- Email: [email protected]
Design and organization of an equine intensive care unit
Vet Clin Equine 20 (2004) 1–10
Design and organization of an equine intensive care unit Joanne Hardy, DVM, PhD Department of Large Animal Medicine and Surgery, Texas A&M University, 4475-TAMU, College Station, TX 77843–4475, USA
Equine intensive care units (ICUs) are currently being integrated in many primary and referral hospitals. These ICUs are created for the purpose of integrating three critical components: the sickest patients, highly technical and expensive equipment, and the staff with knowledge and experience to treat these patients. The goals of these units are to improve efficiency and efficacy, reduce costs, and ultimately improve patient outcome. In a growing number of institutions, emergency and critical care programs are also being integrated in the veterinary student core curriculum, because the need for such discipline is recognized not only in referral hospitals but by the general practitioner. The decision to offer ICU services must be based on the population needs, the consideration that emergency services should be offered in conjunction, and the economic environment of the hospital. Currently, few studies exist that describe the general case population, commonly performed procedures and treatments, and overall cost-benefit ratios of equine ICUs. One study described the overall case distribution of emergencies based on monthly admissions, the proportion of cases requiring surgery, and the most commonly performed treatments [1]. Because equine emergency patients are often hospitalized in ICUs, such information provides an initial database for understanding population dynamics. In that study, 20% of hospital admissions for a referral were received as after-hour emergencies. Approximately 60% of emergencies were colics, of which approximately half were surgical abdomens. Other emergencies were distributed among the following categories: neonates (8%), orthopedics (7%), lacerations (5%), enteritis/ colitis (4%), neurologic (4%), reproductive (4%), respiratory (4%), and others. In the miscellaneous category, esophageal obstruction, ocular emergencies, rectal tears, hemorrhage, and undefined sickness were cited. E-mail address: [email protected] 0749-0739/04/$ - see front matter Ó 2004 Elsevier Inc. All rights reserved. doi:10.1016/j.cveq.2003.11.004
2
J. Hardy / Vet Clin Equine 20 (2004) 1–10
Although this case distribution probably reflects the overall equine emergency caseload accurately, it is important to review the anticipated distribution of cases within a given area and the monthly distribution of cases. This should ensure appropriate allocation of staff and equipment tailored to the needs of the population. For example, in the previously quoted study, the peak colic case admission rate was in August. In contrast, the peak neonatal case admission rate was in April and May. In general, in the northern hemisphere, peak foal season extends from February through June, whereas in the southern hemisphere, a September to January incidence is anticipated. Such distribution requires different staffing needs. During foal season, technicians trained in the use of mechanical ventilators, blood gas analyzers, glucometers, capnographs, intravenous fluid pumps, or other specialty equipment may be needed. The addition of temporary unskilled staff (foal sitters) to help with management of neonates is useful. Review of equipment and training on the use of new equipment with staff, technicians, and clinicians on a regular basis are essential for the smooth running of an equine ICU. Commonly anticipated procedures performed in ICUs include monitoring, fluid administration, and pain control. Monitoring includes not only physical parameters but use of monitoring equipment. Fluid administration encompasses not only routine administration of crystalloids but administration of colloids, blood, blood components (eg, plasma), and blood substitutes. Providing appropriate analgesia can vary widely, depending on the origin of pain (musculoskeletal versus abdominal) and the possible side effects of different medications. All these considerations need to be based on the specific needs of the equine patient.
Design of an equine intensive care unit The design of the ICU unit should accommodate the need for care of horses with abdominal disorders, care of neonates, care of horses with various critical illnesses, and care of horses with infectious diseases that require isolation. In addition, one or two stalls can be designed for the management of neurologic patients. Some recommendations for design can be derived from human ICUs (for recommended standards for newborn ICU design, the reader is referred to: www.nd.edu/kkolberg/frmain.htm). A central office facilitates administration, organization, charting, and issuing of directives. An integrated or separate small office for performance of statim laboratory tests is useful. A separate rest area, which could include a kitchenette, is also useful for staff and clinician use. Fig. 1 provides an example of an equine ICU floor plan. Sufficient storage space should be available to protect equipment while not in use. Ideally, the adult ICU should be separate from the foaling and neonatal stalls. All surfaces, including walls, floors, and ceilings, should be made of material that can
J. Hardy / Vet Clin Equine 20 (2004) 1–10
3
Fig. 1. Floor plan example of an equine intensive care unit (excluding isolation). (Courtesy of S. Wigington, Texas A & M University, College Station, TX.)
sustain repeated cleaning and disinfection. Wall surfaces should also have protection at points where contact with movable equipment is likely to occur. Windows and natural lighting should also be provided. Although not demonstrated in horses, natural lighting has been shown to have important psychologic benefits not only to the patient but to the staff and caretakers [2,3]. Natural light also facilitates evaluation of skin and mucous membrane color. The ambient temperature can be maintained at 68 F to 72 F, with a relative humidity of 30% to 60%. If a separate neonatal area is available, higher ambient temperatures are recommended; temperatures from 72 F to 78 F are recommended for human neonates. Stalls All stalls in the ICU should have equipment for hanging fluids (International Win, Ltd, Kennett Square, PA), and each stall should have
4
J. Hardy / Vet Clin Equine 20 (2004) 1–10
access to at least two standard duplex electrical outlets, one oxygen outlet, one vacuum outlet, and one air outlet. Each stall should have a separate light that can be turned on to allow examination of the patient. Each stall should be within easy access of a hand-washing sink. Stalls should have sealed rubber floors for safe footing and easy disinfection. Within each stall, recessed rings should be available for tying horses and also to allow head and tail rope support should the need arise. Although automatic waterers are often included in hospital stalls, a bucket should also be available in every stall for watering animals, because not all patients know how to use an automatic watering system. Each stall should have a place for patient identification and for feeding directives. Suggestions for stall dimensions are 12 ft 12 ft for regular stalls and 17 ft 12 ft for foaling stalls. The foaling stalls can have mobile separators for foals receiving intensive care. Fig. 2 and Fig. 3 show examples of foaling stalls, where a separate movable pen can be used to allow care of the foal. One or two stalls designed for neurologic patients can also be designed. These neurologic stalls need to be padded and to have no protruding structures on which an unsteady animal could get hurt. The ceiling structure needs to be able to support a hoisting unit capable of supporting at least 3000 lb. A wide door to the outside can facilitate the unloading of down horses. Commercially available equipment is now available for loading and unloading down animals (The Slide, B & M Plastics, Greenville, SC). In locations with a large neonatal caseload, a separate room can be designed to manage foals separately from their dam. This enables provision for increased ambient temperature, increased cleanliness, and facilitation of monitoring and management. Ideally, all stalls would have television cameras with monitors at the nurses’ station. This becomes particularly useful for isolation units, where the building is usually constructed separately and at a distance from the main hospital. Electronic monitoring (telemetry) can be added for patient monitoring (Fig. 4). Isolation units should be available, ideally in a stand-alone building separate from the main hospital. Each unit should have a storage and gowning area, transition area, and patient area. Strict isolation protocols should be established and followed by all personnel. Each patient should have its own restraint equipment (eg, halter, lead rope, twitch), monitoring equipment (eg, thermometer, stethoscope), feeding equipment (eg, feed tubs, buckets), and grooming equipment. Each unit should be equipped with all materials necessary to manage each patient, including syringes, needles, specimen collection equipment, and gloves. All equipment should be disinfected between patients. Strict disinfection and isolation protocols should be in place to prevent the spread of infectious disease and to avoid nosocomial infections. The use of hand washing and even foot baths between patients should be encouraged, particularly when dealing with infectious diseases, even when these are not contagious. Hand rubbing with an alcohol-based solution is more effective than hand washing with an antiseptic, probably because it does not require
J. Hardy / Vet Clin Equine 20 (2004) 1–10
5
Fig. 2. Illustrations of a foaling stall with a separate holding pen that allows treatment of foals while still in contact with the mare. The pen can be folded when not in use. (Courtesy of S. Wigington, Texas A & M University, College Station, TX.)
rinsing and drying of hands; adoption of this practice can significantly reduce cross-contamination between patients [4]. This is also important when dealing with exudative wounds, where the growth of resistant organisms can occur. Growth of an oxacillin-resistant Staphylococcus species should alert staff to the presence of a methicillin-resistant organism. Guidelines for the judicious use of antibiotic regimens are available for human ICUs, and some of these guidelines are applicable to equine ICUs [5]. Salmonella organisms can also be a cause of nosocomial infection in equine hospitals [6]. Salmonella shedding is greater in horses with colic, and transmission is favored through the use of common equipment, such as stomach tubes and pumps [7–9]. Careful attention to hospital design and disinfection practices can help to minimize the risk of hospital outbreaks [10,11].
6
J. Hardy / Vet Clin Equine 20 (2004) 1–10
Fig. 3. Illustration of a different style of holding pen for foal management. (Courtesy of Pam Wilkins, DVM, PhD, Kennett Square, PA.)
A separate food preparation bay should be available for preparation of enteral feeding. Staff should pay attention to cleanliness in this area and particularly avoid washing of hands or contaminated material in the same sink as that used for food preparation. Technicians and staff available in the unit should be trained in techniques performed in the ICU as well as in early recognition of problems related to equipment malfunction and in invasive and noninvasive monitoring techniques. Technicians also need to be trained in identification of changes in patient status. When complex cases are undergoing continuous monitoring, the continuous presence of a veterinarian may be needed. Most hospital databases are computerized. Several workstations should be available for access to patient data, laboratory submission and results, and easy Internet access for retrieval of information. Storage space should be available for equipment that is not in continuous use, such as ventilators, fluid pumps, and monitoring equipment. In addition, at least one refrigerator should be available for the storage of drugs. A separate non–frost-free ÿ20 F freezer (to avoid freeze-thaw cycles)
J. Hardy / Vet Clin Equine 20 (2004) 1–10 7
Fig. 4. Illustration of an example of an equine monitoring and treatment sheet. (Courtesy of the ICU Committee, Texas A & M University, College Station, TX.)
8
J. Hardy / Vet Clin Equine 20 (2004) 1–10
should be available for the storage of plasma (Pam Wilkins, DVM, PhD, personal communication, 2003). Ideally, a fluid warmer unit should also be available. A lock box should be provided for storage of controlled substances, with an appropriate form for recording the use of such substances. Drugs can be dispensed from a central pharmacy to each patient; alternatively, for large hospitals, a drug-dispensing unit that allows recording of each medication provided to the patient chart can be provided. Such a unit is particularly useful for nighttime dispensing of drugs, by minimizing the need for staffing a central pharmacy. Equipment The equipment used in an equine ICU should be tailored to the anticipated case population and varies, depending on the maximal level of care anticipated for that population. It would be a poor economic decision to purchase a ventilator if mechanical ventilation is rarely performed. Alternatively, the possibility for rental of medical equipment from suppliers in the area should be investigated for such intermittent needs. The most commonly performed procedure in the equine ICU is catheter placement, followed by intravenous fluid replacement. In adults, intravenous fluids are usually hung using several 3- to 5-L bags and are administered by gravity flow. A pulley system facilitates hanging of fluid bags in the volumes needed for fluid administration in horses (International Win, Ltd). Commercially available coil sets enable intravenous fluid administration without restraint. The drip chamber should be large enough to be visible from outside the stall. It is convenient to have a drip chamber that allows administration of other medication (‘‘piggy-backing’’). Smaller horses, ponies, miniature horses, and foals benefit from a more precise means of monitoring the volume of fluid administered. This can be accomplished with the use of volumetric fluid chambers or fluid pumps; however, commercially available pumps can only deliver up to 999 mL/h, which may be insufficient for standard-sized horses. For rapid administration of large volumes of fluids, for example, in the treatment of shock, peristaltic pumps are available that allow delivery of 20 to 40 L of fluids in the first hour. Because of the pulsatile nature of the fluid flow, this method of fluid administration causes more damage to the venous endothelium. For administration of constant rate infusions of small quantities of drugs, syringe pumps are also available. Standard monitoring equipment for use in the ICU includes an electrocardiogram/blood pressure monitor, an ultrasound unit, a centrifuge for hematocrit determination, a refractometer for total protein and urine specific gravity determination, and a urine test strip for urinalysis. Other equipment to consider includes a glucometer, a urine centrifuge, a microscope with 100 magnification, cytology and Gram stains, and a blood gas and electrolyte monitoring unit. A colloid osmometer is a useful unit for
J. Hardy / Vet Clin Equine 20 (2004) 1–10
9
determination of colloid oncotic pressure in sick animals. If provision of mechanical ventilation is planned, useful monitoring equipment includes capnographs and pulse oximeters. Monitoring equipment is frequently equipped with quality control measures that must be performed regularly to ensure accuracy. Appropriate sampling procedures should be followed for each type of equipment. Oxygen ports for supplementation through nasal insufflation or for mechanical ventilation should be available. When installing a new ICU, oxygen, vacuum, and air ports should be considered. A remote gas source and a pipeline system allow for delivery of oxygen. Compressed gas cylinders can be used but must be stored and handled appropriately to avoid injury. For each cylinder type, knowing the capacity of the cylinder and the flow rate being delivered enables calculation of the amount of time oxygen should be provided. The small and more portable E cylinders, containing 655 L of oxygen when full, would provide oxygen for 260 minutes when set at a flow rate of 5 L/min. In adults, flow rates of 10 to 15 L/min are required to increase the fraction of inspired oxygen (FIO2) to approximately 40%. Larger G or H cylinders containing 5290 L or 6910 L, respectively, would allow oxygen supplementation for longer periods. Tight-fitting masks have been used satisfactorily in foals for management of hypoxemia; however, nasal insufflation using an oxygen cannula is better tolerated in adults. In adults with severe respiratory distress that require a greater FIO2, a tracheostomy can be performed using a cuffed silicone cannula (Bivona Medical Technologies, Gary, IN) for administration of oxygen. Oxygen should be humidified, and the estimated FIO2 should not exceed 50% for a prolonged period. An emergency (crash) cart should be available in the ICU. These can be placed in the crash cart for easy reference. In addition, emergency tracheostomy packs should be placed in key areas, such as near the stall of patients with possible respiratory distress, near recovery stalls, and in the patient receiving area. The availability of ultrasonography has also become an essential component of ICUs. Ultrasound can be used for identification and monitoring of effusions, intestinal distention or motility, identification of umbilical structures, imaging of joint effusions, diagnosis of the presence and location of uroabdomen, pregnancy monitoring, evaluation of correct nasogastric feeding tube placement, and imaging of ocular structures among other things. To enable imaging of different structures, 3.5-mHz, 7.5-mHz, and rectal probes are the minimum needed for these purposes. Monitoring Patients in ICU require frequent monitoring. All monitored parameters should be recorded and preferably displayed on or near the patient’s door for rapid review. More complete or extensive laboratory results can be
10
J. Hardy / Vet Clin Equine 20 (2004) 1–10
stored in the patient’s chart. Fig. 4 shows an example of a large animal monitoring and treatment sheet. On this sheet, the patient’s orders are listed and parameters are recorded for easy review.
Summary Careful planning and design of a new ICU are warranted to maximize use of the facility, minimize the risk of hospital-acquired infection, and improve overall patient outcome. In addition, personnel satisfaction improves with an improved work environment. A functional equine ICU is also tailored to the geographic area, local needs of the practice, and anticipated investment.
References [1] Hardy J, Burkhardt HA, Beard W. Equine emergency and intensive care: case survey and assessment of needs (1992–1994). In: Proceedings of the American Association of Equine Practioners, 42nd Annual Convention, Denver, CO; 1996. p. 182–3. [2] Mirmiran M, Ariagno R. Influence of light in the NICU on the development of circadian rhythms in the pre-term infant. Semin Perinatal 2000;24:247–57. [3] Rea M. Lighting handbook. 9th edition. New York: Illuminating Engineering Society of North America; 2000. [4] Girou E, Loyeau S, Legrand P, et al. Efficacy of handrubbing with alcohol based solution versus standard handwashing with antiseptic soap: randomised clinical trial. BMJ 2002; 325:362–7. [5] Niederman MS. Appropriate use of antimicrobial agents: challenges and strategies for improvement. Crit Care Med 2003;31:608–16. [6] Schott HC II, Ewart SL, Walker RD, et al. An outbreak of salmonellosis among horses at a veterinary teaching hospital. J Am Vet Med Assoc 2001;218:1152–9. [7] House JK, Mainar-Jaime RC, Smith BP, et al. Risk factors for nosocomial Salmonella infection among hospitalized horses. J Am Vet Med Assoc 1999;214:1511–6. [8] Traub-Dargatz JL, Garber LP, Fedorka-Cray PJ, et al. Fecal shedding of Salmonella spp by horses in the United States during 1998 and 1999 and detection of Salmonella spp in grain and concentrate sources on equine operations. J Am Vet Med Assoc 2000;217: 226–30. [9] Kim LM, Morley PS, Traub-Dargatz JL, et al. Factors associated with Salmonella shedding among equine colic patients at a veterinary teaching hospital. J Am Vet Med Assoc 2001;218:740–8. [10] Tillotson K, Savage CJ, Salman MD, et al. Outbreak of Salmonella infantis infection in a large animal veterinary teaching hospital. J Am Vet Med Assoc 1997;211:1554–7. [11] Ewart SL, Schott HC II, Robison RL, et al. Identification of sources of Salmonella organisms in a veterinary teaching hospital and evaluation of the effects of disinfectants on detection of Salmonella organisms on surface materials. J Am Vet Med Assoc 2001;218: 1145–51.
Design and organization of an equine intensive care unit Joanne Hardy, DVM, PhD Department of Large Animal Medicine and Surgery, Texas A&M University, 4475-TAMU, College Station, TX 77843–4475, USA
Equine intensive care units (ICUs) are currently being integrated in many primary and referral hospitals. These ICUs are created for the purpose of integrating three critical components: the sickest patients, highly technical and expensive equipment, and the staff with knowledge and experience to treat these patients. The goals of these units are to improve efficiency and efficacy, reduce costs, and ultimately improve patient outcome. In a growing number of institutions, emergency and critical care programs are also being integrated in the veterinary student core curriculum, because the need for such discipline is recognized not only in referral hospitals but by the general practitioner. The decision to offer ICU services must be based on the population needs, the consideration that emergency services should be offered in conjunction, and the economic environment of the hospital. Currently, few studies exist that describe the general case population, commonly performed procedures and treatments, and overall cost-benefit ratios of equine ICUs. One study described the overall case distribution of emergencies based on monthly admissions, the proportion of cases requiring surgery, and the most commonly performed treatments [1]. Because equine emergency patients are often hospitalized in ICUs, such information provides an initial database for understanding population dynamics. In that study, 20% of hospital admissions for a referral were received as after-hour emergencies. Approximately 60% of emergencies were colics, of which approximately half were surgical abdomens. Other emergencies were distributed among the following categories: neonates (8%), orthopedics (7%), lacerations (5%), enteritis/ colitis (4%), neurologic (4%), reproductive (4%), respiratory (4%), and others. In the miscellaneous category, esophageal obstruction, ocular emergencies, rectal tears, hemorrhage, and undefined sickness were cited. E-mail address: [email protected] 0749-0739/04/$ - see front matter Ó 2004 Elsevier Inc. All rights reserved. doi:10.1016/j.cveq.2003.11.004
2
J. Hardy / Vet Clin Equine 20 (2004) 1–10
Although this case distribution probably reflects the overall equine emergency caseload accurately, it is important to review the anticipated distribution of cases within a given area and the monthly distribution of cases. This should ensure appropriate allocation of staff and equipment tailored to the needs of the population. For example, in the previously quoted study, the peak colic case admission rate was in August. In contrast, the peak neonatal case admission rate was in April and May. In general, in the northern hemisphere, peak foal season extends from February through June, whereas in the southern hemisphere, a September to January incidence is anticipated. Such distribution requires different staffing needs. During foal season, technicians trained in the use of mechanical ventilators, blood gas analyzers, glucometers, capnographs, intravenous fluid pumps, or other specialty equipment may be needed. The addition of temporary unskilled staff (foal sitters) to help with management of neonates is useful. Review of equipment and training on the use of new equipment with staff, technicians, and clinicians on a regular basis are essential for the smooth running of an equine ICU. Commonly anticipated procedures performed in ICUs include monitoring, fluid administration, and pain control. Monitoring includes not only physical parameters but use of monitoring equipment. Fluid administration encompasses not only routine administration of crystalloids but administration of colloids, blood, blood components (eg, plasma), and blood substitutes. Providing appropriate analgesia can vary widely, depending on the origin of pain (musculoskeletal versus abdominal) and the possible side effects of different medications. All these considerations need to be based on the specific needs of the equine patient.
Design of an equine intensive care unit The design of the ICU unit should accommodate the need for care of horses with abdominal disorders, care of neonates, care of horses with various critical illnesses, and care of horses with infectious diseases that require isolation. In addition, one or two stalls can be designed for the management of neurologic patients. Some recommendations for design can be derived from human ICUs (for recommended standards for newborn ICU design, the reader is referred to: www.nd.edu/kkolberg/frmain.htm). A central office facilitates administration, organization, charting, and issuing of directives. An integrated or separate small office for performance of statim laboratory tests is useful. A separate rest area, which could include a kitchenette, is also useful for staff and clinician use. Fig. 1 provides an example of an equine ICU floor plan. Sufficient storage space should be available to protect equipment while not in use. Ideally, the adult ICU should be separate from the foaling and neonatal stalls. All surfaces, including walls, floors, and ceilings, should be made of material that can
J. Hardy / Vet Clin Equine 20 (2004) 1–10
3
Fig. 1. Floor plan example of an equine intensive care unit (excluding isolation). (Courtesy of S. Wigington, Texas A & M University, College Station, TX.)
sustain repeated cleaning and disinfection. Wall surfaces should also have protection at points where contact with movable equipment is likely to occur. Windows and natural lighting should also be provided. Although not demonstrated in horses, natural lighting has been shown to have important psychologic benefits not only to the patient but to the staff and caretakers [2,3]. Natural light also facilitates evaluation of skin and mucous membrane color. The ambient temperature can be maintained at 68 F to 72 F, with a relative humidity of 30% to 60%. If a separate neonatal area is available, higher ambient temperatures are recommended; temperatures from 72 F to 78 F are recommended for human neonates. Stalls All stalls in the ICU should have equipment for hanging fluids (International Win, Ltd, Kennett Square, PA), and each stall should have
4
J. Hardy / Vet Clin Equine 20 (2004) 1–10
access to at least two standard duplex electrical outlets, one oxygen outlet, one vacuum outlet, and one air outlet. Each stall should have a separate light that can be turned on to allow examination of the patient. Each stall should be within easy access of a hand-washing sink. Stalls should have sealed rubber floors for safe footing and easy disinfection. Within each stall, recessed rings should be available for tying horses and also to allow head and tail rope support should the need arise. Although automatic waterers are often included in hospital stalls, a bucket should also be available in every stall for watering animals, because not all patients know how to use an automatic watering system. Each stall should have a place for patient identification and for feeding directives. Suggestions for stall dimensions are 12 ft 12 ft for regular stalls and 17 ft 12 ft for foaling stalls. The foaling stalls can have mobile separators for foals receiving intensive care. Fig. 2 and Fig. 3 show examples of foaling stalls, where a separate movable pen can be used to allow care of the foal. One or two stalls designed for neurologic patients can also be designed. These neurologic stalls need to be padded and to have no protruding structures on which an unsteady animal could get hurt. The ceiling structure needs to be able to support a hoisting unit capable of supporting at least 3000 lb. A wide door to the outside can facilitate the unloading of down horses. Commercially available equipment is now available for loading and unloading down animals (The Slide, B & M Plastics, Greenville, SC). In locations with a large neonatal caseload, a separate room can be designed to manage foals separately from their dam. This enables provision for increased ambient temperature, increased cleanliness, and facilitation of monitoring and management. Ideally, all stalls would have television cameras with monitors at the nurses’ station. This becomes particularly useful for isolation units, where the building is usually constructed separately and at a distance from the main hospital. Electronic monitoring (telemetry) can be added for patient monitoring (Fig. 4). Isolation units should be available, ideally in a stand-alone building separate from the main hospital. Each unit should have a storage and gowning area, transition area, and patient area. Strict isolation protocols should be established and followed by all personnel. Each patient should have its own restraint equipment (eg, halter, lead rope, twitch), monitoring equipment (eg, thermometer, stethoscope), feeding equipment (eg, feed tubs, buckets), and grooming equipment. Each unit should be equipped with all materials necessary to manage each patient, including syringes, needles, specimen collection equipment, and gloves. All equipment should be disinfected between patients. Strict disinfection and isolation protocols should be in place to prevent the spread of infectious disease and to avoid nosocomial infections. The use of hand washing and even foot baths between patients should be encouraged, particularly when dealing with infectious diseases, even when these are not contagious. Hand rubbing with an alcohol-based solution is more effective than hand washing with an antiseptic, probably because it does not require
J. Hardy / Vet Clin Equine 20 (2004) 1–10
5
Fig. 2. Illustrations of a foaling stall with a separate holding pen that allows treatment of foals while still in contact with the mare. The pen can be folded when not in use. (Courtesy of S. Wigington, Texas A & M University, College Station, TX.)
rinsing and drying of hands; adoption of this practice can significantly reduce cross-contamination between patients [4]. This is also important when dealing with exudative wounds, where the growth of resistant organisms can occur. Growth of an oxacillin-resistant Staphylococcus species should alert staff to the presence of a methicillin-resistant organism. Guidelines for the judicious use of antibiotic regimens are available for human ICUs, and some of these guidelines are applicable to equine ICUs [5]. Salmonella organisms can also be a cause of nosocomial infection in equine hospitals [6]. Salmonella shedding is greater in horses with colic, and transmission is favored through the use of common equipment, such as stomach tubes and pumps [7–9]. Careful attention to hospital design and disinfection practices can help to minimize the risk of hospital outbreaks [10,11].
6
J. Hardy / Vet Clin Equine 20 (2004) 1–10
Fig. 3. Illustration of a different style of holding pen for foal management. (Courtesy of Pam Wilkins, DVM, PhD, Kennett Square, PA.)
A separate food preparation bay should be available for preparation of enteral feeding. Staff should pay attention to cleanliness in this area and particularly avoid washing of hands or contaminated material in the same sink as that used for food preparation. Technicians and staff available in the unit should be trained in techniques performed in the ICU as well as in early recognition of problems related to equipment malfunction and in invasive and noninvasive monitoring techniques. Technicians also need to be trained in identification of changes in patient status. When complex cases are undergoing continuous monitoring, the continuous presence of a veterinarian may be needed. Most hospital databases are computerized. Several workstations should be available for access to patient data, laboratory submission and results, and easy Internet access for retrieval of information. Storage space should be available for equipment that is not in continuous use, such as ventilators, fluid pumps, and monitoring equipment. In addition, at least one refrigerator should be available for the storage of drugs. A separate non–frost-free ÿ20 F freezer (to avoid freeze-thaw cycles)
J. Hardy / Vet Clin Equine 20 (2004) 1–10 7
Fig. 4. Illustration of an example of an equine monitoring and treatment sheet. (Courtesy of the ICU Committee, Texas A & M University, College Station, TX.)
8
J. Hardy / Vet Clin Equine 20 (2004) 1–10
should be available for the storage of plasma (Pam Wilkins, DVM, PhD, personal communication, 2003). Ideally, a fluid warmer unit should also be available. A lock box should be provided for storage of controlled substances, with an appropriate form for recording the use of such substances. Drugs can be dispensed from a central pharmacy to each patient; alternatively, for large hospitals, a drug-dispensing unit that allows recording of each medication provided to the patient chart can be provided. Such a unit is particularly useful for nighttime dispensing of drugs, by minimizing the need for staffing a central pharmacy. Equipment The equipment used in an equine ICU should be tailored to the anticipated case population and varies, depending on the maximal level of care anticipated for that population. It would be a poor economic decision to purchase a ventilator if mechanical ventilation is rarely performed. Alternatively, the possibility for rental of medical equipment from suppliers in the area should be investigated for such intermittent needs. The most commonly performed procedure in the equine ICU is catheter placement, followed by intravenous fluid replacement. In adults, intravenous fluids are usually hung using several 3- to 5-L bags and are administered by gravity flow. A pulley system facilitates hanging of fluid bags in the volumes needed for fluid administration in horses (International Win, Ltd). Commercially available coil sets enable intravenous fluid administration without restraint. The drip chamber should be large enough to be visible from outside the stall. It is convenient to have a drip chamber that allows administration of other medication (‘‘piggy-backing’’). Smaller horses, ponies, miniature horses, and foals benefit from a more precise means of monitoring the volume of fluid administered. This can be accomplished with the use of volumetric fluid chambers or fluid pumps; however, commercially available pumps can only deliver up to 999 mL/h, which may be insufficient for standard-sized horses. For rapid administration of large volumes of fluids, for example, in the treatment of shock, peristaltic pumps are available that allow delivery of 20 to 40 L of fluids in the first hour. Because of the pulsatile nature of the fluid flow, this method of fluid administration causes more damage to the venous endothelium. For administration of constant rate infusions of small quantities of drugs, syringe pumps are also available. Standard monitoring equipment for use in the ICU includes an electrocardiogram/blood pressure monitor, an ultrasound unit, a centrifuge for hematocrit determination, a refractometer for total protein and urine specific gravity determination, and a urine test strip for urinalysis. Other equipment to consider includes a glucometer, a urine centrifuge, a microscope with 100 magnification, cytology and Gram stains, and a blood gas and electrolyte monitoring unit. A colloid osmometer is a useful unit for
J. Hardy / Vet Clin Equine 20 (2004) 1–10
9
determination of colloid oncotic pressure in sick animals. If provision of mechanical ventilation is planned, useful monitoring equipment includes capnographs and pulse oximeters. Monitoring equipment is frequently equipped with quality control measures that must be performed regularly to ensure accuracy. Appropriate sampling procedures should be followed for each type of equipment. Oxygen ports for supplementation through nasal insufflation or for mechanical ventilation should be available. When installing a new ICU, oxygen, vacuum, and air ports should be considered. A remote gas source and a pipeline system allow for delivery of oxygen. Compressed gas cylinders can be used but must be stored and handled appropriately to avoid injury. For each cylinder type, knowing the capacity of the cylinder and the flow rate being delivered enables calculation of the amount of time oxygen should be provided. The small and more portable E cylinders, containing 655 L of oxygen when full, would provide oxygen for 260 minutes when set at a flow rate of 5 L/min. In adults, flow rates of 10 to 15 L/min are required to increase the fraction of inspired oxygen (FIO2) to approximately 40%. Larger G or H cylinders containing 5290 L or 6910 L, respectively, would allow oxygen supplementation for longer periods. Tight-fitting masks have been used satisfactorily in foals for management of hypoxemia; however, nasal insufflation using an oxygen cannula is better tolerated in adults. In adults with severe respiratory distress that require a greater FIO2, a tracheostomy can be performed using a cuffed silicone cannula (Bivona Medical Technologies, Gary, IN) for administration of oxygen. Oxygen should be humidified, and the estimated FIO2 should not exceed 50% for a prolonged period. An emergency (crash) cart should be available in the ICU. These can be placed in the crash cart for easy reference. In addition, emergency tracheostomy packs should be placed in key areas, such as near the stall of patients with possible respiratory distress, near recovery stalls, and in the patient receiving area. The availability of ultrasonography has also become an essential component of ICUs. Ultrasound can be used for identification and monitoring of effusions, intestinal distention or motility, identification of umbilical structures, imaging of joint effusions, diagnosis of the presence and location of uroabdomen, pregnancy monitoring, evaluation of correct nasogastric feeding tube placement, and imaging of ocular structures among other things. To enable imaging of different structures, 3.5-mHz, 7.5-mHz, and rectal probes are the minimum needed for these purposes. Monitoring Patients in ICU require frequent monitoring. All monitored parameters should be recorded and preferably displayed on or near the patient’s door for rapid review. More complete or extensive laboratory results can be
10
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stored in the patient’s chart. Fig. 4 shows an example of a large animal monitoring and treatment sheet. On this sheet, the patient’s orders are listed and parameters are recorded for easy review.
Summary Careful planning and design of a new ICU are warranted to maximize use of the facility, minimize the risk of hospital-acquired infection, and improve overall patient outcome. In addition, personnel satisfaction improves with an improved work environment. A functional equine ICU is also tailored to the geographic area, local needs of the practice, and anticipated investment.
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