Orthostatic Hypotension Occurs Frequently in the First Hour After Anesthesia

Prevalence and associated factors of postoperative orthostatic intolerance at University of Gondar Comprehensive Specialized Hospital, Northwest Ethiopia, 2022: cross sectional study

BACKGROUND

Postoperative orthostatic intolerance is an inability to maintain an upright position because of symptoms of cerebral hypoperfusion. It is a common problem in the early postoperative period and hinders early mobilization, however, there is limited information about factors associated with it. Thus, the main aim of this study was to determine the prevalence and identify factors associated with postoperative orthostatic intolerance.

METHOD

Hospital based cross-sectional study was conducted from April 08 to July 20, 2022, at University of Gondar comprehensive Specialized Hospital. A semi-structured questionnaire containing sociodemographic variables and perioperative factors related to anesthesia and surgery was used for data collection. The presence of postoperative orthostatic intolerance during the first ambulation was evaluated with a standardized symptom checklist which contains symptoms of orthostatic intolerance. Binary logistic regression analysis was performed to assess factors associated with postoperative orthostatic intolerance. In multivariable regression, variables with P-value < 0.05 were considered statistically significant.

RESULT

A total of 420 patients were included in this study with a response rate of 99.06%. Postoperative orthostatic intolerance was experienced in 254 (60.5%) participants. Being female (AOR = 2.27; 95% CI = 1.06-4.86), low BMI (AOR = 0.79; 95% CI = 0.71-0.95), ASA II and above (AOR = 3.34; 95% CI = 1.34-8.28), low diastolic blood pressure (AOR = 0.82; 95% CI = 0.88-0.99), general anesthesia (AOR = 3.26, 95% CI = 1.31-8.12), high intraoperative blood lose (AOR = 0.93, 95% CI = 0.88-0.99), high postoperative fluid intake (AOR = 2.09, 95% CI = 1.23-3.55), pain before ambulation (AOR = 1.99, 95% CI = 1.28-3.11) and pain during ambulation (AOR = 1.82, 95% CI = 1.23-2.69) were the significant factors associated with orthostatic intolerance.

CONCLUSION

Our study revealed that postoperative orthostatic intolerance was experienced in nearly two-thirds of participants. During the time of ambulation, assessing patients for the presence of orthostatic intolerance is necessary to reduce the adverse effects of postoperative OI. In addition, maintaining preoperative normotension, reducing intraoperative blood loss and optimizing postoperative pain control is recommended to reduce the risk of postoperative orthostatic intolerance.

Steroids Significantly Decrease Postoperative Postural Hypotension in Total Knee Replacement

Total knee replacement (TKR) is one of the most common orthopaedic procedures performed, and enhanced recovery after surgery (ERAS) has been developed and incorporated into inpatient surgical pathways to improve patient outcomes. Under ERAS recommendations, multimodal prophylaxis has been used to help manage postoperative nausea and vomiting (PONV) following TKR. Dexamethasone is one of the commonly used for this and the anti-inflammatory properties could depress vagal activity, reducing postural hypotension (PH). The hypothesis of this study is that postoperative dexamethasone use is associated with lower rates of early postoperative PH following TKR surgery. In our institution, patients who undergo elective primary TKR are admitted on the day of surgery and follow a standardized ERAS protocol. Data on patients who underwent elective primary TKR under a single adult reconstruction team from September 2017 to March 2020 were reviewed and analyzed. A review of demographic characteristics, surgical data, postoperative medications, and postoperative notes was performed. Binary logistic regression was used to assess the effect of the use of dexamethasone on PH, with an adjusted odds ratio (OR) calculated after accounting for potential confounders. Of the 149 patients were included in the study, 78 had dexamethasone postoperatively, and 71 did not. Patients who had received dexamethasone were statistically less likely to suffer from PH (OR = 0.31, p = 0.03) and less likely to develop PONV (OR = 0.21, p = 0.006). Patients who had received dexamethasone were more likely able to participate in early physiotherapy (OR = 2.42, p = 0.14), and this result was statistically insignificant. The use of postoperative intravenous dexamethasone is significantly associated with lower rates of postoperative PH after TKR. However, more studies are required to assess the optimal dosing amount and frequency, as well as to assess other factors which can enhance early postoperative patient mobilization as part of our goals for ERAS. This therapeutic study reflects level of evidence III.

Considerations for Better Management of Postoperative Pain in Light of Chronic Postoperative Pain: A Narrative Review

Chronic postoperative pain (CPOP) is prevalent, with particularly high rates in breast surgery, thoracotomy, and amputation. As the world emerges from the coronavirus disease 2019 (COVID-19) lockdowns, it is expected that there will be an increase in surgical procedures, elevating the importance of preventing CPOP in the coming years. Risk factors are emerging to better stratify patients at high risk for CPOP. Perioperative analgesia plays an important role in managing acute postoperative pain and in some cases may limit its transition to CPOP. Acute postoperative pain is adaptive, normal, expected, and has a well-defined trajectory, while CPOP is maladaptive and, as a form of chronic pain, is challenging to treat. Good analgesia, early ambulation, and rehabilitation efforts may be helpful in preventing CPOP following certain surgeries. Enhanced Recovery After Surgery (ERAS) protocols present guidance to help promote recovery and prevent CPOP.

Anesthetic management of hypertensive patients

It is important for the clinicians to have a clear understanding of the anesthetic implications and increased risks due to hypertension to ensure safe surgical procedures in hypertensive patients. Preoperative hypertension is associated with greater intraoperative hemodynamic lability and an increased risk of perioperative cardiovascular complications. In addition to the patients’ baseline blood pressure (BP), the presence and severity of target organ damage and cardiovascular comorbidities should be evaluated preoperatively. Delaying surgery in hypertensive patients may be justified if there is an evidence of target organ damage that can be improved by such a delay. Further evaluation of suspected target organ damage before the surgery is also justified. Except withholding angiotensin-converting enzyme inhibitors/angiotensin receptor blockers 10 to 24 hours before the surgery, the continuation of preoperative antihypertensive therapy is generally recommended. Though maintaining perioperative BP within the range of 80%–90% to 110%–120% of the baseline BP (permissible BP decrease/increase ≤10%–20%) is generally recommended, an individualized and pathophysiology-based approach to control BP might be the best option throughout the perioperative period. In other words, BP targets in the perioperative period should be determined based on the type of surgery, patients’ baseline BP, risks of hypotension-related organ ischemia, and hypertension-related bleeding.

Effect of pre-operative methylprednisolone on orthostatic hypotension during early mobilization after total hip arthroplasty

BACKGROUND

Orthostatic hypotension (OH) and intolerance (OI) are common after total hip arthroplasty (THA) and may delay early mobilization. The pathology of OH and OI includes a dysregulated post-operative vasopressor response, by a hitherto unknown mechanism. We hypothesized that OI could be related to the inflammatory stress response which is inhibited by steroid administration. Consequently, this study evaluated the effect of a pre-operative high-dose methylprednisolone on OH and OI early after THA.

METHODS

Randomized, double-blind, placebo-controlled study in 59 patients undergoing elective unilateral THA with spinal anesthesia and a standardized multimodal analgesic regime. Patients were allocated (1 : 1) to pre-operative intravenous (IV) methylprednisolone (MP) 125 mg or isotonic saline (C). OH, OI and cardiovascular responses to sitting and standing were evaluated using a standardized mobilization protocol pre-operatively, 6, and 24 h after surgery. Systolic and diastolic arterial pressure and heart rate were measured non-invasively (Nexfin^® ). The systemic inflammation was monitored by the C-reactive protein (CRP) response.

RESULTS

At 6 h post-operatively, 11 (38%) versus 11 (37%) patients had OH in group MP and group C, respectively (RR 1.02 (0.60 to 1.75; P = 1.00)), whereas OI was present in 9 (31%) versus 13 (43%) patients (RR 0.76 (0.42 to 1.36; P = 0.42)), respectively. At 24 h post-operatively, the prevalence of OH and OI did not differ between groups, though CRP levels were significantly reduced in group MP (P < 0.001).

CONCLUSION

Pre-operative administration of 125 mg methylprednisolone IV did not reduce OH or OI compared with placebo despite a reduced inflammatory response.

Experience of Immediate Ambulation and Early Discharge After Tumescent Anesthesia and Propofol Infusion in Cosmetic Breast Augmentation

INTRODUCTION

Current cosmetic breast augmentation relies on general anesthesia that normally requires 40 min to total recovery. With experience, the surgical procedure can be completed expediently in 20 min under tumescent anesthesia and propofol full sedation to achieve immediate postoperative ambulation and home discharge readiness, and thus improve patient satisfaction and reduce cost. We retrospectively examined the outcomes of the protocol.

MATERIALS AND METHODS

Per protocol, 1200 female patients underwent simple cosmetic breast augmentation accomplished with tumescent anesthesia, immediate mobilization, and early home discharge readiness after surgery. The following records were analyzed: vital sign stability during mobilization in the first 30 cases (primary goal), duration of surgery and anesthesia, frequency of intraoperative opioid use, frequency of ambulation needing assistance, Verbal Analog Scores and incidences of pain, orthostatic intolerance events, incidences of postoperative nausea and vomiting or anti-emetic use, and complications at follow-up visits (secondary goal).

RESULTS

Hemodynamics during immediate postoperative mobilization demonstrated no statistically significant fluctuations and/or orthostatic intolerance requiring interventions. The mean duration of surgery was 20.4 ± 4.1 min. The mean duration of anesthesia was 25.2 ± 6.8 min. All patients tolerated immediate postoperative ambulation well. Adverse postoperative events were scarce. Only 9.1% reported postoperative pain, and 5.7% reported postoperative nausea and vomiting. One percent had transit post-ambulation dizziness needing supine positioning for less than 3 min. The average time to meet home-readiness criteria was 4.7 min, and there was no incidence of hematoma, infection, or complaints at follow-ups.

CONCLUSIONS

For simple cosmetic breast augmentation, instead of general anesthesia and 40 min of recovery time, a tumescent anesthetic technique can be used for immediate postoperative ambulation and a 4.7-min home discharge readiness without a decrease in anesthesia quality and safety.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Assessment of effects of differences in trunk posture during Fowler's position on hemodynamics and cardiovascular regulation in older and younger subjects

Background

Downward shifts in blood volume with changing position generally cause tachycardic responses. Age-related decreases in vagal nerve activity could contribute to orthostatic hypotension in older individuals. Fowler’s position is a reclined position with the back between 30° and 60°, used to facilitate breathing, eating, and other routine daily activities in frail and elderly patients.

Objective

This study examined whether stroke volume (SV) was higher and heart rate (HR) lower in Fowler’s position with an upright upper trunk than in Fowler’s position with the whole trunk upright in both older and younger subjects, based on the assumption that lower HR would result from reduced sympathetic activation in older individuals.

Methods

We assessed hemodynamics and HR variability from electrocardiography, noninvasive arterial pressure and impedance cardiography in 11 younger male subjects (age range, 20–22 years) and 11 older male subjects (age range, 64–79 years), using three positions: supine, or Fowler’s positions with either 30° of lower trunk inclination and 60° of upper trunk inclination (UT60) or 60° of whole trunk inclination (WT60). Comparisons were then made between age groups and between positions.

Results

Reductions in SV and tachycardic response were smaller with UT60 than with WT60, in both younger and older subjects. In addition, reduced tachycardic response with upright upper trunk appeared attributable to decreased vagal withdrawal in younger subjects and to reduced sympathetic activation in older subjects.

Conclusion

Our findings indicate that an upright upper trunk during Fowler’s position allowed maintenance of SV and inhibited tachycardic response compared to an upright whole trunk regardless of age, although the autonomic mechanisms underlying tachycardic responses differed between younger and older adults. An upright upper trunk in Fowler’s position might help to reduce orthostatic stress and facilitate routine activities and conversation in frail patients.

Hemodynamic challenge to early mobilization after cardiac surgery: A pilot study

Background:

Active mobilization is a key component in fast-track surgical strategies. Following major surgery, clinicians are often reluctant to mobilize patients arguing that circulatory homeostasis would be impaired as a result of myocardial stunning, fluid shift, and autonomic dysfunction.

Aims:

We examined the feasibility and safety of a mobilization protocol 12–24 h after elective cardiac surgery.

Setting and Design:

This observational study was performed in a tertiary nonacademic cardiovascular Intensive Care Unit.

Materials and Methods:

Over a 6-month period, we prospectively evaluated the hemodynamic response to a two-staged mobilization procedure in 53 consecutive patients. Before, during, and after the mobilization, hemodynamics parameters were recorded, including the central venous oxygen saturation (ScvO₂), lactate concentrations, mean arterial pressure (MAP), heart rate (HR), right atrial pressure (RAP), and arterial oxygen saturation (SpO₂). Any adverse events were documented.

Results:

All patients successfully completed the mobilization procedure. Compared with the supine position, mobilization induced significant increases in arterial lactate (34.6% [31.6%, 47.6%], P = 0.0022) along with reduction in RAP (−33% [−21%, −45%], P < 0.0001) and ScvO₂ (−7.4% [−5.9%, −9.9%], P = 0.0002), whereas HR and SpO₂ were unchanged. Eighteen patients (34%) presented a decrease in MAP > 10% and nine of them (17%) required treatment. Hypotensive patients experienced a greater decrease in ScvO₂ (−18 ± 5% vs. −9 ± 4%, P = 0.004) with similar changes in RAP and HR. All hemodynamic parameters, but arterial lactate, recovered baseline values after resuming the horizontal position.

Conclusions:

Early mobilization after cardiac surgery appears to be a safe procedure as far as it is performed under close hemodynamic and clinical monitoring in an intensive care setting.

Decreased heart rate variability responses during early postoperative mobilization--an observational study

BACKGROUND

Intact orthostatic blood pressure regulation is essential for early mobilization after surgery. However, postoperative orthostatic hypotension and intolerance (OI) may delay early ambulation. The mechanisms of postoperative OI include impaired vasopressor responses relating to postoperative autonomic dysfunction. Thus, based on a previous study on haemodynamic responses during mobilization before and after elective total hip arthroplasty (THA), we performed secondary analyses of heart rate variability (HRV) and aimed to identify possible abnormal postoperative autonomic responses in relation to postural change.

METHODS

A standardized mobilization protocol before, 6 and 24 h after surgery was performed in 23 patients scheduled for elective THA. Beat-to-beat arterial blood pressure was measured by photoplethysmography and HRV was derived from pulse wave interbeat intervals and analysed in the time and frequency domain as well as by non-linear analysis using sample entropy

RESULTS

Before surgery, arterial pressures and HR increased upon standing, while HRV low (LF) and high frequency (HF) components remained unchanged. At 6 and 24 h after surgery, resting total HRV power, sample entropy and postural responses in arterial pressures decreased compared to preoperative conditions. During standing HF variation increased by 16.7 (95 % CI 8.0-25.0) normalized units (nu) at 6 h and 10.7 (2.0-19.4) nu at 24 h compared to the preoperative evaluation. At 24 h the LF/HF ratio decreased from 1.8 (1.2-2.6) nu when supine to 1.2 (0.8-1.8) nu when standing.

CONCLUSIONS

This study observed postoperative autonomic cardiovascular dysregulation that may contribute to limited HRV responses during early postoperative mobilization.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01089946.

Effects of trunk posture in Fowler's position on hemodynamics

We speculated that stroke volume would be higher and heart rate would be lower when the head and upper trunk were mainly upright in the Fowler's position. We therefore analyzed the effects of three trunk postures in Fowler's position on heart rate, blood pressure and circulatory volume. Heart rate (HR), blood pressure (BP), stroke volume (SV), cardiac output (Q), systemic vascular resistance (SVR), ejection time (ET) and pre-ejection period (PEP) were measured in 10 healthy male volunteers (mean age ± SEM, 20.7 ± 0.5 y; range, 19-23 y) while in three trunk postures in Fowler's position. Stroke volume and Q were measured using impedance cardiography. The three trunk postures were 30° of lower and upper trunk inclination (WT30°), 30° and 60° of lower and upper trunk inclination (UT 60°), respectively and 60° of upper and lower trunk inclination (WT60°). Both SV and ET were significantly higher and HR and PEP were lower at UT60° than at WT60° (p < 0.01) whereas these values did not significantly differ between WT30° and UT60° (p > 0.05). None of Q, SVR and BP significantly differed among the three conditions (p > 0.05). These findings suggested that SV and preload are higher when the upper trunk is upright (UT60°) than when the entire trunk is upright (WT60°) while in Fowler's position. In addition, Q might be maintained without increasing HR through vagal withdrawal when only the upper trunk is upright in healthy young males in Fowler's position.

[Effect of intraoperative esmolol infusion on anesthetic, analgesic requirements and postoperative nausea-vomitting in a group of laparoscopic cholecystectomy patients]

PURPOSE

Postoperative pain and nausea/vomitting (PNV) are common in laparoscopic cholecystectomy patients. Sympatholytic agents might decrease requirements for intravenous or inhalation anesthetics and opioids. In this study we aimed to analyze effects of esmolol on intraoperative anesthetic-postoperative analgesic requirements, postoperative pain and PNV.

METHODS

Sixty patients have been included. Propofol, remifentanil and vecuronium were used for induction. Study groups were as follows; I - Esmolol infusion was added to maintenance anesthetics (propofol and remifentanil), II - Only propofol and remifentanil was used during maintenance, III - Esmolol infusion was added to maintenance anesthetics (desflurane and remifentanil), IV - Only desflurane and remifentanil was used during maintenance. They have been followed up for 24h for PNV and analgesic requirements. Visual analog scale (VAS) scores for pain was also been evaluated.

RESULTS

VAS scores were significantly lowest in group I (p=0.001-0.028). PNV incidence was significantly lowest in group I (p=0.026). PNV incidence was also lower in group III compared to group IV (p=0.032). Analgesic requirements were significantly lower in group I and was lower in group III compared to group IV (p=0.005). Heart rates were significantly lower in esmolol groups (group I and III) compared to their controls (p=0.001) however blood pressures were similar in all groups (p=0.594). Comparison of esmolol groups with controls revealed that there is a significant decrease in anesthetic and opioid requirements (p=0.024-0.03).

CONCLUSION

Using esmolol during anesthetic maintenance significantly decreases anesthetic-analgesic requirements, postoperative pain and PNV.

Orthostatic intolerance ambulation in patients using patient controlled analgesia

Background

Opioid analgesics are widely used to reduce postoperative pain and to enhance post-operative recovery. However, orthostatic intolerance (OI) induced by opioid containing intravenous patient controlled analgesia (IPCA) may hinder postoperative recovery. This study investigated factors that affect OI in patients receiving IPCA for postoperative pain control.

Methods

OI was instantly evaluated at the time of first ambulation in 175 patients taking opioid containing IPCA after open and laparoscopic subtotal gastrectomies. Patients were classified as having OI if they experienced dizziness, nausea/vomiting, blurred vision, headache, somnolence and syncope. Factors contributing to OI were assessed with logistic regression analysis.

Results

Out of 175 patients, 61 (52.6%) male and 44 (74.6%) female patients experienced OI at the time of first ambulation. The frequency of OI related symptoms were dizziness (97, 55.4%), nausea (46, 26.3%), headache (9, 5.1%), blurred vision (3, 1.7%) and vomiting (2, 1.1%). Significant risk factors for OI were gender (P=0.002) and total amount of opioids administered (P=0.033).

Conclusions

The incidence of OI is significantly higher in male than in female patients and is influenced by the opioid dose.

Dysautonomia: perioperative implications

Severe autonomic failure occurs in approximately 1 in 1,000 people. Such patients are remarkable for the striking and sometimes paradoxic responses they manifest to a variety of physiologic and pharmacologic stimuli. Orthostatic hypotension is often the finding most commonly noted by physicians, but a myriad of additional and less understood findings also occur. These findings include supine hypertension, altered drug sensitivity, hyperresponsiveness of blood pressure to hypo/hyperventilation, sleep apnea, and other neurologic disturbances. In this article the authors will review the clinical pathophysiology that underlies autonomic failure, with a particular emphasis on those aspects most relevant to the care of such patients in the perioperative setting. Strategies used by clinicians in diagnosis and treatment of these patients, and the effect of these interventions on the preoperative, intraoperative, and postoperative care that these patients undergo is a crucial element in the optimized management of care in these patients.

Anaesthesia for patients with idiopathic environmental intolerance and chronic fatigue syndrome

BACKGROUND

Idiopathic environmental intolerance syndrome (IEI), formerly known as multiple chemical sensitivity syndrome (MCSS), and chronic fatigue syndrome (CFS) are controversial diseases and there is little information in the literature regarding the appropriate conduct of anaesthesia in such patients.

METHODS

We studied 27 patients referred to our anaesthetic allergy clinic with IEI and CFS and performed literature and web searches on anaesthesia in these disorders.

RESULTS

The patients had a significant incidence of adverse events related to anaesthesia which were not allergic in nature. The adverse effects usually occurred postoperatively and were self limiting. Patients with IEI and CFS are not at risk of anaphylaxis and there is no scientific evidence that any drug or technique is excessively hazardous. Neither our patients nor the review of the scientific literature supported available web-based recommendations for the anaesthetic management of patients with IEL and CFS.

CONCLUSIONS

We suggest that the anaesthetist may be best to use the technique they would use if the patient did not have CFS or IEI but avoid drugs to which there is a history of adverse response. Anaesthesia is likely to be associated with adverse effects in these patients but the effects are not likely to be severe. A series of recommendations for the safe and harmonious conduct of anaesthesia in patients with CFS and IEI are provided.

Inguinal herniorrhaphy under monitored anesthesia care with ilioinguinal-iliohypogastric block: the impact of adding clonidine to ropivacaine

There is no information concerning the association of ropivacaine and clonidine for ilioinguinal-iliohypogastric block. In this prospective, double-blind study, we randomly assigned 40 adult patients scheduled for inguinal herniorrhaphy under monitored anesthesia care to receive either 225 mg ropivacaine (7.5 mg/mL) alone (control group) or combined with 75 mug clonidine (clonidine group) for preoperative ilioinguinal-iliohypogastric block. After completion of surgery, patients were transferred to the postanesthesia care unit and were asked to stand up and walk around at the second postoperative hour. After leaving the postanesthesia care unit, patients could take oral propacetamol (500 mg) and codeine (30 mg) on request. Pain intensity was assessed with a 100 mm visual analog scale. Time to first request of supplemental analgesics (median [95% confidence interval]) was 10 h (7.1-14.5 h) and 9 h (6.4->24 h) respectively in the clonidine and control groups (P = 0.83). Pain at rest did not differ between groups whereas pain at motion was reduced on the third postoperative day in the clonidine group. More patients who received clonidine experienced orthostatic hypotension upon standing up within the first postoperative hours (6 of 20 versus 1 of 20 in the control group; P < 0.05). In conclusion, the benefit of adding clonidine 75 mug to ropivacaine for ilioinguinal-iliohypogastric block for motion pain on the third postoperative day must be balanced with an increasing risk of orthostatic hypotension in the immediate postoperative period.