Percutaneous Aspiration of Intra-Peritoneal Fluid in Weightlessness: A Potential Component for the Management of Secondary Peritonitis in Deep Space: Treatment Options Suggested by the NASA MicrogravityResearch Program
1A.W. Kirkpatrick, 2M. R. Campbell, 1S. Nicolaou, 2A.E. Sargsyan, 3S.A. Dulchavsky, 2S. Melton, 4D. L. Dawson, 4R. D. Billica, 4D. R. Williams, 4S. L. Johnston, 2D. R. Hamilton
1Vancouver General Hospital Vancouver, British Columbia.
2Wyle Life Sciences, Houston, TX.,
3Wayne State University Detroit, MI.
4Space and Life Science Directorate National Aeronautics and Space Administration Houston, TX.,
(Address for Correspondence)
AW Kirkpatrick MD FRCSC
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Abstract
Background Introduction:Secondary peritonitis is a medical emergency that usually requiringes surgeryical intervention. Often fatal without appropriate treatment, peritonitis can develop as a consequence of diseases that can affect even well-screened, healthy individuals. If an astronaut develops an acute abdomen with peritonitis during a long-duration space exploration mission, on-board urgent and follow-up on care will have to be provided, but resource constraints and environmental factors may dictate significant deviations from traditional terrestrial medical management approaches. While traditional surgical approaches are possible they are not feasible now or in the near future for space. Medical management can successfully treat many intra-abdominal processes that lead to secondary peritonitis, but treatment failures are inevitable. Percutaneous aspiration with real time sonographic guidance can provide “rescue” from the need for emergency surgery by providing a drainage route for abscesses or infectedion enteric contents drainage without the physiologic consequences or logistical requirements of surgery. Percutaneous fluid aspiration has not previously been reported in weightlessness.Investigations in the microgravity research environment of parabolic flight, have direct applications to promulgating treatment strategies that are feasible in weightlessness.
Hypothesis: Successful sonographically guided percutaneous aspiration of intra-peritoneal fluid can be performed with attention to restraint of the subject, operators, and equipment.
Methods: Investigations were carried out in the weightless environment of NASA’s KC-135 research aircraft (0g). The study subjects were a series of fully anesthetisedanesthetized female 50kg Yorkshire pigs. The procedures were rehearsed in a tererestrialterrestrial animal lab (1g). Prior to flight, intra-peritoneal catheters (_____) were placed, and 500. Five hundred cc of colored saline were introduced during flight. Both high-definition broadband (HDI-5000A , ATL, USA) and a 2.4 kg portable handheld (Sonosite 180, Sonosite, WA) ultrasound systems were_____ ultrasound machine was used to guide the percutaneous placement of a 16 guagegauge needle into the peritoneal cavity and to aspirate the colored fluid. Still digital and analogue video recordings were made the aspiration. In a series of eight flights aboard NASA’s KC-135 microgravity research aircraft, the characteristics in weightlessness of open and endoscopic surgical procedures, endoscopic surgical procedures, sonographic diagnostic techniques, and sonographically directed interventional techniques were examined. Endoscopic surgical techniques included thoracoscopy and laparoscopy. Interventional techniques for percutaneous aspiration of simple fluid collections, and hollow organsgallbladders, and urinary bladders were examined.
Results: Intra-peritoneal fluid collections were easily identified in sub-peritoneal locations, that, that were distinct from surrounding viscera, and on occasion became more obvious during transition from hypergravity to weightless conditions. The aspiration needle could readily be followed during the insertion phase,phase and fluid easily withdrawn from the peritoneum. The subjective difficulty was no more demanding with adequate restraint of the subject and operators than during the 1g rehearsals.
Findings: Both open and endoscopic surgical procedures are feasible if equipment and supplies are available, and there is careful attention to restraint of operators, patients, and equipment. Endoscopic procedures offer the advantages of a semi-closed surgical environment and the potential for lessened post-operative requirements, but at the expense of greater logistic requirement and a need for advanced surgical proficiency. Evaluations of diagnostic ultrasound imaging have shown that results in weightlessness can match or exceed those in 1g. The first successful sonographically-guided percutaneous interventional techniques in weightlessness were successfully completed.
Conclusions:Sonographically directed percutaneous aspiration of intra-peritoneal collections is feasible in weightlessness. OpResource constraints limit treatment options for secondary peritonitis during operations in distant space. Both open and endoscopic surgical interventions could be performed if the equipment and trained operators were aboard. Given practical limitations, alternatives could involve such as primary emphasis on medical (pharmacological) treatment of most inflammatory conditions that can lead to peritonitis, with secondary reliance on a sonographically guided percutaneous aspiration for the rescue of treatment failures. This compromise strategy may simplify treatment in antheresource-limited operational setting, but at the risk of treatment failures. This strategy cannot guarantee the return to health of all afflicted but may have the highest level of practicality given resource limits. Definitive surgical interventions in space remain a long-term goal.
Keywords: Weightlessness, Space Flight, Peritonitis, Surgery, Percutaneous Drainage
Introduction
With the reality of the Medical care capabilities for the International Space Station (ISS), planning is beginning for and future exploratory space missions. A manned mission to Mars is planned for his century. Numerous human health risks have been identified which include microgravity specific health concerns as well as routine medical care. Addressing the care and management of intra-abdominal conditions are a high priority for space medicine because there are a number of potentially fatal disease processes that can arise in the previously healthy young adult. Emergent surgical conditions such as acute appendicitis are potentially disastrous to both an individual’s health and the entire mission6 20 22 30 (Trunkey 1992)(Trunkey 1986)(MCCuaig 1992)(Campbell 93)(McCuaig 1994). Acute surgical emergencies have already been considered in the differential diagnosis of previous Russian space illnesses3 4(Campbell 1998)(Trunkey 1986)(Campbell 1992 blue). The most common and hence likely surgical emergencies are the spontaneous causes of secondary peritonitis; aappendicitis, perforated peptic ulcers, perforated sigmoid colon (diverticulitis, volvulus, or cancer), strangulation or obstruction of the small intestine, necrotising pancreatitisfrom 2 27. Intra-abdominal abscesses are a sequalae of these conditions that may arise in the course of disease, even with the best of treatment.
Often these conditions may arise without there being any pre-existing signs that would allow detection during pre-flight screening. Acute appendicitis afflicts one in seven individuals at some point in our lives31. Risk factors for diverticulitis, neoplastic obstruction, inflammatory bowel disease, or pancreatitis may or may not be detected through detailed pre-flight testing. New conditions may arise during a five year mission, especially with an older astronaut population or due to the many physiological stressors to be faced in space16. None the least of which includes ionizing radiation with carcinogenic risks. Gene probe testing has the potential to detect genetic pre-disposition to various serious disease, but has limited scope at present and unresolved ethical issues regarding personal privacy ethics15.
Unless a palliative approach to serious illness and injury is decided upon for a potential Mars mission, the ability to treat intra-abdominal pathology predisposing to peritonitis will be required. A limited number of studies have examined formal open and minimally invasive surgery in weightlessness. These studies have demonstrated that surgical procedures are feasible, but realistic logistical constraints may override this need.If surgery is not feasible though another approach ids required. The likely approach will be medical management of inflammatory conditions such as appendicitis as it is now practiced in the submarine population who remain submerged for many months. With an evacuation delay of 9 to 12 months for a Mars Mission required for a treatment failure though, a “rescue” option will beis still required for these failures. Image guided percutaneous aspiration of fluid is a potential rescue approach that has never been reported before in weightlessness.
The diagnosis and treatment of urologic disorders such as urinary retention and urinary calculi are a high priority as these conditions mandate definitive treatment to reduce the chance of mission ending consequences.
The risk of urinary retention is increased in older astronauts and can be compounded by flight medications to combat motion sickness. Pre-flight screening for urinary calculi reduces the early risk of this problem, however, elevated urinary excretion of calcium due to bone resorbtion may lead to stone formation in long duration flights.A previous medical evaucation from the Russian space program was nearly required because of an episode of urtolithiasis (Campbell 1999).(I also think there was an evacuation for prostatitis but I can’t come up with the ref right now – Maybe Mark knows!).
Foley catheters are manifested in the Shuttle and International Space Station Medical Kit, however, the inability to pass a urinary catheter would present significant medical and logistic problems. Percutaneous bladder catherization is a terrestrial standard of practice in patients who are unable to be catherized. The technique can be reliably accomplished with minimum morbidity following modest training. This report documents the first microgravity bladder catherization in an animal model during parabolic flight on the NASA KC-135.
BackgroundThe International Space Station is a now reality, and there is an increased risk of both spontaneous and traumatic conditions requiring surgical intervention. Surgical procedures in space were carried out for the first time using animal models, aboard the Space Shuttle Columbia, during the Neurolab mission. Previous research in Space analogue environments allowed predictions to be made regarding surgical care in space. The ability to complete surgical tasks in continuous microgravity was evaluated in the context of these prior predictions.
MethodsSurgical procedures were performed on live anaesthetised rats, in the General Purpose Work Station (GPWS) of the Space Shuttle Endeavour. Surgical procedures were performed in different body areas, including the extremities, thoracic, and abdominal cavities.
ResultsThere were no obvious proprioceptive changes in the operators and the technical performance of complex surgical procedures did not appear to be compromised. The inconvenient aspects of weightlessness including lack of fixation, vertical reference, and inertia, could be satisfactorily overcome with attention and planning in preparing equipment and in the conduct of a procedure. Biological fluids remained localised to the operative fields forming fluid domes. Simple means of controlling biological fluids relying primarily on the property of surface tension were remarkably effective.
ConclusionsThere did not appear to be obvious physical and psychomotor changes in the operators due to short-term microgravity exposure. Surgical procedures could be performed in a manner analogous to both the 1g reference, and previous 0g parabolic flight models. Concepts and techniques developed in previous terrestrial investigations during parabolic flight appear to be valid when tested in the actual space environment. Work should continue in parabolic flight to prepare and validate techniques and equipment that can be further tested, or even used clinically in orbit should the requirement for surgical intervention arise.
Keywords:Weightlessness, Injury, Surgery, Surgical Techniques
Introduction
The International Space station in orbit now, signals a new commitment to manned Space exploration. Further interplanetary voyages are now being planned. Exploration will not be without risks to the individuals selected to carry out these missions. Although countermeasures to prevent a medical occurrence requiring surgical intervention in space are preferable, contingency plans for actual surgical interventions are required. Traumatic injuries occur at unanticipated times, affect the healthiest of individuals, and have been ranked at the highest levels when considering their potential impact on the outcomes of space missions{Billica RD, Pool SL, et al. 1994 #10} (Billica 1994). Emergent surgical conditions such as acute appendicitis are potentially disastrous to both an individual’s health and the entire mission{Trunkey DD & Frank IC 1986 #2540}{McCuaig KE & Houtchens BA 1992 #390}{Campbell MR, Billica RD, et al. 1993 #2410}{McCuaig K 1994 #310} (Trunkey 1992)(Trunkey 1986)(MCCuaig 1992)(Campbell 93)(McCuaig 1994). Acute surgical emergencies have already been considered in the differential diagnosis of previous Russian space illnesses and evacuations and are operational concerns {Campbell MR & Billica RD 1992 #2440}{Campbell MR 1999 #210}(Campbell 1998)(Trunkey 1986)(Campbell 1992 blue). Despite an enormous capital expenditure on transportation systems for space exploration, there has been only a limited evaluation of the enabling technologies to provide the critical care and surgical procedures that might be required to treat acute surgical conditions in space.
In an absolutely hostile environment, biomedical engineers have been remarkably successful in protecting humans from many of the potential hazards including; hypoxia; short-term radiation injury; environmental toxicants, and extremes of temperature, acceleration, and barometric pressure. Human physiology remains a limiting factor though. Physiological changes due to weightlessness are serious obstacles to long duration space exposure. Initial investigations into the ability to provide artificial gravity, or analogue physical forces to simulate gravitational effects, have been encouraging, but are still logistically daunting{Davis JR 1998 #2470}{Sieving DL 1996 #2550} (Sieving 1996)(Davis 1998) . Planning of surgical interventions must therefore plan for the delivery of surgical care in the weightless environment of orbital flight, technically known as the microgravity environment{Kirkpatrick AW, Campbell MR, et al. 1997 #60} (Kirkpatrick 1997) .
Methods
Four (n = 4) fifty (50 kg) female Yorkshire pigs were used as the experimental model. Ethical approval was obtained for the study from the NASA/JSC ,and University of Texas Medical Branch-Galveston, and the University of British Columbia Animal Use Committees. The procedures described herein conformed to the NIH Guidelines for the Care of Laboratory Animals. and were approved by the NASA/JSC and University of Texas Medical Branch-Galveston Animal Use Committees. The animal was prepared at an offsite animal facility (UTMB-Galveston) prior to transport to Ellington Field, Texas for the flight. The animals wereas anesthetized with pentobarbital, intubated, and maintained with intravenous pentobarbital. Arterial and venous catheters were inserted and a foley catheter was placed to drainage. In order to perform trauma sonography and laparoscopic investigations (not reported herein) Aa single midline 8 french gauge radoiopaqueradiopaque 23.5 cm peritoneal lavage catheter (Arrow International, Reading, PA) Peritoneal Lavage Catheter: 8 French gauge radoiopaque 23.5 cm peritoneal lavage catheter rperitoneal lavage catheters (Arrow International, Reading, PA) was inserted using a closed Seldinger technique. Laparoscopic ports were also placed under direct and laparoscopic visualization in order to perform further sonographic and laparoscopic investigations (not reported herein). The animals were ventilated with a portable transport ventilator (Model 754 Impact Instrumentation, Caldwell, NJ),LAMA or Autovent ventilator and closely monitored with EKG, arterial blood pressure, tidal volume, oximetry, and end tidal capnography. In order to perform trauma sonography and laparoscopic investigations (not reported herein) the animals were prepared with single midline 14g peritoneal lavage catheters (manufact).
ZThe zero gravity (0g) studies were performed onboard the NASA KC-135 aircraft during parabolic flight. Each parabola consisted of two phases lasting approximately 2 minutes; 30-40 seconds of 2g followed by approximately 15-20 seconds of transition, followed by 30-40 seconds of 0g flight followed by another transition period. The animal, life support, monitoring equipment, and ultrasound equipment were secured to the aircraft floor for parabolic flight prior to takeoff.. (figure 1.). HARDWARE
Diagnostic imaging was performed with an Advanced Technologies Laboratory model HDI 5000 ultrasound system (Bothell, Wa) that is functionally identical to the repackaged model designed to fit within the Human Research Facility (HRF) rack in the laboratory module of the International Space Station Human Research Facility. The 2.75 mHz curved array transducer used for this experiment was also identical to that being flown with the HRF ultrasound. A portable 2.4 kg portable handheld (Sonosite 180, Sonosite, WA) was also used for imaging. The output from both ultrasound units was visualized real-time on a separately mounted monitor and was video-recorded and annotated for later analysis.
Prior to the percutaneous interventions parabolic flight, 500200 cc of colored saline was instilled in the peritoneal cavity through the peritoneal lavage catheters. An 18 gauge 6.35 cm XTW needle with a 5 cc Arrow Raulerson syringe (Arrow International, Reading, PA) (central line catheter – get manufact) was utilisedutilized for intra-peritoneal imaging and fluid aspiration. The aspiration procedure was rehearsed in a ground lab animal facility to framiliarisefamiliarize the operators with the technique, anatomy, and fluid behavior in the porcine peritoneal cavity. During the flight phase, ubladder through a Foley catheter which was clamped for the duration of the flight. Ultrasound of the abdomen and pelvis was performed during all phases of the flight toflight to evaluate human factors, ultrasound image quality, and visualization of the intra-peritoneal fluid collections, and the feasibility of real time fluid aspiration in weightlessnessbladder for subsequent percutaneous bladder catherization procedures.
A 10.3 F, hydrophilic pigtail catheter was used for catherization of the bladder (Catalog # 27-135, Boston Scientific, Boston MA). The intra-peritoneal fluid collectionbladder was visualized during the 0g, 2g, and transition portions of the flight profile. Actual aspiration of fluid and the catherization was done during the 0 g maneuver. An autopsy was performed at the animal care facility to evaluate catheter placement and to exclude abdominal visceral injury. The return of colored fluid with aspiration along with imagingwith imaging of the needle within the fluid collection was used as a indicator of task completion.
The laparoscopic and thorascopic procedures were performed on ten adult pigs weighing approximately fifty kilograms under general intravenous anesthesia (Pentobarbital titration) followed by euthanasia at the end of each flight. The animals were maintained on a LAMA or Autovent ventilator and closely monitored with EKG, arterial blood pressure, tidal volume, oximetry, and end tidal CO2. The procedures were performed on a series of eight flights in the NASA Reduced Gravity Program utilizing a modified KC-135 from 1993 to 2000. A parabolic simulation system for Advanced Life Support had previously been developed and was used for this project. This system incorporated standardized equipment, procedural techniques, porcine animal model, and project team members to eliminate as many investigational variables as possible. Twenty to forty parabolas, each containing approximately thirty seconds of zero gravity alternating with 2-g pullouts, were used for laparoscopic or thorascopic investigation on each flight. If a part of the surgical procedure was time consuming and not critical to evaluation, such as equipment deployment, then it was performed during the pullout before the next zero gravity window. The project was reviewed and supervised by the Institutional Animal Care and Use (IACUC) committees at NASA Johnson Space Center, Houston, TX, the St. Joseph’s Surgical Training Center in Houston, TX, the University of British Columbia, Vancouver, Canada, and the University of Texas Medical Branch in Galveston, TX following the "Guide for the Care and Use of Laboratory Animals - NIH Publication #86-23". The project was also reviewed by the Institutional Review Board at NASA Johnson Space Center in Houston, TX.