Rescue Events Research Articles

Analysis of Lifeguard-Recorded Data at Hanauma Bay, Hawaii

To describe rescue events at Hanauma Bay using data collected by lifeguards stationed at the bay. Lifeguard collected data documenting estimates of daily beach attendance, and characteristics of rescue victims and events were analyzed for the period 2000 to 2007. A total of 4888 Logsheets spanning 2000 to 2007 and 1567 Incident Reports spanning 2000 to 2002 and 2006 to 2007 documenting 1249 rescues were available for analyses. Lifeguard estimates of attendance summing tallies made at 12, 2, and 4 pm overestimated actual attendance by a factor of 1.78 (SD = 0.08) while estimates summing 12 and 4 pm tallies underestimated actual attendance by a factor of 0.91 (SD = 0.04). Both estimates were strongly correlated with actual attendance values (R = 0.98 and R = 0.98, respectively). The average rescue rate for the study period was 7 rescues per 10,000 bathers. Nonresidents accounted for 88% of all visitors to the bay and accounted for a disproportionate percentage of the rescue population (96%, p-value = 0.04). A majority of rescues (63.2%) occurred at a single location called "The Slot." Following rescues, 91.4% of rescue victims were released to the beach, 5.9% were released to their parents or guardians, and 1.4% required transfer to a hospital via ambulance. Lifeguard estimates of attendance at Hanauma were precise, and summing 12 and 4 pm attendance tallies provided the most accurate estimate of actual attendance. Rescues at Hanauma Bay occurred predominantly among nonresidents and were concentrated to a single location called "The Slot."

In Reply

We appreciate the interest Dr. and Mrs. Rampil have taken in our recent article in Anesthesiology.1As highlighted in their letter, the introduction of surveillance monitoring, as commonly used in the intensive care unit or the operating room, into the general-care setting (a traditionally unmonitored environment) does break new ground. It provides tremendous opportunities for research, education, and improvement in patient safety.In our article, we demonstrated a reduction in intensive care unit transfers by almost 50% and a decrease in rescue events by 65%; in our view, these are meaningful changes. Although we did see a statistically significant reduction in mortality, we deemphasized that change because of a possible small number effect. Even though Dr. and Mrs. Rampil are concerned about adequate power, the study's sample size with 19,070 patient days analyzed was clearly sufficient; indeed, as stated above, we chose to not emphasize some changes (such as mortality), even though they were statistically significant.We do agree that a reduction in intensive care unit transfers and rescue events are proxy outcomes as a measure of escalation in care and that better surveillance prompts earlier intervention, which leads to a reduction in escalation in care. Our interpretation is indeed, as hypothesized by the Rampils, that improved monitoring leads to an increase in early interventions and thus prevents adverse events and an escalation in care. Nursing interventions, such as those triggered by the monitoring system, were by protocol. A measure of these early interventions may be desirable, but we had decided that if a clear link could be established between the introduction of the system and a decrease in escalation of care, we may conclude that it is due to earlier interventions without measuring them directly.We are continuously monitoring overall patient satisfaction, as well as nurse satisfaction, with Patient Surveillance. Patient satisfaction has not changed with the introduction of Patient Surveillance on the unit we reported on, nor on two more surgical units that the system has been introduced to since, while nurse satisfaction has increased.Abenstein and Narr2stated in an accompanying editorial to our article, “Early intervention guided by this system reduced the need for patient rescue interventions, including Intensive Care Unit transfers. These results could have important implications for hospital wards throughout the country.” We entirely agree and would like to point out that much work remains to be done in the area of Patient Surveillance. Our publication was a first step in that direction. We hope that anesthesiologists, given their expertise in patient safety and monitoring, will be at the forefront of these exciting developments.*Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire. andreas.h.taenzer@dartmouth.edu

Where Is the Impact?

As an advocate for patient safety and for the introduction of appropriate monitoring technology into perioperative practice, I read the recent article by Taenzer et al. 1with anticipation. Unfortunately, the conclusions reached by the authors do not appear to be supported by the evidence provided in the article. Specifically, the authors conclude “our results demonstrate that continuous patient surveillance can improve outcomes in a postoperative orthopedic ward setting.” There was no meaningful difference in death, intensive care unit transfer, or hospital stay; the only reported difference was in the number of “rescue” events. The rescue events consisted of several levels of intervention ranging from conventional code blue teams to a bedside visit of an intensive care nurse and a respiratory care technician within 10 min of call. Surely, the “rescues” at the latter end of the range cannot be considered significant clinical or resource utilization outcomes as described within. Although the authors note that the types of rescues activated were collected, the actual distribution by type of event before and after surveillance was not provided in the article.This article does break with tradition in a positive way in that it studies the impact of Spo2surveillance in a clinical area where, by routine practice, patients are only assessed intermittently and where hypoxic events are not rare. In the past, the value of pulse oximetry was assessed in areas where intensive monitoring was already the rule.2One cannot help but be a bit confounded by the results of this study because important data are absent. At its heart, the authors claim that surveillance reduces interventions, but how is this possible? A priori , more monitoring should detect more true hypoxia, which in turn should lead to more interventions (at an earlier stage, perhaps), not fewer, in order to improve true clinical outcomes. Are there important patient care interventions that are excluded from reporting in this article, such as direct nursing care and calls to and action by responsible physicians, among others? No mention is made of what process a floor nurse was to follow, protocol-driven or ad hoc , once notified by the central paging system. Did the frequency of nurse intervention in adjusting a patient's posture or supplemental oxygen delivery, among other actions, change with surveillance?Finally, one is left curious about the impact of more intense respiratory monitoring on postoperative management and patient satisfaction because these are not addressed in the article. We look forward to further research using this model once adequately powered to discern clinically relevant outcomes.*Health Science Center, Stony Brook University, Stony Brook, New York. ira.rampil@sunysb.edu

Wood Cell-Wall Structure Requires Local 2D-Microtubule Disassembly by a Novel Plasma Membrane-Anchored Protein

Plant cells have evolved cortical microtubules, in a two-dimensional space beneath the plasma membrane, that regulate patterning of cellulose deposition. Although recent studies have revealed that several microtubule-associated proteins facilitate self-organization of transverse cortical microtubules, it is still unknown how diverse patterns of cortical microtubules are organized in different xylem cells, which are the major components of wood. Using our newly established in vitro xylem cell differentiation system, we found that a novel microtubule end-tracking protein, microtubule depletion domain 1 (MIDD1), was anchored to distinct plasma membrane domains and promoted local microtubule disassembly, resulting in pits on xylem cell walls. The introduction of RNA interference for MIDD1 resulted in the failure of local microtubule depletion and the formation of secondary walls without pits. Conversely, the overexpression of MIDD1 reduced microtubule density. MIDD1 has two coiled-coil domains for the binding to microtubules and for the anchorage to plasma membrane domains, respectively. Combination of the two coils caused end tracking of microtubules during shrinkage and suppressed their rescue events. Our results indicate that MIDD1 integrates spatial information in the plasma membrane with cortical microtubule dynamics for determining xylem cell wall pattern.

Microtubule length distributions in the presence of protein-induced severing

Microtubules are highly regulated dynamic elements of the cytoskeleton of eukaryotic cells. One of the regulation mechanisms observed in living cells is the severing by the proteins katanin and spastin. We introduce a model for the dynamics of microtubules in the presence of randomly occurring severing events. Under the biologically motivated assumption that the newly created plus end undergoes a catastrophe, we investigate the steady-state length distribution. We show that the presence of severing does not affect the number of microtubules, regardless of the distribution of severing events. In the special case in which the microtubules cannot recover from the depolymerizing state (no rescue events) we derive an analytical expression for the length distribution. In the general case we transform the problem into a single ordinary differential equation that is solved numerically.

Impact of Pulse Oximetry Surveillance on Rescue Events and Intensive Care Unit Transfers

Some preventable deaths in hospitalized patients are due to unrecognized deterioration. There are no publications of studies that have instituted routine patient monitoring postoperatively and analyzed impact on patient outcomes. The authors implemented a patient surveillance system based on pulse oximetry with nursing notification of violation of alarm limits via wireless pager. Data were collected for 11 months before and 10 months after implementation of the system. Concurrently, matching outcome data were collected on two other postoperative units. The primary outcomes were rescue events and transfers to the intensive care unit compared before and after monitoring change. Rescue events decreased from 3.4 (1.89-4.85) to 1.2 (0.53-1.88) per 1,000 patient discharges and intensive care unit transfers from 5.6 (3.7-7.4) to 2.9 (1.4-4.3) per 1,000 patient days, whereas the comparison units had no change. Patient surveillance monitoring results in a reduced need for rescues and intensive care unit transfers.

THIS MONTH IN Anesthesiology

Postoperative noninvasive ventilation can help prevent postoperative hypoxemia and acute respiratory failure.Chinese anesthesiologists are poised to play a significant role in tobacco control in China.Hypercapnia may be beneficial in early sepsis, but potentially deleterious in prolonged sepsis. See the accompanying Editorial View on page 269 Dose of local anesthetic but not concentration and volume influence nerve block characteristics.Techniques on ultrasound-guided peripheral nerve blocks of the extremities and trunk are discussed.Unrecognized patient deterioration in the postoperative period may lead to increased intensive care unit (ICU) admission rates or even death. A patient surveillance system based on pulse oximetry and wireless pagers was used for nursing notification of violation of alarm limits. Data were collected on a postoperative orthopedic ward for 11 months before and 10 months after implementation of the system and compared with matched outcome data on two other postoperative units. Rescue events decreased by 2.2 per 1,000 patient discharges and ICU transfers by 1.7 per 1,000 patient days while the comparison units had no change. Rescue events and ICU transfers were decreased after implementation of this patient surveillance system on a postoperative orthopedic ward. See the accompanying Editorial View on page 272 Factor VII is affected during the early phase of warfarin therapy and high international normalized ratios (INR > 1.4) are considered unsafe for epidural catheter placement or removal by the American Society of Regional Anesthesia. Data from 121 patients who took warfarin after undergoing total joint surgery and had INRs and factor VII levels determined were reviewed. Patients had INR > 1.4 on postoperative days (POD) 1 (n = 11), POD 2 (n = 78), and POD 3 (n = 84) and mean factor VII activities were 60 ± 28%, 32 ± 15%, and 44 ± 19%, respectively. Predictors of INR > 1.4 on POD 2 were warfarin dose on POD 1 and factor VII activity on POD 2. The range of factor VII activities in the patients with INR > 1.4 within 12 h of warfarin therapy was compatible with adequate hemostasis. Based on factor VII activity levels, the authors found no evidence that epidural catheters should not be removed even with INR up to 1.9, the highest INR on POD 1 noted in their study. See the accompanying Editorial View on page 277 Intubation efficiency varies depending on the type of laryngoscope blade used. In a multicenter cluster randomized trial, 1,072 adult patients undergoing general anesthesia under emergency conditions and requiring rapid sequence induction were randomly assigned on a weekly basis to either single-use or reusable metal blades. The rate of failed intubation was significantly decreased with metal single-use blade at the first attempt compared with the reusable blade (2.8% vs. 5.4%). The proportion of grades 3 and 4 in Cormack and Lehane score were also significantly decreased with single-use metal blade (6% vs. 10%). The global complication rate tended to be lower in the single-use group (6.8% vs. 11.5%). The single-use metal blade was more efficient than a reusable metal blade in rapid sequence induction of anesthesia for emergency surgery.

An Ounce of Prevention May Equate to a Pound of Cure

An Ounce of Prevention May Equate to a Pound of Cure

Kinetochores Generate Microtubules with Distal Plus Ends: Their Roles and Limited Lifetime in Mitosis

SummaryIn early mitosis, microtubules can be generated at kinetochores as well as at spindle poles. However, the role and regulation of kinetochore-derived microtubules have been unclear. In general, metaphase spindle microtubules are oriented such that their plus ends bind to kinetochores. However, we now have evidence that, during early mitosis in budding yeast, microtubules are generated at kinetochores with distal plus ends. These kinetochore-derived microtubules interact along their length with microtubules that extend from a spindle pole, facilitating kinetochore loading onto the lateral surface of spindle pole microtubules. Once kinetochores are loaded, microtubules are no longer generated at kinetochores, and those that remain disappear rapidly and do not contribute to the metaphase spindle. Stu2 (the ortholog of vertebrate XMAP215/ch-TOG) localizes to kinetochores and plays a central role in regulating kinetochore-derived microtubules. Our work provides insight into microtubule generation at kinetochores and the mechanisms that facilitate initial kinetochore interaction with spindle pole microtubules.

γ-Tubulin ring complexes regulate microtubule plus end dynamics

gamma-Tubulin is critical for the initiation and regulation of microtubule (MT) assembly. In Drosophila melanogaster, it acts within two main complexes: the gamma-tubulin small complex (gamma-TuSC) and the gamma-tubulin ring complex (gamma-TuRC). Proteins specific of the gamma-TuRC, although nonessential for viability, are required for efficient mitotic progression. Until now, their role during interphase remained poorly understood. Using RNA interference in Drosophila S2 cells, we show that the gamma-TuRC is not critical for overall MT organization. However, depletion of any component of this complex results in an increase of MT dynamics. Combined immunofluorescence and live imaging analysis allows us to reveal that the gamma-TuRC localizes along interphase MTs and that distal gamma-tubulin spots match with sites of pause or rescue events. We propose that, in addition to its role in nucleation, the gamma-TuRC associated to MTs may regulate their dynamics by limiting catastrophes.

Irc15 Is a Microtubule-Associated Protein that Regulates Microtubule Dynamics in Saccharomyces cerevisiae

Microtubules are polymers composed of alpha-beta tubulin heterodimers that assemble into microtubules. Microtubules are dynamic structures that have periods of both growth and shrinkage by addition and removal of subunits from the polymer. Microtubules stochastically switch between periods of growth and shrinkage, termed dynamic instability. Dynamic instability is coupled to the GTPase activity of the beta-tubulin subunit of the tubulin heterodimer. Microtubule dynamics are regulated by microtubule-associated proteins (MAPs) that interact with microtubules to regulate dynamic instability. MAPs in budding yeast have been identified that bind microtubule ends (Bim1), that stabilize microtubule structures (Stu2), that bundle microtubules by forming cross-bridges (Ase1), and that interact with microtubules at the kinetochore (Cin8, Kar3, Kip3). IRC15 was previously identified in four different genetic screens for mutants affecting chromosome transmission or repair [11-14]. Here we present evidence that Irc15 is a microtubule-associated protein, localizing to microtubules in vivo and binding to purified microtubules in vitro. Irc15 regulates microtubule dynamics in vivo and loss of IRC15 function leads to delayed mitotic progression, resulting from failure to establish tension between sister kinetochores.

Wilderness Rescue and Border Enforcement Along the Arizona Mexico Border—The Border Patrol Search, Trauma and Rescue Unit

To introduce and describe the US Border Patrol (USBP) Tucson Sector Border Patrol Search, Trauma and Rescue Unit (BORSTAR) and to analyze whether the frequency of its activities were associated with the amount of total border patrol law enforcement activities in the area. Descriptive and nonparametric analysis was conducted on data that were obtained on total USBP apprehensions of undocumented immigrants and BORSTAR activities for a consecutive 3-year period. From October 2004 to September 2007 over 1 million apprehensions occurred within the Tucson Sector. During this time, a large number of search, rescue, and medical intervention events occurred. However, only a weak association was found between the frequency of apprehensions and BORSTAR activities. The BORSTAR unit of the Tucson Sector commonly encounters harsh conditions and provides search, rescue, and medical interventions to undocumented immigrants. The frequency of BORSTAR activities is not strongly associated with the volume of USBP law enforcement activities.

Detection of GTP-Tubulin Conformation in Vivo Reveals a Role for GTP Remnants in Microtubule Rescues

Microtubules display dynamic instability, with alternating phases of growth and shrinkage separated by catastrophe and rescue events. The guanosine triphosphate (GTP) cap at the growing end of microtubules, whose presence is essential to prevent microtubule catastrophes in vitro, has been difficult to observe in vivo. We selected a recombinant antibody that specifically recognizes GTP-bound tubulin in microtubules and found that GTP-tubulin was indeed present at the plus end of growing microtubules. Unexpectedly, GTP-tubulin remnants were also present in older parts of microtubules, which suggests that GTP hydrolysis is sometimes incomplete during polymerization. Observations in living cells suggested that these GTP remnants may be responsible for the rescue events in which microtubules recover from catastrophe.

The Prevalence of and Risk Factors for Adverse Events in Children Receiving Patient-Controlled Analgesia by Proxy or Patient-Controlled Analgesia After Surgery

Recent reports emphasize the risks associated with patient-controlled analgesia by proxy (PCA-P), yet data regarding such risks in children remain sparse. We compared the prevalence of clinically significant adverse events in children receiving PCA-P versus PCA, and examined factors that place children at increased risk. The records were reviewed of opioid-naïve children, ages birth to 18 yr, who received PCA or PCA-P after surgery. Data included demographics, comorbidities, perioperative information, pain, sedation, and respiratory assessments, oxygen saturation, analgesics, adverse outcomes, and interventions. This study included 145 children who received PCA-P and 157 PCA. The PCA-P group was younger and had more comorbidities (P < 0.05). Opioid orders were similar, but pain scores and opioid dosages were lower, and fewer children received diazepam in the PCA-P group (P < 0.05). Clinically significant adverse events (i.e., those requiring intervention) occurred in 22% and 24% of patients in the PCA-P and PCA groups, respectively; however, more children in the PCA group had "threshold events" (minor intervention) and more in the PCA-P group had "rescue events" (opioid reversal or escalation of level of care). Respiratory events occurred earlier in the PCA-P group (P < 0.05). Factors associated with adverse events included orthopedic surgery, cognitive impairment, respiratory comorbidity, use of continuous basal opioid infusion, use of diazepam, and larger opioid doses on days 1, 2, and 3. Yet, cognitive impairment and opioid dose on day 1 were the only factors independently predictive of these events. This study found that although a significant number of children receiving PCA and PCA-P experienced adverse events, there was no difference in the prevalence between groups. The PCA-P group was at greater risk for events requiring rescue interventions, perhaps due to the prevalence of underlying comorbidities. These findings emphasize the need for vigilant monitoring to facilitate early recognition and timely intervention of respiratory depression.

Failure to Rescue

Rapid response teams have been advocated as an intervention to reduce failure to rescue events. Such teams can improve nurse autonomy and control to rescue patients deteriorating in a medical surgical setting. The purpose of this review is to enhance nurse executives' understanding of failure to rescue as a nurse sensitive outcome, tested interventions, and implications for future research. The emergence of failure to rescue as an outcome measure will be initially discussed. Research regarding the relationship between failure to rescue and registered nurse staffing as well as research examining the potential to reduce failure-to-rescue events will be explored.

Appropriate suppression of Notch signaling by Mesp factors is essential for stripe pattern formation leading to segment boundary formation

Mesp1 and Mesp2 are homologous transcription factors that are co-expressed in the anterior presomitic mesoderm (PSM) during mouse somitogenesis. The loss of Mesp2 alone in our conventional Mesp2-null mice results in the complete disruption of somitogenesis, including segment border formation, rostro-caudal patterning and epithelialization of somitic mesoderm. This has led us to interpret that Mesp2 is solely responsible for somitogenesis. Our novel Mesp2 knock-in alleles, however, exhibit a remarkable upregulation of Mesp1. Removal of the pgk-neo cassette from the new allele leads to localization of Mesp1 and several gene expression, and somite formation in the tail region. Moreover, a reduction in the gene dosage of Mesp1 by one copy disrupts somite formation, confirming the involvement of Mesp1 in the rescue events. Furthermore, we find that activated Notch1 knock-in significantly upregulates Mesp1 expression, even in the absence of a Notch signal mediator, Psen1. This indicates that the Psen1-independent effects of activated Notch1 are mostly attributable to the induction of Mesp1. However, we have also confirmed that Mesp2 enhances the expression of the Notch1 receptor in the anterior PSM. The activation and subsequent suppression of Notch signaling might thus be a crucial event for both stripe pattern formation and boundary formation.

Adverse Patient Events and Knowledge Development Needs

Extensive initiatives are under way to improve the quality of patient care and to create safer patient care environments. Some of these efforts focus on creating a culture of safety that overtly encourages and supports reporting of any patient care circumstance that threatens the safety of patients or caregivers. Others focus on specific processes of care where patients are known to be at high risk for developing complications. In general these complications are viewed as adverse events, and efforts are directed toward identifying how they might be prevented from occurring. Various types of events have been identified and research is ongoing to analyze their possible root causes and to design and test interventions that might prevent their occurrence in the future. Adverse events are defined as any patient injury caused by clinical care. An adverse event does not imply error or poor quality care, although in some situations this may be the case. The label of adverse event simply indicates that an undesirable clinical outcome has resulted from some aspect of diagnosis or therapy, which may be associated with an underlying disease process (Agency for Healthcare Research and Quality, 2006). These adverse events are equivalent to iatrogenic events. An example to illustrate an adverse event due to different circumstances is anaphylactic reaction to penicillin. A serious allergic reaction to penicillin in a patient with no prior history of this allergy would be classified as an adverse drug event. Another example of an adverse event would be a patient with a known history of penicillin allergy who receives penicillin due to a prescribing error. Both examples are classified as adverse events, but only the prescribing error would be considered preventable. A number of adverse events are receiving intense scrutiny because they are deemed preventable. Some have been labeled as failure to rescue events, or the failure to prevent a clinically important deterioration in the patient such as death or permanent disability from a complication of an underlying illness (Silber, Williams, Krakauer, & Schwartz, 1992). An example of this type of complication is occurrence of a cardiac arrest or a major hemorrhage after thrombolysis in acute myocardial infarction. Failure to rescue provides a measure of the degree to which clinicians respond to adverse events that developed in patients under their care. These types of events may reflect the quality of monitoring of high-risk patients, the effectiveness of actions taken-or not taken-once early complications are recognized, or both. Rates of failure to rescue have been found to correlate with other measures of quality of care (Silber, Rosenbaum, Schwartz, Ross, & Williams, 1995). They have also served as outcome measures in studies examining the impact on quality care of nurse staffing ratios and educational levels (Aiken, Clarke, Sheung, Sloane, & Silber, 2003; Aiken, Clarke, Sloane, Sochalski, & Silber, 2002). Some adverse events have been labeled as nurse-sensitive outcomes, or outcomes that are influenced in some way by nursing practice. These include the development of complications such as deep venous thrombosis (DVT), pulmonary embolus (PE), and acquired pneumonia in ventilated-assisted patients (National Quality Forum, 2006). Including nursing practice as a key variable in adverse clinical outcomes generates an urgent need for research and knowledge development around nursing's contribution to and role in providing safe patient care. …

Making Microtubules and Mitotic Spindles in Cells without Functional Centrosomes

Centrosomes are considered to be the major sites of microtubule nucleation in mitotic cells (reviewed in ), yet mitotic spindles can still form after laser ablation or disruption of centrosome function . Although kinetochores have been shown to nucleate microtubules, mechanisms for acentrosomal spindle formation remain unclear. Here, we performed live-cell microscopy of GFP-tubulin to examine spindle formation in Drosophila S2 cells after RNAi depletion of either gamma-tubulin, a microtubule nucleating protein, or centrosomin, a protein that recruits gamma-tubulin to the centrosome. In these RNAi-treated cells, we show that poorly focused bipolar spindles form through the self-organization of microtubules nucleated from chromosomes (a process involving gamma-tubulin), as well as from other potential sites, and through the incorporation of microtubules from the preceding interphase network. By tracking EB1-GFP (a microtubule-plus-end binding protein) in acentrosomal spindles, we also demonstrate that the spindle itself represents a source of new microtubule formation, as suggested by observations of numerous microtubule plus ends growing from acentrosomal poles toward the metaphase plate. We propose that the bipolar spindle propagates its own architecture by stimulating microtubule growth, thereby augmenting the well-described microtubule nucleation pathways that take place at centrosomes and chromosomes.

Surviving Collapsed Structure Entrapment after Earthquakes: A “Time-to-Rescue” Analysis

Massive earthquakes often cause structures to collapse, trapping victims under dense rubble for long periods of time. Commonly, this spurs resource intensive, dangerous, and frustrating attempts to find and extricate live victims. The search and rescue phase usually is maintained for many days beyond the last "save," potentially diverting critical attention and resources away from the pressing needs of non-trapped survivors and the devastated community. This recurring phenomenon is driven by the often-unanswered question "Can anyone still be alive under there?" The maximum survival time in entrapment is an important issue for responders, yet little formal research has been conducted on this issue. Knowing the maximum survival time in entrapment helps responders: (1) decide whether or not they should continue to assign limited resources to search and rescue activities; (2) assess the safety risks versus the benefits; (3) determine when search and rescue activities no longer are indicated; and (4) time and pace the important transition to community recovery efforts. The time period of 1985-2004 was selected for investigation. Medline and Lexis-Nexis databases were searched for earthquake events that occurred within this timeframe. Medical literature articles providing time-torescue data for victims of earthquakes were identified. Lexis-Nexis reports were scanned to select those with time-to-rescue data for victims of earthquakes. Reports from both databases were examined for information that might contribute to prolonged survival of entrapped individuals. A total of 34 different earthquake events met study criteria. Forty-eight medical articles containing time-to-rescue data were identified. Of these, the longest time to rescue was "13-19 days" post-event (secondhand data and the author is not specific). The second longest time to rescue in the medical articles was 8.7 days (209 hours). Twenty-five medical articles report multiple rescues that occurred after two days (48 hours). Media reports describe rescues occurring beyond Day 2 in 18 of 34 earthquakes. Of these, the longest reliably reported survival is 14 days after impact, with the next closest having survived 13 days. The average maximum times reported from these 18 earthquakes was 6.8 days (median = 5.75 days). The event with the most media reports of distinct rescue events was the 1999 Marmara, Turkey earthquake (43 victims). Times range from 0.5 days (12 hours) to 6.2 days (146 hours) for this event. Both databases provide little formal data to develop detailed insight into factors affecting survivability during entrapment. A thorough search of the English-language medical literature and media accounts provides a provocative picture of numerous survivors beyond 48 hours of entrapment under rubble, with a few successfully enduring entrapment of 13-14 days. These data are not necessarily applicable to non-earthquake collapsed-structure events. For incident managers and their medical advisors, the study findings and discussion may be useful for post-impact decision-making and in establishing and/or revising incident priorities as the response evolves.

Stochastic models in population biology and their deterministic analogs

We introduce a class of stochastic population models based on "patch dynamics." The size of the patch may be varied, and this allows one to quantify the departures of these stochastic models from various mean-field theories, which are generally valid as the patch size becomes very large. These models may be used to formulate a broad range of biological processes in both spatial and nonspatial contexts. Here, we concentrate on two-species competition. We present both a mathematical analysis of the patch model, in which we derive the precise form of the competition mean-field equations (and their first-order corrections in the nonspatial case), and simulation results. These mean-field equations differ, in some important ways, from those which are normally written down on phenomenological grounds. Our general conclusion is that mean-field theory is more robust for spatial models than for a single isolated patch. This is due to the dilution of stochastic effects in a spatial setting resulting from repeated rescue events mediated by interpatch diffusion. However, discrete effects due to modest patch sizes lead to striking deviations from mean-field theory even in a spatial setting.