cunty. Leukosilk, Hy.tape, Leukopore et Transpore. Sept méthodes d’ancrage ont été utilisées pour la rétention du TET conformément à la largeur du ruban et selon qu’il était divisé sur son axe longitudinal ou non. Chaque méthode d’ancrage était mise à l’épreuve 20 fois (7 méthodes x 5 rubans x 3 directions) pour un total de 2100 tests.RésultatsAvec le ruban Cunty, la traction minimale requise pour déloger le tube était plus élevée (P < 0,05) (moyenne ± ET: 135 ± 75 N) qu’avec les autres rubans (Leukosilk 93 ± 52 N. Hy.tape 78 ± 34 N, Leukopore 47 ± 32 N et Transpore 37 ± 23 N). La méthode la plus efficace pour l’ancrage du TET consistait à faire le tour du tube avec deux rubans Cunty de 2.5 cm de large et de les fixer à la commissure du modèle buccal et de les renforcer avec deux rubans appliquées logitudimalement à travers les limites de l’ouverture buccale (méthodes 7). Les méthodes d’ancrage consistant à séparer le ruban en deux sur son axe longitudinal ont été les moins efficaces lorsque que la force d’extraction était dirigée du côté de l’attache (P < 0,05vs direction droite ou verticale).ConclusionLa force requise pour déloger un TET et les mécanismes de déplacement sont différents selon la méthode d’ancrage et le type de ruban adhésif utilisé.

Desflurane is not associated with faster operating room exit times in outpatients

STUDY OBJECTIVE To determine the influence of anesthetic technique and primary drug on operating room (OR) exit time (time between end of surgery until time patient exists the OR) after addition of desflurane to the hospital formulary. DESIGN Prospective study. SETTING Ambulatory surgery unit of a university hospital. PATIENTS 1,568 outpatients requiring anesthesia. INTERVENTIONS Addition of desflurane to the hospital formulary, and substitution of desflurane vaporizers for enflurane vaporizers in the ambulatory surgery unit. MEASUREMENTS AND MAIN RESULTS The following information was recorded for all anesthetic encounters over a six-month time interval: demographics, duration of surgery, primary anesthetic technique, primary anesthetic drug, and exit times. General anesthesia was used in 907 patients [desflurane: 209 patients, isoflurane: 429 patients, halothane: 192 patients, propofol: 72 patients, other intravenous (i.v.): 5 patients], major conduction anesthesia (spinal and epidural) in 43 patients, peripheral nerve blocks in 90 patients, and i.v. sedation in 528 patients. The exit time was significantly greater ( < 0.05) in patients who received general anesthesia (mean +/- SEM 14 +/- 0.2 min) compared with spinal/epidural (8 +/- 0.7 min), nerve blocks (8 +/- 0.4 min) and i.v. sedation (7 +/- 0.2 min). Exit times were longer in older patients receiving general anesthesia (exit time = 12.3 + 0.04 x age, SE = 6.7 min, p < 0.0009), whereas exit times were shorter in older individuals receiving i.v. sedation (exit time = 8.97 - 0.038 x age, SE = 3.6 min, p < 0.0001). For patients receiving i.v. sedation, exit times were shorter as duration of surgery increased (exit time = 7.86 - 0.015 x duration of surgery, SE = 3.6 min, p < 0.0002). Primary anesthetic drug did not affect exit times. CONCLUSION Regional anesthesia and i.v. sedation were associated with faster OR exit times compared with general anesthesia. Despite desfluranes shorter elimination kinetics and recovery characteristics, use of this drug did not result in shorter exit times.

Intubating conditions and neuromuscular block after divided dose mivacurium or single dose rocuronium

PurposeTo evaluate the tracheal intubating conditions and neuromuscular blocking charactenstics of divided dose mivacurium or single dose rocuronium.MethodsThirty-two patients undergoing elective surgery were studied. Anaesthesia was with propofol 2 mg · kg−1, followed by an infusion of l50 μg · kg−1 · min−1. Patients were randomized to receive either mivacurium-0.15 mg · kg−1 followed 30 sec later by 0.1 mg · kg−1, or rocuronium-0.9 mg · kg−1, followed 30 sec later by placebo. Tracheal intubating conditions were assessed 90 sec after the initial dose of relaxant by an anaesthetist who was unaware of patient group. The electromyographic (EMG) response of the first dorsal interosseus muscle to ulnar nerve train-of-four was measured.ResultsSuccessful tracheal intubation was performed in all patients after both mivacurium and rocuronium. Intubating conditions (jaw relaxation, open visible vocal cords) were judged to be good-excellent in all but one patient before insertion of the tracheal tube. However, patients receiving mivacunum were more likely to experience coughing and bucking after tracheal tube insertion (10/16 patients) than those receiving rocuronium (3/16 patients, P < 0.05). No patient in the rocuronium group experienced moderately vigorous coughing and bucking after insertion of the tracheal tube vs six patients in the mivacurium group (P < 0.05). Time to 10 and 25% recovery of neuromuscular function was faster (P < 0.05) after divided dose mivacunum (20 ± 1 and 23 ± 1 min, respectively) than after rocuronium (45 ± 5 and 57 ± 8 min, respectively).ConclusionThe results suggest that, during conditions of the study, divided dose mivacurium is not recommended for a 90-sec tracheal intubation in patients where moderate coughing and bucking is deemed unacceptable.RésuméObjectifÉvaluer les conditions de l’intubation de la trachée et les caractéristiques du bloc neuromusculaire au mivacunum à dose fractionnée et au rocuronium à dose unique.MéthodesCette étude réunissait 22 patients programmés pour une chirurgie non urgente. Lanesthésie était réalisée avec du propofol 2 mg · kg−1, suivi d’une perfusion de 150 μg · kg−1 · min−1. Les patients recevaient aléatoirement soit du mivacunum 0, 15 mg · kg−1 suivi 30 sec plus tard par 0, 1 mg · kg−1, sort du rocuronium 0, 9 mg · kg−1, suivi 30 sec plus tard d’un placebo. Les conditions d’intubation de la trachée étaient évaluées 90 sec après la dose initiale de myorelaxant par un anesthésiste ignorant le groupe auquel le patient appartenait. La réponse électromyographique (EMG) à la stimulation au train-de-quatre (TOF) du premier muscle interosseux dorsal était mesurée.RésultatsLintubation de la trachée a été réussie chez tous les patients des deux groupes. Les conditions d’intubation (relaxation de la mâchoire, visualisation de cordes vocales béantes) avant l’insertion de la canule tracheale étaient jugées de bonnes à excellentes chez tous les patients à l’exception d’un seul. Cependant, les patients sous mivacunum étaient plus sujets à la toux et au cabrage après l’insertion de la canule (10/16 patients) que ceux qui avaient reçu le rocuronium. (3/16 patients, P< 0,05). Aucun des patients du groupe rocuronium n’a présenté de toux et de cabrage notoires après l’insertion de la canule comparativement à six patients du groupe mivacunum (P< 0,05). Le temps de récupération à 10% et 25% de la fonction neuromusculaire était plus rapide (P< 0,05) après le mivacurium à dose fractionnée (respectivement 20±1 min et 23 ±1 min) qu’après le rocuronium (respectivement 45 ±5 et 57 ±8 min).ConclusionCes résultats suggèrent que dans les conditions de l’étude, le mivacurium à dose fractionnée n’est pas recommandé après 90 sec pour une intubation de la trachée chez des patients chez qui une toux ou un cabrage d’intensité modérée sont jugés inacceptables.

The influence of tape type and of skin preparation on the force required to dislodge angiocatheters.

The study evaluated the effects of different techniques used to secure intravenous (iv) catheters. An angiocatheter attached to standard iv tubing was taped to human forearm using a standard taping method. A calibrated piezoelectric force transducer was attached to the iv tubing. The force applied along the longitudinal axis to pull out the taped catheter was measured and recorded on paper. Three tape types, Curity, Leukopor and Transpore, were evaluated alone, with benzoin skin pretreatment and with mastisol pretreatment. A randomized 3 × 3 block design with 20 replications per block was utilized, and a total of 180 pullout tests were performed on two adult volunteers. Without pretreatment, the forces required to dislodge catheters were (means ± SEM) 46 ± 2, 37 ± 2 and 38 ± 2 Newtons for Curity, Leukopor and Transpore tape, respectively. Corresponding values for mastisol pretreatment (64 ± 1,64 ± 3 and 52 ± 3 Newtons) were greater (P < 0.05) for each tape compared with benzoin (54 ± 3, 53 ± 2 and 40 ± 2 Newtons) and no pretreatment. The most frequent failure mode for Transpore tape was by tape fracture, for Curity tape was by separation from the skin of tape and catheter as a single unit, and for Leukopor tape was by catheter separation while tape remained attached to skin (P < 0.001). The data suggest that the application of mastisol prior to taping iv catheters with Curity or Leukopor tape helps to minimize the risk of accidental dislodgement.RésuméCette étude vise à évaluer l’efficacité de différentes méthodes de fixation à la peau des canules iv. Un canule veineuse reliée a une tubulure ordinaire est fixée avec un ruban adhésif sur l’avant-bras selon une méthode standard. Un transducteur piézo-électrique calibré est attaché à la tubulure. La force appliquée sur l’axe longitudinal de la canule nécessaire pour l’enlever est mesurée et enregistrée sur papier. Trois type de rubans adhesifs Curity, Leukopor et Transpore sont évalués seuls et apres preparation de la peau au benjoin et au mastisol. Un schema randomisé de blocs 3 × 3 avec 20 répliques par bloc est utilisé, et un total de 180 tests d’extraction sont pratiqués sur deux volontaires adultes. Sans préparation de la peau, la force requise pour déloger la canule est (moyenne ± SEM) 46 ± 2, 37 ± 2 et 38 ± 2 newtons respectivement pour les rubans adhésifs Curity, Leukopor et Transpore. Les valeurs correspondantes pour la préparation au mastisol (64 ± 1, 64 ± 3 et 52 ± 3 newtons) sont plus élevées (P < 0,05) pour chacun des rubans adhésifs comparativement au benjoin (54 ± 3, 53 ± 2 et 40 ± 2 newtons) et à l’absence de préparation. Pour le ruban Transpore, la source la plus importante d’échec a été le bris du ruban, pour le ruban Curity la séparation du ruban et du cathétr en un seul bloc, et pour le ruban Leukopor par la séparation du cathéter alors que le ruban demeure collé à la peau (P < 0,001). Ces données suggèrent que l’application de Mastisol avant la fixation de la canule avec du ruban adhésif Leukopor ou Curity en diminue le risque de déplacement.

Evaluation of different methods of securing intravenous catheters: measurement of forces during simulated accidental pullout

The purpose of the study was to compare the relative effectiveness of several combinations of tapes and taping methods with respect to the force required to pull out intravenous catheters. A simulated forearm model consisting of a section of firm PVC pipe was used for the first and second series of experiments. In the third experiment, one method of taping catheters was compared in the PVC model and in volunteers. Pull-out forces were measured with a force transducer and recorded on paper. In the first experiment, catheters secured with Curity tape resisted pullout to a greater extent than those with Transpore tape and provided approximately twice the force advantage (P < 0.05). In the second experiment using Curity tape, minimum forces to dislodge the catheters were (means ± SD) 53 ± 13, 82 ± 13, 113 ± 29, 124 ± 24, 176 ± 29 and 141 ± 46 N, for methods 1–6, respectively. In the third series, the minimum pullout forces were higher for Curity than with Transpore tape for both the human and simulated PVC forearm surfaces (63 ± 11 and 55 ± 12 N vs 52 ± 7 and 44 ± 12 N, P < 0.01), and the pullout forces were higher for the simulated vs the human skin surface for both tape types (P < 0.01). Compared with Curity tape, Transpore tape was more likely to fail by tape fracture in both the simulated and human skin surfaces (P < 0.05). The data suggest that there are important differences in pullout forces and mechanisms of dislodgement depending on taping method and tape type. Curity tape, using method 5 or 6, was superior to Transpore tape and the other taping methods in resisting pullout.RésuméCette étude vise à comparer l’efficacité relative de différentes combinaisons de ruban adhésif et méthodes de fixation par rapport à la force requise pour extraire une canule intraveineuse. Un modèle factice d’avant-bras composé d’une section de tube en CPV est utilisé pour la première et la deuxième série d’expériences. Pour la troisième série, la comparaison de la méthode de fixation de la canule se fait entre le modèle en CPV et des volontaires. La force nécessaire pour l’extraction est mesurée avec une jauge de contrainte et enregistrée sur papier. Au cours de la première expérience, les canules fixées avec du ruban Curity résistent environ deux foix mieux à l’extraction que celles qui sont fixées avec le ruban Transpore (P < 0,05). Au cours de la deuxième expérience avec le ruban Curity appliqué à la surface du membre factice, les forces minimales requises pour déplacer la canule sont respectivement de (moyenne ± SD) 53 ± 13, 82 ± 13, 113 ± 29, 124 ± 24, 176 ± 29 et de 141 ± 46 N avec les méthodes 1 à 6. Dans la troisième série, les forces minimales d’extraction sont plus élevées pour le ruban Curity que pour le Transpore tant sur la peau humaine que sur le membre factice (63 ± 11 et 55 ± 12 N vs 52 ± 7 et 44 ±12 N, P< 0,01); avec les deux rubans, la force d’extraction est plus élevée sur le bras factice que sur la peau humaine (P < 0,01). Comparativement au ruban Curity, le ruban Transpore est plus susceptible de se briser tant sur le bras factice que sur la peau humaine (P < 0,05). Ces données suggèrent que les méthodes de fixation et les types de ruban adhésif sont des facteurs déterminants sur les forces d’extraction et les mécanismes de déplacements des canules. Avec les méthodes 5 et 6, le ruban Curity résiste mieux à l’extraction que le ruban Transpore et que les autres méthodes.

PAIN MANAGEMENT IN TRAUMA

Effective management of trauma victims necessitates a multidisciplinary approach that must include pain management specialists. This is because the effect of pain and the related stress response is almost always detrimental to patients. The immediate effects of pain, mediated by metabolic and neurohormonal mechanisms, lead to hyperglycemia, lipolysis, protein catabolism, increased antidiuretic and catecholamine levels, immunosuppression, and a hypercoagulable state (Table 1). 18 Clinically, these manifest as hypertension, tachycardia, deep venous thrombosis, pulmonary embolism, immobility, splinting, ventilation perfusion mismatch, reduced gastrointestinal motility, water and salt retention, hypoxia, and infections. Collectively, these result in high morbidity, prolonged hospitalization, and higher costs. Adequate pain management in the acute setting also aids earlier rehabilitation and may reduce the incidence of long-term chronic pain syndromes. The purpose of this article is to familiarize readers with the factors that are important in the management of pain in the trauma setting, with emphasis on practicality. Although different regions of the body are considered separately, it is important to realize that trauma patients frequently present with injuries to multiple areas of the body, necessitating flexibility on the part of the pain management specialist. In the management of trauma patients, it is important to communicate with surgical colleagues. Issues such as monitoring of cerebral function need to be addressed in patients with head trauma. In patients with neurologic peripheral injuries, it is also often necessary to avoid the use of analgesic techniques that may reduce the surgeons ability to evaluate sensory and motor function. 28 At all periods of intervention, the nature of current problems must be understood. This is best achieved by maintaining a current list of active problems because conditions are constantly changing in patients with severe acute trauma, and this may influence the nature of the interventions that pain management specialists can offer. This article is divided into two sections. The first section deals with the management of acute trauma pain, and the second section highlights the commonly encountered chronic pain syndromes resulting from trauma.

ASSOCIATION OF REQUIREMENT FOR TRANSFUSION TO COST OF CARE, LENGTH OF STAY AND INCIDENCE OF ADVERSE EVENTS IN PERCUTANEOUS LEFT ATRIAL APPENDAGE CLOSURE

There is an increase in use of percutaneous left atrial appendage closure (PLAAC) for prevention of stroke in atrial fibrillation. This study compares the in-hospital outcomes of PLAAC in patients requiring transfusion of whole blood/blood products versus those who do not require transfusion. The