Anesthesia in the News
  • Inadvertent Hypothermia Under Anesthesia

    Inadvertent hypothermia in anesthesia and clinical perioperative nursing care may cause serious complications for patients, including cardiac events, infections, and increased risk of surgical bleeding.  Yet the authors of a recent qualitative, explorative, and descriptive study state that “the importance of inadvertent hypothermia for the patient and community has not achieved the attention it deserves” (Sessler, 2005) (Bridges, 2009).

    The objective of this 2020 study, published in the Journal of PeriAnesthesia Nursing, was to describe nurse anesthetists’ and operating theater nurses’ experiences with inadvertent hypothermia in a perioperative context and to heighten the understanding of this clinical phenomenon.  The study authors state that they hope that its findings can contribute to improving the quality of perioperative nursing, promote patient safety, and increase the appreciation of how inadvertent hypothermia can cause patient suffering.

    Additive risks

    The surgical patient is typically exposed to mild inadvertent hypothermia, with the most important form of heat transfer from the surgical patient’s body being radiation, the researchers note.  When general anesthesia is initiated, vasodilatation causes the patient’s heat to travel from the core to the periphery, causing a 1 to 1.5°C drop in the core temperature.  Further, metabolism is reduced by approximately 30% during anesthesia, and the patient is exposed to a cool environment, evaporation from operating wounds, and administration of room-temperature infused fluids.  The core temperature can be reduced by 2 to 3°C if preventive nursing interventions are not implemented. (Sessler, 2009) (de Brito Proveda, 2013) (Connelly, 2017).

    ‘Not fully realized’

    Although the study authors acknowledge that there are many manuals and guidelines for preventing perioperative hypothermia, in citing Hooper and colleagues (2010) they write that “this study is important because this knowledge is not fully realized in clinical anesthesia and perioperative nursing care.”

    The study entailed semi-structured focus group interviews conducted with 16 nurse anesthetists and operating theater nurses who related experiences with inadvertent hypothermia in their clinical perioperative nursing care.  Data collection was conducted at 4 different hospitals in Norway and was limited to the maintenance of the heat balance in adult patients during general anesthesia.  The transcribed proceedings yielded 71 pages of text.

    The participant group consisted of eight nurse anesthetists and eight operating theater nurses.  Each focus group was comprised of two nurse anesthetists and two operating theater nurses.  The age of the participants ranged between 29 and 58 years and all participants had worked in emergency medicine for an average of 7.5 years.

    Don’t miss this valuable AANA hypothermia guidance by clicking thermoregulation standard and scrolling to Standard 9 on page 3.

    Inadequate implementation

    The chief findings of the study are that taking patients’ temperature and employing measures against inadvertent hypothermia perioperatively are not always systematically implemented.  In analyzing the data, the authors found that three primary categories or “thematic units” emerged:  routines and habits, the culture of the perioperative unit, and what they termed patients’ “silent suffering.”

    #1  Routines and risk

    What the authors primarily found emerging from the focus groups’ experiences under the routines and habits category was that the surgical patient can often be regarded as a passive recipient of nursing care.  That is, the patient is expected to fit into the routines set up by the perioperative unit.  The potential patient risk this presents, they contend, is that this structure does not usually allow for changes.

    For instance, the participants stated that, within their 4 hospitals, taking the patient’s temperature and recording it is not a routine for all surgeries but is dependent upon the nature of the operation, its expected duration, and patient’s risk factors.  Instead, the authors conclude in their analysis, the nurse’s task is to make a clinical assessment of the need for temperature measurement.

    The authors observe that habits can be understood as repetitive actions that ultimately become routines that the nurse does not really think about.  Thus, it is possible to consciously or unconsciously create various routines and habits related to hypothermia within the clinical perioperative context.

    #2  Unit culture

    The understanding of clinical perioperative nursing care includes knowledge of hypothermia necessary to prevent complications.  Yet, heat-applied measures are often performed according to the internal cultural norms and habits of the individual perioperative unit in addition to the subjective clinical assessment based on experience, routines, and rules previously mentioned.

    In the perioperative unit, professional and ethical internal codes are used in clinical practice.  Heat conservation measures are general and routine for most operations.  But not always.  One study participant related:  “We have such a culture here that arthroscopic procedures do not use hot rinse fluid.  I’m not sure where this thinking comes from.  The arthroscopies of the day unit…are often very cold.  The arthroscopies are rinsed with cold water…Large amounts of cold water…If there is an arthroscopy in one hour…then there is a lot of rinse liquid…”

    The study authors state that it is the nurse’s responsibility to manage the culture, traditions, and habits of a perioperative unit — which also implies respect for patients and colleagues.  Yet the care of the perioperative patient can sometimes be perceived by the clinicians themselves as inadequate despite the unit culture in place.

    The authors perceive this through an ethical perspective, writing: “A nurse who ignores the patient’s temperature or does not take it seriously may violate the patient’s health and dignity.”

    #3  ‘Silent suffering’

    The researchers’ principled vantage point extends into their third observed category, “silent suffering” stressing that the anesthesia provider holds a unique responsibility given the ultimate vulnerability of their anesthetized patients.

    “A caring patient-nurse relationship should be understood as a space where the ethical value of care is highlighted and where responsibility for and safeguarding human dignity and alleviating suffering is fundamental.  In anesthesia and perioperative nursing care, patients give their life mandate and put their trust in the surgical team.”

    Therefore, they indicate a special duty to try to overcome the barriers to achievement of the common clinical task and goal of following-up on the patient’s perioperative temperature.  They write: “The patient’s body has a human value.  The nurse may have good intentions of keeping the patient normothermic but for various reasons is prevented from doing so.  This can cause a silent suffering that is connected with the existential aspects of the human being.”

    ‘Caring science research’ needed

    The authors conclude that while their work finds that the use of active warm-up methods during perioperative therapy appears to be the most effective measure for keeping the patient normothermic, critical knowledge gaps remain.  Despite their study results, “No normative or pragmatic conclusions can be drawn about which of these [active warm-up methods] is the optimal treatment method.”

    “Systematic longitudinal evidence-based studies describing nurse anesthetists’ and operating theater nurses’ experiences with the use of perioperative warming methods in a clinical context are still scant and deserve greater attention and continued studies in caring science research.”

    How do your experiences with inadvertent hypothermia with patients compare with your anesthesia colleagues’?  Read them in their own words in, “Nurse Anesthetists’ and Operating Theater Nurses’ Experiences with Inadvertent Hypothermia in Clinical Perioperative Nursing Care.” J Perianesth Nurs. 2020 Dec;35(6):676-681. at: